4 Canadian Record of Science. 
where the pin is fastened the cross bar is bent outwards to 
bring the jaws of the clamps into the line of traction. The 
shoulder thus formed bears the entire strain in opening and 
closing the bottle as both ends of the clamp are balanced 
beneath it. It will be seen that these attachments are not 
rigid, thus preventing any straining or jamming of the 
stopper. 
A loop of heavy brass wire L connects the two side bars 
F. F. above and another loop M is attached to the cross bar 
A. ‘To these loops strings are attached enabling apparatus 
to be worked under water. 
A pair of spiral springs G. G. made of No. 23 wire are 
hooked over the ends of the cross bar A above and fastened 
to the foot of the upright bar below. They close the 
bottle when it has been opened and keep it closed at other 
times. To place a bottle in the frame the ends of the 
clamps Cand C are compressed between the thumb and fore- 
finger sufficiently to open the jaws. The frame, with bottle 
in position, is then lowered by means of a heavy string N 
attached to the loop L, when the desired depth is reached the 
stopper is raised by pulling a lighter string N, attached to 
the cross bar loop O. On releasing this again the springs 
close the bottle. The movement of raising the stopper can 
easily be felt at a depth of 15 or 20 feet. 
The bottle fills in about 20 to 30 seconds and the bubbles 
of displaced air can usually be seen. It is better not to fill 
the bottles quite full, but to leave some space for subse- 
quent shaking. 
In very swift currents or when the sample is to be taken 
at a greater depth than 30 feet an additional weight in the 
form of a small bag of shot may be tied to the lower part of 
the frame. 
To prevent any tendency of this frame to rotate while 
being lowered in a current, and thereby tangle the strings, 
I allow one string to glide in each side of my forefinger or 
else hold one in each hand. 
Before placing a bottle in the frame it is well to ascertain 
