39? 
F I 
ftraw, hay: nor can any of thefe things be fet on fire 
after being immerfed in it. It may be kept dry for cen¬ 
turies ; and it lofes nothing of its edential properties from 
the acquifition of moifture: for, when dried, pounded, 
and lifted, it again becomes as good as ever. Moreover, 
the materials are by no means expenfive, becaufe, when 
mixed in proper proportion with one tun of water, they 
produce a greater effecl than 3000 kanns of fimple water. 
The pipes of the engine fuftain very little injury, if they 
be walked immediately afterward.” 
The experiments made by M. Von Aken appear fo fa- 
tisfa&ory, and are fo refpeftably attefted, that we con¬ 
ceive it highly requifite to give them at full length. 
Exp. 1. Four fmall houfes built of dry old wood, and 
filled with combuftible fubftances, were fuccelTively fet 
on fire. The firfi was extinguilhed with water. The 
bufinefs went on (lowly : 1500 kanns of water were ufed ; 
the roof was quite burned away, and of the Tides there 
remained but a few firebrands. The fire in the fecond 
houfe was extinguilhed in lefs than ten minutes : forty 
kanns of a compound water were confurned ; yet the fire 
was not put out till the roof was burned ; the Tides were 
faved. In the third, the flames were extinguilhed in a 
fliorter time : though the Tides were tarred within, and 
the quantity of combuflible materials was much greater 
than in the firfi: two experiments. Still lefs compound 
water was ufed in this experiment. The fourth houfe 
(built, we fuppofe, of materials rendered incombuflible,) 
received no injury whatever, either in the roof, Tides, or 
floor, though all the combufiibles within were confurned. 
A piece of gypfum, fufpended to the roof, fell Toon after 
the fire was lighted ; yet the fire did not feize the tube 
that ferved to hold the gypfum. The heat was fuch as 
to make the Tides appear red-hot externally. The fmoke 
made its way through Tome joints of the timber; and the 
matter with which it was impregnated Teemed to boil ; 
neverthelefs the fire did not feize the houfe. Theattefia- 
tion is figned by above forty names of men of fcience, re¬ 
putable citizens, &c. 
Exp. 2. Before the governor of the province, and 
others.—A wooden houle was erefted on ports ; between 
every piece of timber, an interval of a finger’s breadth 
was left ; and every piece was fmeared all over with tar: 
the houfe was fixteen feet fquare and ten high ; it was 
covered with fods ; doors and windows were open ; and 
it was filled with combuftible materials, as faggots and 
fhavings. The (havings which filled up the windows on 
the fouth fide were lighted ; the fire was blown up by 
bellows on the eaft fide, and Toon fpread over the whole 
houfe ; the roof was burned, and the combufiibles and 
the walls emitted fmoke and flames, when M. Von Aken 
began to play on them with his compofition from a fmall 
engine ; in five minutes, the violence of the conflagration 
was To far fubdued, though the wind tended conliderably 
to increafe it, that no fire appeared but at a few filTures; 
and this might eafily have been extinguiflied with plain 
water : but none being at hand, M. Von Aken was obliged 
to go on with his compofition ; in lefs than ten minutes, 
the whole fire, both within and without, was completely 
extinguilhed. The magiftrates found the (ides fuperfici- 
ally fcorched, as well as the foil ten feet round the houfe. 
Exp. 3. In prefence of the king and many attendants.-— 
A houfe, fixteen feet fquare, ten high, of old dry tim¬ 
ber, fmeared with tar within and without, with two doors 
and two windows open and caulked, and furrounded with 
a covering of earth. Alfo a houfe twenty-four feet long, 
fixteen broad, and ten and a quarter high, with a roof of 
tarred boards. This houfe was of new fir, and furrounded 
with earth. One of thefe houfes was caulked, in order 
to prove the applicability of this method to fliips. The 
earth thrown up on the fides ferved to hinder the heat 
from fpreading to the Toil around, and injuring the feet 
of the perfons employed in extinguilhing. It might 
have been removed from the larger houfe, but, as earth 
newly thrown up is lefs compact than the foundation of 
Vol. VII. No. 436. 
R E. 
a houfe, this was thought unneceflary, the air having 
abundant accefs to this houfe as it was open on all fides. 
It was fired on the 26th of October, 1791, having firfi 
been filled with draw and other combuftible materials, 
and faggots having been hung about the fides. In thir¬ 
teen minutes, the faggots being partly confurned, the roof 
having fallen in, and the timber being on fire, the king 
gave orders to begin to extinguifh. In lefs than three 
minutes, the fire was quite out, except a few embers in 
the faggots which water would have quenched, though 
they could not do any damage. Forty kanns of the pre¬ 
paration were ufed, but fome was loft from the aukward- 
nefs of the firemen. In the caulked houfe, the fides were 
befet with dry faggots, and the infide was filled with 
ftraw, pitch, and tar, to the top ; over which was laid a 
covering, that was alfo heaped with combufiibles. The 
houfe, being fired at all the four corners at once, was 
perfeftly in flames in fix minutes ; they then began to 
play the engine, and the fire abated wherever the ftremu 
could reach : but the covering prevented the preparation 
from getting to the roof; and it was neceflary to make an 
opening, on which "the flames were extinguiflied in lefs 
than eight minutes : except the roof and the faggots, 
which yet burned, nothing had fallen in, and the timber 
was not touched ; in fix minutes more, the fire was com¬ 
pletely out. Of fix tuns of materials deftined for this ex¬ 
periment only half was ufed.—His majefty was pleafed to 
teftify his fatisfadlion on the occafion. 
Exp. 4. Ten barrels were placed circularly at a fmall 
diftance from each other; and on thefe, ten others, all 
tarred within and without. In the intervals, dry fir twigs 
were placed fo as to rife rather above the calks ; and to 
tliefe was added a pile of boards and dry wood alfo tarred. 
In the middle, was a kettle containing fixty pounds of 
pitch, which was then made to boil till it overflowed and 
fet the calks on fire; the whole burned with great vio¬ 
lence. It was however extinguiflied in one minute, by 
five kanns of the compofition. The coating of the calks 
was burned a quarter of an inch deep, fo that the effeft 
took place when the fire had attained its utmoft violence. 
The perfons prelent concluded that a fhip on fire might 
be faved by this method. 
Exp. 5. A boat, furrounded with one hundred tarred 
calks filled with ftraw and other combufiibles, the whole 
placed fo that there might be the freeft pofiible accefs of 
ajr, was fired on a windy day ; the materials on fire pre- 
fented a furface of 1800 fquare feet. A column of flame 
rofe forty feet high, and was topped by a pillar of fmoke 
of equal height. When the conflagration had attained 
its utmoft violence, it was extinguilhed in four minutes 
by one ton and a half of the prepared water. The calks, 
except a few almoft confurned which lay to windward, 
were found in the fame order in which they were placed, 
and charred within and without. M. Von Aken’s engine 
throws the ftream only twenty feet ; it has a leathern 
feeding pipe of fixteen feet, and a fpout nine inches long, 
with an orifice of three lines, fcarcely large enough there¬ 
fore to admit a goofe-quill : it is worked by three men ; 
one pumps, the fecond holds the leathern pipe, the third 
guides the fpout. 
We fiiould efteem ourfelves fortunate if this ftatement 
of fails, apparently fo well authenticated and important, 
fhould induce any fociety or fet of individuals in this 
country to treat with M. Von Aken for the difclofure of 
his fecret. We think his preparation not likely to differ 
much from fome of M. Nyftroem’s mixtures: but M. Von 
Aken would probably demand only a very moderate pre¬ 
mium, to which lie feems well entitled; and his compofi¬ 
tion, if we may place confidence in the preceding narra¬ 
tive, mult be applicable on mod, though perhaps not on 
all, occafions of diftrefs and danger from fire.—Might it 
not be worthy the attention of the government, or of the 
infurance offices jointly connected ? 
dn the Memoirs of the Philofophical Society of Lau- 
fanne, vol.iii. the abbe Bertholou gives an account of a 
5 1 fubftance 
