EXPLANATION OP THE PLATES. 
375 
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injecting too little water into them when 
their speed is great, thereby deteriorating 
the vacuum and reducing the power of 
the engines, and that at the time when 
the greatest power is required. 
11. In injection engines, the proper 
supply of water to the boilers is depend 
ent upon and entirely at the mercy of 
the engineers, from whose negligence such 
serious accidents arise as those of the ex 
plosion of the two Hull steam vessels, the 
Union and Victoria, and many others, by 
which a most serious loss of life has taken 
place and great injury has been done to 
the reputation of steam navigation. 
12. In injection engines, the vacuum is 
injured by the air which is in mechani 
cal combination with the injection water 
being conveyed by it into the condenser. 
In the patent engines, the boilers are 
never liable to be burnt down or injured 
by the water becoming in them, by acci 
dent or by the carelessness of engineers, 
too low, for as every cubic foot of water 
which is converted into steam is by con 
densation reconverted into precisely the 
same quantity and returned to the boil 
ers, the water is always kept in them at 
exactly the same height without any at 
tention on the part of the engineer. 
In the patent engines, a superior va 
cuum is obtained, owing to no air being 
introduced into the condensers, and to the 
condensation being more perfect than can 
be effected by injection.” 
« ADVANTAGES APPERTAINING TO THE PATENT IMPROVEMENTS. 
“First, from the various causes above mentioned, a saving of at least one third part 
of the fuel is effected in the patent engines, or in other words injection engines con 
sume half as much more fuel as the patent engines. 
Second, for every ton of coal that is saved, a ton of profitable freight may be sub 
stituted. 
Third, as vessels with engines to which the patent improvements are applied 
make their passages nearly as quick in stormy as in fine weather, and as they do 
not require during or at the end of their passages, however numerous, any blowing 
out or cleaning of the boilers, to occasion delays, every vessel is capable of making 
more passages and of becoming in that ratio more profitable. 
Fourth, as boilers supplied with pure distilled water will endure a much greater 
length of time than those in which salt water is used, not only is the annual expense 
of the boilers greatly diminished, but the loss of the time of the profitable use of the 
vessel during the taking out of old boilers and the replacing them with new ones 
is also avoided, to say nothing of the breaking up of the decks and other expenses 
attending the business.