REPORT OF COMMISSIONERS OF INLAND FISHERIES. 93 



peller shaft. The two pieces of the latter are held into the sleeve 

 coupling by set screws (fig. 19). As the set screws would be too 

 heavy for galvanized piping, the lower part of the propeller shaft is 

 continued upward by means of a piece of ordinary cold-rolled steel 

 shafting (fig. 19). This is more easily shown in the figures than 

 described. 



Driving shafts and gears. — The gear on the top of the vertical pro- 

 peller shaft engages a similar gear with half the number of teeth on 

 the longitudinal driving shaft (fig. 4). The latter is supported 

 above the shaft beam by adjustable hangers. All the gears are 

 cast instead of cut and have large teeth (fig. 20). For our 

 purposes they are probably more satisfactory, and are certainly 

 much cheaper, than cut gears. A nice adjustment is not necessary 

 and the speed of all the shafting is low, being 36 to 18 revolutions for 

 the horizontal shafts and 9 for that of the propeller. 



The longitudinal driving shaft connects by means of mitered gears 

 to a transverse shaft running back toward the house boat and engine 

 (diagram and figs. 2, 3, and 7). Between this and the transverse shaft 

 of the houseboat is a pair of ball joints of the common type and the 

 peculiar extension device referred to before (figs. 7 and 17). The 

 latter consists of a sleeve made of two heavy castings fitting loosely 

 over two pieces of square shafting. The two sleeve castings are pro- 

 vided with flanges and are held together by screws, and, to avoid their 

 accidentally slipping off into the water, one end is made fast to the 

 shaft with set screws. Several holes are bored through the sleeve 

 for convenience in oiling. This device allows the square shafting to 

 slide back and forth in the sleeve easily and it has the advantage of 

 being very cheap. It is also very strong, because the shaft has a 

 bearing on the sleeve on all four of its surfaces. 



Shafting, pnlleys, and engine on houseboat. — The transverse shaft 

 on the houseboat connects with that on both pairs of side floats in the 

 manner described, and is itself connected with the engine within the 

 house by two sets of ordinary pulleys and belt drives in which the 



