I went to the museum in Oxford yesterday to view mechanism of the measuring wheel or waywiser as they called them in 1833 when it was designed by Everest for use in India. It was hard to photo without flash in a glass cabinet. click for large image
Clever use of a worm driving two gears one with 60 teeth and one with 59, gives a differential rotation of the two plates carrying the scales. Notice that the device could probably be read to about one foot (ie one fifth of the divisions on the thousandths scale). The lower scale rolls over after 6 miles. So it is rather like the Jones counter 140 years later, a little less precise and harder to read, but I am sure it served well during the survey for approximate measurements. The surveyor's wheel to which it was attached would be 8.8 feet in circumference, rather more than our bike wheels today.