220 ^ TWO MARINE INSTALLATIONS OF PRODUCER GAS. 



Air starting and reversing and direct connected to propeller shaft. 

 Propeller, 3 -blade — 



Diameter 44 in. 



Pitch 56 in. 



• SUPERIOR. 



Length over all 65 ft. 



Beam 12 ft. 9 in. 



Depth of hold 4 ft. 



Producer — 



Diameter of shell 3 ft. 6 in. 



Height 6 ft. 6 in. 



Engine, two-cylinder 50 B. H. P. 



Bore 9 in. 



Stroke 12 in. 



Air starting, fitted with reverse gear. 

 Propeller, 3 -blade — 



Diameter 40 in. 



Pitch 54 in. 



The same general description will cover the interesting points of the 

 power equipment of both boats. The producers used in both installations 

 are the same type and make as fitted in the Marenging and Carnegie. The 

 producer as shown in the photograph is a cylindrical steel shell lined with 

 asbestos and fire-brick to such a thickness that, when running at full load, 

 the heat radiation is not important. While the shell is rather warm to 

 the touch, it cannot be regarded as hot. With proper ventilation this heat 

 in summer is not objectionable, while it is most agreeable in other seasons 

 of the year. The whole principle being one of suction or vacuum, there 

 is no escape of gas into the boat. The writer has been aboard the Mary 

 A. Sharp after she had been closed up for a week, excepting about half 

 an hour every other day when a little additional draft was given to the 

 producer to keep the fire alive, and found no odor of gas in the engine- 

 room. At a suitable distance above the bottom to form an ash-pit is located 

 the grate and on a line with this are two fire-doors for slicing the fire and 

 raking off the ashes. An ash-pit door is fitted for the removal of ashes 

 and clinkers. The coal is fed into the producer through a hopper on top, 

 and just below, reaching into the center, is the gas take-off pipe. The 

 side walls of fire-brick are substantially vertical and we have then a fire- 



