238 Proceedings of Royal Society of Edinburgh. [sess. 
On some Modifications of the Water-Bottle and Thermo- 
meter for Deep-Sea Research. By J. Y. Buchanan. 
(Read January 10, 1893.) 
The instruments exhibited were especially fitted for working with 
the “ messenger,” a perforated weight which is allowed to glide down 
the line or wire at a suitable interval behind the apparatus which it is 
to act on. The apparatus immediately acted on in this case is a 
trigger., or disengaging hook, of very simple construction, which is 
attached independently to the line above the principal apparatus. 
Separating the arrangement for freeing the apparatus (whether ther- 
mometer or water-bottle or other instrument) has many advantages. 
Being very light, it can be attached to the line by twine, or to the 
wire by a small clamp ; and the principal apparatus can be attached 
in any convenient way, without it being necessary to pay minute 
attention to the knots or hitches that may be required. Further, in 
almost all cases, the principal apparatus and the separate trigger are 
much cheaper than the two combined. The separate trigger was 
exhibited attached to two forms of water-bottle for collecting water 
at intermediate depths. In one, which is a modification of a bottle 
for collecting bottom water, and is figured and described in the 
Challenger Reports, Narrative, vol. i. p. 117, the weights, which 
are provided to fall down and rest on the india-rubber valves K and H 
in the figure, are suspended by a line or wire to the trigger, and 
when the messenger falls on the trigger the line is slipped and the 
weights fall on the valves, which are then fixed, and enclose the 
sample. The pressure on the valves may be equally well produced 
by springs. 
The other water-bottle was one of the stop-cock type, with which 
all the intermediate waters of the Challenger Expedition were col- 
lected. It is figured and described in Challenger Narrative, p. 113, 
and consists essentially of a straight tube with a stop-cock at each 
end. The stop-cocks are worked by levers, which are connected by 
a rod, so as always to be equally open or equally shut. When the 
messenger is not used, the connecting-rod carries a metal flap, which 
