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The Calometer and Harrison H. Boyce Moto Meter designs

As was mentioned in our earlier Moto Meter post, a follow up would be coming to show you the very interesting Calometer, along with the prolific designs of Harrison H. Boyce, who developed the Boyce Moto Meter. He invented many other interesting devices, but seemed to concentrate on temperature recording devices for vehicles.

Mr. T. H. Whiting of Edgbaston, England, who worked at the Wilmot Manufacturing Co. Ltd. of Birmingham, England, invented the unusual temperature gauge seen (above). The principle the Calometer operates on, was based on two strips of dissimilar metals (bi- metal), mounted lengthwise in a vertical tube and attached at one end to a toothed quadrant. When the temperature rises, the two strips of metal expand differently and  straighten, with the result that the quadrant moves and the pointer turns. The Calometer (introduced in 1925), was a fairly common and accurate temperature gauge in the UK  by the late 1920s.


The photo (left above) shows how the Calometer looks from the cockpit of a Model T Ford. The period illustration in the (center above) is an ad by Wilmont. The (right hand) patent drawing, shows a very similar design by Boyce, who filed for a patent on his design on May 27, 1927. If you study his drawing, it will give you a very clear view of how these types of bi – metal devices work. Color photos courtesy of Chris Bamford.

One difficulty with any of these devices is they are quite hard to read at night and that led to the lighted Moto Meter coming on the scene next. The design above by Boyce, was very interesting, but how well it actually worked in practice is unknown. He mounted a tube filled with neon gas inside of the body of the unit and used the high voltage current from a spark plug lead to ignite the neon gas.


Three more Boyce designs are see here, (above left) is another spring controlled unit with a dial and pointer. In the (center above) is a device for measuring the temperature of the water, instead of the air temperature above it, as the liquid type of Moto Meter does. On the (right above) is a device for telling the motorist the level of the water in the radiator.


Boyce also later on designed an add on device for illuminating the standard type of meter (left above), but this time mounted the device on the outside on the unit. He also developed and patented other standard types of temperature gauges and in the (center above), can be seen one for an air – cooled engine, which is dipicted on Franklin. And finally perhaps he could see the end of the Moto Meter was coming (right above), when he designed this “Instrument Board Mounting” and applied for a patent in 1927, which he received in 1930.

To see more of his designs and patents of follow this link to see the Harrison H. Boyce patent drawings. If you missed the earlier post you can access it here.

3 responses to “The Calometer and Harrison H. Boyce Moto Meter designs

  1. If I may add, hopefully, a little clarification to a point made on this blog article with all deference and respect to the author.

    The patent diagram that you use above (meta tagged Meter III) from Harrison H. Boyce’s May 27th, 1927 (patent application filing date), December 10th, 1929 (U.S. Patent Doc. No. 1,739,285 grant/issuance) for the “Multiple Indicating Temperature Responsive Device” that utilized a semaphore , flag-like (“semaphore”) red metal colored circle on a rack attached to a bi-metal temperature sensitive metal within the gauge instrument’s hollow tube was more apply applied to and later licensed from Boyce by and to other non-Moto-Meter Co. of Long Island City, N.Y. companies like Simplex Manufacturing Company (of Mineapolis, Minnesota) for its Simplex Motor Gauge competing product and not the Wilmot-Breeden Ltd. manufacturing company for its early Calometer (note spelling). And while, Carl Breeden became acquainted with the Boyce Moto-Meter during the 1920s and at his behest directed Mr. Whiting to create a working replica/replacement so that such a device could be sold as a substitute to the Morris Motor Car Company, the designs of the Calometer and of its successor the “Calormeter” never used a semaphore type auto engine temperature heat indicating device as such.
    The product name “Calormeter” stemmed from the fact that in 1926, Wilmot-BreedenLtd and the Morris Motor Car Co. were successfully sued by H. H. Boyce, et al, for patent infringement, interference/disruption with a contract and contract unfulfillment (by Morris) resulting in the former dgauge being re-designed slightly but enough to avert further suit along with a name change to the later with the letter “r” added to avoid confusion with another similar product.

    Boyce received patents, indeed, for many similar devices, some he assigned to the Moto-Meter company, others he licensed to other companies, which is why there are even a few engine temperature gauge product survivors today from these competitors to the Mot-Meter Co. Inc’s market monopoly (although their quality and metal rationing during two World Wars and lack of public appetite also contributed to their limited success, if any.

    Just because the two designs used a rack did not mean that they exactly similar, being rather technical and downright “Geeky” about it.

  2. I have the one similar to Studebaker; but has more wing area, patent march 17-14 across to other side July 16-15, Aug. 13-18 gold face black back face ;could this be from a truck . Also has chain from the base.

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