وی همچنین برنده جوایزی همچون لژیون دونور (فرمانده) شده است.
وی وسایل متعددی را طراحی یا کامل کرد که مهمترین و معروفترین آنها لامپ رشتهای است.
هنگامی که ادیسون در دوره ابتدایی درس میخواند مدیر مدرسه وی اعتقاد داشت که ادیسون شاگرد کودنی است و عذر وی را از مدرسه خواست.[نیازمند منبع] ادیسون در طول حیات علمی خویش توانست ۲۵۰۰ امتیاز اختراع را در ایالات متحده آمریکا، بریتانیا، فرانسه و آلمان به نام خود ثبت کند که رقمی حیرتانگیز و باورنکردنی به نظر میرسد. واقعیت این است که بیشتر اختراعات وی تکمیل شدهٔ کارهای دانشمندان پیشین بودند و ادیسون کارمندان و متخصصان پرشماری در کنار خود داشت که در پیشبرد تحقیقات و به سرانجام رسانیدن نوآوریهایش یاریش میکردند. دهنی زغالی تلفن، ماشین چاپ، میکروفن، گرامافون، دیکتافون، کینتوسکوپ (نوعی دستگاه نمایش فیلم)، دینام موتور و لاستیک مصنوعی از جمله مواد و وسایلی هستند که بدست ادیسون و همکارانش ابداع یا بهینه شدند.
ادیسون از اولین مخترعانی بود که توانست با موفقیت، بسیاری از اختراعات خود را به تولید انبوه برساند.
نخستین پلههای ترقی[ویرایش]
در سال ۱۸۶۹ ادیسون که ادارهٔ راهآهن را ترک کرده بود، بهعنوان سرپرست فنی به استخدام یک مؤسسهٔ صرافی بزرگ در نیویورک در آمد. در این مقام او توانست نخستین اختراع موفقش را که نوعی تلگراف چاپی بود، به نام خود ثبت کند. تلگراف ادیسون برخلاف انواع رایج که علائم مورس را به صورت صداهای کوتاه و کشیده به گوش اپراتور میرسانیدند، آنها را به شکل خط و نقطه بر روی نوار کاغذی چاپ میکرد. او حق امتیاز اختراعش را در مقابل ۴۰۰۰ دلار به مدیر صرافخانه واگذار کرد و با پول آن در نیوآرک، نیوجرسی یک کارگاه تحقیقاتی برای خود برپا نمود. در محل جدید او علاوه بر تکمیل لوازم جانبی تلگراف، یک سامانهٔ پیشرفتهٔ نمایشگر اطلاعات بورس را طراحی کرد که سود هنگفتی از آن حاصل آمد.
ادیسون مدت ها این فکر را در سر داشت که کارگاهش را به محل بازتر و بزرگتری منتقل کند. با فراهم شدن سرمایهٔ کافی، سرانجام در سال ۱۸۷۶ م. در منطقهٔ «منلوپارک» نیوجرسی یک لابراتوار پژوهشی مجهز بنیاد نهاد و گروهی از افراد لایق و مستعد را به همکاری فراخواند.
تأسیس این آزمایشگاه نقطهٔ عطفی در رشته فعالیتهای ادیسون و از بزرگترین ابتکارهای او به شمار میرود. آزمایشگاه منلو پارک نخستین مؤسسهای بود که منحصراً با هدف تولید و تکمیل ابداعات علمی برپا شد و آن را باید نمونهٔ اولیهٔ آزمایشگاههای تحقیقاتی بزرگی دانست که از آن پس تمام صنایع مهم در کنار کارگاههای خود ایجاد کردند. در سایهٔ نظارت و سازماندهی توماس ادیسون و کار گروهی کارمندان وی صدها اختراع کوچک و بزرگ در این مؤسسه به ثمر رسیدند که البته همگی به نام ادیسون تمام شدند.
ازدیرباز، داشتن وسیلهای که بتوان با آن صدا را ضبط کرد از آرزوهای بشر بودهاست. قبل از آنکه توجه ادیسون به این مقوله جلب شود، لئون اسکوت مارتینویل فرانسوی (۱۸۵۷) و دیگران تحقیقاتی کرده و گامهایی در این راه برداشته بودند؛ اما دستگاههای آنها عملاً قابل استفاده نبود زیرا تنها با یک دور گوش دادن، صدای ضبط شده از بین میرفت.
در سال ۱۸۷۷ ادیسون موفق به ساخت وسیلهای شد که واقعاً کار میکرد؛ یعنی میتوانست صدا را ضبط و دو تا سه بار پخش کند. «ضبط صوت» ادیسون که فونوگراف (آوانگار) نام گرفته بود، ساختمانی ساده داشت: استوانهای فلزی بود با یک دستهٔ گرداننده که در یک انتهای آن سوزنی همراه با یک بوق تعبیه شده بود. وقتی کسی استوانه را میچرخاند و درون بوق صحبت میکرد، بر اثر ارتعاش سوزن، روی ورقهٔ نازک حلبیِ دور استوانه خراشهایی میافتاد. برای شنیدن صدای ضبط شده نیز کافی بود سوزن را به ابتدای مسیر برگردانده و دوباره استوانه را به چرخش در آورند. کیفیت صدا البته بسیار پایین بود و صفحه حلبی هم پس از چند بار استفاده خراب میشد. با اینحال همین وسیله ابتدایی در نظر مردم بسیار شگفتانگیز مینمود و بشدت مورد استقبال قرار گرفت. روزنامهها ادیسون را «جادوگر منلوپارک» لقب دادند. حتی دولت رسماً وی را به واشینگتن دعوت کرد تا اختراعش را در برابر مقامات به نمایش بگذارد. ده سال بعد (۱۸۸۷ م) ادیسون (یا به روایتی الکساندر گراهام بل)، استوانهٔ مومی را جایگزین ورق حلبی کرد و بالاخره امیل برلینر مخترع آمریکایی آلمانیتبار با تبدیل استوانهٔ مومی به صفحهٔ پلاستیکی، گرامافون را به شکل امروزی درآورد.
صدای ضبط شده توماس ادیسون[ویرایش]
توماس ادیسون لامپ حبابی را ابداع نکرد و قبل از وی نوعی لامپ اختراع شده بود او در سال ۱۸۸۰ یک طرح قابل تحقق و تولید برای لامپ حبابی مطرح کرد (با استفاده از یک رشته از جنس بامبوی کربنیزه) که مورد استفاده منازل و خانهها شد و البته یک سال بعد جوزف سوان در سال ۱۸۸۱ یک ساختار کارآمدتر را (با استفاده از رشتهٔ سلولوزی) مطرح نمود.
سابقهٔ سیستم روشنایی الکتریکی به اواسط قرن نوزدهم میرسد. در سال ۱۸۵۴ هاینریش گوبل نخستین لامپ برق را اختراع کرد که حدود چهارصد ساعت نور میداد اما آن را به نام خود به ثبت نرساند. پس از وی جیمز وودوارد، ویلیام سایر، متیو ایوانز (۱۸۷۵) و جوزف سووان (۱۸۷۸ م) مدلهای دیگر چراغهای الکتریکی را ارائه کردند.
کمی پیش از آنکه ادیسون نیز وارد این عرصهٔ جدید شود، والیس صنعتگر آمریکایی نوعی چراغ برق را روانهٔ بازارکرده بود که نمونهای از آن به دست ادیسون رسید (۱۸۷۸). دستگاه والیس تشکیل میشد از چارچوبی با یک حباب و دو میلهٔ فلزی متحرک که به هر کدام تکه زغالی متصل بود. عبور جریان برق از میلهها باعث میشد که دو قطعه زغال بسوزند و میانشان قوس الکتریکی بسیار درخشانی به رنگ آبی پدیدار شود.
این چراغ الکتریکی ابتدایی بازده پایینی داشت زیرا مصرف برق آن زیاد و عمر زغالهایش کم بود. با این وجود، ادیسون که به اهمیت اختراع والیس پیبرده بود، تصمیم گرفت آن را اصلاح کند و به جای زغال مادهٔ مناسب تری بیابد که با برق کمتر مدت درازی روشنایی بدهد و به مرور زمان نسوزد و از بین نرود.
پس از یک سال تلاش بیوقفه و آزمایش صدها مادهٔ گوناگون، سرانجام ادیسون و همکارانش توانستند با خالی کردن هوای داخل حباب و استفاده از نخ معمولی کربونیزه (زغالیشده) لامپی بسازند که تا چهل ساعت نور بدهد. این موفقیت اولیه موجب شد تا آنها با پشتکار بیشتری به تحقیقات خود ادامه دهند و زمانیکه موفق شدند عمر متوسط چراغ برق را به پانصد ساعت برسانند، ادیسون تشخیص داد که زمان مناسب برای نمایش آن فرا رسیدهاست.
البته نمونه لامپ ادیسون قبل از ارائه توسط شخص دیگری تولید و در اداره ثبت بریتانیا به اسم دانشمندی به نام سوان ثبت شده بود و این ثابت میکند لامپ ادیسون چیز جدیدی نبود ولی با این حال نباید تلاشهای ادیسون را در راستای ترویج این تکنولوژی نادیده گرفت
او از روزنامهنگاران و صاحبان سرمایه دعوت کرد تا در شب ۳۱ دسامبر ۱۸۷۹ برای دیدن اختراع جدیدش به منلوپارک بیایند. به دستور او آزمایشگاه و اطراف آن را با صدها لامپ برق آراستند بطوریکه محوطهٔ منلوپارک و جادهٔ منتهی به آن غرق در نور شده بود. ادیسون میهمانان خود را با چیزی روبرو کرده بود که برایشان سابقه نداشت. منظرهٔ لامپهای نورانی بازدیدکنندگان را به شدت تحت تأثیر قرار داد؛ بطوریکه وقتی ادیسون نقشهٔ خود را برای تأسیس یک کارخانهٔ بزرگ الکتریسیته در نیویورک مطرح کرد پیشنهادش با استقبال گرم سرمایهداران حاضر روبرو شد.
در ۲۷ ژانویه ۱۸۸۰ ادیسون تقاضانامهٔ دریافت امتیاز اختراع «لامپ روشنایی الکتریکی» را به ادارهٔ اختراعات آمریکا تسلیم کرد اما با درخواستش موافقت نشد. کارشناسان سازمان معتقد بودند که طراحی و ساخت لامپ ادیسون بر مبنای مطالعات ویلیام سایر انجام شده است؛ بنابراین تنها امتیاز اختراع رشتهٔ زغالی شده پرمقاومت (مادهٔ تولیدکنندهٔ نور لامپ) به ادیسون تعلق گرفت.
در ۱۳ فوریه ۱۸۸۰ وی به کشف یک پدیدهٔ مهم فیزیکی نائل آمد که اکنون به اثر ادیسون معروف است.
دو سال پس از نمایش عمومی لامپ الکتریکی، (۱۸۸۲) ساختمان کارخانهٔ مرکزی تولید برق موسوم به «ایستگاه پرل استریت» به پایان رسید و در چهارم سپتامبر همان سال نخستین سیستم توزیع نیروی الکتریسیته در جهان با قدرت ۱۱۰ ولت و ۵۹ مشتری در پایین محلهٔ منهتن به دست ادیسون افتتاح گردید.
چندی بعد ادیسون کوشید تا حق امتیاز لامپ برق را در بریتانیا از آن خود کند و بر رقیبش جوزف سووان – که مستقل از ادیسون موفق به اختراع لامپ حرارتیِ رشته کربنی شده بود- پیروز شود اما پس از یک دعوای حقوقی بیحاصل، دو طرف با یکدیگر به توافق رسیدند و برای بهرهمند شدن از منافع اختراعشان در بریتانیا شرکت «ادیسون» را تأسیس کردند. این شرکت در سال ۱۸۹۲ جزئی از کمپانی بزرگ جنرال الکتریک (متعلق به ادیسون) گردید.
همانطور که گفته شد، بیشتر اختراعات ادیسون حاصل تکمیل ایدههای دیگران و کار دستهجمعی گروه بزرگی از تکنسینها و کارمندانی بود که تحت نظارت او به تحقیق و آزمایش میپرداختند. لویس لاتیمر دستیار آفریقایی-آمریکایی ادیسون که در پروژهٔ چراغ الکتریکی نقش مهمی داشت، از جملهٔ این افراد است. اگر امروز کمتر نامی از کسانی مانند او به میان میآید، به این دلیل است که ادیسون غالباً همکاران خود را در افتخار و اعتبار اختراعاتش سهیم نمیکرد. با این همه شکی نیست که بدون قدرت سازماندهی و خصوصاً همت بلند ادیسون دست یافتن به این همه موفقیت ممکن نبود. نیکلا تسلا فیزیکدان بزرگ و یکی از همکاران ادیسون دربارهٔ روش او برای حل مسائل مینویسد:
ادیسون خود نیز در اینباره گفتهاست:
تسلا دانشمندی شایسته و بهترین کارمند ادیسون بود. او ابتدا از طرف ادیسون مأمور شده بود تا راههای توسعهٔ سیستمهای جریان مستقیم (DC) را بررسی کند اما چون پس از پایان کار ادیسون تعهدات مالی خود را زیر پا گذاشت تسلا تصمیم به ترک شرکت او گرفت. با پذیرش استعفای تسلا، ادیسون مرتکب اشتباه بزرگی شد چرا که چندی بعد تسلا با کشف جریان متناوب (AC) در برابر امپراتوری ادیسون و سیستم DC او قد علم کرد. او با حمایت جرج وستینگهاوس کارخانهدار معروف سامانههای چندفازی توزیع برق را برپایهٔ جریان AC تکامل بخشید که بسیار کارآمدتر از سیستم ادیسون بود. با وجود تبلیغات منفی جنرال الکتریک، جریان AC روز به روز رواج بیشتری یافت و سرانجام سلطه ادیسون را بر بازار صنایع الکتریکی درهم شکست.
نوشتار(های) وابسته: بورس تریاک چینی
در سال ۱۸۸۹ یکی از کارمندان شرکت ادیسون به اسم ویلیام کندی دیکسون نوعی دستگاه نمایش فیلم اختراع کرد که پنج سال بعد (۱۸۹۴) با نام تجاری کینهتوسکوپ (متحرک نما) در نیویورک به معرض نمایش گذاشته شد. کینهتوسکوپ دستگاهی بود که هرکس از سوراخ آن به درون مینگریست و دستهای را میچرخاند، تصاویر متحرکی را مشاهده میکرد. این وسیله ابتدا بهعنوان مکمل گرامافون و برای رونق بخشیدن به بازار آن طراحی شده بود و هدف آن بود که با افزودن امکان تماشای عکس متحرک، بر جذابیت گرامافون نزد خریداران افزوده شود.
با وجود اهمیت این اختراع، ادیسون یا دیکسون را نمیتوان پایهگذار سینما دانست؛ کینهتوسکوپ آنها بیشتر به ماشین «شهر فرنگ» شبیه بود و دریک زمان بیش از یک نفر نمیتوانست از آن استفاده کند. چنین دستگاهی در عصر جدید که تودهٔ مردم به هیجان و سرگرمیهای دستهجمعی نیاز داشتند چندان به کار نمیآمد. ایدهٔ بزرگ کردن تصاویر و بکارگیری پردهٔ نمایش هرگز به ذهن ادیسون نرسید چون همانطور که گفتیم از اختراع کینهتوسکوپ مقصود دیگری داشت ولی حدود یک سال بعد لویی لومیر صنعتگر ثروتمند فرانسوی با ساختن دوربین فیلمبرداری و پروژکتور و افتتاح اولین سالن سینما در گراند کافه پاریس (۲۸ دسامبر ۱۸۹۵) نخستین گامها را برای علاقهمند کردن مردم به این پدیدهٔ نو برداشت. پس از گذشت چند سال، سالنهای نمایش فیلم در اروپا و آمریکا آن قدر فراوان شده بود که ادیسون نیز چارهای جز پیوستن به این جریان و کنار گذاشتن سینمای تک نفرهاش ندید.
ادیسون در تبدیل سینما به رسانهای همگانی و صنعتی سودآور نقش مؤثری ایفا کردهاست. فیلم استاندارد ۳۵ میلیمتری با چهار روزنه در لبهٔ هر فریم که هنوز مورد استفاده قرار میگیرد از یادگارهای ادیسون است. وی همچنین مؤسس اولین استودیوی فیلمسازی دنیا (بلک ماریا در ایالت نیوجرسی) است. نخستین فیلم کپی رایت شدهٔ تاریخ سینما با عنوان «عطسهٔ فرد اُت» در این استودیو ساخته شد. همچنین فیلم فرانکنشتاین (۱۹۱۰) نیز در استودیو و شرکت فیلمسازی وی ساخته شده است.
در اول فوریه ۱۸۹۳ ادیسون ساختمان «بلک ماریا» نخستین استودیوی تصاویر متحرک را در اورنج غربی، نیوجرسی به پایان برد. او کوشید تا اختراع دوربین فیلم برداری را تماماً به خود نسبت دهد و حق استفادهٔ انحصاری از آن را به دست آورد اما در ۱۰ مارس ۱۹۰۲ ادعای او در یک دادگاه استیناف ایالات متحده رد شد.
در ۶ ژانویه ۱۹۳۱ ادیسون درخواستنامهٔ ثبت آخرین اختراع خود «وسیلهٔ نگهدارندهٔ اشیاء هنگام آبکاری» را به ادارهٔ ثبت اختراعات فرستاد اما پیش از دریافت پاسخ ، اَجل به او مهلت نداد و این مخترع بزرگ در اواخر همان سال در سن ۸۴ سالگی چشم از جهان فرو بست.
پیوند به بیرون[ویرایش]
Thomas Alva Edison (February 11, 1847 – October 18, 1931) was an American inventor and businessman. He developed many devices that greatly influenced life around the world, including the phonograph, the motion picture camera, and the long-lasting, practical electric light bulb. Dubbed "The Wizard of Menlo Park", he was one of the first inventors to apply the principles of mass production and large-scale teamwork to the process of invention, and because of that, he is often credited with the creation of the first industrial research laboratory.
Edison was a prolific inventor, holding 1,093 US patents in his name, as well as many patents in the United Kingdom, France, and Germany. More significant than the number of Edison's patents was the widespread impact of his inventions: electric light and power utilities, sound recording, and motion pictures all established major new industries world-wide. Edison's inventions contributed to mass communication and, in particular, telecommunications. These included a stock ticker, a mechanical vote recorder, a battery for an electric car, electrical power, recorded music and motion pictures.
His advanced work in these fields was an outgrowth of his early career as a telegraph operator. Edison developed a system of electric-power generation and distribution to homes, businesses, and factories – a crucial development in the modern industrialized world. His first power station was on Pearl Street in Manhattan, New York.
Thomas Edison was born in Milan, Ohio, and grew up in Port Huron, Michigan. He was the seventh and last child of Samuel Ogden Edison, Jr. (1804–1896, born in Marshalltown, Nova Scotia) and Nancy Matthews Elliott (1810–1871, born in Chenango County, New York). His father, the son of a Loyalist refugee, had moved as a boy with the family from Nova Scotia, settling in southwestern Ontario (then called Upper Canada), in a village known as Shewsbury, later Vienna, by 1811. Samuel Jr. eventually fled Ontario because he took part in the unsuccessful Mackenzie Rebellion of 1837. His father, Samuel Sr., had earlier fought in the War of 1812 as captain of the First Middlesex Regiment. By contrast, Samuel Jr.'s struggle found him on the losing side, and he crossed into the United States at Sarnia-Port Huron. Once across the border, he found his way to Milan, Ohio. His patrilineal family line was Dutch by way of New Jersey; the surname had originally been "Edeson."
His mother taught him at home. Much of his education came from reading R.G. Parker's School of Natural Philosophy and The Cooper Union for the Advancement of Science and Art.
Edison developed hearing problems at an early age. The cause of his deafness has been attributed to a bout of scarlet fever during childhood and recurring untreated middle-ear infections. Around the middle of his career, Edison attributed the hearing impairment to being struck on the ears by a train conductor when his chemical laboratory in a boxcar caught fire and he was thrown off the train in Smiths Creek, Michigan, along with his apparatus and chemicals. In his later years, he modified the story to say the injury occurred when the conductor, in helping him onto a moving train, lifted him by the ears.
Edison's family moved to Port Huron, Michigan, after the railroad bypassed Milan in 1854 and business declined. Edison sold candy and newspapers on trains running from Port Huron to Detroit, and sold vegetables to supplement his income. He also studied qualitative analysis, and conducted chemical experiments on the train until an accident prohibited further work of the kind.
Edison obtained the exclusive right to sell newspapers on the road, and, with the aid of four assistants, he set in type and printed the Grand Trunk Herald, which he sold with his other papers. This began Edison's long streak of entrepreneurial ventures, as he discovered his talents as a businessman. These talents eventually led him to found 14 companies, including General Electric, which is still one of the largest publicly traded companies in the world.
Edison became a telegraph operator after he saved three-year-old Jimmie MacKenzie from being struck by a runaway train. Jimmie's father, station agent J.U. MacKenzie of Mount Clemens, Michigan, was so grateful that he trained Edison as a telegraph operator. Edison's first telegraphy job away from Port Huron was at Stratford Junction, Ontario, on the Grand Trunk Railway.
In 1866, at the age of 19, Edison moved to Louisville, Kentucky, where, as an employee of Western Union, he worked the Associated Press bureau news wire. Edison requested the night shift, which allowed him plenty of time to spend at his two favorite pastimes—reading and experimenting. Eventually, the latter pre-occupation cost him his job. One night in 1867, he was working with a lead–acid battery when he spilled sulfuric acid onto the floor. It ran between the floorboards and onto his boss's desk below. The next morning Edison was fired.
One of his mentors during those early years was a fellow telegrapher and inventor named Franklin Leonard Pope, who allowed the impoverished youth to live and work in the basement of his Elizabeth, New Jersey, home. Some of Edison's earliest inventions were related to telegraphy, including a stock ticker. His first patent was for the electric vote recorder, (U.S. Patent 90,646), which was granted on June 1, 1869.
Marriages and children
On December 25, 1871, Edison married 16-year-old Mary Stilwell (1855–1884), whom he had met two months earlier; she was an employee at one of his shops. They had three children:
Mary Edison died at age 29 on August 9, 1884, of unknown causes: possibly from a brain tumor or a morphine overdose. Doctors frequently prescribed morphine to women in those years to treat a variety of causes, and researchers believe that some of her symptoms sounded as if they were associated with morphine poisoning.
On February 24, 1886, at the age of thirty-nine, Edison married the 20-year-old Mina Miller (1865–1947) in Akron, Ohio. She was the daughter of the inventor Lewis Miller, co-founder of the Chautauqua Institution and a benefactor of Methodist charities. They also had three children together:
Beginning his career
Edison began his career as an inventor in Newark, New Jersey, with the automatic repeater and his other improved telegraphic devices, but the invention that first gained him notice was the phonograph in 1877. This accomplishment was so unexpected by the public at large as to appear almost magical. Edison became known as "The Wizard of Menlo Park," New Jersey.
His first phonograph recorded on tinfoil around a grooved cylinder. Despite its limited sound quality and that the recordings could be played only a few times, the phonograph made Edison a celebrity. Joseph Henry, president of the National Academy of Sciences and one of the most renowned electrical scientists in the US, described Edison as "the most ingenious inventor in this country... or in any other". In April 1878, Edison travelled to Washington to demonstrate the phonograph before the National Academy of Sciences, Congressmen, Senators and US President Hayes. The Washington Post described Edison as a "genius" and his presentation as "a scene... that will live in history". Although Edison obtained a patent for the phonograph in 1878, he did little to develop it until Alexander Graham Bell, Chichester Bell, and Charles Tainter produced a phonograph-like device in the 1880s that used wax-coated cardboard cylinders.
Edison's major innovation was the first industrial research lab, which was built in Menlo Park, a part of Raritan Township, Middlesex County, New Jersey (today named Edison in his honor). It was built with the funds from the sale of Edison's quadruplex telegraph. After his demonstration of the telegraph, Edison was not sure that his original plan to sell it for $4,000 to $5,000 was right, so he asked Western Union to make a bid. He was surprised to hear them offer $10,000 ($209,100 in today's dollars.), which he gratefully accepted. The quadruplex telegraph was Edison's first big financial success, and Menlo Park became the first institution set up with the specific purpose of producing constant technological innovation and improvement. Edison was legally attributed with most of the inventions produced there, though many employees carried out research and development under his direction. His staff was generally told to carry out his directions in conducting research, and he drove them hard to produce results.
William Joseph Hammer, a consulting electrical engineer, began his duties as a laboratory assistant to Edison in December 1879. He assisted in experiments on the telephone, phonograph, electric railway, iron ore separator, electric lighting, and other developing inventions. However, Hammer worked primarily on the incandescent electric lamp and was put in charge of tests and records on that device (see Hammer Historical Collection of Incandescent Electric Lamps). In 1880, he was appointed chief engineer of the Edison Lamp Works. In his first year, the plant under General Manager Francis Robbins Upton turned out 50,000 lamps. According to Edison, Hammer was "a pioneer of incandescent electric lighting". Frank J. Sprague, a competent mathematician and former naval officer, was recruited by Edward H. Johnson and joined the Edison organization in 1883. One of Sprague's contributions to the Edison Laboratory at Menlo Park was to expand Edison's mathematical methods. Despite the common belief that Edison did not use mathematics, analysis of his notebooks reveal that he was an astute user of mathematical analysis conducted by his assistants such as Francis Robbins Upton, for example, determining the critical parameters of his electric lighting system including lamp resistance by an analysis of Ohm's Law, Joule's Law and economics.
Nearly all of Edison's patents were utility patents, which were protected for a 17-year period and included inventions or processes that are electrical, mechanical, or chemical in nature. About a dozen were design patents, which protect an ornamental design for up to a 14-year period. As in most patents, the inventions he described were improvements over prior art. The phonograph patent, in contrast, was unprecedented as describing the first device to record and reproduce sounds.
In just over a decade, Edison's Menlo Park laboratory had expanded to occupy two city blocks. Edison said he wanted the lab to have "a stock of almost every conceivable material". A newspaper article printed in 1887 reveals the seriousness of his claim, stating the lab contained "eight thousand kinds of chemicals, every kind of screw made, every size of needle, every kind of cord or wire, hair of humans, horses, hogs, cows, rabbits, goats, minx, camels ... silk in every texture, cocoons, various kinds of hoofs, shark's teeth, deer horns, tortoise shell ... cork, resin, varnish and oil, ostrich feathers, a peacock's tail, jet, amber, rubber, all ores ..." and the list goes on.
Over his desk, Edison displayed a placard with Sir Joshua Reynolds' famous quotation: "There is no expedient to which a man will not resort to avoid the real labor of thinking." This slogan was reputedly posted at several other locations throughout the facility.
With Menlo Park, Edison had created the first industrial laboratory concerned with creating knowledge and then controlling its application.
Carbon telephone transmitter
In 1877–78, Edison invented and developed the carbon microphone used in all telephones along with the Bell receiver until the 1980s. After protracted patent litigation, in 1892 a federal court ruled that Edison and not Emile Berliner was the inventor of the carbon microphone. The carbon microphone was also used in radio broadcasting and public address work through the 1920s.
Main article: History of the light bulb
In 1878 Edison began working on a system of electrical illumination, something he hoped could compete with gas and oil based lighting. He began by tackling the problem of creating a long lasting incandescent lamp, something that would be needed for indoor use. Many earlier inventors had previously devised incandescent lamps, including Alessandro Volta's demonstration of a glowing wire in 1800 and inventions by Henry Woodward and Mathew Evans. Others who developed early and commercially impractical incandescent electric lamps included Humphry Davy, James Bowman Lindsay, Moses G. Farmer, William E. Sawyer, Joseph Swan and Heinrich Göbel. Some of these early bulbs had such flaws as an extremely short life, high expense to produce, and high electric current drawn, making them difficult to apply on a large scale commercially.:217–218 Edison realized that in order to keep the thickness of the copper wire needed to connect a series of electric lights to an economically manageable size he would have to come up with a lamp that would draw a low amount of current. This meant the lamp would have to have a high resistance and run at a relatively low voltage (around 110 volts).
After many experiments, first with carbon filaments and then with platinum and other metals, in the end Edison returned to a carbon filament. The first successful test was on October 22, 1879;:186 it lasted 13.5 hours. Edison continued to improve this design and by November 4, 1879, filed for U.S. patent 223,898 (granted on January 27, 1880) for an electric lamp using "a carbon filament or strip coiled and connected to platina contact wires". This was the first commercially practical incandescent light.
Although the patent described several ways of creating the carbon filament including "cotton and linen thread, wood splints, papers coiled in various ways", it was not until several months after the patent was granted that Edison and his team discovered a carbonized bamboo filament that could last over 1,200 hours. The idea of using this particular raw material originated from Edison's recalling his examination of a few threads from a bamboo fishing pole while relaxing on the shore of Battle Lake in the present-day state of Wyoming, where he and other members of a scientific team had traveled so that they could clearly observe a total eclipse of the sun on July 29, 1878, from the Continental Divide.
In 1878, Edison formed the Edison Electric Light Company in New York City with several financiers, including J. P. Morgan and the members of the Vanderbilt family. Edison made the first public demonstration of his incandescent light bulb on December 31, 1879, in Menlo Park. It was during this time that he said: "We will make electricity so cheap that only the rich will burn candles."
Henry Villard, president of the Oregon Railroad and Navigation Company, had attended Edison's 1879 demonstration. Villard quickly became impressed and requested Edison install his electric lighting system aboard his company's new steamer, the Columbia. Although hesitant at first, Edison relented and agreed to Villard's request. Following most of its completion in May 1880, the Columbia was sent to New York City, where Edison and his personnel installed Columbia's new lighting system. Due to this, the Columbia became Edison's first commercial application for his incandescent light bulb. The Edison equipment was eventually removed from Columbia in 1895.
Lewis Latimer joined the Edison Electric Light Company in 1884. Latimer had received a patent in January 1881 for the "Process of Manufacturing Carbons", an improved method for the production of carbon filaments for lightbulbs. Latimer worked as an engineer, a draftsman and an expert witness in patent litigation on electric lights.
George Westinghouse's company bought Philip Diehl's competing induction lamp patent rights (1882) for $25,000, forcing the holders of the Edison patent to charge a more reasonable rate for the use of the Edison patent rights and lowering the price of the electric lamp.
On October 8, 1883, the US patent office ruled that Edison's patent was based on the work of William E. Sawyer and was therefore invalid. Litigation continued for nearly six years, until October 6, 1889, when a judge ruled that Edison's electric-light improvement claim for "a filament of carbon of high resistance" was valid. To avoid a possible court battle with Joseph Swan, whose British patent had been awarded a year before Edison's, he and Swan formed a joint company called Ediswan to manufacture and market the invention in Britain.
Mahen Theatre in Brno (in what is now the Czech Republic), which opened in 1882, was the first public building in the world to use Edison's electric lamps, with the installation supervised by Edison's assistant in the invention of the lamp, Francis Jehl. In September 2010, a sculpture of three giant light bulbs was erected in Brno, in front of the theatre.
Electric power distribution
After devising a commercially viable electric light bulb on October 21, 1879, Edison went on to develop an electric "utility" designed to compete with the then existent gas lighting utilities. On December 17, 1880, he founded the Edison Illuminating Company and during the 1880s he patented a system for electricity distribution. The company established the first investor-owned electric utility in 1882 on Pearl Street Station, New York City. It was on September 4, 1882, that Edison switched on his Pearl Street generating station's electrical power distribution system, which provided 110 volts direct current (DC) to 59 customers in lower Manhattan.
Earlier in the year, in January 1882, he had switched on the first steam-generating power station at Holborn Viaduct in London. The DC supply system provided electricity supplies to street lamps and several private dwellings within a short distance of the station. On January 19, 1883, the first standardized incandescent electric lighting system employing overhead wires began service in Roselle, New Jersey.
War of currents
Main article: War of Currents
As Edison was expanding his direct current (DC) power delivery system he began receiving stiff competition from companies installing alternating current (AC) systems. From the early 1880s on AC arc lighting systems for streets and large spaces had been an expanding business in the US. With the development of transformers in Europe and by Westinghouse Electric in the US in 1885-1886 it became possible to transmit AC very long distances over thinner and cheaper wires, and "step down" the voltage at the destination for distribution to users. This allowed AC to be used not only in street lighting but also in lighting for small business and domestic customers, the market Edison's patented low voltage DC incandescent lamp system had been designed to supply. Edison's DC empire began suffering from one of its chief drawbacks: it was suitable only for the high density of customers found in large cities. Edison's DC plants could not deliver electricity to customers who were more than one mile from the plant and the short range left a patchwork of un-supplied customers in-between plants. Small cities and rural areas could not afford an Edison style system at all. This left a large part of market without electrical service and AC companies were expanding into this gap.
Edison expressed views that AC was unworkable and the high voltages used were dangerous. As George Westinghouse was installing his first AC systems in 1886, Thomas Edison began a pattern of striking out personally against his chief rival stating, "Just as certain as death, Westinghouse will kill a customer within six months after he puts in a system of any size. He has got a new thing and it will require a great deal of experimenting to get it working practically." Many reasons have been put forward for Edison's anti-AC stance. One notion is that the inventor may not have been able to grasp the more abstract theories behind AC and was trying to avoid developing a system he did not understand. Edison also appeared to have been worried about the high voltage from some competitor's misinstalled AC system killing customers and hurting the sales of electric power systems in general. On top of all that was the simple fact that Edison Electric had based their entire design on low voltage DC and switching a standard after they had installed over 100 systems was, in Edison's mind, out of the question. By the end of 1887 Edison Electric was beginning to lose market share with Westinghouse, who had built 68 AC-based power stations to Edison's 121 DC-based stations. To make matters worse for Edison, the Thomson-Houston Electric Company of Lynn, Massachusetts (another AC-based competitor) had built 22 power stations.
Parallel to the expanding competition between Edison and the AC companies was a rising public furor over a series of deaths in the spring of 1888 caused by pole mounted high voltage alternating current lines that turned into a media frenzy against the current and the seemingly greedy and callous lighting companies that used it. Edison took advantage of the public perception that AC was dangerous and teamed up with the self-styled New York anti-AC crusader Harold P. Brown in a propaganda campaign, aiding Brown in the public electrocution of animals with AC as well as supported legislation to control and severely limit AC installations and voltages (to the point of making it an ineffective power delivery system) in what was now being referred to as a "battle of currents". The development of the electric chair was used in an attempt to portray AC as having a greater lethal potential than DC and smear Westinghouse at the same time via Edison colluding with Brown and Westinghouse's chief AC rival, the Thomson-Houston Electric Company, to make sure the first electric chair was powered by a Westinghouse AC generator.
Thomas Edison's staunch anti-AC tactics were not sitting well with his own stock holders. By the early 1890s Edison's company was generating much smaller profits than its AC rivals, and the War of Currents would come to an end in 1892 with Edison being forced out of controlling his own company. That year the financier J P Morgan engineered a merger of Edison General Electric with Thomson-Houston that basically put the board of Thomson-Houston in charge of the new company called General Electric (dropping "Edison" from its name). General Electric now controlled three quarters of the US electrical business and would go on to compete with Westinghouse for the AC market.
Other inventions and projects
Edison is credited with designing and producing the first commercially available fluoroscope, a machine that uses X-rays to take radiographs. Until Edison discovered that calcium tungstate fluoroscopy screens produced brighter images than the barium platinocyanide screens originally used by Wilhelm Röntgen, the technology was capable of producing only very faint images.
The fundamental design of Edison's fluoroscope is still in use today, although Edison himself abandoned the project after nearly losing his own eyesight and seriously injuring his assistant, Clarence Dally. Dally had made himself an enthusiastic human guinea pig for the fluoroscopy project and in the process been exposed to a poisonous dose of radiation. He later died of injuries related to the exposure. In 1903, a shaken Edison said "Don't talk to me about X-rays, I am afraid of them."
The key to Edison's fortunes was telegraphy. With knowledge gained from years of working as a telegraph operator, he learned the basics of electricity. This allowed him to make his early fortune with the stock ticker, the first electricity-based broadcast system. On August 9, 1892, Edison received a patent for a two-way telegraph.
Edison was also granted a patent for the motion picture camera or "Kinetograph". He did the electromechanical design, while his employee W.K.L. Dickson, a photographer, worked on the photographic and optical development. Much of the credit for the invention belongs to Dickson. In 1891, Thomas Edison built a Kinetoscope, or peep-hole viewer. This device was installed in penny arcades, where people could watch short, simple films. The kinetograph and kinetoscope were both first publicly exhibited May 20, 1891.
In April 1896, Thomas Armat's Vitascope, manufactured by the Edison factory and marketed in Edison's name, was used to project motion pictures in public screenings in New York City. Later he exhibited motion pictures with voice soundtrack on cylinder recordings, mechanically synchronized with the film.
Officially the kinetoscope entered Europe when the rich American Businessman Irving T. Bush (1869–1948) bought from the Continental Commerce Company of Frank Z. Maguire and Joseph D. Baucus a dozen machines. Bush placed from October 17, 1894, the first kinetoscopes in London. At the same time the French company Kinétoscope Edison Michel et Alexis Werner bought these machines for the market in France. In the last three months of 1894, The Continental Commerce Company sold hundreds of kinetoscopes in Europe (i.e. the Netherlands and Italy). In Germany and in Austria-Hungary the kinetoscope was introduced by the Deutsche-österreichische-Edison-Kinetoscop Gesellschaft, founded by the Ludwig Stollwerck of the Schokoladen-Süsswarenfabrik Stollwerck & Co of Cologne.
The first kinetoscopes arrived in Belgium at the Fairs in early 1895. The Edison's Kinétoscope Français, a Belgian company, was founded in Brussels on January 15, 1895, with the rights to sell the kinetoscopes in Monaco, France and the French colonies. The main investors in this company were Belgian industrialists.
On May 14, 1895, the Edison's Kinétoscope Belge was founded in Brussels. The businessman Ladislas-Victor Lewitzki, living in London but active in Belgium and France, took the initiative in starting this business. He had contacts with Leon Gaumont and the American Mutoscope and Biograph Co. In 1898 he also became a shareholder of the Biograph and Mutoscope Company for France.
Edison's film studio made close to 1,200 films. The majority of the productions were short films showing everything from acrobats to parades to fire calls including titles such as Fred Ott's Sneeze (1894), The Kiss (1896), The Great Train Robbery (1903), Alice's Adventures in Wonderland (1910), and the first Frankenstein film in 1910. In 1903, when the owners of Luna Park, Coney Island announced they would execute Topsy the elephant by strangulation, poisoning, and electrocution (with the electrocution part ultimately killing the elephant), Edison Manufacturing sent a crew to film it, releasing it that same year with the title Electrocuting an Elephant.
As the film business expanded competing exhibitors routinely copied and exhibited each other's films. To better protect the copyrights on his films, Edison deposited prints of them on long strips of photographic paper with the U.S. copyright office. Many of these paper prints survived longer and in better condition than the actual films of that era.
In 1908, Edison started the Motion Picture Patents Company, which was a conglomerate of nine major film studios (commonly known as the Edison Trust). Thomas Edison was the first honorary fellow of the Acoustical Society of America, which was founded in 1929.
Edison said his favorite movie was The Birth of a Nation. He thought that talkies had "spoiled everything" for him. "There isn't any good acting on the screen. They concentrate on the voice now and have forgotten how to act. I can sense it more than you because I am deaf." His favorite stars were Mary Pickford and Clara Bow.
In 1901, Edison visited an industrial exhibition in the Sudbury area in Ontario, Canada and thought nickel and cobalt deposits there could be used in his production of electrical equipment. He returned as a mining prospector, and is credited with the original discovery of the Falconbridge ore body. His attempts to mine the ore body were not successful, however, and he abandoned his mining claim in 1903. A street in Falconbridge, as well as the Edison Building, which served as the head office of Falconbridge Mines, are named for him.
Edison became concerned with America's reliance on foreign supply of rubber and was determined to find a native supply of rubber. He partnered with Harvey Firestone and Henry Ford (all three contributing $25,000 each) to create the Edison Botanic Research Corp. in 1927 and constructed a laboratory in Fort Myers, Florida the following year. Edison did the majority of the research and planting, sending results and sample rubber residues to his West Orange Lab. After testing 17,000 plant samples eventually finding a source in the Goldenrod plant.
West Orange and Fort Myers (1886–1931)
Edison moved from Menlo Park after the death of his first wife, Mary, in 1884, and purchased a home known as "Glenmont" in 1886 as a wedding gift for his second wife, Mina, in Llewellyn Park in West Orange, New Jersey. In 1885, Thomas Edison had bought property in Fort Myers, Florida, and built what was later called Seminole Lodge as a winter retreat. Edison and Mina spent many winters at their home in Fort Myers, and Edison tried to find a domestic source of natural rubber.
Henry Ford, the automobile magnate, later lived a few hundred feet away from Edison at his winter retreat in Fort Myers. Ford once worked as an engineer for the Edison Illuminating Company of Detroit and met Edison at a convention of affiliated Edison illuminating companies in Brooklyn, NY in 1896. Edison was impressed with Fords internal combustion engine automobile and encouraged its developments. They were friends until Edison's death. Edison and Ford undertook annual motor camping trips from 1914 to 1924. Harvey Firestone and John Burroughs also participated.
In 1928, Edison joined the Fort Myers Civitan Club. He believed strongly in the organization, writing that "The Civitan Club is doing things—big things—for the community, state, and nation, and I certainly consider it an honor to be numbered in its ranks." He was an active member in the club until his death, sometimes bringing Henry Ford to the club's meetings.
Edison was active in business right up to the end. Just months before his death, the Lackawanna Railroad inaugurated suburban electric train service from Hoboken to Montclair, Dover, and Gladstone, New Jersey. Electrical transmission for this service was by means of an overhead catenary system using direct current, which Edison had championed. Despite his frail condition, Edison was at the throttle of the first electric MU (Multiple-Unit) train to depart Lackawanna Terminal in Hoboken in September 1930, driving the train the first mile through Hoboken yard on its way to South Orange.
This fleet of cars would serve commuters in northern New Jersey for the next 54 years until their retirement in 1984. A plaque commemorating Edison's inaugural ride can be seen today in the waiting room of Lackawanna Terminal in Hoboken, which is presently operated by New Jersey Transit.
Edison was said to have been influenced by a popular fad diet in his last few years; "the only liquid he consumed was a pint of milk every three hours". He is reported to have believed this diet would restore his health. However, this tale is doubtful. In 1930, the year before Edison died, Mina said in an interview about him, "correct eating is one of his greatest hobbies." She also said that during one of his periodic "great scientific adventures", Edison would be up at 7:00, have breakfast at 8:00, and be rarely home for lunch or dinner, implying that he continued to have all three.
Edison died of complications of diabetes on October 18, 1931, in his home, "Glenmont" in Llewellyn Park in West Orange, New Jersey, which he had purchased in 1886 as a wedding gift for Mina. He is buried behind the home.
Edison's last breath is reportedly contained in a test tube at the Henry Ford Museum. Ford reportedly convinced Charles Edison to seal a test tube of air in the inventor's room shortly after his death, as a memento. A plaster death mask was also made. Mina died in 1947.
Views on politics, religion and metaphysics
Historian Paul Israel has characterized Edison as a "freethinker". Edison was heavily influenced by Thomas Paine's The Age of Reason. Edison defended Paine's "scientific deism", saying, "He has been called an atheist, but atheist he was not. Paine believed in a supreme intelligence, as representing the idea which other men often express by the name of deity." In an October 2, 1910, interview in the New York Times Magazine, Edison stated:
Edison was accused of being an atheist for those remarks, and although he did not allow himself to be drawn into the controversy publicly, he clarified himself in a private letter:
He also stated, "I do not believe in the God of the theologians; but that there is a Supreme Intelligence I do not doubt."
Nonviolence was key to Edison's moral views, and when asked to serve as a naval consultant for World War I, he specified he would work only on defensive weapons and later noted, "I am proud of the fact that I never invented weapons to kill." Edison's philosophy of nonviolence extended to animals as well, about which he stated: "Nonviolence leads to the highest ethics, which is the goal of all evolution. Until we stop harming all other living beings, we are still savages." He was a vegetarian but not a vegan in actual practice, at least near the end of his life.
In 1920, Edison set off a media sensation when he told B. C. Forbes of American Magazine that he was working on a "spirit phone" to allow communication with the dead, a story which other newspapers and magazines repeated. Edison later disclaimed the idea, telling the New York Times in 1926 that "I really had nothing to tell him, but I hated to disappoint him so I thought up this story about communicating with spirits, but it was all a joke."
Views on money
Thomas Edison was an advocate for monetary reform in the United States. He was ardently opposed to the gold standard and debt-based money. Famously, he was quoted in the New York Times stating "Gold is a relic of Julius Caesar, and interest is an invention of Satan."
In the same article, he expounded upon the absurdity of a monetary system in which the taxpayer of the United States, in need of a loan, be compelled to pay in return perhaps double the principal, or even greater sums, due to interest. His basic point was that if the Government can produce debt-based money, it could equally as well produce money that was a credit to the taxpayer.
He thought at length about the subject of money over 1921 and 1922. In May 1922, he published a proposal, entitled "A Proposed Amendment to the Federal Reserve Banking System". In it, he detailed an explanation of a commodity-backed currency, in which the Federal Reserve would issue interest-free currency to farmers, based on the value of commodities they produced. During a publicity tour that he took with friend and fellow inventor, Henry Ford, he spoke publicly about his desire for monetary reform. For insight, he corresponded with prominent academic and banking professionals. In the end, however, Edison's proposals failed to find support, and were eventually abandoned.
The President of the Third French Republic, Jules Grévy, on the recommendation of his Minister of Foreign Affairs Jules Barthélemy-Saint-Hilaire and with the presentations of the Minister of Posts and Telegraphs Louis Cochery, designated Edison with the distinction of an 'Officer of the Legion of Honour' (Légion d'honneur) by decree on November 10, 1881; He also named a Chevalier in 1879, and a Commander in 1889.
Life magazine (USA), in a special double issue in 1997, placed Edison first in the list of the "100 Most Important People in the Last 1000 Years", noting that the light bulb he promoted "lit up the world". In the 2005 television series The Greatest American, he was voted by viewers as the fifteenth-greatest.
In 2008, Edison was inducted in the New Jersey Hall of Fame.
In 2010, Edison was honored with a Technical Grammy Award.
Places and people named for Edison
Several places have been named after Edison, most notably the town of Edison, New Jersey. Thomas Edison State University, nationally known for adult learners, is in Trenton, New Jersey. Two community colleges are named for him: Edison State College in Fort Myers, Florida, and Edison Community College in Piqua, Ohio. There are numerous high schools named after Edison (see Edison High School) and other schools including Thomas A. Edison Middle School. Footballer Pelé's father originally named him Edson, as a tribute to the inventor of the light bulb, but the name was incorrectly listed on his birth certificate as "Edison".
In 1883, the City Hotel in Sunbury, Pennsylvania was the first building to be lit with Edison's three-wire system. The hotel was renamed The Hotel Edison upon Edison's return to the City on 1922.
Museums and memorials
In West Orange, New Jersey, the 13.5 acres (5.5 hectares) Glenmont estate is maintained and operated by the National Park Service as the Edison National Historic Site, as is his nearby laboratory and workshops including the reconstructed Black Maria- the world's first movie studio. The Thomas Alva Edison Memorial Tower and Museum is in the town of Edison, New Jersey. In Beaumont, Texas, there is an Edison Museum, though Edison never visited there. The Port Huron Museum, in Port Huron, Michigan, restored the original depot that Thomas Edison worked out of as a young newsbutcher. The depot has been named the Thomas Edison Depot Museum. The town has many Edison historical landmarks, including the graves of Edison's parents, and a monument along the St. Clair River. Edison's influence can be seen throughout this city of 32,000.
In Detroit, the Edison Memorial Fountain in Grand Circus Park was created to honor his achievements. The limestone fountain was dedicated October 21, 1929, the fiftieth anniversary of the creation of the lightbulb. On the same night, The Edison Institute was dedicated in nearby Dearborn.
He was inducted into the Automotive Hall of Fame in 1969.
Companies bearing Edison's name
Awards named in honor of Edison
The Edison Medal was created on February 11, 1904, by a group of Edison's friends and associates. Four years later the American Institute of Electrical Engineers (AIEE), later IEEE, entered into an agreement with the group to present the medal as its highest award. The first medal was presented in 1909 to Elihu Thomson. It is the oldest award in the area of electrical and electronics engineering, and is presented annually "for a career of meritorious achievement in electrical science, electrical engineering or the electrical arts."
In the Netherlands, the major music awards are named the Edison Award after him. The award is an annual Dutch music prize, awarded for outstanding achievements in the music industry, and is one of the oldest music awards in the world, having been presented since 1960.
Other items named after Edison
The United States Navy named the USS Edison (DD-439), a Gleaves class destroyer, in his honor in 1940. The ship was decommissioned a few months after the end of World War II. In 1962, the Navy commissioned USS Thomas A. Edison (SSBN-610), a fleet ballistic missile nuclear-powered submarine.
In popular culture
Main article: Thomas Edison in popular culture
Thomas Edison has appeared in popular culture as a character in novels, films, comics and video games. His prolific inventing helped make him an icon and he has made appearances in popular culture during his lifetime down to the present day. Edison is also portrayed in popular culture as an adversary of Nikola Tesla.
"Camping with Henry and Tom", a fictional play based on Edison's camping trips with Henry Ford, written by Mark St.Gemain. First presented at Lucille Lortel Theatre, New York, February 20, 1995.
On February 11, 2011, on Thomas Edison's 164th birthday, Google's homepage featured an animated Google Doodle commemorating his many inventions. When the cursor was hovered over the doodle, a series of mechanisms seemed to move, causing a lightbulb to glow.
List of people who worked for Edison
The following is a list of people who worked for Thomas Edison in his laboratories at Menlo Park or West Orange or at the subsidiary electrical businesses that he supervised.
Information and media