CATALOG OF THE MECHANICAL COLLECTIONS I59 



College at Cornell University, Avhere Manly was a student, and he 

 assumed charge of the experimental work as assistant in charge of 

 experiments in June 1898. It Avas then the intention of Dr. Langley 

 to have the engine for the aerodrome constructed for him by some 

 established engine builder, while he and Manly constructed the aero- 

 drome proper. A contract was therefore made with a builder who 

 agreed to construct an engine to weigh not more than 100 pounds 

 and to develop not less than 12 horsepower. This arrangement failed 

 to produce an engine, and a new contract was entered into with 

 S. M. Balzer, automotive engine builder of New York City, who 

 agreed to furnish an engine of the above description before March 1, 

 1899. 



The engine was not delivered within the contract time, and in May 

 1900 Manly went to New York to assist in the completion. \Vlien it 

 was found then that the engine developed not quite 3 horsepower, 

 it was decided that Manly should accompany Dr. Langley, who was 

 then preparing to leave for Europe, and they would attempt to have 

 the engine built abroad. No one in France, Germany, or England 

 would attempt the job, and Langley was told rather generally that 

 such an engine was an impossibility. Tlie two returned in August 

 1900 and found the engine still below specifications, whereupon Balzer 

 was paid the contract price for the engine as it stood, and Manly 

 returned to Washington to continue the construction of the engine 

 himself. Using some of the parts from the Balzer engine and con- 

 structing others. Manly within little more than a month had an 

 experimental engine at work that developed 18^2 horsepower on 

 the Prony brake at 715 revolutions per minute and weighed 108 

 pounds. This was a "patched up" affair that was provisionally cooled 

 by wrapping wet cloths around the cylinders and accordingly could 

 run for only a few minutes at a time. It was so successful, however, 

 that plans were made to construct an engine for the full-size aero- 

 drome immediately. Another delay was met in obtaining materials 

 for the engine, and construction was not started until the summer of 

 1901. The first part of the year was not wasted, however, as a long 

 series of tests was run on the experimental engine to determine the 

 most satisfactory carburetor and ignition arrangement. The wiping 

 contact sparker proved unsatisfactory and was abandoned, and Manly 

 then devised what is supposed to have been a new and valuable 

 multiple-sparking arrangement whereby only one batterj^ one coil, 

 and one contact maker were utilized for causing the spark in all five 

 cylinders. 



A small commutating arrangement in the high-tension circuit dis- 

 tributed the sparks to the proper cylinders. Most of the spark plugs 

 then available were found unsatisfactory, and so Manly constructed 

 his own. In this connection he effected one minor improvement that 



