Plate 12. 



Raising the car by means of windlass. Ropes from the drums of the windlass 

 are fastened by hooks to rings in the lower corners of the car. 



Plate 13. 



View of the interior of a car, showing filter of gravel and sand placed over one 

 of the bottom windows. Arrangement for rearing very minute larvae or those for 

 which screen windows would be dangerous. The car is caulked tight, water is 

 poured over the top by bucket chains and its only exit is through this bottom 

 filter. Slot and the doors at end of car show in the upper right-hand corner of 

 the photograph. The picture shows also the boards used to truncate the angles 

 between the adjacent sides 1 and between the sides and bottom 2. 



Plate 14. 



"Filter Car" in operation. Short propeller hung about eighteen inches below 

 the surface. Trough 1 with canvas lining for conducting incoming water; float- 

 ing shallow bag of scrim 2 used in hatching certain fish eggs. The arrangement 

 of shafts and gears shows well in the figure. 



Plate 15. 



Filter car, showing bucket chain in operation. One of the buckets has just 

 emptied itself, and the stream of water is faintly shown running into the trough. 



Plate 16. 



Filter car with canvas lining. Chain buckets on the left. The propeller blades 

 may be seen in the water. 



Plate 17. 



Detail of device for extension and universal movement: adjustable shaft- 

 hanger 1 ; ball joint 2; square shafting 3, fastened by set-screws into ball-joint at 

 left 4 and also by set-screws into sleeve 5; set-screws holding sleeve on shaft to 

 prevent the sleeve from falling off into the water 6 ; screws through flanges of 

 sleeve holding the two sides together; oil holes; square shaft which slides in and 

 out of sleeve 7; shaft-hanger upon side float 8. 



