78 REFORT OF COMMISSIONERS OF INLAND FISHERIES. 



The success of these experiments led the commission the past 

 year, 1902, to enlarge the plant and to attempt to raise to the 

 fourth stage a large number of lobsters, hoping to show that lob- 

 ster culture upon a large scale is practicable. The apparatus used 

 in 1901 was correct in principle, but there were three objections 

 to it : first, the bags were too small for work upon a large scale ; 

 second, the material used in construction was not very durable, 

 and also became foul quickly ; and- third, the rope-belts were 

 troublesome on account of their shortening and lengthening, and 

 also because they were more or less in the way. To correct these 

 difficulties, larger bags of two different sizes were used : — The 

 smaller ones were 6 feet square and 5 feet deep, and each had a 

 capacity of 151 cubic feet. Three of these occupied the well be- 

 tween the pontoons of the house-boat, and took the place of the 

 twelve smaller bags of the previous year, and had Dearly twice 

 their capacity. Besides these, six others, 12 feet square and 5 feet 

 deep, were placed in two large floats built especially for this pur- 

 pose, and moored on either side of the house-boat. The nine bags 

 which were used in this summer's experiments had a total capac- 

 ity of 3,955 cubic feet, which is sixteen times the total capacity of 

 the twelve bags used last year. 



The material which was used in the construction of the bags 

 was 8-ounce canvas, and was, of course, much more durable than 

 the scrim which had been used previously. In order to admit a 

 free circulation of water in these bags, windows of copper screen- 

 ing were placed in the bottom and in the sides near the top. The 

 rotating propellers created an upward current through the bottom 

 windows and flowed out through the windows at the side. The 

 rope-belts were displaced by a system of worm wheels and 

 matched gears which gave a neater construction and a more 

 direct transmission of power, and which had the additional advan- 

 tage of not being affected by the weather. All of these changes 

 proved to be advantageous, and the apparatus is now so satisfact- 

 ory that the commission propose few changes during the coming 

 year. 



