August i6, 1889.] 



SCIENCE. 



107 



AN IMPROVED AIR-ENGINE. 



During the past ten or twelve years the firm of Woodbury, 



Merrill, Patten, & Woodbury, of Boston, Mass., have been steadily 



at work developing and perfecting an air-engine ; and, as a result 



of their labors, they are now about to place on the market engines 



superior in durability and economy to any heretofore constructed. 

 In a test made in South Boston in March last, the quantity of coke 

 consumed was 1.54 pounds per indicated horse-power per hour. 

 A representative of Science, on seeing the engine, was surprised at 

 its general excellence and smoothness of movement. 



AN IMPROVED AIR-ENGINE. 



of their construction in sizes ranging from five to a hundred horse- 

 power. A few experimental engines were built from time to time, 

 as the inventors approached their ideals, and some of those engines 

 are said to have done satisfactory work during a run of five years. 

 But the engines as made at present are claimed to be much 



The essential features of this engine are a heater, a regenerator, 

 and a cooler, which three in combination are called a reverser. 

 The engine illustrated is'composed of two reversersand two double- 

 acting cylinders, the cut being a section through one reverser and^ne 

 cylinder. Each reverser is provided_with a reverser heater, within a 



