no 
REAPING MACHINE. 
The theory 
becomes more 
difficult from 
the remarka- 
ble fact of bog 
timber being 
delineated 
apon ice. 
Great advan- 
tages to be de- 
rived from an 
extended pub- 
lication of use- 
ful machines, 
lee. 
P. S.-— Since the above was written, T have seen the curious 
observations of Mr. Harvey, and likewise the very extraordi- 
nary fact of trees being discovered under the Irish bogs by a 
corresponding delineation upon the surface of the ice above 
them, as stated by Dr. Chichester, This fact, as it seems to 
occur frequently, deserves to be fully investigated by competent 
persons. Had these trees only been at the bottom of the 
water, and not within the bog, I should have ascribed their ap- 
pearance on the ice either to a generation of bubbles from the 
tree, rising to the surface in the shape of the branches, or by 
their having intercepted the bubbles rising from the bottom of 
the bog, when they generated no bubbles ; thus varying the 
conducting power of the ice, and affecting its attractive influ- 
ence towards the deposition of the hoar frost. But I suspect 
from this fact that there is something more extraordinary in 
these ice figures than the ascending streams of heated water, 
oleagenous particles, or bubbles, will account for. 
IV. 
Description of a Machine for reaping , used anciently by the 
Gauls*. 
T HAT nothing should be neglected which relates to the 
arts, but that all the known processes ought to be de- 
scribed with care and precision, has been incessantly repeated. 
M. Lenormand, Professor of Natural Philosophy and Chemise 
try, and the author of various memoires, expressed his persua- 
sion, that the arts would have made a more rapid progress if a 
collection had been long ago made to form a work containing 
all the inventions which have been known. In such a general 
repertory, where every one could refer to that which might 
be most useful to his pursuits, he thinks the most inferior ma- 
chine, or the most indifferent process, might give birth to some 
valuable conclusions in the minds of such ingenious individuals, 
as are endowed by nature with the talent of inventing, or of 
bringing to perfection, discoveries already made. Impressed 
with this conviction, he has thought it incumbent on him not 
[. - r&'p'jt 
* A finales des Arts, XL. 138. 
to 
* • . 
■ 
