Star.
London, England, 1811-08-05 00:00:00

WOOLF'S PA FENT STEAM ENGINE.
London, Aril 17, 1811.
'l'l ?IS is to certify, That we, the undersigned, were
present on the 14th of March, 1811, on the premises of
John liodsson, Esq. and Co. at Battersea, to witness an experi-
ment madu with a Steam Engine of eight horses' power erected
by Megan. Bolton and Watt, to ascertant-wbst quantity otW heat
could be ground Ay the said Engine with a given quantity of
Coals. The Engine was in good working condition, the Mill-
stones Lk gisLorder, and the experiment was made with one
pair efikones, Trench Bun, 4 feet S inches diameter.
The Engine was Worked with proper care and attention for
thee beers and fifty minutes, and in that time ground three
quarters, seven bushels and a half of Wheat, Winchrster ma-
ture Wth five bushels awl one third of a bushel of Coals. The
we:r,ht of the Wheat was 59 pounds, neat, per bushel. The Coals
wet: front Collingwood Main, 448 pounds.
James Burton, Engineer. Richard Dewdney,Miller.

George Nicholls, Miller at
Messrs. Hodgson..
tondon, 17th April, 1811.
This is to certify, That we, the undersigned, were present on
the 17th of April, 1811, on the premises of Messrs. Woolf and
Edwards, Mill-street; Lambeth, to witness an experiment made
with a Steam Engine, constructed by them on Mr. Wooles Pa-
tent Principle, to ascertain what quantity of Wheat could he
ground by the said Engine with a given quantity of Coals. The
Engine was in good working condition, the millstones in good
order, and the experiment was made with two pair of stones,
French burs, four feet diameter. The Engine was worked with
proper care and attention for two hours and 44 minutes, and in
that tinte ground 33 bushels of Wheat, Winchester measure,
with one bushel, three peeks, and 14 lbs. (say 161 lbs.) of Coals
of Coßingwood Main. 1 be weight of the Wheat was :1911)4. neat,
per bushel. The Engine is estimate') at nine horse,' power.
Richard Trevithiek, Engineer. Richard Dewdncy, Miller.
James Burton, Engineer. George Nicholls, Miller at
John Penn, Engineer. Messrs. Hodgson..
Richard Pierce, Miller. Henry Harvey,lron Founder.
On the 12th day of July, 1811, an experiment, similar to the
above, was performed with Woolfs Engine, at Woolf and Ed.
ward's, %then upwards of 34 bushels of Wheat were ground into
Flour, with twn bushels or 188 pounds of Newcastle Coals. The
Wheat was of the weight of 58ilbs. per bushel. Certified by
Peter Keir, Engineer. John Norton, Engineer.
Bryan Dunkin, Engineer. Joshua Field, Engineer.
Rich. Jackson, Engineer. James Smith, Engineer.
John Penn, Engineer, Chas. Fairborne, M athema-
James lin ri on, F oe:oeer. tical Instrument-maker.
Joseph Ttlachin, kncineer. Richard Dewdney, Miller,
John Edwards, Engineer.

John Perin, Engineer.
Richard Pierce, Miller.

London, July 19,1511.

This is to certif,,r, That we, the Subscribers hereto, were pre-
sent on the Premises of Woolf andEdwar,:s, at Mill-street, Lam-
beth, on Friday the 19th day of J ely, :tit 1. to witness an expe-
riment nude with a Steam Engine of Arthur Wooli's Patent Con-
struction, to ascertain how much Wheat could be ground into
flour by two pair of French bur stones, of four feet diameter earls,
attached to the said Engine, with a given quantity of Coals, anti
that the following was the result. Worked the Engine four hours
and 11 minutes, and burnt 9 bushels of NewcauleCoals, weighing
25,21bs.During the above time and with the above quantitt of fuel,
ene pair of the now Stones ground St; Bushels and 4411h5. and
Ilse other pair 24 Etwtheis andl2slbs. malting together 61 Bmhell
and I Mahe.; and it is our opinion, that if the second pair of Stones
had been in as good order as the first, there would have-been
ground wish the above fuel at !east 731 Bushels. The Wheat
'Neighed 5711bs per bushel.
:I(r.eph Brautab, Engineer.

John Dickson, Engineer.
Jobe Sherwin, F.ng.neer.
Thomas Rowaree, Engineer.
Charles Fairborn., Mathemad•

I:,hn Penn, Engineer.
John Edwards, Engineer.
Peter Keir, Engineer.
James Moorman, Engineer.
lames Smith, Engineer.
ktchard Jackson, Engineer.
Jolt: Norton, Engineer.
h Machin, Engineer.
Jan es button, Engineer.
m the above Certificates it appears, that with one of Messrs.
1",,1t0n and Watt's best Engines at eight horses' power, not quite
sat bteheis of wheat, Winchester measure, can be ground into
Emir with one bushel or 84 pounds cf Newcastle coals; anal that
with the same quantity of coals, Woolf's nine horse Engine can
Iran .a 0 to 24 bushels of the same whht. It: other words,
alt's Patent Steam Engine of nine hoc-.'s power can hit front
4t; to 4.1 millions of pounds one foot high, with one bushel o
ros;..—Ee6i cum of greater power can lift considerably more wit
the same quantity of fvel.
Engineer., by applying to the Patentee, Arthur Woolf, No. g,
• Savdle-place, .Lambetls-walk, may he accommodated with LI-
• genres to construct these Engines on eqintable terms.
N.E. Engines on Mr. Watt's principle may be altered so as to
inninale Woolt impurententS, at a meilerate espeace.

cal instrument Maker.
Timmaa Jones, Mathematical

lostrumetit Maker.
Richard De.viincy,
George Nicholls, Miller.