LIBERTY MOTOBS 474 LIBRA their production, and in many plants the manufacture of motors for motor cars gave way to the production of Liberty motors or their parts, and many other plants produced the tools, jigs, and other fixtures necessary for the quantity pro- duction of these motors. Up to the time of the Armistice, the government had let contracts for about 100,000 airplane motors, of which num- ber about 60,000 were to be Liberty motors. The first Liberty motor built upon the quantity production basis was shipped from the Packard plant on Thanksgiving Day, 1917, and quantity production was so well organized that by the time of the armistice, the government had ac- cepted 15,000 Liberty motors, the daily production being over 150, while England was after four years producing Rolls Royce engines at the rate of but 59 a day. Since this country was the only one of the powers which was producing airplane motors faster than it was pro- ducing airplanes, the planes of the other nations were designed to take our motors. Among the larger contractors were the Packard Company and the Lincoln Motor Company, which had each a con- tract for 6,000 motors, the Ford Com- pany with a contract for 5,000, Nordyke and Marmon for 3,000, and the General Motors for 2,000. The early designs called for an eight cylinder motor, but demands from France caused the plans to be changed, and most of the motors built were twelve cylinder models, which weighed about 825 pounds and developed as high as 480 horse power, its weight being less than two pounds per horse power, which is considered very light. The original motors were tested at the summit of Pike's Peak, and in a special vacuum room at the Bureau of Stand- ards, both of which preliminary tests were passed satisfactorily. The Liberty motor is a twelve cylinder, V-type motor of five inch bore by seven inch stroke, with a cubic capacity of 905 inches. The angle between the cylinders is 45°, which produces a rigid motor, and offers less resistance to the air than the generally used 60° angle. The motor is made up of individual steel cylinders. Until this motor was introduced, ' this country had not manufactured many successful steel cylindered motors, cast iron being the usual material. The early cylinders were bored from steel castings, which was a slow and expensive process, but the Ford Motor Company soon intro- duced a method of forging the cylinders out of seamless steel tubing, which by means of cylinder presses and bulldoz- ers can be converted into a headed and flanged cylinder blank at small expense and with great rapidity. The cylinders are fitted with a stamped steel jacket which is welded to the cylinder. Be- cause of the unequal thickness of the metal in the cylinder, and the jacket, dif- ficulties were experienced in the welding of the parts because of the unequal heat- ing, but they were overcome by raising joining flanges upon the heavier cylin- der, to which flanges the jacket was welded. Ignition caused some difficulty, and various types of magnetos and ignition devices were experimented with before a specially designed Delco system was used. The pistons of the Liberty motor are of Hall-Scott design, the connecting rods are of the forked type such as were first used in America by the Cadillac, the crank shaft is a standard twelve-cylin- der type except for the special oiling de- vices. A special pump pressure oiling device is used. The water is kept in circulation by a pump developed by the Packard Company, a special carburetor was designed for this motor, and the shaft drive was developed by the Hall- Scott Company. There is one cam shaft for each set of cylinders. The valves are set in the head of the motor and are operated by a mechanism more or less resembling that of the German Mercedes. The inlet valves of the motor are on the inside, in order that the travel of the gas may be shortened, while the exhaust valves are located on the outside. The motor was subject to the most se- vere tests, and may be cited as a great triumph of American engineering and methods. LIBERTY PARTY, THE, in the United States, grew out of the Anti- slavery Society, and was more widely known for the persistent agitation of its adherents than for its numbers. In 1840 it nominated James G. Bir- ney, secretary of the Anti-slavery So- ciety for president, casting 7,059 votes; and again, in 1844, when he received 62,- 300 votes. It contained such men as William Lloyd Garrison, Wendell Phil- lips, Lewis Tappan, Gerrit Smith, Sam- uel Lewis, and Salmon P. Chase. It merged into the Free Soil party in 1848. LIBITINA, the Roman goddess of the dead and of funerals. LIBRA, one of the 12 ancient zodiacal constellations. It is surrounded by the constellations Scorpio, Ophiuchus, Virgo, Centaurus, and Lupus. It contains no stars of the first magnitude. Also the 7th sign of the zodiac. Owing to the
