Plate 6. 



View into rearing car raised. Several of the cars in position. The length of 

 the propeller blades is shown by comparison with the young man, five feet six 

 inches tall, who is holding the propeller. The following are shown: slot in end 

 of car 1 ; doors for closing the slot when a car is lowered 2 ; side screen windows 

 3 ; bottom windows 4, 5 ; box covering gear trains which connect transverse and 

 longitudinal shafts 6 ; transverse shaft 7 ; longitudinal shaft 8 ; towing car 9. 



Plate 7. 



Interior of rearing car. Preparing to caulk small cracks before lowering the 

 car. Side window 1, slot in end 2, and doors 3 with buttons 4 to hold them shut 

 may be seen. Passing through the slot may be seen longitudinal shaft and shaft- 

 beam. The gear train connecting vertical propeller shaft and horizontal shaft 

 and the adjustable shaft-hanger are shown in the foreground. 5, 6, and 7 show 

 the connection of shaft on the houseboat with that of the float. 8 is the engine 

 muffler. 



Plate 8. 



Lifting the disconnected propeller out of the water. The upper portion of the 

 shaft with the sleeve coupling is seen at 1 . 



Plate 9. 



The propeller removed, showing the disconnected shaft. Tlie upper part of the 

 shaft and the coupling are faintly visible under the shaft beam. The photograph 

 shows well the size and shape of the propeller blades and the silt which accumu- 

 lates during the two weeks it is in operation. 



Plate 10. 



Starting to knock out the wooden cleats at the end of the holding-down planks 

 in order to release the car and allow it to rise. 



Plate 11. 



The cleats 1 being removed, the car rises part way through its own buoyancy. 

 Carrying off the holding-down planks 2 and opening the doors of the slot at end 

 of car to admit the longitudinal shaft-beam 3 and so allow the car to be entirely 

 raised. Side windows show well 4, 5. 



