142 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
The Nansen-Pettersson water-bottle has given every 
satisfaction. An occasional difficulty in locking was 
remedied by the adjustment of the catches on the lateral 
rods, and by close attention to the cleanness of the latter. 
The closure of this water-bottle is very complete. When 
it has been locked it has been found impossible to open it 
even when the catches at the sides are loosed, until the 
valve at the top is opened. It would be an advantage if 
the copper wire ropes carrying the weight could be 
replaced by chains, for the wires of these ropes are apt to 
break and cut the hands of those working the apparatus. 
With this apparatus it is found possible to take 
hydrographic soundings even in a fairly rough sea. 
Soundings are always made on the windward side of the 
vessel and with the wind about three to five points on the 
port side (on which the davit is placed). Careful 
manceuyring of the vessel is, of course, necessary, but we 
have very seldom found the weather bad enough to 
prevent the work being done. In a rough sea it is 
necessary to make allowance for the rise and fall due to 
the heave of the ship, in converting the fathoms of depth 
indicated by the sounding machine into metres (which 
are indicated on the metre wheel). It would be an 
advantage in practical working if the Lucas machines 
were made to indicate metres, and if the gearing of the 
clock were made to indicate units and tens on different 
dials. Sounding machine and metre wheel give almost 
identical readings, and when only one or two metres are 
allowed for clearance from the sea bottom, it is often 
found that the pitching of the vessel in a seaway 1s 
sufficient to make the water-bottle weight just touch the 
bottom. 
Ordinary surface tow-nets are hauled from forward 
on the windward side of the vessel. It has been found 
