Early Adding Machine

Early Adding Machine, probably England, late18th/early 19th century, signed "J. Probasco, Patent," with geared operating arm, figure eight shaped engraved brass plate, divided at the top 0-50 for the manual addition, index dial divided I-X with index arm moving with the operating handle and causing the geared dial in the center to turn, divided 5-30 to turn, on varnished beech base, in shaped tin case with lid, ht. 4 3/4 in. Note: This adding machine works by moving the arm to the desired number up to 50 by aligning it to the graduation. This in turns moves another arm to the appropriate number in the 100s. The movement of this second arm engages with the small dial at the bottom and moves it along one thousand at a time, up to thirty thousand. Earlier research did not find a US patent associated with this machine, nor has recent research at the British Patent Office. It was found in the Lancaster, Pennsylvania, area by a previous owner. However, the use of beech suggests British as does the style of the engraving. The quality of the construction and engraving suggest a clock maker. The fact that the apostrophe in the name is bellow the letter and not above, suggest the maker was not a native English speaker.