Verea (Replik)

Direct multiplier

1878

In 1878 Ramon Verea was granted patent US 207918 "Improvement in Calculating-Machines" which he submitted in July 1878. It describes a multiplication mechanism that uses the multiplication tables for calculating, but mechanically represents them in a completely different way than Léon Bollée did in his construction of 1887. The main component of the machine, the representation of all entries of the small multiplication table, consists of a ten-sided vertical prism per calculating point, whereby each of the rectangular surfaces of the casing is intended for a single row of the multiplication table (e.g. for the set of seven 1x7 to 9x7). For each of these multiplication tasks, a pair of holes (one for the unit, one for the tenner of the product) is drilled into the cylinder side by side. The diameters of the holes vary according to the respective numbers in the multiplication table product. They are tapped off by two conical pins which - depending on the diameter of the holes - plunge into the cylinder at varying depths. It is noteworthy that the products are represented as the complement of nine, i.e. that e.g. the product 6x7 = 42 is represented by its complement of nine 57. Furthermore, the tens and units are reversed in the prism, so 6x7 = 42 corresponds to the pair of holes 7 5. The different immersion depths are digitized measures for the numbers 0 to 9, where 0 is only an indicated indentation of the surface and 9 corresponds to a hole with the largest diameter. The other numbers are represented by holes with linearly graded diameters. During the calculation process, the prisms are guided to the conical pins, which plunge into the holes to different depths and are moved with the impact, whereby the corresponding numerical value is transmitted to the display unit. The tapered pin that enters hole 7 is moved by 2 units (corresponding to the ones digit of product 42), the pin that enters hole 5 is moved by 4 units (corresponding to the tens digit of product 42). Figure 10 from patent US 207918 shows the hole plan of all disposable inserts. The product-box must be moved one position after each multiplication.

Little is known about the inventor, the Spaniard Ramon Verea: He was born on 11.12.1833 and later lived in New York, where he died on 6.2.1899.