alike constituted to succeed in mental computations; but I do say that, so far as I can judge, there may be as large a number of successful mental calculators as there are who attain eminence in any other branch of learning." Mr. Bidder urged that the proficiency at which he eventually arrived was mainly the result of assiduous application. His father was a working mason, and his elder brother, who pursued the same calling, first taught the little boy to count 100. He counted the numbers over and over in tens. The numerals became as it were his friends, and he knew all their relations and acquaintances. He next set about learning the multiplication table in his own way, by means of peas or marbles; and a smallbag of shot which he obtained, proved a great treasure to him. These he arranged into squares, each line consisting of an equal number of shot, and, counting their sides, he thus learned to multiply up to 10 times 10. Opposite his father's house lived a blacksmith, who, not having any children, had taken a nephew as his apprentice. With this old gentleman the boy Bidder struck up an acquaintance, and was allowed the privilege of running about his workshop. As his strength increased he was raised to the dignity of being permitted to blow the bellows for him, and on winter evenings he was allowed to perch himself on the forge-hearth, listening to his stories. On one of these occasions somebody by chance mentioned a sum,—perhaps 9