Steering wheel first button added to the steering wheel was a switch to activate the car's electric horn. Traditionally located on the steering wheel hub or center pad, the horn switch was sometimes placed on the spokes or activated via a decorative horn ring which obviated the necessity to move a hand away from the rim. Electrical connections are made via a slip ring. A further development, the Rim Blow steering wheel, integrated the horn switch into the steering wheel rim. In 1966, Ford offered the Highway Pilot Speed Control Option, with steering wheel pad mounted rocker switches, on its Thunderbird. Uniquely,
Counting rods ancient counting rods, and further explanation, you can visit the sites Counting rods Counting rods () are small bars, typically 3–14 cm long, that were used by mathematicians for calculation in ancient East Asia. They are placed either horizontally or vertically to represent any integer or rational number. The written forms based on them are called rod numerals. They are a true positional numeral system with digits for 1–9 and a blank for 0, from the Warring states period (circa 475 BCE) to the 16th century. Chinese arithmeticians used counting rods well over two thousand years ago. In 1954 forty-odd