Bridge

1932 — Features: Announcement, with photos, that after seven years of research, the Caterpillar Tractor Company has applied the diesel engine successfully to the tractor. Contains fascinating two-page wide graphic which illustrates and describes business cycles and patent applications from 1840 to 1932 Articles: The transmission engineer's job - to design a n electrical transmission line, tie in a number of power stations, and solve the many attendant problems oftern requires years of work; Editorials - too old at 40? - airplane engine reliability - peace in radio - expensive babies; Gold from goldfish - goldfish, once imported, now raised in great numbers here; Star colors and star temperatures - the problems with which astrophysicists deal in determining the heat given off by flaming heavenly bodies; The business man takes wings - an account of an actual business trip around the country in which much time and money were saved; New light on Sasanian culture - culture of the peoples whose lands were the scene of the wars of Alexander the Great, as shown by recent archeological finds; Concrete bridge makes new record - George Westinghouse Bridge has America's longest concrete span; Is space curved? - some confusing concepts of the physicists cleared up by simple scissors work; Looking at stresses - complex stresses in structures directly vivible by new method; Big Springs - Some springs in this country flow great rivers of water; Why a watch keeps time - two years' time is often required to design a watch that will consistently keep accurate time; Gun recoil control - simple muzzle attachment reduces recoil of guns and prevents lift of the muzzle off the target; Endurance cut from the hillside - stone for modern buildings is cut in huge blocks by methods that have felt the touch of the machine age. Moderate to average wear. Magazine