344 
Steam Engine. 
methods now in common use. I need not stop here to 
shew the reason why, even in the case of throwing the 
steam directly into the still, the spirituous part will be the 
first to rise and pass over into the receiver. 
I might mention many other useful applications that 
may be made of my invention ; but I shall only state one 
more, namely, to the drying of gunpowder y and lessening 
the danger of explosions in the manufacture of that article. 
By means of my invention, any desired temperature, ne- 
cessary for that purpose, may be produced where the pow- 
der is to be dried, without the necessity of having fire in, 
or so near the place as to endanger its safety ; for by em- 
ploying steam only, conveyed through pipes, and proper- 
ly applied and directed, without allowing any of it to 
escape into the room or apartment where the powder is, 
any competent workman can produce a heat equal to that 
found necessary for drying gunpowder, or much higher 
if required. Nor is* the lessening of the danger of explo- 
sions the only advantage which this way of diydng gun- 
powder holds out — it presents another and an essential one 
for the goodness of the article — the heat can be complete- 
ly regulated so as to prevent, or at least lessen, the partial 
decomposition of the powder by the sublimation of the 
sulphur, which is found to take place by the methods at 
present in use.” 
In every case Mr. Woolf uses two safety valves at 
least, in his apparatus, to prevent accidents : a precaution 
which cannot be too strongly enforced ; as it may happen, 
when but one is employed, it may by some accident get 
locked, and the works and people about them be exposed 
to the danger of an explosion. 
Besides the common safety valves, Mr. Woolf has also 
introduced a valve, of a new construction, into the steam- 
pipe itself, to regulate the quantity that shall pass from 
the boiler. In fact, it is a self-acting regulator ; and 
