in such v.. vray thr.t they both direct tlie r/r.ter upv;ard.s and disturb the 

 forracition of eddios end dead points. One of the frnraes vras fasten- 



ed to the bctton on r. 20 degree anj^le, the other one at the storface, 

 on the opposite side of the propeller shaft* The cxorrent v/as in this 

 vmy turned into a scre-.v-like motion; at the same tirne the rerevral of 

 Y/ater vms improved because the suction fron the bottom v.dndcaTs 

 increased* 



In the course of the experiments it appeared that the best results 



-vTere alv/ays obtained in boxes vrith these current regulators; hoiTever I 



do not vmnt to give any fij^ures as other things also ni'^^ht have played 

 a part* 



Professor AppelWf has in his earlier v/orks strongly emphasized 

 the danger in using brass raesh for the v/indoiTs, or in any vvay let the 

 copper compounds cone close to the rearing boxes, as the brood v;as 

 very sensitive to these compounds. As, however, copper paint e::cel- 

 lently prevents all parasites, there v/erc made experiments with three 

 rearing boxes: the inside v/as given c. coat of copper paint - and one 

 of the boxes was also given a windov;' of brass mesha 



The result was that the boxes x/itii copper print gave just as 

 good results as those, which were only paintcc', an'" the box with the 

 brass mesh ;:f»ve even the best result nf them alio 



After the ergine had been stopped for a longer time, there was 

 a considerable death rate in a box, v;hich had Just been painted vjith 

 copper paint, but it is hard to decide whether the death rate vras 

 due to the copper, to the lack of -v7ater circulation, or bothc 



There is hardly any reason for not_ usin-; copper paint v/here this 

 is desirable; I Icnov; that in Sweden exclusively copper paint is used 

 for the rearing boxes. 



Prom Fl/devigen I have experienced the harmfiil effect of grease 

 on the cod young, I therefore iiiade an experiment to find out how the 

 lobster young Vi'ould react if there should be any lubrication oil or 

 petroleum from the inx. chine- (barge) in the \Tater of the roaring boxes. 



In box G (see table) I added a little lubrication oil mixed with 

 petroleum every day - only so much that it gave a visible film on the 

 Virater* After five days ~ irhen the experiment had to be stopped, there 

 were 30 young lobsters lel^ of 50; in the control box v;ithout oil, 

 however, 37<. There v/as no time for further experiments, but the above 

 results indicate thct v/e ought to be aware of this. If \re do not shoiY 

 the utmost care it is impossible to prevent grease from coining into 

 the boxes, at least as long as we have to use petrolem.1 engines. 



Yflth regard to the influence of the temperat-ore on the brood, it 

 is very difficult to make experiments in this respect with the present 

 location of the rearing station. In order to get the right undcrstand- 



40 



