Mechanical counters are digital counters built using mechanical components. Long before electronics became common, mechanical devices were used to count events. They typically consist of a series of disks mounted on an axle, with the digits zero through nine marked on their edge. The right most disk moves one increment with each event. Each disk except the left-most has a protrusion that, after the completion of one revolution, moves the next disk to the left one increment. Such counters were used as

odometer An odometer or odograph is an instrument used for measuring the distance traveled by a vehicle, such as a bicycle or car. The device may be electronic, mechanical, or a combination of the two (electromechanical). The noun derives from ancient Gr ...

s for bicycles and cars and in

tape recorders An audio tape recorder, also known as a tape deck, tape player or tape machine or simply a tape recorder, is a sound recording and reproduction device that records and plays back sounds usually using magnetic tape for storage. In its present- ...

and

fuel dispenser A gasoline pump is a machine at a filling station that is used to pump gasoline (petrol), diesel, or other types of liquid fuel into vehicles. Gasoline pumps are also known as bowsers or petrol bowsers (in Australia), petrol pumps (in Common ...

s and to control manufacturing processes. One of the largest manufacturers was the Veeder-Root company, and their name was often used for this type of counter.. Mechanical counters can be made into electromechanical counters, that count electrical impulses, by adding a small

solenoid upright=1.20, An illustration of a solenoid upright=1.20, Magnetic field created by a seven-loop solenoid (cross-sectional view) described using field lines A solenoid () is a type of electromagnet formed by a helix, helical coil of wire whose ...

History

An odometer for measuring distance was first described by

Vitruvius Vitruvius (; c. 80–70 BC – after c. 15 BC) was a Roman architect and engineer during the 1st century BC, known for his multi-volume work entitled ''De architectura''. He originated the idea that all buildings should have three attribute ...

around 27 and 23 BC, although the actual inventor may have been

Archimedes of Syracuse Archimedes of Syracuse (;; ) was a Greek mathematician, physicist, engineer, astronomer, and inventor from the ancient city of Syracuse in Sicily. Although few details of his life are known, he is regarded as one of the leading scientists ...

(c. 287 BC – c. 212 BC). It was based on chariot wheels turning 400 times in one Roman

mile The mile, sometimes the international mile or statute mile to distinguish it from other miles, is a British imperial unit and United States customary unit of distance; both are based on the older English unit of length equal to 5,280 English ...

. For each revolution a pin on the axle engaged a 400 tooth cogwheel, thus turning it one complete revolution per mile. This engaged another gear with holes along the circumference, where pebbles (''

calculus Calculus, originally called infinitesimal calculus or "the calculus of infinitesimals", is the mathematical study of continuous change, in the same way that geometry is the study of shape, and algebra is the study of generalizations of arithm ...

'') were located, that were to drop one by one into a box. The distance traveled would thus be given simply by counting the number of pebbles.Sleeswyk, Andre, ''Vitruvius' odometer'', Scientific American, vol. 252, no. 4, pages 188-200 (October 1981) The odometer was also independently invented in

ancient China The earliest known written records of the history of China date from as early as 1250 BC, from the Shang dynasty (c. 1600–1046 BC), during the reign of king Wu Ding. Ancient historical texts such as the '' Book of Documents'' (early chapte ...

, possibly by the profuse inventor and early scientist

Zhang Heng Zhang Heng (; AD 78–139), formerly romanized as Chang Heng, was a Chinese polymathic scientist and statesman who lived during the Han dynasty. Educated in the capital cities of Luoyang and Chang'an, he achieved success as an astronomer, ma ...

(78 AD – 139 AD) of the

Han Dynasty The Han dynasty (, ; ) was an imperial dynasty of China (202 BC – 9 AD, 25–220 AD), established by Liu Bang (Emperor Gao) and ruled by the House of Liu. The dynasty was preceded by the short-lived Qin dynasty (221–207 BC) and a warr ...

(202 BC–220 AD). By the 3rd century (during the

Three Kingdoms The Three Kingdoms () from 220 to 280 AD was the tripartite division of China among the dynastic states of Cao Wei, Shu Han, and Eastern Wu. The Three Kingdoms period was preceded by the Han dynasty#Eastern Han, Eastern Han dynasty and wa ...

Period), the Chinese had termed the device as the 'jì lĭ gŭ chē' (記里鼓車), or ' li-recording drum carriage'Needham, Volume 4, 281. Chinese texts of the 3rd century tell of the mechanical carriage's functions, and as one li is traversed, a mechanical-driven wooden figure strikes a drum, and when ten li is traversed, another wooden figure would strike a gong or a bell with its mechanical-operated arm.

Examples

Odometer An odometer or odograph is an instrument used for measuring the distance traveled by a vehicle, such as a bicycle or car. The device may be electronic, mechanical, or a combination of the two (electromechanical). The noun derives from ancient Gr ...

s *

Arithmometer The arithmometer (french: arithmomètre) was the first digital mechanical calculator strong enough and reliable enough to be used daily in an office environment. This calculator could add and subtract two numbers directly and could perform lon ...

* Babbage's

difference engine A difference engine is an automatic mechanical calculator designed to tabulate polynomial, polynomial functions. It was designed in the 1820s, and was first created by Charles Babbage. The name, the difference engine, is derived from the method ...

and

analytical engine The Analytical Engine was a proposed mechanical general-purpose computer designed by English mathematician and computer pioneer Charles Babbage. It was first described in 1837 as the successor to Babbage's difference engine, which was a des ...

* Mechanical counter were used to accumulate totals in

tabulating machine The tabulating machine was an electromechanical machine designed to assist in summarizing information stored on punched cards. Invented by Herman Hollerith, the machine was developed to help process data for the 1890 U.S. Census. Later models w ...

s that pioneered the data processing industry. * Older

s (gas pumps) * Mechanical

voting machine A voting machine is a machine used to record votes in an election without paper. The first voting machines were mechanical but it is increasingly more common to use ''electronic voting machines''. Traditionally, a voting machine has been defin ...

s *

Tally counter A tally counter is a mechanical, electronic, or software device used to incrementally count something, typically fleeting. One of the most common things tally counters are used for is counting people, animals, or things that are coming and going fr ...

s *

Knitting counter A row counter for hand knitting is a tally counter for counting rows or courses worked, for counting stitch pattern repetitions, or for counting increases or decreases of the number of stitches in consecutive rows. The first commercially prod ...

s *

Electricity meter North American domestic analog electricity meter. Electricity meter with transparent plastic case (Israel) North American domestic electronic electricity meter An electricity meter, electric meter, electrical meter, energy meter, or kilowa ...

s * Elapsed time meters

History

Examples

References

Further reading