The radiator cap mounted engine temperature gauge bridges a time period between the plain utilitarian radiator cap and the cap-mounted mascot. In the early years, there was no way to tell the engine temperature unless the driver saw steam coming from the radiator cap! There was a need to know the temperature of the engine cooling system. The systems were very crude by today's standards and very susceptible to overheating.
The first cooling systems were not pressurized and the coolant had a low boiling point. To monitor the temperature, a simple device was invented that would display the engine temperature to the driver. This was very important to maintain the most efficient engine operating temperature and to prevent the destruction of the engine if it overheated. These devices took different approaches from complex gear type indicators using a bi-metallic device manufactured by Wilmot-Breeden in England, to the simple thermometer commonly referred to as a Motor Meter. Probably the best-known manufacture was Boyce in the United States. Their factory was located in Long Island City, New York and their device was known as the Boyce Moto Meter. Some companies copied the device and patent infringement battles were fought over their manufacture.
Types of Devices:
In England, one of the most popular temperature indicating devices was manufactured by Wilmot-Breeden. This started life as the "Wilmot All-British Calometer". The design was based on the principle of two strips of dissimilar metal moving a gear device. This moves a needle that indicates the temperature as the engine temperature changes. These devices were first used on the Morris automobile, and later other marques that included Austin, Ford, Triumph, Wolsely, Jowett, Lanchester, M.G. and Standard. An excellent reference can be found at: http://www.moreg.org.au/calormeter.htm.
Many different and novel devices evolved during this period that ranged from float type temperature indicators such as the "Jarvis Water Indicator" manufactured by the W.B. Jarvis Co. of Grand Rapids, Michigan, to the Moore Semaphoric Indicator Co. of Chicago, Illinois.
The Jarvis Water Indicator had a long tube that extended into the radiator tank and used a float inside the tube to indicate the water level in the radiator. As the water level would rise and fall, the red indicator would move up and down inside the cap mounted dial indicating "Full" or "Refill".
The "Moore Motor Semaphore" temperature meter used a green and red disk to indicate motor temperature. There was a hole on each side of the meter that would show a green disk if the motor was cool. The device would rotate, as engine temperature would increase causing the red disk to move into the other hole showing half green on one side and half red on the other. All red on one side indicated an over heated engine!
Moto Meter "Toppers", "Mini-Mascots", and Attachments:
As the use of Moto Meters grew, small sculptures or "Moto Meter Toppers" mounted on top of the device started appearing. These were small "Mini-Mascots" that were added to the meter to make the device more attractive and distinctive. These ranged from birds and animals to fraternal organizations and female figures. Many were made by L.V. Aronson and are dated. L.V. Aronson was also known as "The Art Metal Works". The company was located in Newark, New Jersey and made many novelty items including mascots, radiator attachments and pocket cigarette lighters. This company became the Ronson Corporation and is located in Somerset, New Jersey today.
In addition to the "toppers", there were many aftermarket accessory mascot attachments that mounted on the radiator cap under the Meter. These were made by companies like The Art Metal Works; Faith Mfg. Co. in Chicago, Illinois; Irving Florman Company, New York, N.Y. and Neal Tanquary of Los Angeles, California to name just a few, as well as many attachments from Great Britain, France, Italy and other countries. Several very good reference books on this subject are "Accessory Mascots", by Dan Smith; "Mascot Catalogs", by Robert Ames, "Mascottes Pasion" by Michel Legrand and of course Bill Williams book, "Motoring Mascots of the World". These books have many great photographs of the attachments and meters and are a wealth of information.
Collecting these devices can take many different approaches. A collection of just Boyce Moto Meters can be started with different styles or models of the device. The models listed in the instruction booklet supplied with a new Boyce Moto Meter were as follows: The "Special for Ford"; the "Truck and Tractor Model"; the "Aristocrat Model for the Ford and other small cars"; the "De Luxe Model"; the "Standard Model"; the "Junior Model"; the "Universal Model" and the "Midget Model".
Collecting the different types of meters such as the mechanical indicator as manufactured by Moore and Wilmot-Breeden, or float type meters can make up a very interesting collection focusing on the different technologies available at the time. There are also meters from France and other countries as well as the US manufacturers that can be included.
Adding the many different insert disks or dials supplied with the Moto Meter can also broaden the range of the collection. The dials, as Boyce called them, ranged from car name plates of the different automobile manufactures to club insignias, Masonic emblems, doctors insignias, initial dials and fraternal organizations. There are also special disks with the car dealers name on the disk advertising their location. From the early teens to late 1920's almost every new car left the factory with a Boyce Moto Meter on its radiator cap. There are hundreds of different makes and designs that one can collect for the Boyce Moto Meter alone.
Combining the mascot attachments and different style caps to the above categories can make the collection very interesting and show the variety available to the motorist of this period to individualize their automobiles.
Most Boyce Moto Meters that have the red liquid filling the glass tube all the way to the top can be made operable again. Try grasping the Moto-Meter and striking the base against an automobile tire. Care must be taken as to the amount of force to use or the stem may be broken. Placing the meter in the freezer for about one half an hour and then striking against a tire can usually free the most stubborn meter. The white on the thermometer can be repaired using "white-out" (Tippex in UK) type corrector. This is sold in bottles in office supply stores and works perfectly. I try to buy old broken meters to use as spare parts. Glass lenses, gaskets, outer rings that hold the glass in place and the small screws can be obtained from these and used to restore a meter that has a good housing. Sometimes a rare disk insert can be obtained this way and exchanged with a good meter with a common disk. There are some meters that have replaceable thermometer tubes. This makes restoration much easier than with the standard Boyce Meter.
Engine temperature is something we take for granted today. The once proud ornaments that adorned the radiator of the cars of the past have been transformed to the status of a lowly light on the dash of our cars. In fact we do not even know it is there until the engine overheats!
The photographs of the Moto Meters, Caps, and Attachments are from our collection and are representative of the vast number of different devices that were manufactured during this period. It is our hope that you enjoy the photos and that we have in some small way added to the information on this subject and perhaps sparked an interest in this part of automotive history.
The collection on this site is dedicated to my wonderful wife Henrietta (Henri) who is a constant source of encouragement, help and support. Our special thanks to John Forde who has provided this great opportunity to display our collection and be a part of his site.