Agricultural Steam-engines at Newcastle. 681 
Neither the boiler nor cylinder were lagged, the exhibitors, 
apparently, not aiming at economy at all, but only to produce a 
rough-and-ready vertical engine of small power, easily prepared 
either for travelling or for work. 
All the various parts constituting the engine are bracketed, 
by means of forgings, piecemeal, so to say, to the boiler, a plan 
of construction which renders each engine an independent 
organism, built up of parts, none of which are interchangeable, 
and depending for the accuracy with which its many pieces are 
assembled entirely on the skill of the smith and erector. In 
this respect, indeed, Messrs. Jeffery and Blackstone have taken 
a path the very opposite of that which is now generally followed 
by engineers. 
The exhibitors declared to run at 160 revolutions and a 
pressure of 60 lbs. with a brake-load of 4^ horse-power. The 
engine ran 4 hrs. 11 mins. actual and 4hrs. 5 mins. brake time, 
using 113 lbs. of coal, a consumption equal to 7 '11 lbs. of coal 
per horse-power per hour. 
Compound Agricultural Self-Moving Engine, by Mr. Thomas 
Cooper (No. 3115). — On the 7th of July a trial was also made 
of Mr. Cooper's engine, which has many novel and interesting 
features. The name of Cooper is new in the field of agricultural 
engineering practice, and it is understood that this engine, made 
by Messrs. Garrett and Sons from Mr. Cooper's designs, is a 
first essay. If this be so, the results are most creditable to that 
gentleman's skill and ingenuity. 
This engine, although a " roadster," and capable of hauling a 
load of some ten tons, has been designed chiefly for threshing ; 
its self-moving qualities being matters of minor consideration. 
Lightness and simplicity have consequently been specially 
studied, with the result that the engine, although fitted with 
road-gear, weighs only five tons, and it is no more than six feet 
wide over all. 
The boiler is of the locomotive type, with a parallel barrel throughout. 
The cylinders are placed forward on the boiler, and the crank shaft, towards, 
but not over, the firebox. Both cylinders are unjacketed, but lagged with, 
felt and wood. The cranks are at right angles to each other, of "slab" 
construction, and shouldered close up to the bearings on either side. The 
slipper-guides are formed, each, by two flat steel bars bolted at their rear end 
to the cylinder and, forward, to a wrought-iron "spectacle" plate which, in 
turn, is carried by two main stays connecting the cylinders and crank 
brackets, the stay and bracket being forged in one piece and attached at the 
crank end to the boiler by means of angle irons. The crank brasses lie in 
their beds at an angle of 45°, and are correspondingly divided. The valve 
gear consists of a single slide valve to each cylinder, driven, each, by a single 
eccentric, without any provision for expansive working, and, equally, without 
reversing link motions. 
In place of a link-motion for reversing, the eccentrics are forced round on 
