244 Sundry Improvements in Apparatus or Manigatation. 
applied to the filling of syphons, and removal of back water from 
water wheels. 
In this view of the subject then, we find the rationale of the col- 
lapse of the reservoir. 
The current through the main being arrested at a point nearer 
the head than that from which the pipe supplying the reservoir pro- 
ceeded, there was an hiatus produced within the main, and cavities 
therewith communicating, which caused the atmospheric pressure 
to be inadequately resisted, and consequently the reservoir, as one 
of those cavities, was crushed. No doubt the pressure of the spring 
water, in which the reservoir was situated, cooperated. At times 
our springs rise much nearer to the surface of the earth than at others. 
When steam is made to pass through a pipe into cold water, @ 
succession of expansions and condensations ensue, producing much 
noise and mechanical jarring, consequent to the alternate absorption 
and expulsion of the water. Agreeably to the rationale respecting 
the collapse of the reservoir, these effects should be productive suc- 
cessively of an inward and an outward pressure upon the surfaces of 
the pipes employed. 
Some years ago, a pipe was submitted to me by Mr. Ewing, 
which, while situated as above described, had been crushed by a 
force which seemed to have exceeded any which could, under any 
circumstances, be expected from the pressure of the atmosphere. 
Possibly an adhesion between the water and the metallic surface, 
. may cooperate in the production of such results. 
Arr. VII.—Sundry Improvements in Apparatus, or Manipulation ; 
by R. Hare, M.D., &c. &c. 
From the Transactions of the American Philosophical Society. 
Improved Cryophorus. 
Two flasks, of which the necks have flanged orifices, are so secuT- 
ed in a wooden frame, that by the pressure of screws SS, and gum- 
elastic disks, the orifices of a tube are made to form with them sev- 
erally, air tight junctures. The orifices of the tube are furnished 
with brass flanges, which correspond with those terminating the 
-necks of the flasks. 
Midway between the junctures a female screw is soldered to the 
tube for the insertion of a valve cock V, by means of which, and 2 
