142 
REMARKS ON MR. REEVE’S EXPERIMENTS. 
and each screw was turned until I could not withdraw the card 
without scratching or tearing it. Finding the card too soft a ma- 
terial for this purpose, in the second and every succeeding expe- 
riment I used small slips of the thinnest tin in the same manner. 
I must warn those who are not aware of the power of a finely 
threaded screw, that the least turn of a finely pointed screw will 
send it through the tin, or at least leave a bulge which will shew 
a corresponding mark on the hoof, and this must be especially 
guarded against, as error will surely arise from a neglect of it. In 
each experiment, after the adjustment of the shoe and screws, the 
horse was mounted, and made to trot and gallop a short distance 
on dry ground ; the horn opposite to the points of the screws was 
then examined by taking each screw out separately, and afterwards 
taking off the experimental shoes for further examination. Such 
being the order of proceeding in each case, it will be taken for 
granted that it will be unnecessar}' for me again to refer to it, and 
therefore only any different circumstances will be noticed. 
Is/ Experiment . — A very heavy mare, wide chested, turns her 
toes slightly inwards; foot strong, and moderately concave. The 
off fore foot, the lateral harrow shoe, No. 3, used, having four nails 
inside and two at the outside towards the toe. 
Result . — The upper screws had all touched the horn to a tri- 
fling degree, and the upper and back screws opposite to the heels 
the most so, I would say to the one-fortieth of an inch ; the other 
marks were scratches. In looking carefully to these marks, I did 
not find a single puncture (properly so called), but they were up- 
and-down scratch, and the back screw had caused a bruise on the 
horn, that is, a much wider mark than corresponded to its point. 
I attributed this to the fact that the foot had slightly yielded back- 
wards and downwards, and pressed on the point of this screw ; 
the marks made by the other screws puzzled me. I fancied I had 
penetrated the card with the point of the screw, but this was not 
the case. 
2 d Experiment . — The same mare. The near fore foot, the 
harrow-shoe, No. 1, used; four nails outside and three 'inside; 
slips of the finest tin used instead of the visiting card, and the tin 
only withdrawn when the points of the screws scratched. 
Result . — On the most careful examination of the sole, not a 
single screw had touched, and there was no mark whatever. 
3c? Experiment . — The same mare. The off fore foot, the first 
experiment repeated, but using the tin instead of the visiting card, 
and the greatest care taken in the adjustment of the screws. 
Result . — There was no particular difference, excepting that the 
marks were confined to the two upper and back screws, and to the 
same extent as before. 
