142 REPORT OF COMMISSIONERS OF INLAND FISHERIES. 



(Plate XX.) It is sometimes necessary to turn the bag upside 

 down and scrub, or even scrape, the underside of the bottom, as in 

 the ten or twelve days that the bag has been in the water the sea 

 squirts (Molgula) and barnacles may set thickly upon it. After the 

 careful scrubbing and washing the bag is pulled up out of the water, 

 the sides raised, and the bag left to dry (Plate XXI) . The drying 

 takes but two or three hours on a clear, warm summer day. The 

 drying of the salt water tends to whiten the bags considerably. 



5. Construction and Adjustment of the Paddles. 



The paddles used at Wickford are two-bladed, not unlike those 

 used overhead in restaurants. (Plate XVIII.) Each blade is made 

 of one-inch cypress and is 8 inches wide at the end nearest the paddle 

 shaft, and tapers to about 4 inches at the outer end. The blades are 

 fastened by clamps to a piece of f-inch galvanized iron pipe which is 

 placed on the under side. Between the two blades is a T coupling, 

 into which a vertical galvanized iron pipe is screwed. This vertical 

 pipe is used as a shaft for that part of the paddle which is under 

 water, and connects directly by a coupling to a short piece of one- 

 inch shafting connecting with the gears. The paddle used at present 

 is broadly beveled on each side, though the double beveling is un- 

 necessary. The length of the paddle should be sufficient to clear the 

 bag by about 6 inches when revolving, and should be raised about 

 the same distance above the bottom of the bag when this is drawn 

 up by the current. The blades of the paddle should, furthermore, 

 be painted white so that the lobsters will avoid them. 



Too great care can not be exercised in the proper adjustment of 

 the paddle. With a paddle of the above width and length ten 

 revolutions per minute are sufficient. The angle which the paddle 

 should oppose to the water is a matter which requires experience to 

 determine. It is, however, a very important factor. Many times in 

 two lots of larvae, under apparently similar conditions, one of them 

 will appear clean and healthy while the other will be covered with 



