September 2018 Article Featuring




September 2018 Article Featuring




Horace Barnes and his partner Ary Benson both of Seattle, Washington are little known motometer making men.


In late 1920 Horace Barnes conceived of and applied for U. S. patent on the “Design for a Radiometer - Case.”


This design, initially shown in his partner’s U. S. patent application for a “Temperature Indicator for Radiators” describes the primary temperature indicating, “shutter” viewing panel(s) sight glass as “formed of a plurality of circular concentric prisms” as shown in Figure 1 from the patent drawing page. 

The opposite viewing window is smallish and merely meant to allow light to pass through and illuminate the internal red colored semaphore temperature indicating panels that rise from the internal sides of the device to form a red bullseye circle in the center of the sight window.


Although previous shown within his partner’s “Temperature Indicator for Radiators” patent that was applied for on November 1st, 1919 in May 1921 Horace received his official U. S. patent months ahead of his partner’s fully functional product patent.


Ultimately their radiator-mounted engine temperature indicator would be commercially marketed and sold as the “Benson Radio-meter,” “Auto Meter” and licensed “Pyrometer” by the National Pyrometricscope Company.



Two model sizes were market – the largest, 3 1/4” DE LUXE and the middle size, 3” STANDARD.  They could be purchased in either nickel or 14-carat gold plate finish at a retail cost of $10.00 and $8.50 in nickel plate finish and $15.00 and $12.50 in gold plating, respectively.

Above: This ad from June 15th, 1921 that appeared in the Motor West trade journal.

Motor West Ad June 15, 1921, page 12

Motor Land Journal June 1921, page 45

Motor Land Journal October 1921, page 43

Shown below is Horace Benson’s actual patent prototype of his case design in gold plate finish (Left) and a photo of a commercial Benson Radio-meter and Horace’s prototype (Right) for direct comparison purpose.

Not a lot of these gauge-devices were sold in comparison to the motometer accessory market leading Moto-Meter Company and its BOYCE MOTO-METER™.


Our friend, author Dr. James Cowill in his Automotive Mascots book “Purpose Form & Function Volume One” shows his excellent condition Benson Auto Meter with and without additional mascot ornament.

Most surviving Benson Auto Radio Meters and National Pyrometroscope Pyrometers failed the test of time due to the choice and quality of temperature indicating panels and the internal temperature sensor material.

Horace Barnes Radiometer Case Design Patent on™
Pyrometer - Benson Auto Radio Meter Ad on™
Benson Radio-Meter Ad Motor West on™
Benson Radio-Meter, Motor Land Journal on™
Auto Radio Meter Ad, Motor Land magazine on™
Horace Benson Prototype.jpg
Benson Auto Radio Meter of James Colwill



SINCE 1912

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