84 Transactions of the American Institute. 



carried out, and reflects much credit upon the skill and mechani- 

 ical resource of its projector. The points of excellence are: 

 1. Economy of space. 2. Ready access to all its parts. 3. Com- 

 bines the feature not possessed by any other trunk engine in its 

 proportionate length of connecting rod, and in the protection of 

 the trunk from radiation by exposure to the atmosphere, admissible 

 in this form of engine, but which is not fully carried out in the 

 engine on exhibition. 



Oscillating Non-condensing Stationary Engine, No. 418, W. E. 

 Bird, is a good design as relates to its arrangement of operating 

 the slide valve, the valve face being stationary, and the joint 

 readily kept tight at the point of contact with the trunnions. 



ENGINES DESIGNED FOR AND ESPECIALLY ADAPTED TO MARINE PURPOSES. 



The only engine presented, brought to our notice, is Allen's 

 propellor steam engine, No. 123. It is a pendulum engine, very 

 compact, and simple in its construction and design. 



The surface condenser attached, with Allen's compressed wood 

 packing, is one of the best (perhaps the best) ever used, the pack- 

 ing being readily renewed, is tight, while it allows for the elonga- 

 tion by expansion of the condenser tubes. 



The engine exhibits a thorough and well studied design, having 

 for ^ts object the most simple arrangement, combining the least 

 number of parts, to secure cheapness, strength and efficiency, and 

 exhibits a thorough appreciation on the part of its designer of the 

 problem connected with the production of the best engines adapted 

 to driving the screw. 



We are not, however, prepared to say this engine combines such 

 superior merit as to recommend its use (in our judgment) in pre- 

 ference to the best design of screw engines. 



STEAM BOILEP.S. 



Gerner's Steam Boiler, Erie Basin Worlis, No. 932, possesses tho 

 novel feature of an interior steam reservoir, surrounded with water, 

 and connected with the steam dome, has a large ratio of effective 

 heating surface; by its arrangement proper circulation of the 

 water is secured; it is an economical steam generator of the 

 strongest form of construction, and is accessible for cleaning and 

 repairs to such of its parts as are most liable to deterioration and 

 wear. 



Root's Sectional Wrought Iron Safety Boiler, No. 720, is com- 

 prised of wrought iron tubes encased in brick work. The tubes 



