172 J- N. Carruthers 



The idea is to have a battery of such indinometers standing in a bath of hot water 

 on deck with their brackets alongside as the cable is veered. With such a situation 

 the brackets are simply affixed and the boxes no less easily clipped in. This inclino- 

 meter has worked well in tests and has congealed conveniently in about 20 minutes, 

 but it would be improved by being made semi-circular to avoid preferential congelation 

 in the corners, and should be lighter. 



If used on the warps of a trawl being towed, there will be some lateral pressure on 

 the box on account of the warps not leading dead astern. The rectangular inclino- 

 meter might not remain completely pendulous under such circumstances unless unduly 

 weighted along its bottom edge. The result might be that the pendulum would not 

 then give the true reading for slope which it provides when towed dead astern. If 

 round jelly bottles be used as slope indicators however, there can be no difficulties 

 due to any rolling out of a pendulous position. If the need be to use them on a thin 

 stranded wire of water-bottle type, they can be used in clamp-fitted holders, as was 

 kindly done for the writer aboard the German research vessel Gauss by Dr. Joseph in 

 March 1955, during a cruise in the North Sea. Two results obtained by Dr. Joseph 

 are pictured (Fig. 3). The slope of the firm slant interfaces which can be very clearly 

 seen was measured with ease by means of a simple goniometer made specially for the 

 purpose. 



Dr. Joseph towed a terminally-weighted wire astern with six of the clamp-fitted 

 jelly bottles affixed at equal intervals along its underwater part. The clear results he 

 got revealed overall downwards concavity of the curved wire with increase of slope 

 towards the weight. 



On another occasion he streamed a buoy astern on a considerable length of wire 

 with a weight hung on about half way along it. Jelly bottles spaced equally, four on 

 each side of the weight, revealed very clearly the opposite slopes of the two halves of 

 the wire. Between the ship and the weight the wire took on a downslope very little 

 removed from straight, though with a very slight downwards concavity. From the 

 weight to the buoy the wire sloped fairly steeply upwards with a very pronounced 

 upward concavity. 



The results will be reported upon in detail on some later occasion when more have 

 been added. 



The two bottles pictured (Fig. 3) had been used on opposite sides of the weight, 

 which was hung midway along Dr. Joseph's towed buoy-line. With his jelly bottles 

 the writer has preferred not to use clamps for attachment purposes, but to employ 

 the same sort of method as was described above in connection with the rectangular 

 inclinometer. To do so avoids limitation of use to one sort and size of line. 



An accompanying picture (Fig. 4) shows two jelly bottles after use in experiments 

 recently conducted in the Crouch estuary from a research vessel belonging to the 

 Ministry of Agriculture and Fisheries. Mr. D. Waugh of the Burnham Fisheries 

 Laboratory very kindly afforded the facilities and gave yeoman assistance. In this 

 picture the convenient goniometer made by Dr. Joseph for measuring the jelly slopes 

 is also to be seen. 



The jelly bottles illustrated are of the usual heat-resistant glass and are of the 

 compass-containing type. To affix them easily to lines of any size or nature the follow- 

 ing was done: 



A convenient length of clean, strong and heavily-lacquered wooden dowel rod was 



