490 
into a frame and made red hot. They 
are then to be immerfed in water, or a 
compofition of greafe or oil, to be har- 
dened in the frame according to the direc- 
tion wanted. When hardened, they. are 
to be tempered, by being kept in motion 
over the fire till the greafe fmokes, and 
until a blue blaze alternately appear and 
difappear. They are then to be ftretched 
with as much power as will bring them 
into the direction required. If they do 
not require hardening, they muft be made 
red-hot, and fuffered to cool in the open 
air; they are then to be ground by a ma- 
chine, which being put in motion will 
pare, tooth, fmith, finifh, fet the teeth 
of faws ; fharpen, grind, and polith plates 
ef fteel and iron; and form beads and 
mouldings and other articles. 
~—— 
MESSRS. JAMES and JOHN ROBERTSON. 
- (GLASGOW) for a METHOD of ap- 
pling STEAM with the greatef? av- 
VANTAGE in working of sTEAM-EN- 
GINES. 
In the beft-conftructed engines; a con- 
fiderable quantity of fteam efcapes by the 
Lift of Difeafes. 
[ June I, 
fides of the piflon, and is loft withont pro« 
ducing any mechdnical effe&t. Mefirs. 
Robertfon’s invention confifts in preven- 
ting, in a great meafure, the efcape of 
the fteam, and in making that which does 
efcape, act on another pifton, and thereby 
augment the power of the engine. In 
thefe engines, there are two fteam-cylin- 
ders, one fmaller than the other, with 
piltons fitted to each, which a& together 
in producing the effect. To the cylinders 
are annexed a condenfing veffel and air- 
pump, which are common to other fteam-~ 
engines ; but the principle of exclufive 
right is founded inthe mode of conduét- ~ 
ing the {team on and between the piftons. 
ae ee 
*,* Tbofe Patcntecs who wifh that an carly notice 
fhould be taken of their inventions and difcoveres, 
will meet with every attention, by tranfmitting 
tothe Editors of the Monthly Magazine, for a. 
Sew days, copies of their pecifications. The plan 
adopted in this publication cannot fail to intereft 
the public in every new and important invention, 
without tending in the fmalleft degree ta diminifp 
the bufinefs of the offices, to which every perjon 
muf? necefJarily apply who wifbes for more exa 
and particular information than thefe notices are 
calculated to furnifb. 
ACCOUNT oF tHe DISEASES in LONDON, 
From the 20th of April to the 20th of May. 
Admitted under the 
Care of the Phyficians of tke Finfbury Difpenfary. - 
lo. of Cafes. 
RHEUMATISMUS « - 28 
Catarrhus - « “ 36 
Dy{pneea Ebriofa - - 19 
Pchifis Pulmonalis > - 3 
Dy{pepfia * = ° 16 
Hypochondriafis > - 3 
Menorrhagia - - - IB 
Leucorrhea - - 9 
Anafarca - - = a 
A{cites 2 - = - 2, 
Epilepfia - - - = 5 
Hyfteria - - - = 13 
Morbi Infantiles  - = = 29 
Diarrhea - “ = - 24. 
Ophthalmia Tarfi et Membranarum Iz 
Typhus - - - 2I 
Rheumatifm, and the various pulmonic 
2ffeStions, have been peculiarly prevalent, 
in confequence of the frequent and abrupt 
vicifitudes of the weather, which, in a 
moft remarkable degree, have charac- 
terized the Jaft month. The inhabitants 
of a town are more particularly liable to 
fuch complaints, from the alternation of 
fun and fhade, to which, in walking the 
fireets, they are continually expoled; win- 
ter is often on one fide of the ftreet, and 
fummerontheother. . | 
To the remarks which have already been 
made on difeafes of this clafs, it will 
appear perhaps fuperfluous to make any 
farther additions: As in fome degree 
however connected with this fubjeét, it 
may not be improper to ftate a fingular 
and interefting conclufion, drawn from 
the obfervation of a great variety of faéts, 
that a habit of intemperance in thofe 
whofe lives are daily and actively employed 
in the open air, fuch as hackney-coach- 
men, poftilions, gardeners, &c. induces 
in general difeafes of the lungs, or of 
fome other of the thoracic vifcera—whereas, 
thofe whofe occupations are fedentary and 
domeftic, are, by this fpecies of excels, 
more peculiarly predifpofed to hepatic or 
other abdominal difor ganizations. 
The fulceptibility of phthifical and other 
morbid affections of the lungs; is in the 
higher claffes confiderably increafed by 
the unwholefome luxury of fpending the 
greater part of their time in apartments 
artificially heated, and almoft hermetically 
fealed 
