LOBSTER SANCTUARIES AND HATCHING PONDS 



53 



SESSIONAL PAPER No. 38a 



gave out. If our machinery had not been delayed in transit, we should probably have 

 been able to complete three hatchings; but it is not likely that the results would have 

 differed much if at all from those recorded in the preceding pages. 



THE MECHANISM OF THE REARING PLANT. 



The mechanism of our plant is very simple. It consists of three skeleton rafts 

 which are buoyed up by empty molasses puncheons. One of the rafts carries the 

 engine house, the other two carry two rearing boxes each. 



The foundation structure of the two rafts which carry the four rearing boxes is 

 easily understood. If looked at from above, it would present the following appearance : 



A 



Q riiifFi I i'miini>iiuijijnii//iijr} in. 'jxa. 



iwiiiiiiiniiiiiiiiiiLijma 



^ 





im 



w 



Fig. 2. — Foundation of a Rafi. 



(Drawn by A. B. Klugh, M.A.) 



AB, CD, EF, GH, are parallel pieces of spruce timber 6 inches by 6 inches, A, G, 

 I J, and B H are cross-timbers of the same size. They are all firmly bolted together 

 and make up the floating part of the raft. At the four corners are fastened four large 

 molasses puncheons. 



The third raft differed from the other two only in the fact that it sujiported the 

 eiigine house and, on account of the extra weight which it had to carry — engine, sluift- 

 ing, tools, etc., it was buoyed up by eight puncheons in place of four. 



REARING BOXES. 



Inside of the two largest areas of the skeleton rafts are placed two hatching or 

 rearing boxes. These measure 10 feet by 10 feet by 4 feet, and are made of planed 

 matched spruce boards |-inch thick, and carefully put together so as to prevent the 

 escape of the larva-. There are no openings into the boxes exceeding ^-inch. Each 

 box has four windows in it; two in the bottom, 2 feet by 2 feet, and two in opposite 

 sides 4 feet by 1 foot. These are screened with bronze or brass cloth of ^-inch mesh. 



Each box is lowered into the water about 3-J feet and kept there while the apparatus 

 is in operation. On each of the rafts which support the hatching boxes is an elevated 

 framework of timber 4 feet by 6 feet and 6 feet high, built for the support of the 

 machinery which is used in making the water circulate. This superstructure, with its 

 accompanying shafting and gegriiig, can be understood by looking at Plate VII. 



When the plant is in operation, the rearing boxes are held down in the water by 

 two planks, one at each end of a box, and the paddles, which will be described presently, 

 are kept revolving at the rate of between eight and nine times per minute. When not 



