MAYALL, Thomas Jefferson, inventor, born in North Berwick, Maine, 10 August, 1826; died in Reading, Massachusetts, 18 February, 1888. He obtained employment in a paper-mill in Roxbury, and soon began inventing, especially making improvements in machinery in the factory, and attracting the attention of his employers by devising the first rubber belt that was ever used in this country. This was followed by a model of the first cylinder printing-machine that was ever made, from which has grown the present industry of wall-paper printing, and calico printing, which previous to that invention was done on blocks. The machine made 1,000 rolls of paper a day, printed in two colors. His other inventions include a method of producing satin-faced paper, a method of vulcanizing rubber (1841), an automatic battery, a revolving cannon, bomb-shells with sharpened edges to bore through the armor of ships, a coffee-hulling machine, which he introduced into Brazil, and self-acting drawbridges for railroads. At the time of his death he was at work on an electric elevated railroad, an electric-cable railroad, and a pneumatic elevated railroad. His revolving cannon was introduced in several countries of Europe. By means of machinery, operated by steam, this gun is loaded and fired forty times a minute, with only one man in attendance, the loading, firing, and swabbing going on at the same time. He took out 200 patents in this country and 70 in England.