Edison, Thomas. (1847–1931). Important Archive of Autograph Letters, Original Diagrams and Instructional Sketches for Disc Record Manufacture. An extraordinary and highly important archive of materials related to the development of Edison's disc records, including the design and production of the records themselves and the machines for the pressing of the discs and their coating in a newly developed material, condensite. Including 23 diagrams and instructional drawings on 22 sheets and 7 notes/letters (4 signed "Edison", one initialed), generally addressed to Charles W. Luhr (Vice President and Works Manager for the Edison Phonograph Works in Orange, New Jersey), some including further diagrams as part of their instructions, covering many components of Edison's invention. Various sizes and formats, mostly on 6 x 9 inch lightly lined off-white paper, in pencil. Most of the archive dating from 1912, with two of the sheets dated August 9 and August 16th of that year. Four other included sheets of pale yellow paper are evidently from a later refinement of the same record production work and include two notes dated 1916 (May 10, June 10). Scattered stains and minor tears, overall in fine condition.
Sold together with an original Edison condensite record ("Light Cavalry Overture" - Edison Concert Band - 80096-R; "La Danseuse-Intermezzo" - American Symphony Orchestra - 80096-L).
The designs and instructions cover many areas of record production, from the overall machine design, to the record materials themselves ("condensite blank submaster"), the width and size of the record blank moulds ("make ring 010 larger than the blanks in Diameter"), the manufacture of struts to hold the records in place, the machine's turning and stamping mechanisms ("if you can find cast iron in Cellar make them - if not hurry + get a pattern + get from Foundry that makes our top plate of disc machine..."), battery power ("switch to put on storage battery in case of shut down while record is covering"), varnish application ("rim to keep varnish from running off"), cooling mechanism ("We want 2 blowing off machines one for Walter Miller + one for Hays in London") etc.
Edison and his lab worked through the early 1900's on a material which could be easily molded into disc shape and would not deform or shrink with heat. They improved the phenol resins first developed by Leo Baekeland and eventually produced a material called condensite, a purer resin with fewer by-products (condensite refers to the condensation of phenol and formaldehyde which produces the resin). The actual cylinder or disc record was never a blank of pure resin but a combination of cheaper materials for the base covered with a "varnish" of the hard recording medium. Various combinations of asphalt, wood flour and china clay were tried, and finally a mixture of phenol and wood flour was used for the record base.
"Two large machines were brought into the laboratory as part of the disc record project. The first was a condensing distilling machine used to make up the phenol resins used to make the disc blanks. It was a pressure container in which a vacuum could be created. A vacuum pump was placed nearby. The container was sheathed in a steam jacket to heat the mixture and steam pipes were attached. At the bottom of the container was a valve to draw off the hot liquid and a manhole cover attached by large bolts was at the top. The various elements of the mixture were pumped in and then condensed under pressure and at high heat. This created the thick resin, called condensite, which when cooled, could be made into blanks."
"This machine would have been made up by the laboratory staff from plans drawn up by experimenters— probably Edison, Sam Moore, and Fred Ott-and copied from existing distilling machines and heated mixers. The condensite project was carried out in great secrecy, for just a few miles away from West Orange, Leo Baekeland was carrying out experiments with the same phenol resins. Baekeland was in the lead in developing these early plastics and had a strong patent position. In 1910 and 1911 Edison negotiated with Baekeland to license his patents while simultaneously attempting to circumvent these patents and set up his own production operation. Secrecy was therefore essential. No publicity was given to this project or to this machine....A Robertson disc press was set up opposite the condensite mixer to press master records unto blanks and make copies. The press was hydraulically operated and could accommodate one disc at a time. A new master could be easily slid into the top part of the press. This machine could also press out a variety of other forms made from condensite....The product of this plating process was a negative, a matrix, of the master. This was used to make a submaster which in turn was used to produce a working master. This working master could be used to stamp out hundreds of copies of the original master disc." ("Historic Furnishings Report: Edison Laboratory--Edison National Historic Site," Andre Millard, Duncan Hay, Mary Grassick; Internet Archive accessed 9/10/14)
Edison was the greatest inventor of the electrical age. His hundreds of inventions made him a giant public figure in America and around the world at the turn of the 20th century. Inventor of the first practical long-lasting light bulb and of the phonograph, it is not hyperbole to say that modern life would probably be very different without him!
Edison, Thomas. (1847–1931). Important Archive of Autograph Letters, Original Diagrams and Instructional Sketches for Disc Record Manufacture. An extraordinary and highly important archive of materials related to the development of Edison's disc records, including the design and production of the records themselves and the machines for the pressing of the discs and their coating in a newly developed material, condensite. Including 23 diagrams and instructional drawings on 22 sheets and 7 notes/letters (4 signed "Edison", one initialed), generally addressed to Charles W. Luhr (Vice President and Works Manager for the Edison Phonograph Works in Orange, New Jersey), some including further diagrams as part of their instructions, covering many components of Edison's invention. Various sizes and formats, mostly on 6 x 9 inch lightly lined off-white paper, in pencil. Most of the archive dating from 1912, with two of the sheets dated August 9 and August 16th of that year. Four other included sheets of pale yellow paper are evidently from a later refinement of the same record production work and include two notes dated 1916 (May 10, June 10). Scattered stains and minor tears, overall in fine condition.
Sold together with an original Edison condensite record ("Light Cavalry Overture" - Edison Concert Band - 80096-R; "La Danseuse-Intermezzo" - American Symphony Orchestra - 80096-L).
The designs and instructions cover many areas of record production, from the overall machine design, to the record materials themselves ("condensite blank submaster"), the width and size of the record blank moulds ("make ring 010 larger than the blanks in Diameter"), the manufacture of struts to hold the records in place, the machine's turning and stamping mechanisms ("if you can find cast iron in Cellar make them - if not hurry + get a pattern + get from Foundry that makes our top plate of disc machine..."), battery power ("switch to put on storage battery in case of shut down while record is covering"), varnish application ("rim to keep varnish from running off"), cooling mechanism ("We want 2 blowing off machines one for Walter Miller + one for Hays in London") etc.
Edison and his lab worked through the early 1900's on a material which could be easily molded into disc shape and would not deform or shrink with heat. They improved the phenol resins first developed by Leo Baekeland and eventually produced a material called condensite, a purer resin with fewer by-products (condensite refers to the condensation of phenol and formaldehyde which produces the resin). The actual cylinder or disc record was never a blank of pure resin but a combination of cheaper materials for the base covered with a "varnish" of the hard recording medium. Various combinations of asphalt, wood flour and china clay were tried, and finally a mixture of phenol and wood flour was used for the record base.
"Two large machines were brought into the laboratory as part of the disc record project. The first was a condensing distilling machine used to make up the phenol resins used to make the disc blanks. It was a pressure container in which a vacuum could be created. A vacuum pump was placed nearby. The container was sheathed in a steam jacket to heat the mixture and steam pipes were attached. At the bottom of the container was a valve to draw off the hot liquid and a manhole cover attached by large bolts was at the top. The various elements of the mixture were pumped in and then condensed under pressure and at high heat. This created the thick resin, called condensite, which when cooled, could be made into blanks."
"This machine would have been made up by the laboratory staff from plans drawn up by experimenters— probably Edison, Sam Moore, and Fred Ott-and copied from existing distilling machines and heated mixers. The condensite project was carried out in great secrecy, for just a few miles away from West Orange, Leo Baekeland was carrying out experiments with the same phenol resins. Baekeland was in the lead in developing these early plastics and had a strong patent position. In 1910 and 1911 Edison negotiated with Baekeland to license his patents while simultaneously attempting to circumvent these patents and set up his own production operation. Secrecy was therefore essential. No publicity was given to this project or to this machine....A Robertson disc press was set up opposite the condensite mixer to press master records unto blanks and make copies. The press was hydraulically operated and could accommodate one disc at a time. A new master could be easily slid into the top part of the press. This machine could also press out a variety of other forms made from condensite....The product of this plating process was a negative, a matrix, of the master. This was used to make a submaster which in turn was used to produce a working master. This working master could be used to stamp out hundreds of copies of the original master disc." ("Historic Furnishings Report: Edison Laboratory--Edison National Historic Site," Andre Millard, Duncan Hay, Mary Grassick; Internet Archive accessed 9/10/14)
Edison was the greatest inventor of the electrical age. His hundreds of inventions made him a giant public figure in America and around the world at the turn of the 20th century. Inventor of the first practical long-lasting light bulb and of the phonograph, it is not hyperbole to say that modern life would probably be very different without him!