The Lorimer System

The Lorimer Brothers

by Bob Estreich


In the 1890s Almon Strowger's automatic telephone switching system was becoming widely known, and it was becoming obvious that automatic switching was going to be needed to carry the volume of calls on large exchanges. Other inventors set to work, with varying degrees of success. One such was Romaine Callender, who patented various automatic switches between 1892 and 1896. The system was ultimately a failure, but inspired two of his young staff, George and James Lorimer, to continue the experiments and development work.

They started their own firm, Canadian Machine Telephone, in 1897 in Peterborough, Ontario. Their first exchange was a very basic development of the Callender system, which was installed in Troy, Ohio in 1897. Its weaknesses were obvious and they redeveloped it to the point that it was now only vaguely descended from Callender's original concept. By 1900 they received a patent for it, They felt that they were ready to sell their new exchange, and converted their small workshop in the nearby town of Piqua into a production workshop under the name of American Machine Telephone.

James Hoyt Lorimer died in 1901 of recurring typhoid and his place was taken by younger brother Egbert. Although James Hoyt was the true inventor of the team and little further development occurred without his mechanical abilities, the remaining two brothers turned into effective salesmen. They missed out on a major sale to the Toronto city council when that body changed its mind about getting involved in telephones, but made minor sales to other smaller towns in Canada and the United States. The biggest was a 500 line exchange in Atlanta.

Although these apparently operated satisfactorily, the Lorimers wanted a big sale to showcase their system. When the Edmonton Telephone Department approached them in 1906 it appeared that their big moment had arrived. Unfortunately this was where it all fell apart. There were unforeseen problems with a larger exchange, and without James Hoyt's inventive abilities these problems proved hard to resolve. The cutover date dragged on for two years without a satisfactory exchange being delivered, and Edmonton cancelled the contract and gave it instead to the Automatic Electric company using Strowger's system. Automatic Electric installed a working system within two months.

Some interest was shown in the Lorimer system in Europe, and a new company, Societe Internationale de l'Autocommutateur Lorimer, was formed in Paris in 1908 to market the system. Although they made some sales to France, Britain and Italy, mostly for the purpose of evaluation by the local administrations, the poor reliability of the exchanges and the slow delivery told against them. The initial sales were not followed up by more orders. The British example appears to be typical. The British Post Office contracted for an evaluation exchange at Caterham in about 1912, Because of the delays it was eventually installed as a 500-line exchange at Hereford in 1914. With the outbreak of the first World War, supplies and support from Canada would be erratic, so the Post Office standardised on the Automatic Electric Strowger system. It was now being produced in Britain by an offshoot of the British Insulated and Helsby company, and was a proven and refined system unlike the Lorimer system.

The Lorimer firm went bankrupt in 1923, but before this the value of its switching system was recognised by no less than American Telephone and Telegraph, the Bell company. AT&T had been watching the growth of Automatic Electric with increasing concern, but because of their need to finance growth, they had not developed an automatic system of their own. They bought the patent rights from the struggling Lorimer company in 1903 and set about redeveloping it into a reliable system. With their resources they were able to refine the system far better than Lorimers could. Their engineers produced two versions, the Panel and Rotary systems. The Panel system went into production in the U.S. and stayed in operation until the 1950s. The Rotary system, named for the rotating disks used in the switchgear, was produced in Europe by Bell Telephone Manufacturing in Antwerp. It proved popular and continued in production when AT&T's overseas assets were bought out by ITT in 1925. Both systems used a (by now) conventional rotating dial rather than Lorimers' switch selectors, and so the ancestry of the system was not evident.

THE LORIMER SYSTEM

Let us now have a look at Lorimer's technology. The telephones were distinctive, but their low production numbers make them quite rare and few still exist. To provide the switching pulses, Lorimers used a disk-and-lever selection system. Four disks of contacts were built into the front of the telephone. The number was selected by pulling each lever to the correct digit of the phone number, corresponding to thousands, hundreds, tens, etc. The number selected was displayed in a small window. Lorimers called these disks "dials" ,and this is where the term "dialling" appears to have come from. A handle was cranked to wind a clockwork mechanism, and the clockwork rotated the disks at a constant speed and sent dialling pulses to the exchange. Although the system seems clumsy, Lorimers made a virtue of it by claiming that it allowed the user to check the number before dialling, reducing the risk of wrong numbers. The signal was sent to a preselector, an original Callender concept.

The exchange switchgear was just about the reverse of the phones. Disks carrying one hundred contacts constantly rotated and a series of wipers completed the circuit when the disk stopped under the influence of the dialling pulses. It was a somewhat slower switching system than the Strowger, but took up less room and used a revolving switch rather than Strowger's bimotional switch, so it would have been quieter and smaller. Unfortunately there were problems with the dialling speed generated by the clockwork in the telephones not matching the switching rotation speed at the telephone exchange, and the exchange gear itself needed constant attention to the bearings and motors to keep the rotation speed constant. From the illustration it can be seen that most of the switchgear and drive shafts were exposed to dust.

The cost of the switchgear was lower, which made it appealing to new customers. The Edmonton system was quoted at $34 per line compared to Automatic Electric's $40 per line. The exchanges came in 100-line modules that could easily be extended, and took up less floor space than the Automatic Electric system. Power consumption would probably have been lower as well. Unfortunately these advantages could not offset the fact that the Lorimer system was unrefined and unreliable.

So far, only four Lorimer telephones have been identified, with minor variations. The first is a long cathedral top wall phone of conventional appearance, with the transmitter arm moved lower on the front of the case to make room for the dialling mechanism. The illustration is from Ron Knappen's "Old Telephones Price Guide and History of Old Telephones", now out of print.

The second model is from the early 1900s and is a smaller wall model from Europe, probably France.

The third model is a compact wall phone from the British installation, and examples are held by the British Telecom Museum and the Milton Keynes Museum.

The fourth version used a candlestick phone with the dialling box set in front of it on a wooden plinth. It appears to have been used only on the Brantford exchange.

The work of the Lorimer brothers has lapsed into obscurity, just a name sometimes mentioned in relation to early automatic switching. It deserves wider recognition.

References....

Knappen R "Old Telephones Price Guide and History of Old Telephones" 1980.

Rens, Jean-Guy "For One Brief, Shining Moment The Lorimer Brothers" Published in "Telecom History" 1995.

Canada Science and Technology Museum website...... http://www.sciencetech.technomuses.ca/English/collection/conn4.cfm

Hallas, Sam, British Telecom Museum memorial website......
http://www.samhallas.co.uk/museum/telephone-2.htm