545 
of Edinburgh, Session 1885-86. 
4. To be closed at pleasure at any depth, or to be hauled 
up open if required. 
5. To hold its charge perfectly secure. 
6. To let the observer know when it closes. 
When it was decided to have such an instrument made, I was 
not acquainted with the description of Meyer’s water-bottle, or any 
other approximately answering the requirements ; as I had not 
then time to search out the scattered papers on the subject, and as 
no list of references could be got, the water-bottle shown to the 
meeting was devised, and by many experiments, with the advice of 
Mr Buchanan, and the assistance of Mr Frazer, who made the 
instrument, it was brought to a satisfactory condition. 
The water-bottle is represented in figs. 1 to 3, Plate XX. Fig. 1 
gives its general appearance when open and ready for use ; fig. 2 is a 
vertical section ; fig. 3 shows it closed ; fig. 4 is the plan of the base- 
plate. The material of the whole is 
brass, with the exception of an india- 
rubber ring and washer. The axis ab 
(see Plate XX.) is a strong tube which 
supports all the fittings, and through 
which the sounding-line passes. The 
funnel-shaped end of the tube b rests 
either on a knot, or on a short bar 
spliced into the rope. The base-plate C 
is provided with a ring p, of peculiarly soft rubber, specially pre- 
pared for the purpose. It is perforated by the stop- cock e , which 
opens by a key to run off the water when the bottle is full, and by 
the tube d, also terminating in a stop-cock, and intended to let in 
air when the bottle is being emptied. Three light radial wings ff 
serve as guides to the slip cylinder. The top plate g has a saucer- 
shaped india-rubber washer h fixed on it by a screw. The slip 
cylinder has its lower edge nn lightly grooved, so as to grip the 
rubber ring, and a flange with a blunt knife-edge ii projects from 
the upper part. Three strong curved strips rr terminate above in 
a tube q, sliding very easily on the central rod. The upper part of 
q is widened, and is provided with an internal groove k, in which the 
bent extremities of three springs ll catch, and so support the slip. 
These springs are bent outwards, and when the bottle is to be 
VOL. xm. 2 o 
