546 
Proceedings of the Royal Society 
closed, a weight slipped down the line strikes the wide tube m, and 
drives it down over the springs ZZ, drawing them in and releasing the 
slip. The knife-edge ii strikes the rubber washer h at the same 
moment as the lower edge n strikes and indents the rubber ring p. 
At the same instant the three springs oo are forced over the base- 
plate, and clasp it tightly, clamping the two together before the 
elasticity of the india-rubber has time to assert itself. An extremely 
tightly-fitting joint is the result. The spring o is supplemented by 
an additional spring s, the action of which enables more flexible 
metal to he used for the catches. It requires a little practice to 
enable one to set the water-bottle again, hut this is soon acquired. 
This water-bottle is believed to possess certain advantages over 
other forms. It can he used in conjunction with the reversing 
thermometers of Messrs JSTegretti and Zambra, when these are fitted 
with the Scottish frame,* and by a very easy adjustment any number 
of thermometers and water-bottles can be used simultaneously on 
one line, thus enabling samples of water and temperature observa- 
tions to he obtained from several positions at once. The impact of 
the messenger on the top of the water-bottle, and the locking of the 
springs below, can he felt distinctly through nearly 100 fathoms 
of line, and so the moment when it shuts is known. The locking 
arrangement is very satisfactory, and so simple that any accident, 
such as the distortion of a spring, can he put right at once. The 
same holds good of the detaching gear. 
The water-bottle shown has been in constant use for a year, both 
on board the “ Medusa,” where it is worked by steam-power, and on 
fishing-boats, where it was managed by hand. 
5. On a Eepetition of Berthelot’s Experiment on the 
Tenacity of Water and its Adhesion to Glass. By H. 
Creelman. Communicated by Professor Tait. 
* Proc. Roy. Soc. Edin., xii. (1884), p. 627 ; xiii. p. 33. 
