Winter–Spring Designs perforators, transmitters, ink recorders, and typewriters for automatic telegraphy.
4 April Gives Harrington power of attorney for disposition of Edison's share in all inventions relating to automatic telegraphy.
9 April Edison's mother, Nancy, dies in Port Huron.
April–May Moves the Newark Telegraph Works from Railroad Ave. to Ward St. and changes the company's name to Edison and Unger.
April–May Manufactures his cotton instrument, developed for Gold and Stock under his contract with Field and Andrews.
26 May Sells the rights to his existing and future printing telegraph patents to Gold and Stock and becomes the company's consulting electrician.
28–29 July Begins series of four notebooks to record his inventive work on printing, automatic, and other forms of telegraphy.
August Begins manufacturing his universal stock printer for Gold and Stock.
October Employs Mary Stilwell for his News Reporting Telegraph Co., which sought to provide general and commercial news in Newark.
22 November Purchases his first house, located on Wright St. in Newark.
28 November Buys stock in the street railway of his brother, William Pitt Edison, in Port Huron.
25 December Marries Mary Stilwell.


top 1872
15–17 January Designs a district telegraph that he assigns to the American District Telegraph Co.
27 January Transforms his universal private line printer into an electric typewriter for automatic telegraphy.
January–February Fills laboratory notebooks with variations for his universal stock printer and his universal private line printer.
5 February Becomes a partner in J. T. Murray and Co., which later becomes Edison and Murray.
May Delivers first models of improved universal private line printer to Gold and Stock.
May–June Supplies his universal stock printer to the Exchange Telegraph Co. of London.
3 July Agrees to purchase Unger's share in Edison and Unger, thereby dissolving their partnership.
5 November Makes an agreement with Josiah Reiff to provide Edison with an annual salary while he works on automatic telegraph improvements.
14 December The Automatic Telegraph Co. opens for business using Edison's automatic telegraph improvements.
Fall Conducts tests of his automatic telegraph system on the lines of the Automatic Telegraph Co. and the Southern and Atlantic Telegraph Co. between New York City, Washington, D.C., and Charleston, S.C.
top 1873
c. 10 February Meets with William Orton, president of Western Union, and makes a verbal agreement to develop duplex telegraphy.
18 February Edison's first daughter, Marion Estelle ("Dot"), is born in Newark.
March 31 Agrees to develop a roman letter automatic telegraph for Harrington and Reiff.
9–22 April Prepares ten patent applications on duplex telegraphy.
23 April Leaves for England.
23–27 May Conducts tests of his automatic telegraph system for the British Post Office.
c. 1–15 June Conducts tests of his automatic telegraph on a cable stored at the Greenwich works of the Telegraph Construction and Maintenance Co.
25 June Returns to Newark from England.
2 August Drafts caveat that contains the basis of the quadruplex.
25 August Executes patent application for his roman-letter automatic-telegraph perforator.
2 September Sells British rights for his automatic telegraph to a London company.
6 September A carbon rheostat for use in artificial-cable telegraph experiments is finished in the shop.
Summer–Fall Devises and experiments with circuit designs for duplex, automatic, and cable telegraphy using electromagnets and storage batteries to counter inductive effects.
  Studies chemistry handbooks, prepares automatic-telegraph experiments using different metal styli, and executes four patent applications for chemical solutions for telegraph recording paper.
  Resumes experiments with three-key automatic-telegraph perforators.
1 October Demonstrates quadruplex telegraph for several important telegraph officials.
28 October Executes first caveats for roman-letter automatic-telegraph circuits.
Fall Makes Charles Batchelor his principal laboratory assistant and conducts experiments on electrolytic solutions in batteries.
  Works with telegraph inventor-manufacturer Jesse Bunnell on a railway signal device.
Late December Conducts test of his automatic telegraph system for several important telegraph officials.


27 January The Automatic Telegraph Co. publicly demonstrates Edison's automatic telegraph system.
1 February Drafts a new roman-letter automatic-telegraph caveat and begins experiments based on its designs.
Winter Continues experiments on battery and automatic-telegraph recording solutions and on cable telegraphy.
  British investors urge his return to England to supervise continuing tests of his automatic telegraph on British Post Office and private cable lines.
  Works in earnest on his proposed book on telegraphy.
March Begins development of a district telegraph and fire alarm system.
26 March Agrees with Joseph Murray and Jarvis Edson to incorporate the Domestic Telegraph Co. to exploit his district-telegraph and fire alarm inventions.
Late March Seeks increased support for duplex telegraph research from Western Union president William Orton.
10 April Discovers electromotograph phenomenon.
c. 16 April Demonstrates roman-letter automatic to George Ward, American manager of the French and Anglo-American cable lines.
18 April Begins experiments on induction coils for electromedical devices.
28 April Shop builds models of the inductorium and of a student telegraph operator's instrument for proposed Scientific Toy Co.
19 May Seeks cooperation of Western Union electrician George Prescott in duplex experiments in exchange for a half interest in resulting patents.
22 May  Begins selling inductorium.
May Searches for a source of tellurium for use as recording stylus in automatic and domestic telegraphy.
1 June Executes a patent application for a tellurium recording stylus for automatic telegraphy.
c. 1 June George Prescott accepts Edison's proposal with approval of President Orton; Edison and Prescott begin quadruplex experiments on Western Union lines and have apparatus made at the Western Union shop.
21 June Drafts partnership agreement with George Prescott regarding duplex and quadruplex.
June Edison and Murray prepares instruments for a July demonstration of Edison's fire alarm system in Utica, N.Y.
Spring George Harrington and Josiah Reiff negotiate to form a new company to exploit Edison's automatic-telegraph inventions.
3 July Mortgage and notes due William Unger; payments made during month by Automatic Telegraph Co. investors in exchange for Edison's promissory notes to Harrington.
8 July  Demonstrates quadruplex to Western Union officials on the company's lines.
9 July  Signs first partnership agreement with George Prescott.
10 July Western Union announces the quadruplex through an article in the New York Times.
18 July Former partner James Ashley begins vituperative attacks on Edison in the Telegrapher.
24 July Finishes several automatic-telegraph patent models for George Harrington, including modifications of the British Wheatstone system.
3 August Resumes electromotograph experiments.
7 August Executes patent application for a telegraph device employing the electromotograph.
19 August Signs a revised partnership agreement with George Prescott and executes several patent applications for duplex and quadruplex telegraphy.
August Becomes science editor of the Operator.
  James Adams joins Edison's experimental staff.
1 September Publishes first of several articles in the Operator.
5 September  Announces electromotograph discovery in the Scientific American.
21 September Begins one month of chemistry lessons under Robert Spice, Brooklyn High School professor of chemistry and natural philosophy.
Late September Successfully tests quadruplex on Western Union line between New York and Boston; commercial operation begins 3 October.
October–November Installs and modifies quadruplex on Western Union lines.
c. 1 November Moves his family to an apartment on Bank St.
2 November  Conducts experiments looking for new forces.
c. 6 November Exhibits electromotograph at the National Academy of Sciences meeting in Philadelphia.
c. 1 December Sells his house on Wright St.
3 December Agrees to establish a Domestic Telegraph Co. in Canada and begins manufacturing new private-line printer for the domestic system.
4 December Successfully establishes quadruplex operation on Western Union line between New York and Chicago with a repeater at Buffalo.
  Executes first four of twelve multiple-telegraph caveats and patent applications prepared during December and January.
9 December  Society of Telegraph Engineers in London elects Edison and Charles Batchelor members.
10 December  Receives $5,000 advance from Western Union for quadruplex.
Mid-December Tries to negotiate sale of quadruplex to Western Union; President Orton departs on business trip.
30 December Josiah Reiff, John McManus, and Jay Gould reach agreement on Atlantic and Pacific Telegraph Co. takeover of Automatic Telegraph Co., with Edison to be company electrician.
  Gould, Thomas Eckert, and Albert Chandler visit Edison at night to see automatic telegraph and quadruplex.
31 December Quadruplex patent application suspended for possible interference.


4 January Sells his quadruplex patent rights to Jay Gould for $30,000.
5–8 January Discusses strategies with Gould for Atlantic and Pacific competition with Western Union.
  Purchases books and scientific equipment.
c. 11 January Visits his family in Port Huron, Mich.
19 January William Orton accepts terms for quadruplex purchase suggested by Edison in December.
20–21 January Files arguments and amendments for applications examined by Patent Office on 31 December 1874 and requests immediate approval of all multiple-telegraphy cases that were not suspended.
23 January Writes Commissioner of Patents to ask that quadruplex patents be assigned jointly with Harrington rather than Prescott.
  Writes William Orton, saying he cannot accept Western Union's terms.
28 January Western Union begins legal proceedings against Edison in New Jersey over the quadruplex.
January Begins serving as electrician of Atlantic and Pacific; inspects New York–Boston line.
  Edison and Murray begins manufacturing domestic-telegraph instruments for New York City lines and automatic instruments for Atlantic and Pacific.
11 February With his wife, Mary, gives a masquerade party on his birthday.
24 February Executes a patent application with Charles Batchelor for the domestic telegraph system.
27 February Jay Gould agrees to pay expenses for roman-letter automatic experiments.
20 March Commissioner of Patents orders that quadruplex patents be assigned jointly with Prescott rather than Harrington.
23 March Files two patent applications (for a quadruplex repeater and for the domestic telegraph system designed with Batchelor); does not file another application for a year.
Late March Demonstrates an automatic telegraph system employing a spectroscope to the secretary of the German telegraph system.
March–Early April Moves family to a house on South Orange Ave. in Newark.
c. 1 April Ezra Gilliland begins selling Edison and Murray products at new store in New York City.
16 April Transfers to George Harrington and Josiah Reiff part of his interest in automatic-telegraph patents in expectation of a settlement from Atlantic and Pacific.
20 April Agrees with Gold and Stock Telegraph Co. to settle their outstanding accounts.
  Assesses his financial situation by preparing a summary account of his assets and liabilities.
27 April Swears affidavit presenting his argument to Secretary of the Interior Delano appealing the Patent Commissioner's decision on quadruplex applications.
30 April Begins experiments to develop a new copying process.
7 May  Begins experiments on electromotograph repeater for automatic telegraphy.
16 May Agrees with Joseph Murray to dissolve their manufacturing partnership; sets up separate laboratory at Ward St. shop.
31 May With Charles Batchelor prepares list of proposed experimental topics and conducts first experiments in new laboratory.
2 June Experiments to find new force for use in telegraphy.
30 June Conceives electric-pen copying system.
15 July  Signs formal agreement dissolving Edison and Murray.
26 July  Proposes lease of Atlantic and Pacific wires for night-letter business to be run from laboratory.
July Meets with William Orton to discuss acoustic telegraphy and draws alternative designs based on article about Philip Reis's telephone.
  Furnishes Ezra Gilliland with space and machinery in the Ward St. shop for the manufacturing enterprise Gilliland & Co.
5 August Prepares list of inventions to be displayed at 1876 Centennial Exhibition in Philadelphia.
August Suggests various terms for settling disputes over automatic and quadruplex patents during negotiations over possible merger of Atlantic and Pacific and Western Union.
16 September Proposes duplexing Atlantic cable of Direct United States Cable Co.
Summer Develops basic electric-pen copying system; begins manufacture and sale of system by early September.
23 September Executes first caveat for electric-pen copying system.
  Leaves for Port Huron to visit family.
1 October  Signs first of several agreements for electric-pen agencies; this one includes his nephew Charles Edison.
2 October Agrees to give Charles Batchelor and James Adams a percentage of profits from electric-pen sales.
c. 5 October Proposes a system for transmitting stockbrokers' private messages to the floor of the New York Stock Exchange.
14–21 October Develops new battery for electric pen.
30 October Drafts caveat for facsimile telegraph system employing ideas from his other inventions—e.g., the electromotograph and electric pen.
16 November Begins acoustic-telegraph experiments for Western Union.
22 November Executes his first acoustic-telegraph caveat and develops new quadruplex designs.
  Notices phenomena he ascribes to "etheric force" while working with acoustic-telegraph apparatus and begins two weeks of intensive experiments on new force.
29 November Gives newspaper reporters first interviews on etheric force.
  Again employs Robert Spice, this time as consultant and assistant on acoustic-telegraph experiments.
1 December Agrees to assign rights in automatic telegraphy to the new American Automatic Telegraph Co. as part of strategy to force Atlantic and Pacific and Jay Gould to settle with those interested in the old Automatic Telegraph Co.
14 December Signs contracts with Western Union to settle their mutual claims regarding the quadruplex controversy and to formalize the company's support for his work in acoustic telegraphy in exchange for control of his inventions.
  Conducts etheric-force experiments with Professor Henry Morton at the Stevens Institute of Technology in Hoboken, N.J.
16 December Demonstrates etheric force with Dr. George Beard at a meeting of the Polytechnic Assoc. of the American Institute of New York.
23 December Demonstrates etheric force at meeting of the Newark Scientific Assoc.
29 December Purchases house and property in Menlo Park, N.J., for new home and laboratory.
December Conducts numerous acoustic-telegraph experiments.


10 January  Edison's first son, Thomas Alva, Jr. ("Dash"), is born in Newark.
Mid-January Executes five acoustic-telegraph caveats.
January–February Begins acoustic-telegraph experiments in laboratory and on Western Union lines.
  Demonstrates a new quadruplex on Western Union lines.
  Begins construction of new laboratory at Menlo Park under the supervision of his father, Samuel.
7 February Improves design of electric pen; laboratory machinists begin altering existing pens for manufacturer Gilliland & Co.
8 February Assigns a one-tenth interest in electric pen to Ezra Gilliland's father, Robert.
7 March Executes a patent application for his electric-pen copying system; files it on 13 March as his first application in one year.
  Arranges public sale of stock in new electric-pen company.
c. 13 March Agrees to share space at Centennial Exhibition with Western Union.
16 March Mary Edison is given a surprise party at the Edison home.
21 March Attempts to withdraw his quadruplex- and automatic-telegraph patent applications and associated powers of attorney in order to negate reactivation of his quadruplex applications by Interior Secretary Chandler.
Winter Continues public dispute over nature of etheric force.
  With Charles Batchelor arranges foreign agencies for electric pen.
c. 26–28 March Moves laboratory and family to Menlo Park.
3 April Executes first patent applications (on acoustic telegraphy) since moving to Menlo Park (his second and third applications after a year-long hiatus).
5 April Sells his stock in Domestic Telegraph Co.
11 April Atlantic and Pacific Telegraph Co. files suit in New York state court against Edison, Lemuel Serrell, Western Union, and George Prescott over rights to Edison's quadruplex telegraph patents.
1 May Signs agreement with Marshall Lefferts regarding foreign rights to the electric pen.
  Begins experimenting in new laboratory, working on a system of acoustic transfer multiple telegraphy.
10 May Centennial Exhibition, at which Edison's inventions are displayed, opens in Philadelphia.
11 May With George Harrington and Josiah Reiff files suit against Western Union, George Prescott, Interior Secretary Zachariah Chandler, and Patent Commissioner Rudolphus Duell in Washington, D.C., to prevent any of Edison's quadruplex patents from issuing jointly with Prescott and being assigned to Western Union.
17 May With George Harrington and Josiah Reiff sues Atlantic and Pacific and Jay Gould in federal court in New York to force payment of money owed to old Automatic Telegraph Co. investors for Edison's automatic telegraph inventions.
26 May? Renews five-year agreement with Gold and Stock Telegraph Co. regarding his patent rights and salary.
31 May Executes an extensive caveat covering his acoustic transfer telegraph system.
7 June Learns of impending patent interferences with Elisha Gray and Alexander Graham Bell over acoustic telegraph inventions.
25 June Alexander Graham Bell demonstrates telephone at Centennial Exhibition.
June Given awards at Centennial Exhibition for his automatic telegraph system and his electric pen and autographic press.
3 July Marshall Lefferts, Edison's mentor and president of Gold and Stock, dies.
c. July 10 Sells British rights to the electric pen to John Breckon and Thomas Clare.
18 July? Visited at Menlo Park by British scientist/engineer William Thomson.
24 July Conducts etheric force experiments in response to published criticisms by Elihu Thomson and Edwin Houston.
25 July Begins tests of acoustic transfer telegraph over line to Philadelphia. 
July Conducts first sustained series of telephone experiments.
3 August Begins two months of experiments with his electromotograph, including its use as an automatic telegraph repeater and as a galvanometer.
c. 15 August John Breckon and Thomas Clare establish the Electric Writing Co. to market the electric pen in Great Britain.
c. 28 August Receives offer for his Port Huron and Gratiot Street Railway Co. stock.
August Files statements in patent interference conflicts with Elisha Gray over acoustic multiple telegraph designs. 
7 September Conceives Morse telegraph recorder/repeater.
13 September Begins experimenting with octruplex acoustic transfer over line to Philadelphia.
Summer Experiments with carbonized paper in an effort to make electrical resistances, and also considers using carbonized paper for battery carbons, chemical crucibles, and other purposes.
18 October? Designs and soon experiments with sewing machine motor that consists of tuning forks set in motion by electromagnets.
30 October Executes two patent applications, one for a tuning fork motor and the other for a telegraph recorder/repeater that uses a punching apparatus to record messages.
3 November Discovers that the laboratory's chemical stocks have been largely damaged by sunlight and begins extensive series of observations of and experiments with the chemicals, publishing some of his observations in the American Chemist.
28 November Agrees to have Western Electric Manufacturing Co. become manufacturer and domestic sales agent for the electric pen and press copying system.
  With Edward Johnson incorporates the American Novelty Co. to sell miscellaneous inventions.
c. 1 December Invents "duplicating ink" for making multiple copies of documents, which is subsequently marketed by American Novelty.
10 December Laboratory building damaged by storm winds, and chemical stocks further damaged by subzero temperatures.


6 January  Resolves two patent interference cases over acoustic multiple telegraphy designs with Elisha Gray by making and receiving formal concessions of priority on various points.
8 January Sketches several ideas for the application of small electric motors that could be marketed by American Novelty.
Mid-January  Begins extensive series of chemical and etheric force experiments.
17 January Begins two months of development work on a rotary, high-speed press for electric pen stencils, much of which is done by Charles Batchelor, who begins to resume role as Edison's chief experimenter.
  With Charles Batchelor proposes a plan to George Bliss for establishing a foreign electric pen company.
18 January Suit against Edison by former Newark landlords of American Telegraph Works, Ezra and Roscoe Gould, commences.
19 January Agrees with Charles Batchelor and Edward Johnson to assign his duplicating ink, Batchelor's door indicator, and Johnson's ribbon mucilage to American Novelty.
20 January First experiments with a telephone transmitter that varies electrical resistance of a circuit by changing the pressure on carbon rather than the amount of carbon.
29 January Proposes new agreement with Western Union for support of his laboratory.
  Stockholders of the two competing Port Huron street railways agree to consolidation after receiving a proposal from Edison.
2 February Complains to Jay Gould about his relations with Thomas Eckert and Atlantic and Pacific.
3 February Executes a patent application for an embossing recorder/repeater.
8 February Conducts first experiments with a two-plate embossing recorder/repeater.
9 February Western Union electrician George Prescott visits the Menlo Park laboratory to examine the recorder/repeater and Edison's telephones.
15 February Edward Johnson proposes name change from American Novelty Co. to Electro Chemical Manufacturing Co.
Mid-February Begins sustained work on telephone.
19 February Urges Jay Gould to settle dispute with Western Union over rights to his quadruplex inventions.
26 February Anson Stager and George Bliss visit Menlo Park to discuss foreign rights to electric pen.
28 February Leaves for Port Huron to effect the merger of the Port Huron and Gratiot Street Railway Co. with the opposition line and to discuss his interest in the Sarnia Street Railway Co. with other stockholders.
  Charles Batchelor accompanies Edison to Port Huron and then goes to Chicago to settle electric pen accounts with Western Electric, returning to Menlo Park on 8 March.
12 March Returns to Menlo Park from Port Huron.
14 March Displays two-plate embossing recorder/repeater at Western Union headquarters in New York.
18 March Devises first electromotograph telephone receiver.
19 March Demonstrates his telephone instruments to Western Union officials in New York over a line to Menlo Park.
21 March Edison's father, Samuel, arrives in Menlo Park for a visit.
Winter–Spring Experiments on waterproof varnishes for paper barrels for the New York Paper Barrel Co.
22 March Signs agreement with Western Union for regular financial support of the Menlo Park laboratory in exchange for all of Edison's future telegraph and telephone patents.
23 March Begins to prepare applications for a telephone patent and for a patent on his new sextuplex (six-message) telegraph system.
30 March Receives permission from William Orton to have Joseph Murray build six two-plate embossing recorder/repeaters.
1 April Devises telephone design that becomes the basis for his later claims to invention of the microphone.
6 April Laboratory staff's "pet" bear gets loose and they kill it.
10 April Begins experiments on telephone transmitter designs relying upon variations of pressure on semiconductors (primarily carbon) and devises pressure relay.
18 April Executes the first of his 1877 telephone patent applications.
24 April Signs agreement with Batchelor, George Bliss, and Charles Holland for marketing the electric pen in Europe.
26 April Begins testimony in New York in the "Quadruplex Case," Atlantic & Pacific v. Prescott and others.
28 April Begins week-long exhibition of his "musical" (electromotograph) telephone at the Newark Opera House.
3 May Finishes primary testimony in Quadruplex Case.
16 May  Signs agreement with his nephew, Charles Edison, and former electric pen agent George Caldwell to exhibit his musical telephone.
18 May Visited at Menlo Park laboratory by British telegraph engineer William Preece.
31 May Begins month-long investigation of plumbago mixtures for telephone transmitter.
  Signs an agreement with George Prescott and Gerritt Smith to pool their British quadruplex patents.
4 June Electro Chemical Manufacturing transfers all of its duplicating ink and ribbon mucilage business to George Bliss and Charles Holland, who had acquired foreign rights a month earlier.
5 June Loses a patent interference case on acoustic multiple telegraphy to Elisha Gray.
c. 6 June Designs combination telephone transmitter–electromotograph receiver.
c. 8 June Tests sextuplex system on Western Union line from New York to Boston after extensive experiments in laboratory and then abandons its development in early July.
28 June Quadruplex Case final arguments conclude.
2 July Samuel Edison leaves Menlo Park for Port Huron.
3 July Demonstrates embossing recorder/repeater to Western Union officials and British telegraph officials William Preece and Henry Fischer.
17 July Conceives telephone message recorder/repeater. 
18 July Conceives phonograph.
19 July Edward Johnson and George Barker exhibit Edison's musical telephone before large crowd at the Permanent Exhibition Hall in Philadelphia.
19 July? Finishes preparing preliminary specification for British telephone patent, which includes description of phonograph.
21 July Visited at Menlo Park laboratory by scientists George Barker and Henry Draper, and electrical manufacturer William Wallace.
27 July Visited at Menlo Park laboratory by Alexander Siemens, nephew of William Siemens.
30 July  Begins to develop carbon "fluff" for telephone transmitters.
1 August Edward Johnson gives second telephone exhibition concert in Philadelphia and then begins a series of concerts along the eastern seaboard that continues through the end of the year.
3 August Begins month-long correspondence with Henry Draper regarding spectroscopy.
4–10 August Conducts telephone experiments with Thomas David at Menlo Park laboratory and over a line in lower Manhattan.
c. 7 August Sends Charles Edison to Port Huron to represent his interest in street railways.
10 August Exhibits combination transmitter–electromotograph receivers built by Joseph Murray to Western Union officials and begins telephone line tests in New York City.
Mid-August  Tests various telephone designs over lines in New York City.
20 August Demonstrates a new telephone design to William Orton and other Western Union officials.
21 August Western Union announces agreement to purchase control of Atlantic and Pacific, thus ending commercial and legal conflicts between the corporations.
24 August Begins designing hand-held telephones.
  Begins using newly installed gas lighting machine at laboratory.
25 August Visited at Menlo Park by Robert Watson of Montreal, who wants to introduce Edison's telephone in Canada.
9 September Resigns his position as Atlantic and Pacific electrician.
  Conducts experiments with electric arc lights.
10 September Files depositions by himself, Batchelor, and Adams in electric pen patent interference case against Henry Trueman and gives evidence in hand-stamp patent interference with A. E. Hix.
c. 10 September Conducts first experiments with incandescent electric lighting.
11–13 September With laboratory staff goes fishing in Raritan Bay.
15 September Signs an agreement with Franklin Badger, associate of Robert Watson, regarding the marketing of his telephone in Canada.
17 September Demonstrates a new transmitter to William Orton, who orders 150 sets of transmitters and receivers for Western Union subsidiary Gold and Stock.
18 September Proposes to George Bliss that Bliss and Charles Holland sell rights to European telephone patents.
  With George Prescott signs agreement with Stephen Field and Cornelius Herz regarding European quadruplex patents.
28 September Learns of successful quadruplex telegraph tests conducted on British Post Office lines by Gerritt Smith and George Hamilton.
29 September Learns first telephone patent application will be suspended pending resolution of patent interference conflicts.
5–8 October Redesigns telephone transmitter being manufactured by Joseph Murray.
6 October Wins electric pen patent interference against Henry Trueman.
18 October Participates in Edward Johnson's telephone exhibition at Jersey City.
22 October Begins using disks of a plumbago-rubber mixture in place of fluff in telephone transmitter.
26 October Begins using disks of lampblack and rubber in telephone transmitter.
17 November Western Union establishes the American Speaking Telephone Co. to combine its interest in Edison's telephone patents with the Harmonic Telegraph Co.'s ownership of Elisha Gray's patents. 
Mid-November Devises induction-coil circuit for telephone.
November Explores alternative, noncarbon transmitter designs.
1–3 December Tests induction-coil circuit for telephone.
1–6 December John Kruesi makes first tin-foil, cylinder phonograph.
7 December Demonstrates his cylinder phonograph at Scientific American office in New York.
12 December Wins electric pen patent interference against Edward Stewart.
15 December Executes first phonograph patent application.
16 December Receives old "Telegraphy" entry for Appleton's Cyclopedia of Applied Mechanics, which he has been commissioned to revise.
17 December Signs agreements with George Bliss and Hungarian Count Theodore Puskas regarding the sale and exploitation of his European telephone and phonograph patents.
Dec 26 Experiments with phonograph recording played over telephone to New Brunswick, N.J.
27 December  Confers at Menlo Park with Edward Johnson, Uriah Painter, and Gardiner Hubbard about their proposals that he break his contract with Western Union and let them form a company to market his phonograph.
c. 29 December Proposed as a scientific member of the American commission to the 1878 Paris Universal Exposition.
31 December Demonstrates phonograph to William Orton.



1–3 January Exhibits phonograph at Western Union offices in New York.
3 January? Designs flywheel phonograph.
7 January Contracts for the development and manufacture of phonographic toys and clocks.
8–10 January Tests telephone at Western Union's New York offices, further straining relations with company electricians.
12 January With George Prescott and Gerritt Smith, makes William Orton trustee of British quadruplex patent rights.
23 January Theodore Puskas leaves for Europe as Edison's agent for the phonograph and telephone.
29–30 January With Charles Batchelor, visits Ansonia (Conn.) Clock Co. and experiments with applying the phonograph to clocks.
30 January Signs agreement for commercial exploitation of the phonograph in the United States.
January Makes flywheel phonographs to give to prominent scientific and technological figures.
  British investors in Edison's automatic telegraph assert claim to the quadruplex, beginning prolonged legal contest.
January–February Edward Johnson undertakes lecture tours promoting Edison's phonograph and carbon telephone.
1 February William Preece and John Tyndall demonstrate the phonograph at the Royal Institution in London, the first exhibition outside the United States.
4 February With Henry Bentley, begins testing the carbon telephone transmitter between New York and Philadelphia.
c. 6 February Completes design of small demonstration phonograph to be sold at Paris Universal Exposition.
19 February Issued first phonograph patent.
22 February Plans series of experiments to develop a telephone receiver that does not infringe Bell patents.
28 February Executes extensive phonograph and telephone caveats and executes three patent applications, for telephone stations and call-signal apparatus, for preventing interference between telephone lines, and for the aerophone.
1 March Sends James Adams to Philadelphia to assist Henry Bentley with telephone tests.
2–8 March Edward Johnson becomes general agent of prospective phonograph company and orders manufacture of first commercial phonographs.
11 March Theodore Puskas demonstrates the phonograph at the Academy of Sciences in Paris, the first public demonstration in Continental Europe.
c. 15 March Begins negotiations with Western Union president William Orton for a new telephone contract with the company.
c. 12 March Devises improved carbon telephone transmitter.
19 March Sends James Adams to London with telephone transmitters and receivers to be tested on British Post Office lines.
20 March First public demonstration of improved carbon telephone transmitter at Franklin Institute, Philadelphia.
Winter–Spring Experiments with hand-powered phonographs and attempts to develop clockwork-driven cylinder and disk phonographs.
  Expands Menlo Park laboratory staff.
22 March Signs agreement, negotiated by Theodore Puskas, with the London Stereoscopic and Photographic Co. for commercial exploitation of the phonograph in Great Britain.
26 March Notification of patent interferences marks beginning of long contest over telephone patents.
29 March The New York World publishes first description of Edison's medicinal preparation for relieving pain ("polyform").
March Newspapers begin extensive coverage of Edison, which help to spread his fame and produce crowds of visitors to Menlo Park.
March–April Discusses with Gardiner Hubbard the possibility of Bell Telephone Co. acquiring rights to the carbon transmitter.
1 April New York Daily Graphic publishes April Fool's hoax describing Edison's "Food Creator."
4 April Returns signed membership forms to Theosophical Society.
6 April Makes first of several loans to Joseph Murray to pay back rent on Ward Street shop in Newark.
8 April Biographical sketch by George Bliss published in the Chicago Tribune.
10 April Dubbed "Wizard of Menlo Park" by the New York Daily Graphic.
18–19 April Demonstrates phonograph for the National Academy of Sciences, members of Congress, and President Rutherford Hayes.
19 April The Washington Star publishes first account of Edison's tasimeter principle and describes his hearing aid device, prompting numerous inquiries.
22 April William Orton dies.
24 April Edison Speaking Phonograph Co. is incorporated.
April  Publishes "The Future of the Phonograph," ghost-written by Edward Johnson, in the North American Review.
1 May Universal Exposition, with Edison exhibit, opens in Paris.
6 May Observes transit of Mercury with borrowed telescope.
c. 8 May Prompts Charles Harris to hire John Ott to develop toy phonograph at Menlo Park.
16 May Develops new tasimeter design.
18 May Offers to pay for father Samuel Edison's trip to Europe.
29 May Executes second phonograph caveat, based on European patent specifications completed in early May.
22 May Visited by a delegation of Boston newspaper reporters and demonstrates telephones, the tasimeter, phonograph, and other acoustic devices.
30 May Demonstrates phonograph with Charles Batchelor and several other associates at the Convent of Mount St. Vincent, a Catholic girls' school near Yonkers, N.Y.
31 May Executes agreement assigning telephone patents to Western Union for six thousand dollars annually for seventeen years.
May Edison Speaking Phonograph Co. hires James Redpath to manage phonograph exhibitions and begins training exhibitors.
May–June Develops new hand phonograph for exhibition.
  Arranges phonograph and telephone sales agencies for Australia and Central and South America.
1 June Makes George Gouraud his agent for telephone in Great Britain.
  Stockton Griffin becomes Edison's secretary.
2 June Starts nephew Charles Edison on experiments to develop a non-infringing telephone receiver.
8 June Publishes letter in the New York Daily Tribune asserting priority to microphone principle claimed by David Hughes, beginning protracted dispute.
12 June Orders twenty-five transmitting and receiving telephone sets for sale abroad from Partrick & Carter in Philadelphia.
26 June Receives first honorary doctorate, from Union College in Schenectady, N.Y.
Spring Attempts to develop hearing aid and other acoustic devices.
3 July With Charles Batchelor, begins to investigate causes of noise along New York's Metropolitan Elevated Railroad.
8 July Writes letter to Chemical News asserting priority over Edwin Houston and Elihu Thomson for the telephone repeater.
13 July Leaves from New York with George Barker for solar eclipse expedition to Rawlins, Wyo., and a month-long vacation in the western United States.
17 July Begins funding Patrick Kenny's facsimile telegraph experiments.
20 July Purchases hunting and fishing equipment in Laramie, Wyo.
29 July Attempts to measure heat of solar corona with tasimeter during total eclipse.
c. 30 July Goes on hunting expedition south of Rawlins.
July–August Charles Batchelor and Edward Johnson make improvements to exhibition phonograph.
1–3 August Visits San Francisco.
c. 6–7 August Tours Yosemite and stays overnight in nearby Mariposa, Calif.
9 August Spends night at Virginia City, Nev., where he inspects mines and discusses problems of heat and ventilation in the shafts.
c. 15 August Goes fishing near Rawlins, Wyo.
21 August  Visits George Bliss in Chicago.
22 August Receives news of award of a Grand Prize from the Paris Universal Exposition.
23 August Presented as new member of American Association for the Advancement of Science at the annual meeting in St. Louis, and delivers a paper on the tasimeter.
24 August Returns to Chicago.
26 August Arrives in Menlo Park.
27 August  Begins electric light experiments.
c. 1 September Edward Johnson begins exhibition of improved phonograph in New York City and later includes other Edison inventions.
8 September With Charles Batchelor, George Barker and Charles Chandler, visits William Wallace's shop in Ansonia, Conn., to see electric light and power apparatus.
10 September Drafts first electric lighting caveat.
13–16 September Announces he has solved problem of incandescent electric lighting.
c.14 September Receives dynamo from William Wallace.
19 September Begins to receive offers from prospective electric lighting investors.
21 September Theodore Puskas forms company for commercial exploitation of Edison and Elisha Gray telephones in France.
27 September Drafts second electric lighting caveat.
3 October Agrees to allow Grosvenor Lowrey to conduct negotiations with prospective investors.
5 October Executes first patent application for electric lighting.
5–18 October Works on new phonograph for business dictation.
16 October Edison Electric Light Co. incorporated, principally by investors connected with Western Union and Drexel, Morgan & Co.
23–26 October Confined to bed by facial neuralgia.
26 October Edison's second son, William Leslie, is born in Menlo Park.
30 October Angered by investors' concern over William Sawyer's and Albon Man's joint claim to priority in electric lighting.
October Executes four patent caveats on electric lighting.
  Purchases a new steam engine, a Weston dynamo, and a second Wallace dynamo.
  Begins construction of new machine shop and office buildings.
6 November Conducts telegraphic conversation with Lemuel Serrell about filing new lamp patent in Britain.
13 November Hires Francis Upton to conduct search of relevant technical and scientific literature in order to allay fears of Edison Electric Light Co. investors.
15 November Assigns lighting patents to Edison Electric Light Company for thirty thousand dollars plus stock and royalties.
c. 20 November Designs two dynamos, one of which is included in a British patent application.
22 November Begins negotiating with Gold and Stock regarding new electromotograph telephone receiver.
23 November With Edison's support, Uriah Painter and Edward Johnson take control of Edison Speaking Phonograph Co.
29–30 November Designs first electric meter.
November–December Displays various electric lighting devices at Menlo Park for Edison Electric Light Co. investors.
  Compares operating costs of gas, arc, and incandescent lighting systems.
3 December Executes first patent application for an electric generator, based on earlier tuning-fork engine.
14 December Laboratory workers begin moving equipment into new building.
c. 15 December Hires Francis Upton as mathematical and experimental assistant.
Fall Charles Edison continues experiments on new telephone receiver.
  Negotiates through Grosvenor Lowrey with Drexel, Morgan & Co. for foreign rights to electric lighting inventions.
December Acquires Siemens and Gramme dynamos and begins extensive tests of existing generator technology.
late December Designs and begins to build new dynamo.


Jan 2 Begins construction of his first generator.
Jan 19-29 Conducts an extensive series of experiments on platinum and other metals.
Mar 14 Edison's nephew, Charles P. Edison, tests the new electromotograph (loud-speaking) telephone receiver in London.
Mar Devises a bipolar generator design ("Long-legged Mary Ann").
May 14 Incorporates the Edison Telephone Company of Europe.
May Provides a generator for running arc lights aboard the USS Jeannette during its Arctic mission.
June 17 Receives an honorary degree of Doctor of Philosophy from the trustees of Rutgers College, New Brunswick, New Jersey.
Spring Begins a search for plentiful supplies of platinum in the mining regions of Canada and in the western and southern United States.
Aug 2 Participates in organizing the Edison Telephone Company of London.
Aug Hires glassblower Ludwig Boehm and begins developing improved vacuum pumps.
Summer Makes improvements in his electromotograph telephone receiver for England.
Oct 14 Signs an agreement with Jose D. Husbands for the sale of Edison telephones in Chile.
Oct 22 Conducts the first successful experiment with a high-resistance carbon filament.
Nov 1 Executes his first patent application for a high-resistance carbon filament (U.S. Pat. 223,898).
Dec 9 Organizes the Edison Ore Milling Company.
Dec 31 Holds the first public demonstration of his incandescent electric lighting system at Menlo Park.


Feb 13 Observes for the first time what becomes known as the Edison Effect.
Winter Expands the Menlo Park laboratory staff and works on the development of components for a complete system of incandescent electric lighting.
Mar 25 Experiments with a process of magnetic ore separation.
late Apr Installs the first commercial marine incandescent electric lighting plant aboard Henry Villard's SS Columbia.
May 13 Tests his experimental electric railway at Menlo Park.
July 3 Provides the principal funding for Science, which begins publication on this date.
July 19 Makes the first lamp tests using bamboo filaments, which become standard in Edison lamps.
Sep Begins construction of a direct-connected dynamo, known as the"Jumbo,"using a Porter-Allen steam engine.
Oct 1 Begins the commercial production of electric lamps at the Edison Lamp Works in Menlo Park.
Dec 17 Participates in organizing the Edison Electric Illuminating Company of New York.
Dec 20 Demonstrates his electric lighting system at Menlo Park to the New York City Aldermen.
Dec 23 Incorporates the Edison Electric Light Company of Europe.