Sometime in 2009 I did a post on the Smiths racing tachometer, the ATRC tachometer, badged Smiths and coded ATRCxxxx...
It has generated interest over the intervening years and I've manufactured a few more as a result of the post.
so lets have another look at this instrument that carries this A.T coding...
They are characterised by the pointer rotating through a slot in the instrument dial with the pointer blade sweeping the surface of the dial rather than from completely above it as in other speedometers made by smiths and other manufacturers.
The A.T Speedometer Company Ltd of 140 Long Acre, London WC was advertising in "Flight" magazine in July 1915 so they are one of the originals in automotive,motorcycle and aviation instrumentation....
Sometime around 1927-1930 Smiths Motor Accessories acquired the firm and they were manufactured in Chronos Works, North Circular Road, London N.W.2...
Their speedometers had been in Rolls Royce cars since the 1920's and in Bentley cars from around this time also....
Simon Roope, with who I have a correspondence has responded with some interesting, additional information in the comments section below but I've incorporated it here....thanks Simon...
The
AT showroom was at 140 Long Acre before the Great War; an original 25 page AT
Speedometer catalogue from 1912 I own
has this address printed on each page.
From the early 1920s AT instruments were fitted to many prestige vintage cars,
including Rolls Royce, Bentley and Frazer Nash. By then, manufacture of AT
instruments had moved to West London and from October 1924 to 20 Avonmore Rd,
London W14 (pg. 36, Motorsport, October 1924)
AT had German parentage (instrument manufacturers Deuta-Werke GmbH, Berlin) and
under the newly formed Trading with the Enemy Act of 1914 company assets were
confiscated at the outbreak of war. Ownership passed to Smiths, then to S.D
Mckellen in 1920, and to Jaeger in December 1928 who in October the previous
year had been bought by Smiths. In 1930 manufacture of AT instruments moved to
the newly built Chronos Works. (pg. 82, James Nye's new book 'A Long Time in
Making; History of Smiths' and pg. 42-44, 'Roadcraft' magazine published by
Smiths for the 1937 London Olympia Motor Show).
In 1931 Bentley Motors went into liquidation and was acquired by Rolls Royce.
Two years later the first Rolls Royce made Bentley car (3 1/2 Litre saloon)
went on sale. So in 1933 it is the model of car that is new not the fitting of
AT instruments to Bentley cars; this had happened ten years earlier.
Lets have a peruse of a 1934 A.T. catalogue to view the items they made then.
In the early 1950's Smiths responded to the demand for a racing tachometer without the inherent lag of the chronometric principled tachometer and introduced the ATRC version....see my 2009 post on this.
Following are examples of car and lorry dashboards from around 1955 which utilise the A.T. versions Smiths made.
Smiths AT speedometer from a Leyland bus....
During 1964,1965 Smiths made industrial versions of the A.T. Tachometer available also....
As mentioned I did a posting in 2009 and this discusses the principle of operation of the A.T instrument and is useful to assist....
Finally, Smiths made hand held industrial tachometers to measure rotating shaft speeds etc and these of the A.T principle.....
They often had multiple scales altered by a knob on the case....
