556 
firefs of weather fhe is unavoidably 
driven on fhore, fhe has the advantage 
of fhips on the common conftruction, as 
they, laying on the edge, eafily roll by 
the agitation of the fea, and ftrike againft 
the ground, and when left by the. tide, 
are often bulged by the overhanging 
weight ; but fhips on this conitruction, 
having one-third of their breadth to fiand _ 
on, will neither roll, mgr be likely to 
buige ; and if, from the declivity, of the 
ground, another thip would overfer, this 
will not, having two-thirds of the 
weight to counteract it. ‘Therefore,.as 
the prefervation of lives and property at 
fea are of great importance, the above 
conftru€tion of fhips is recommended to 
all whom it may concern. The patentee 
requires only a fmall compenfation per 
ton to allow any fhip-builder the benefit 
of his invention. 
MR. EDWARDS THOMASON’S, (BIR- 
MINGHAM,) for am IMPROVEMENT ?z 
HEARTH-BRUSHES, 
Our readers will be furprized to hear, 
that, for the fake of hiding the briftles of 
hearch-brufhes, this patent has been ob- 
tained. Inftead of imple and inexpenfive 
articles, as thefe in general are, we have 
a fort of frame-work, into which the 
briftles are to be drawn when net in ule ; 
two or three tubes of which the handle 
confifts ; and metal racks, and a wheel, 
included in thefe tubes. With this de- 
fcription the nature of the invention will 
be cafily underftood, and its value pro- 
perly appreciated. 
aarti 
MR. DANIEL CRAANEN’S,(FENCHURCH-. 
STREET,) for making VERDIGRIS in 
LUMPS or POWDER, with INGREDI- 
ENTS the PRODUCE of GREAT BRI- 
TAIN. 
Upon fheets of copper, the edges. of 
which are turned up all the way round, 
pour the following mixture: one part of 
fal-ammoniac, one quarter part of oil of 
vitriol, one half part of aquafortis, one 
quarter part of muriatic-acid, and twelve 
parts of cold fpring-water. ‘This mix- 
ture 1s to be well flirred up every two or 
three hours, until the fame 3s difcovered 
to be of a green or bluifh caft ; it muft 
remain a few hours, until it is fettled, 
and the water at top perfeétly clear, 
which will happen fooner or later, ac- 
cording to the temperature of the armo- 
fphere. ‘The water is then to be carefully 
poured off, leaving the fediment at the 
New Patents lately enrolled. 
[ jan. 35 
bottom, which muft be put into a vefel, 
wafhed, and the water poured away.— 
The paint may then be taken and prepar= — 
ed in Jumps, by the affiftance of proper 
moulds, obferving, afterwards, to keep 
them in a warm room. When dry, it 
may either be ground into powder, or re- 
main in the lumps, as moft convenient. 
MR. CHESTER GOULD’s, (CLERKEN- 
WELL,) for a new HYDROMETER. | 
The confiruftion of this patent inftru- 
ment may be thus defcribed. Two glafs 
cylinders, or tubes, the bore of which is 
abcut the fize of a goofe-quill, and thirty 
inches long, are inclofed ina brafs tube.— 
On one end of thefe cylinders is fitted a 
{mall fyringe, for the purpofe of exhauft-. 
ing the air from both at the fame time.— 
It water is drawn into the cylinders, it 
will rife to an equal height by the weight 
of the atmofphere ; but if a column of 
water isdrawn into one, and a column o 
the higheft reCiified fpirit into the other, 
the two columns will rife to different 
heights, in proportion to their fpecific 
gravities. The difference of height will 
determine the length of a fcale, which is 
to be graduated by adtual experiment, by 
diluting the fpirit one per cent. at a 
time, and repeating the procefs till the 
fcale is finifhed. It is then fitted to the 
glafs tubes near the fyringe, to be applied 
like the fcale of an hydrometer. On the 
other end of the infrument a fmall veffel 
is fitted to receive the liquors. This vef- 
felis feparated into two equal parts by a 
partition, fo that one part mayrbe filled 
with water, and theother with {pirit, and 
both remain feparate.. This partition 
pafles between the two glafs tubes.— 
When a fample of fpirits is to be tried, 
one fide of this vefel muft be filled with 
water, and the other with the fpirit; they 
are then to be drawn into the infrument, 
till the water rifes exaétly to the bottom 
of the feale, and the {pirits will then rife 
higher to the proof-mark, cor above, or 
below, according toits firength. If fpi- 
rits are compared with fpirits of known .. 
procf, the differences will appear.on the 
fcale withéut the affiftance of the thermo- 
meter, becaufe the fiate of the atmofphere 
affects both famples alike, or very nearly 
fo. . The fize and proportions of this in- 
firument may. be varied at pleafure.— 
Some of them are provided with a ftop- 
cock, for the purpefe of more conveni- 
ently retaining the fluids in the inftru- 
ment till the obfervation is madés 
