438

BURSTALL AND HILL'S NEW PATENT STEAM-COACH.

The engines are what are called high-pressure, and capable of working to 10-horse power, and the steam is purposed to be let off into an intermediate vessel, that the sound emitted may be regulated by one or more cocks.

From the Repertory of Putent Inventions. The patentees seem to have taken great pains to render this steam-carriage as perfect as the knowledge as yet acquired, relative to this mode of conveyance, would permit; and the evident improvement which it exhibits on some of its predecessors, gives great hopes that the desirable object of making steam-carriages capable of moving effectually on common roads, will be attained at no distant period.

The great impediment to the application of steam-carriages to common roads, is their enormous weight, which, in few cases yet made public, has been much less than eight tons; to which, if the usual load of goods put on an eight-horse waggon were added (to supply the place of stagewaggons being one of the objects of the patentees), no common road yet made could support them. It would therefore be an object wel worth that ingenuity which the patentees have shown in the construction of their steam-carriage, to contrive means for lessening the weight of those vehicles in every possible way, as well as to pursue the plan already used on railways, of having carriages for conveying the mercantile goods, or the passengers, quite distinct from that of the steamengine, which, for the latter purpose, would also be desirable for other obvious reasons; for, exclusive of the idea of danger, which sitting close to a caldron of boiling water, subject to be precipitated on them by an unlucky stone or rut in the road, might give to people, otherwise not very timorous, the great heat of the furnace and boiler would be very objectionable, at least during the warm months. In this way the steam-carriages would serve the purpose of horses to draw other carriages (which they so far resemble, that on the railroads where they are used they are called, we are informed, iron horses,

by the workmen); and for common roads this separation of the weight on separate carriages would be even much more necessary than for railroads, on account of their being formed of materials so much less hard and durable. Among the methods proposed for making engines more light, that of using boilers constructed of small pipes seems very worthy of attention, several modes of which have been already made public; among the more recent of which, that for which Mr. Theodore Paul has lately obtained a patent, seems in some respects to deserve a preference; but requiring, in order to complete it, the addition of Mr. Perkins's patent principle, of confining the heated water in the pipes by a weighted valve, till the instant of its being let off to act on the piston of the engine in the form of steam; as the water without this would be blown totally out of the pipes by the steam formed in its lower extremities

The method of forcing the water into the boiler by the pressure of air, in an engine where no condensation i required, which is the case in that of the patentees, can do no injury to the general effect, and may be of some service on the principle applied in M. Latour's air-engine (for which see Nicholson's Phil. Journal, vol. xxix., p. 175), who caused a wheel to revolve by the expansion which the air received in passing from cold water into that heated to the boiling point; and as some of the air pressed into the patentees' water reservoir will be absorbed by the water, and pass over with it into the boiler, it will so far have a similar effect. It is also probable that the air-pumps will keep longer and better in order han small water forcing-pumps, both from air having less action on metal, and not being so liable to carry along with it extraneous sub

stances.

MANUFACTURE OF RED CRAYONS.

The Red Crayon, and its use, are too well known in daily life to require any thing to be said of them. The preparation of the red crayon,

THE SINGLE-WHEEL CLOCK.

which is best adapted for painting,
is less known. The following is the
manner in which it is performed
A quantity of hematite is pounded
in a porphyry mortar, with filtered
water, until it be extremely divided,
so as to form an impalpable powder.
This powder is again diffused through
a quantity of water sufficient to allow
the mixture to pass through a fine
sieve, placed above a large vessel
filled with water. The liquid hold-
ing the hematite in suspension is
then agitated, and, after this, al-
lowed to rest four-and-twenty hours.
At the end of this time there is
formed at the bottom of the vessel a
deposit of hematite, in the form of a
very fine powder: the water is cau-
tiously decanted from it. To form
crayons of this impalpable powder,
a uniting substance is necessary.
This is afforded by gum arabic or
isinglass, of which the proportions
vary according to the use to which
the crayon is destined, less of it
being required for soft crayons,
which consequently leave their co-
louring matter more readily, and
more for the hard ones, which pre-
serve their point longer. The fol-
lowing are the proportions, deduced
from experiment, to be employed in
the five kinds of crayons, which we
shall enumerate. 1. For the red
crayons, with large marks, 18 grains
of dry gum arabic to one ounce of
prepared hematite powder. 2. For
the hard-grained crayons, 21 grains
of gum to one ounce of hematite
powder. 3. For the crayons, with
small and fine marks, 27 grains of
gum to one ounce of hematite. 4. For
the crayons, with less fine marks than
the preceding, 22 grains of gum.
5. For the crayons, with shining
marks, 36 grains of ichthyocolla to
one of prepared hematite powder.
The gum or isinglass is dissolved in
a suficient quantity of water; the
solution is passed through a linen
cloth;
the powder is then added;
the liquid is brought near a gentle
fire, until the mass is somewhat
thickened; it is then removed from
the fire. The mixture is very care-

fully bruised upon the porphyry, to
render it as intimate as possible; and
it is then formed into crayons. The

439

mass, when it has acquired the proper consistence, is made to pass through a cylinder; the sticks thus formed are dried, and divided into crayons of two inches long; they are sharpened, and the skin which has formed upon them, while drying, is removed.

THE SINGLE-WHEEL CLOCK.

SIR,-Having sent to your valuable journal for the promulgation of mechanical science, an account of a very simple Clock, or rather Timepiece, in my possession, consisting of only one wheel, and which you were pleased to publish in vol. III. page 319, I have since observed in your Miscellany, No. 106, page 341, vol. IV. that one of my brother subscribers, dated Royston, states that he has made a clock agreeably to my given plan and principle, but that he is much disappointed to find it did not answer, as, when the barrel was wound up, it unwound itself in two minutes, and could not, by any weight, be prevented from thus rapidly descending. I have, in consequence thereof, more minutely examined the clock (which I have by me), and I find little difference in the dimensions which he has given of the proportionate lengths and diameters of the works, except that the wheel diameter may be called five inches; but this difference I do not look upon as material. Being determined, however, to ascertain the reason of the failure, I have accordingly dissected the barrel containing the liquid which unwinds the catgut off the spindle, or rather arbor, and I find the tin barrel is divided into five cells, having five tin partitions soldered in at equal distances, which cells or divisions are continued to within 1-8th of an inch of the arbor or spindles, so that they are all open to each other, and the water can pass out of one cell to the other, running out at the small opening next the arbor. I also observe there is a small hole, not larger than the smallest shot-hole, in the centre of each tin division within a quarter of an inch of the outer rim; this I conclude is for an air vent. These divi

440

WORKING OF ANIMAL HORN.

sions, by letting the water flow only
gradually, constitute, I imagine, the
grand secret of its being enabled to
keep time, the same being checked
again by the hook and line passing
round the grooved wheel, and ba-
lanced by shot. I have also to ob-
serve that I found the barrel, when
opened, to contain about half a pint
of fetid water, strongly impreg-
nated with verdigris from the ma-
terials of the barrel. The water is
put in after the barrel and divisions
are all nicely soldered, by a small
hole in the side near the entrance of
the arbor, the hole being afterwards
soldered up.

I am, Sir,
Your obliged servant,
B-P-C.

Thirza-place, Kent-road.

ON THE EMPLOYMENT AND WORKING
OF ANIMAL HORN IN GENERAL.

BY M. VALLET.

[Translated from the French.]

Horn, particularly of oxen, cows, goats, and sheep, is a substance soft, tough, semitransparent, and susceptible of being cut and pressed into a variety of forms; it is this property that distinguishes it from bone. Turtle or tortoise shell seems to be of a nature similar to horn, but, instead of an uniform colour, it is variegated with spots.

These valuable properties being known, renders horn susceptible of being employed in a variety of works fit for the turner, comb and snuff-box maker. The means of softening the horn need not be described, as it is well known to be by warmth; but an account of the cutting, polishing, and soldering it, so as to make plates of large dimensions, suitable to form a variety of articles, may be desirable. The kind of horn most to be preferred is that of goats and sheep, from its being whiter and more transparent than the horn of any other animals. When horn is wanted in sheets or plates, it must be steeped in water, to be able to separate the pith from the kernel, for about fifteen days in summer, and a month in winter; and when it is soaked, it must be taken out by one end, and

well shook and rubbed, in order to get off the pith, after which it must be put for half an hour into boiling water,

and then taken out and the surface sawed even lengthways; it must again be put into the boiling water to solten it, so as to render it capable of separating, then, with the help of a small iron chisel, it can be divided into sheets or leaves. The thick pieces will form three leaves; those which are thin will form only two, whilst young horn, which is only one quarter of an inch thick, will form only one. These plates or leaves must again be put into the boiling water, and when they are sufficiently soft, they must be well worked with a sharp cutting instrument, to render those parts that are thick, even and uniform; it must be put once more into the boiling water, and then carried to the press.

At the bottom of the press employed there must be a strong block, in which is formed a cavity of uine inches square, and of a proportionate depth; the sheets of horn are to be laid within this cavity in the following manner, at the bottom :-First a sheet of hot iron, upon this a sheet of horn, then again a sheet of hot iron, and so on, taking care to place at the top a plate of iron even with the last, and the press must then be screwed down tight.

There is a more expeditious process, at least in part, for reducing the horn iuto sheets, when it is wanted very eveu. After having sawed it with a very fine and sharp saw, the pieces must be put into a copper used for the purpose, and there boiled until sufficiently soft, so as to be able to be split with pincers: then bring quickly the sheets of horn to the press, where they are to be placed in a strong vice, the chaps of which are of iron and larger than the sheets of horn, and screw the vice as quick and tight as possible; let it then cool in the press or vice, or it is as well to plunge the whole into cold water. The last mode is preferable, because the horn does not dry up in cooling. Now draw out the leaves of horn, and introduce other horn to undergo the same process. The horn so enlarged in pressing is to be submitted to the action of the saw, which ought to be set in an iron frame, if the horn is wanted to be cut with advantage, in sheets of any desired thickness, which cannot be done without adopting this mode. The thin sheets thus produced must be kept constantly very warm, between plates

NEW METHOD OF BLEACHING SPONGE.

of hot iron, to preserve their softness. Every leaf must be loaded with a weight heavy enough to prevent its warping. To join the edges of these pieces of horn together, it is necessary to provide strong iron moulds suited to the shape of the article wanted, and to place the pieces in contact with copper-plates, or with polished metal surfaces against them; when this is done, the whole is to be put into a vice and screwed up tight, then plunged into boiling water, and after some time it is to be removed from thence and immersed in cold water, which will cause the edges of the horn to ceinent together, and become perfectly united.

To complete the polish of the horn, the surface must be rubbed with the subnitrate of bismuth by the palm of the hand. The process is short, and has this advantage, that it makes the horu dry promptly.

When it is wished to spot the horn in imitation of tortoise-shell, metallic solution must be employed, as follows. To spot it red, a solution of gold in aqua regia must be employed; to spot it black, a solution of silver in nitric acid must be used; and for browu, a hot solution of mercury in nitric acid. The right side of the horn must be impregnated with these solutions, and they will assume the colours intended. The brown spots can be produced on the horn by means of a paste made of red lead, with a solution of potash, which must be put in pieces on the horn, and subjected some time to the action of heat. The deepness of the brown shades depends upon the quantity of potash used in the paste, and the length of time the mixture lays on the horn. A decoction of Brazil wood, a solution of indigo, with sulphuric acid, a decoction of saffron, and Barbary tree wood, is sometimes used. After having employed these materials, the horn may be left for half a day in a strong solution of vinegar and alum. In France, Holland, and Austria, the comb-makers and horn-turners use the clippings of horn, which are of a whitish yellow, and tortoise-shell skins, out of which they make suul-boxes, powderhorus, and many curious and handsome things. They first soften the horn and shell in boiling water, so as to be able to submit them to the press in iron moulds, and by the means of heat form it into one mass. The degree of heat necessary to join the horu clippings must be stronger than that

441

for shell skins, and which can only be attained by experience: the heat must not be too great, for fear of scorching the horn or shell. Considerable care is required in these operations not to touch the horn with the fingers, nor with any greasy body, because the grease will prevent its joining perfect. Wooden instruments should be used to move them while they are at the fire, and for carrying them to the moulds.

NEW METHOD OF BLEACHING

SPONGE.

To bleach Sponge and render it perfectly white, it is necessary to soak it in cold water. But if it does not become soft, it must be immersed in boiling water; but this should, if possible, be avoided, for it has a bad effect on the sponge; particularly in cooling, it causes it to shrink and to become hard, and bleached; but if the sponge is soaked so tough as to prevent its being in cold water, and that water be changed three or four times every day, and every time the water is drawn off, the sponge should be pressed perfectly dry; this process being repeated for five or six days, it will, at the expiration of that time, be ready for bleaching.

If the sponge, as is frequently the case, should contain small pieces of chalk and shells, which cannot, be got out without tearing it, the sponge must be soaked for twentyfour hours in muriatic acid, with twenty parts of water, which will and carbonic acid gas to be liberated, cause an effervescence to take place, when the shells and chalk will become perfectly dissolved; after that it must be carefully washed in fresh water, and immersed in sulphuric acid, the specific gravity of which must be 1,024 or 4 deg. on the hydrometer of Beaumé. The immersion of the sponge in this acid should continue for about eight days, but it must occasionally be pressed dry and thoroughly washed. After having been perfectly washed and cleaned, it should be sprinkled with rose water, to give it a pleasant smell, which completes the process.

RESULTS OF A METEOROLOGICAL JOURNAL, FOR SEPTEMBER, 1825.*

Kept at the Observatory of the Royal Academy, Gosport, Hants.

for the Lunar period, ending the 12th inst.......30.003 for 15 days, with the Moon in North declination..29.924 for 14 days, with the Moon in South declination.. 1..30.082 Spaces described by the rising and falling of the Mercury.. 4.190 Greatest variation in 24 hours..

0.360

.21

A clear sky, 3; fine, with various modifications of clouds, 15; an overcast sky, without rain, 63; raiu, 41⁄2.-Total, 30 days.

CLOUDS.

Cirrus, Cirrocumulus, Cirrostratus, Stratus, Cumulus, Cumulostratus, Nimbus.

*The Report for the preceding month was transinitted to us by Dr. Burney, but unfortunately miscarried. We hope to be able to continue them regularly in future.