REPORT OF COMMISSIONERS OF INLAND FISHERIES. 89 



(fig. 20). The transverse shaft of the float is connected to a similar 

 one across the house boat, by a set of universal ball joints and an 

 extensible shaft and sleeve device, invented for this particular pur- 

 pose, which allows for several inches of variation in the length of the 

 shafting system (figs. 2 and 17). The transverse shaft on the house- 

 boat runs through the side of the house, and inside the latter is con- 

 nected with the engine by two sets of pulleys and belts which greatly 

 reduce the speed (diagram). 



A small gasoline engine furnishes the power. The engine speed 

 of 324 revolutions per minute is reduced to about 36 revolutions 

 per minute in the transverse shafting; then, by gears, to 18 revo- 

 lutions in the longitudinal shafting, and to 9 revolutions per minute 

 for the propeller blades within the boxes. 



Four horizontal driving shafts running lengthwise of the float are 

 each 63A feet long. The transverse shafts connecting these back to 

 the engine have a combined length of 43 feet. The four large floats 

 are only skeletons in structure. Both they and the houseboat to 

 which they are attached float upon the water and are subjected to 

 considerable motion from the waves and from the swells of passing 

 vessels. A too rigid construction, therefore, is not permissible. 

 Indeed, a friend of the station who is familiar with mechanical con- 

 struction facetiously observed that any reputable engineer to whom 

 we might submit the plans of our apparatus would without hesitation 

 assert that it probably would not work. However, it runs con- 

 tinously with hardly an hour of interruption for three or four months 

 at a time. 



Several devices have been adopted which together make sufficient 

 allowance for the inevitable rocking movement of the floats and for 

 the warping of. the light timbers viz., comparatively light shafting 

 (1 inch), which in long pieces is flexible; adjustable hangers; large- 

 tooth cast gears; and the sliding shaft and universal joint which has 

 been mentioned. No trouble with the running of the apparatus has 

 ever arisen from the motion of the water, though the latter is some- 

 times strong enough to break out the screen windows. 



