Victorian S Johnson's Patent Revolution Indicator or Odometer
A Victorian Johnson’s Patent Revolution Indicator or Odometer
Invented and patented in 1876 by Sidney Johnson, the patent revolution indicator was one of a number of patents that this inventor sought to cover under patents during the late nineteenth century. He seems to have been mostly concerned in inventions for carriages and velocipedes or early bicycles. His first in 1871 (US Patent 117638) is a design for a three wheeled velocipede which was considered for use on both land and water and was posted in the London Gazette on April the 4th 1871, making Johnson a rather early designer of these types of vehicle. The velocipede was only starting to become popularised at around 1860 and saw its heyday during the 1880’s.
His next was the odometer currently offered for sale here and is described in the 1874 patent documentation as being, “a new and useful improvement in machinery for indicating the distance travelled by vehicles”.
His final offering in 1894 is an improvement on the arrangement for spokes on a wheel including a clutch for engaging a wheel with its axle.
Given that Johnson was inventing for a period of twenty four years it seems a shame that so little is known of the man. He had various addresses mentioned in the patents and seems to have moved from West Croydon in Surrey to The Strand in London and finally residing in Ilford in Essex in 1894.
This interesting and unusual piece of engineering history is a rare example of an odometer allowing for the distance to be measured in miles. It comes with its original scaling card which would allow the user to work out distance based upon the diameter of the wheel to which it was attached. It works by use of a ball bearing inside the brass casing, which turns using gravity creating by the turning of the wheel. The weight of the ball bearing turns a ratchet mechanism inside the case which in turn registers the measurement on the front silvered dial. The dial is engraved with the words, “S Johnson’s Patent Revolution Indicator” and bears a Royal Coat of Arms however I can find no evidence that Johnson had the right to use such a title. The odometer also comes complete with its original leather case allowing for it to be attached to the desired wheel.
A super rare piece of travel history which would have had equally useful application for bicycles (velocipedes) or carriages during the period in which it was invented.