Report on the Trials of Implements at Reading. 689 
it was impossible for the air to get through. It was like a 
raw cow-hide." 
Nothing could illustrate more forcibly the bad effect of a 
fixed cage within the shaft than this occurrence. Where such 
a prop is left in the centre of the stack the hay settles unequally, 
a portion of the rick is left comparatively open, while another 
part, which most requires ventilation, is totally impervious to 
the air. In speaking of the condition of other stacks when 
opened, this effect of the fixed cage has been already noted and 
commented upon. 
After the reconstruction of the stack, the fan was worked at 
intervals by a 4-horse-power engine until the 16th of August, 
and altogether for about 53 hours on 13 different days ; the 
whole period over which this work extended being three weeks 
(see Table XIV., p. 716). 
This stack, which contained about 13 tons of hay, sold for 
26Z. When it was opened the hay was still very warm, and 
much of it was very black. If it had been left for any length 
of time it might very probably have fired ; some veins of mould 
appeared, and the whole rick was of very inferior quality. 
In the previous account of the different hay-stacks the prac- 
tice of each exhibitor has been noted, and some details of the 
temperature which was observed and of the fan-workings have 
been given. As it is, however, probable that some inquirers 
may be desirous to obtain more minute particulars of the various 
modifications of the Neilson system adopted by different exhibi- 
tors, and more precise records of the variations of temperature. 
Tables, which give rather copious information on these points, 
have been appended to this Report (pp. 703-726).* 
It had been the intention of the Judges to give a trial to 
Mr. Neilson's fan which he had presented to the Society, but 
the whole of the grass available for the purpose had been used, 
and there was nothing left but the trimmings from under the 
trees and other places inaccessible to the mowing-machines. In 
* It may be well to remark that, though the records of temperature are tnie as 
far as they go, they do not pretend to represent the whole truth. The changes of 
temperature were so frequent and sudden, and the variations in the heat at diffe- 
rent points not far removed from each other were so great, that there is a possi- 
bility, nay, a great probability, that in some of the stacks the hottest part was 
never probed. It was impossible for the Judges to take all the observations, 
which extended over a period of seven weeks, personally ; they were obliged in 
their absence to delegate some part of this duty to others, but they have every 
reason to believe that the work was carefully done. The earlier observations, 
down to the 28th of July, were almost entirely made by the Judges themselves. 
The figures given are but a few of those recorded ; but where the temperature 
remained stationary, or in some cases where it showed a continrous rise or fall, 
it did not seem necessary to state the fact, 
VOL. XVIII. — S. S. 2 Y 
