Frank S. Baldwin, a construction engineer, living in the United States, began to work on calculating machines in 1870. In 1874 he received a patent for a small hand adding machine. In 1875 a patent was granted him on a calculating machine. This machine was along entirely original lines. Mr. Baldwin did not even know of the existence of the Thomas machine at that time. The machine had a number of important advantages over the Thomas system. Scientists were very much interested in the invention at the time, and the John Scott medal for meritorious inventions was conferred upon Mr. Baldwin by the Franklin Institute. The only other invention being honored in that year (1875) was the George Westinghouse air brake. [Illustration: THE MODERN ADDING MACHINE _Courtesy of the Monroe Calculating Machine Company._] This calculating machine, however, seemed to be too much in advance of the times, and Mr. Baldwin was unable to interest capital in it. He was very successful in his business as construction engineer and continued to spend all his spare time and money in experimental work. He brought out a number of models at later dates with important improvements. In the early eighties one of Mr. Baldwin’s 1875 models found its way to Europe into the hands of one Ohdner, a Swede. He took out patents in all European countries on a machine that did not vary in any important particular from Mr. Baldwin’s machine, and several large manufacturing companies in Europe took it up. It is now appearing under ten to fifteen different names in Europe, the most important being “Brunsviga” and Triumphator in Germany. There is no essential difference between the machines they are turning out today and Mr. Baldwin’s original machine. More than 50,000 machines of this type have been sold throughout the world. [Illustration: ONE OF THE FIRST SUCCESSFUL ADDING AND LISTING MACHINES _Courtesy of the Burroughs Adding Machine Company._] In 1883 a young man who started to work in a bank in Auburn, N. Y., discovered that nine-tenths of his work was mechanical addition. He also found that the human brain is but an imperfect tool, incapable of sustained effort without accident. His health gave way under the strain, and he quit the bank to begin work in a machine shop in St. Louis. This was William S. Burroughs. He was of mechanical turn of mind, with an intense hobby for painful accuracy. By lamplight at home he worked out pencil outlines of a machine which would write figures and at the same time add them. It required the most painstaking work for him to make a machine to do what he had in mind. His early associates say of Burroughs that no ordinary materials were good enough for his creation. His drawings were on metal plates that would not stretch nor shrink by the fraction of a hair. He worked with hardened tools ground to a point, and when he struck a center or drew a line, he did it under a microscope.