BuL. U. S. B. F., 1908. 



Plate XCIX. 



Fig. 19. — Detail of propeller shaft couplings, i, underside of shaft beam; 3, upper steel portion 

 of shaft, which bears gear on toj) and enters sleeve coupling below; 4. cast sleeve coupling; 

 3, set screws holding shafts in coupling; 6, short piece of steel shaft; 7. pipe coupling; S, lower 

 part of shaft, made of pipe; g. measuring stick, made of sections 6 inches long. 



Fig. 20. — Detail of gears on float at junction of transverse and longitudinal shafts. (Compare 

 fig. 4, pi. xci.) I. gear on horizontal shaft from house boat: 2. large gear on longitudinal 

 shaft, reducing speed one-half; 3, gear on the inner end of transverse shaft (4); 4, shaft 

 transmitting power to outer float; 5. longitudinal shaft on inner float; ft. oil box. 



