290 llcjwrt on the Trials of Reaping Machines at Leamington, 
with a certain amount of violence, and being brought into- 
intimate contact with the water, an instantaneous condensation 
takes place, and a vacuum is in consequence so rapidly formed 
in the just emptied chamber that the steam-ball is pulled over 
into the seat opposite to that which it had occupied during the 
emptying of the chamber, closing its upper orifice and pre- 
venting the further admission of steam, allowing the vacuum 
to be completed ; water rushes in immediately through the 
suction-pipe, lifting the inlet-valve (E), and rapidly fills the 
chamber (A) again. Matters are now in exactly the same state 
in the second chamber as they were in the first chamber when 
our description commenced, and the same results ensue. The 
change is so rapid that, even without an air-vessel on the 
delivery, but little pause is visible at the discharge opening,, 
and the stream is, under favourable circumstances, very nearly 
continuous. The air-cocks are introduced to prevent the 
too rapid filling of the chambers on low lifts and for other 
purposes, and a very little practice will enable any unskilled 
workman or boy so to set them by the little milled nut that the 
best effect may be produced. The action of the steam-ball is 
certain, and no matter how long the pump may have been 
standing, it will start as soon as steam is admitted. 
The steam-ball, if once made true, wears itself and its seats 
true, as it turns in its bed at every stroke, so that no part of its 
surface falls twice in succession upon its seat. 
It is claimed for this pump that you cannot wear it out ; that 
it requires no oil, tallow, or packing ; that it wants no skilled 
attendance ; that it occupies less space than any other pump : 
that it is cheaper than any other pump ; and that it will pump 
almost anything, — as, for instance, water full of sand-grit and 
chips, mud, sewage, gas-tar, molasses, water mixed with grain, 
paper-pulp, oil, and (when made of suitable materials) acids oi 
every kind. The Judges inspected the pump in operation, 
and considered it to be making satisfactory work and to possess 
very great advantages for special purposes and for low lifts, 
as compared with pumps having pistons or plungers ; but as an 
economical application of motive-power, the principle of con- 
densing steam at high pressure with no expansion cannot be 
commended. 
The Steam-blast for Cleaning the Tubes of Steam-boilers, of 
Messrs. Brown and May, of Devizes (No. 5602), is a very 
simple, effective, and useful invention. There is no novelty in 
discharging an upward jet of steam in a boiler chimney to 
increase the draught ; but the application in this case is such as 
to induce a current sufficiently violent to drive or sweep out 
the soot from the boiler-tubes. The steam is taken from the 
