■j^^O BULLETIN 173, U. S. NATIONAL MUSEUM 



was purchased by the United Fire Engine Co. No. 3 of Frederick, 

 Md., and was used continuously until 1912. It is a remarkably well 

 preserved example of the best in steam fire engines of the period of 

 1876. The United Co. has a collection of about 20 trophies that have 

 been awarded to it over a period of many years for achievements of 

 the engine. The engine has for many years been known throughout 

 the vicinity of Frederick as the "Lily of the Swamp." It proudly 

 carries the motto of the United Co., Veni-Vidi-Vici. 



The engine has a vertical boiler, with both fire tubes and water 

 tubes. The fire tubes extend from the crown sheet of the fire box 

 up through the top of the shell and the water tubes hang from the 

 crown. The outer rows of water tubes extend nearly to the bottom 

 of the fire box and surround rows of shorter tubes, which are about 

 half the length of the outer row. In each water tube long narrow 

 sheet-metal diaphragms form a triangular passage in the center of 

 the tube for the return of water carried up by the steam. The dia- 

 phragms are stamped with lipped openings turned upward, which 

 serve to drain into the return passage much of the water lifted with 

 the steam before it reaches the top of the tube. 



The pump is 1-cylinder, double-acting, and horizontal. The water 

 enters the pump in the center of the front head and is distributed to 

 all sides of the pump cylinder and the valve chambers through an 

 annular space that surrounds the entire cylinder. This space is so 

 designed that it makes a very free watercourse to the valves and also 

 retains sufficient water in the pump to assure positive starting with- 

 out priming even against very high suction lifts. No connection to 

 the boiler or other means of priming with grease or water is provided 

 on the engine. The intake valves of the pump are arranged in a 

 ring surrounding each end of the cylinder. This ring is easily re- 

 moved with the cylinder head. The valves of either end are the same 

 and are interchangeable. The discharge valve is a ring of india 

 rubber attached to the front cylinder head but is enough longer than 

 the head to reach over an annular space at the center of the cylinder 

 and lap over a ring on the cylinder that forms the valve seat. This 

 annular space or band around the middle of the cylinder is con- 

 nected to the discharge gates and discharge dome. The air chambers 

 provided permit the pump to work at very high speeds. The piston 

 is all metal and is water packed. 



The steam engine that drives the pump is small, double-acting, 

 direct-connected, and horizontal. A cross head is provided from 

 which a connecting rod drives a shaft on which are a pair of light 

 flywheels and an eccentric for operating the valves of the engine. 



Wlien first made the engine was drawn by hand, but in 1905 it 

 was slightly remodeled by adding a sliaft and a driver's seat, so that 

 it could be drawn by horses. 



