450 Report on the Trials of Implements at Oxford. 
It will be seen by an examination of Table I. tbat tbe three engines wLicli 
were provided with horizontal boilers gave the best results, and there is no- 
doubt that had the Reading Iron Works not laboured under the disadvantage 
of being unable to use their loose feed-water heater, their engine would have 
exhibited the larger economy of about 15 per cent., due (as has been already 
explained) to the use of heated feed water, and thus the three engines pro- 
vided with horizontal boilers would have been still farther ahead in point of 
economy of any of those provided with vertical boilers. 
We consider there are points of merit about u horizontal boiler ■which it is 
difficult, if not impossible, to equal in a vertical boiler ; and one, and a 
principal one, of these points is that in a horizontal boiler there is a very 
large surface of water from which the particles of steam can be disengaged, 
and thus there is far less danger of the steam carrying up particles of water 
with it. 
This liability of carrying over water with the steam (i.e. of "priming")- 
increases with the amount of steam delivered in a given time, and therefore 
the exhibitors of vertical boilers were placed during the trial under extremely 
favourable conditions as comj^ared with those in which they would have been 
in ordinary working, because the engines were restricted to developing only 
their nominal power; while in actual work, as has already been stated, they 
would be urged to a far greater power than this. It is a fact, although a 
regrettable one, that in engines, as in other matters, there arise fashions, and 
there is no doubt tliat for the last few years vertical boilers (vulgarly called 
" coffee-pots ") have come into fashion. 
In certain cases, such as on swinging cranes, for which these boilers are very 
largely used, their form is convenient, and there may be other cases, such, 
for example, as those where floor-space is extremely limited, in which it 
may be desirable to use boilers and engines which occupy height rather than 
breadth and width ; but these cases are more likely to arise in crowded printing- 
offices and in little manufactories in the City, where ground is very valuable, 
than on farm premises. For the agriculturist's purposes we see nothing 
beyond tlie saving of a very few pounds (from 101. to 30?.) in the original cost 
of the 4-horse engine to tenijit the farmer to purchase the vertical form in lieu 
of the horizontal — a dear first economy, looking at the perpetual extra cost of 
working, as shown by the trials. 
With resi^ect to the table which follows, and with respect to that which will 
be given for Class 2, it may be well to call the reader's attention to the fact, 
that column No. 9, which shows the total revolutions of the break, is not by 
itself any indication whatever of the merits of these engines, because these 
total revolutions depend not alone upon the time during which the engine is 
capable of running before it has consumed its allotted coal, but also upon the 
size of the pullej-s ; and in the same way the succeeding column. No. 10, which 
records the weight held suspended by the break in the case of each engine is by 
itself no guide of the power developed, inasmuch as that weight varies inversely 
as the sjieeds; but column 11, which represents the product obtained by mul- 
tiplying the total number of revolutions of the break into the weight held sus- 
pended in each case, gives results which truly represent the relative performances 
of the different engines tried. 
On mature consideration as to the most practical way of testing engines and 
boilers of this class, so that a purchaser might best be able to judge whether a 
particular engine would suit his requirements or not, we decided with the full 
concurrence of Mr. C. E. Amos, the Society's engineer, and witli the sanction of 
the Stewards, that instead of a number of persons being allowed to assist, and, 
if we may use the expression, " nurse " the engine, by oiling various parts, 
breaking the coal for the stoker, and spending much time in attending to the 
heat of the feed water, &c., that one man only should drive the engine, stoka 
