444 
Report on the Trials of Implements at Oxford. 
a nominal horse-power laid down for the Bury meeting, has both its advantage 
and its disadvantage. The advantage is, that full play is given to the talent 
and ingenuity of the Exhibitor to so proportion his engine as to develope on 
the Society's break, in the most economic manner as regards fuel, and with the 
least costly engine, the stipulated or nominal power. The disadvantage is, that 
i t leaves to the intending purchaser the task of ascertaining whether, when he 
purchases the engine nominally of 10 horse-power of A, he is getting as large 
and powerful a machine for his money as when he purchases the nominal 
10 horse-power engine of B. It may be said by those readers of this Report who 
are neither engine makers nor engine purchasers that, as the engine of each 
Exhibitor is at its trial made to exert the nominal power, the purchaser may 
be certain, whatever the dimensions of any engine may be, that engine has 
been shown to be capable of working up to its nominal power, and thus the 
purchaser is relieved of all further consideration of the dimensions of the 
engine, because he has got that which he bargained for, viz. an engine capable 
of working up to its stated power. 
Unfortunately, however, this simple and logical rule has long been broken 
through, and no purchaser would now-a-days be content unless his engine were 
competent to develop a power largely in excess of the nominal for which it 
was sold ; he would certainly look for double the power ; he would not be at 
all surprised to find treble ; and he would be only too glad were he to find 
quadruple the power. Indeed, if the purchaser resided in the neighbourhood 
of a seaport, and got his notions from those acquainted with the horse-power 
developed by marine steam engines, nothing short of six times the nominal 
power would satisfy him. ' 
It is a great pity that purchasers as well as manufacturers do not describe 
engines exactly according to their actual horse-power, viz., 33,000 lbs. lifted 
one foot high per minute ; as this is the only real standard, we have thought it 
absolutely necessary to give, in the tables which accompany this report, the 
dimensions of the cylinders of all the engines which competed, the lengths of 
their strokes, and the number of revolutions at which the Exhibitors elected 
they should run while under trial ; so that those of our readers who are 
acquainted with engineering matters might have the necessary data to form 
an approximate opinion as to what the purchaser who bought the particular 
article against which the dimensions are written, would get for his money. 
These dimensions are sufScient in respect to Class 2 (tlie fixed engines 
without boilers), but for Class 1, where the Exhibitor supplies the boiler with 
the engine, then the purchaser should also know what amount of heating 
surface each boiler contains, as the extent of heating surface in the boiler is 
(within reasonable limits) the true index of the power of doing work. 
Notunfrequently, and, in fact, on several occasions during the Oxford Show, 
some very distinguished members of Agricultural Societies other than theEoyal 
expressed their doubts as to whether there is any practical utility in the trials 
to which engines (and other machinery) are subjected by this Society ; and 
these doubters point to the circumstance that other societies, notably the Bath 
and West of England, do not put machinery to any test, but are content with 
the opinion that can be formed upon inspection. 
We, however, can by no means go with the doubts of these persons : doubts^ 
which we cannot help thinking are somewhat suggested by tlie idea in the 
minds of the doubters that if, from the appearance and the evidence afforded 
by touch, "stock" judges are enabled to assess the merits of a shorthorn, a 
pig, or a sheep, engineering judges, if equally competent, ought to be able tO' 
arrive by the eye alone at a true estimate of the economic value of a steam- 
engine. 
Assuming an engineering judge to be a man of the very highest ability in 
his profession, and to have so large an amount of time afforded him for 
