110 COMMISSIONERS OF INLAND FISHERIES. 



ed of 6 x 6 spruce, and each one contains two rearing cars. These 

 cars or boxes are ten feet square and four feet deep and are made of 

 matched spruce. Four carefully screened windows, two in the bottom 

 and one on each of two opposite sides, are set in the cars and provide 

 for the necessary circulation of water. More detailed account of the 

 various constructions and operations is given in the following para- 

 graphs. 



2. STRUCTURE OF THE FLOATS. 



Reference to Plates XV, XVI will give an idea of the manner 

 in which a raft unit is constructed. In brief, it is a skeleton raft, 

 with two alleyways running the length of the float, one on either side, 

 for the supporting barrels. Between the alleyways are two open 

 pools, 12 feet square, in which the rearing cars are placed. At the 

 corners of each pool are uprights which are connected across the top 

 by cross beams. Running the full length of the raft and supported 

 by these cross beams is a beam which crosses the center of each 

 pool and furnishes support for the shafting and gears. Two sets of 

 these units are employed, one on each side of the houseboat. 



3. ENGINES AND GEARING. 



A three horse-power engine of the Fairbanks-Morse Vertical Type, 

 located in the houseboat, furnishes the power necessary to operate 

 the 28 nine-feet paddles now in use. Because of the distance from 

 repair shops, and also because a stop of an hour's duration would 

 result in considerable loss, we have installed two of these engines in 

 the houseboat. These are arranged so that they may be used inde- 

 pendently. That this size engine is capable of doing the work re- 

 quired of it and even more is shown by the fact that this past season 

 (1910) one was used day and night for over two months before it 

 became necessary to shut it down for slight repairs. The other engine 

 has been in use for eight years and is still capable of carrying the entire 

 load. It is further to be remembered that the constant bending of 

 the floats by the motion of the water makes necessary the transmis- 



