682 Report on the Trials of Implements at Taunton. 
and is carried round to the point E, Fig. 51 ; at this point there 
is a pair of spring-roller jaws, FF, Fig. 51, which disconnects 
the potato from the needle ; the tuber being liberated by these 
jaws, as shown at H, Fig. 50, drops into the furrow formed 
by the shares, G G, Figs. 50 and 51, the mould-boards, H, close 
the furrow and cover up the potato. 
The neck of the arm then passes through a narrow opening 
between the jaws to pick up another potato. It will be seen 
by the drawing that the hopper is made contracted at the 
bottom, so as to assist in firmly fixing the potatoes upon the 
needles. The implement is small and compact, but being a new 
invention may be open to improvement. 
The Royal Agricultural Society's engineers tested two steam- 
boilers with considerable care ; the first was No. 3641, by 
Davey, Paxman, and Co. The Society is well acquainted with 
it, and it has earned for itself a good reputation in actual work. 
It is a 6-horse-power nominal vertical boiler, with their patent 
water-tubes and tube-valves, having about 100 feet of heating 
surface. As it has never before been tried by them for duty, 
the engineers thought it would be interesting and useful to the 
Society to prove its powers. The result turned out to be very 
high, viz., 11"26 lbs. of water at 212° Fahr., evaporated into 
steam at 212° per lb. of good Welsh coal. It was not, however, 
considered sufficiently new to be entitled to the Society's medal. 
The other, No. 3726, by K. W. Hedges and Co., was a 4-horse- 
power vertical multitubular boiler ; but the trial was unsatis- 
factory, not so much from the shortcomings of the boiler, as 
from the way in which it was managed. 
Brown and May's Spark Catcher, No. 3853, was tested, at 
considerable pains, and found to be very efficient. It consists 
of an annular pan round the top of the chimney, which is filled 
with water, forced up from the boiler by means of a pipe and 
cock. The top of the chimney and the inner half of the pan 
are covered by a shallow domed cover, which reflects sparks, as 
they rise, on to the surface of the water. 
The objections to the apparatus are, that it entails another 
steam connection to the boiler, and a coupling which must be 
disconnected every time the chimney is lowered. The pan 
also must be cleansed periodically, and before steam is raised 
it can only be filled with water by hand. 
These requirements rendered it probable that the apparatus, 
if fitted to an engine, would seldom be properly attended to in 
actual practice. It was also considered that few stackyard 
fires are caused by sparks flying from the chimneys of portable 
engines. 
