1799+] 
than the cutters, and there are groves in 
the fides of the guides, that the teeth of 
the cutters may 
ing their fide-fets.. 
The writer had an opportunity of 
examining one of the cutters of this ar- 
rift, which had been given by him toa 
friend, It was beautifully wrought, 
very uniform in its thicknefs, which was 
about the 1}, of an inch, and the fets 
of the teeth which feemed to have been 
affected-by the blow of a punch on-eyery 
other tooth, was extremely accurate. 
It was not perfeétly flat, but had that 
kind of flexure which workmen call a 
buckle. He alfo faw an ivory. comb of 
forty teeth in the inch, which was 
yery uniform, and equal to the bef work 
done by hand, except that the cut feem- 
ed a little too wide. _ 
It appears to be placed beyond a 
doubt, that combs may really be cur in 
this way; but whether to advantage, 
muft depend on the caft and durability 
of the cutters, which, it is to be feared, 
may be bended and fpoiled, in a courfe 
of work, by their inceflant friction be- 
tween the guides. It may alfo be re- 
marked, that they cannot be taken off 
the arbor to fharpen or repair, and be put 
on again, without changing the degree of 
finenefs in the comb they will cut. For, if 
we fuppofe an error of one-thowfandth of 
an inch, in grinding and callipering the 
cutters and wafhers, or in the different 
force of ferewing them together on the 
arbor; ‘this will make a difference. of, 
one-third of an inch, or the breadth of 
icventeen teeth, in a fuperfine comb, No. 
6, which, if coarfer, would bring it more 
than half-way to the fort called dandriff, 
or, if frner, would equal the box comb, 
Befides which a much lefs difference 
would totally deftroy the agreement or 
fitring between cutting and pointing. _ 
Mr. LOwNDEs’s GYMNASTICON. 
(With a Copper-plate.) 
In our Magazine for Novemver, 1796, 
we noticed a patent having been granted 
to Mr. Francis Lownopes, of St. 
Paul’s Church-yard, for a machine, in- 
New Patents.—Mr. Lowndes’ s Gymnafticon. 
pafs clear-notwithftand- 
477 
vented. by him, for exercifing weak, 
contraéted, and paralytic limbs, called a 
Gymnafiicon.. Having now obtained a 
farther detail refpecting its conftruction 
and experienced utility, we have annex- 
ed a copper-plate reprefentation of it, 
and of a gentleman fuppofed to be in the 
act of exercifing himfelf in a fitting 
pofture. . 
By means cf this machine, it will be 
obvious, that any fingle limb may be ex- 
ercifed, even if it fhould be totally de- 
prived of voluntary power; and, in like 
manner, the whole body in any pofition, 
ftanding, fitting, or in’a reclining pof- 
ture, however helplefs the perfon may 
be; and whether the infirmity arifes from 
want of will, or want of power, the 
Gymafticon, at once, furnifhes the fick 
with the convenience of a cradle, and 
the benefit of exercife; and when pecu- 
liar or fedentary occupations enforce 
confinement to the houfe, it promifes to 
be equally ufeful to the heaithy as to 
the fick. The merchant, without with- 
drawing his attention from his accounts, 
and the ftudent, while occupied in writ~ 
ing or reading, may have his lower limbs 
kept in conftant motion by the flightet 
exertion, or, by the affiftance of a child. 
Mr. Lowndes has likewife, with much © 
ingenuity, applied various fubfidiary 
contrivances, for ftrengtbening weak, 
and ftraightening contracted joints. 
The number and variety of the dif- 
orders to which it may be ufefully ap- ° 
plied, will, we underfiand, be fuliy i- 
iuftrated by the inventor himfelf, in a 
publication, which he is now preparing 
for the prefs, wherein a number of fuc- 
cefsful cafes, in gout, pally, rheumatifm, 
‘debility, contraction, &c.-will be brought 
forward. | iB 
*.% We have received two communica- 
tions réfpecting the patents of Mr. A. G. 
Eckbardt, for manufacturing carpets; con- 
taining obfervations which require certain 
enquiries to be made before we can give a 
fuller and more perfect account. Tbe tate 
period of the month neceffarily obtiges’ us 
to pofipone the fubjed? to our next. 

ACCOUNT or DISEASES In LONDON, 
From the 20th of November to the 20th of December. 
ACUTE.DISEASES. 
° No. of Cafes. 
& ATARRH - 12 
Peripneumony 2 - I 
Enteritis - * ied = y 
. No. of Cafes 
Acute Rheumatifm - - 2 
Inflamed and Ulcerated Sore-Throat 5 
Scarlatina Anginofa~ -. Ova 
Meafles "e - -* 3 
Hooping - 

