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ENGINEERING

Fax and Context

Henry Petroski

Telephone Networks

Among the reasons fax machines were not more widely incorporated into offices earlier than they were, at least in America, has to do with the communications infrastructure that had developed in the early 20th century. The telephone system consisted of effective monopolies, with the American Telephone and Telegraph Company controlling large networks of phones and phone lines. Customers did not even own their telephones, but rather leased them from AT&T, or what was known as the Bell System, and nothing but the phone company's instruments could be attached to their lines. In the 1930s AT&T decided not to pursue the development of wirephoto or other facsimile transmission services over its lines, and since AT&T was a monopoly, this natural infrastructure for transmitting data was not readily available to independent inventors or engineers, or to other companies. This is why newspapers used UHF radio waves as a transmitting medium in their earlier experiment.

In the late 1960s, the Federal Communications Commission, which regulates telephone networks in the United States, decided to allow non–Bell System equipment to use the established public switched-telephone network (known in the industry as PSTN). Similar deregulation occurred in the early 1970s in Japan, which meant that facsimile transmission now had an intercontinental communication infrastructure available for its use. Hence, electronics companies and their engineers began to work with renewed interest on the development of improved fax machines that could be linked through the PSTN via acoustic couplers over which the analog data was transmitted much as the voice was.

Competition had its downside, however. Growing numbers of electronics companies, driven by free access to the telephone network, soon introduced a plethora of new equipment that was not readily compatible with the other equipment on the market. This was clearly not a desirable development, for businesses that wished to invest in fax machines wanted to be able to send faxes to every other business with a fax machine; communication between any two independently purchased units was not unlike a return to the earliest fax technology in which machines that were not paired in design did not work.

The dissemination of technology in a free market cannot proceed very effectively if each manufacturer works in total disregard of all the others. Purchasers and users like to be able to mix and match products and components for maximum convenience. When a new technology is being introduced, however, it is not uncommon for different manufacturers to be pursuing similar but different ways of dealing with the technical details. The first light bulbs, for example, did not have standardized bases, but now we expect different brands to be made with the same screw base so that they can be used interchangeably.





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