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own estates. It must be borne in mind that
Barton Moss is only seven miles from Man-
chester, where there is an unlimited supply
of manure, and a never-failing demand for
farm produce; that the Manchester and Li-
verpool Railway passes through the whole
length of the estate, from East to West; that
the navigable river Irwell runs parallel with
the railway on the opposite side of the land,
and that the means of drainage is complete,
while the beds of marl are inexhaustible.

In all places where these advantages are
enjoyed this kind of cultivation may be pro-
secuted with success, and on this account the
whole of the six thousand acres we have
mentioned will eventually be reclaimed; but
without these, or similar advantages, we
should hesitate to recommend the cultivation
of peat soils upon a large scale.—Leeds

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New Antarctic Erpedition.—The following par-
ticulars relating to the Antarctic expedition, when
on the point of sailing, we copy from the Court
Gazette:—“Great ingenuity has been displayed in
providing the means of taking and preserving what-
ever may be important to natural history. Walk-
ing sticks, not larger than those commonly in use,
have been hollowed, so as to carry nets for catch-
ing insects. The ferule at the bottom is removed,
and the nets are drawn forth ready for instant use.
Spirits of wine, in bottles of all sizes, have been
furnished to preserve the insects. Small conserva-
tories are on board, which can be kept at any tem-
perature, with a view of bringing home living
plants; and long gauze bags, with mouths of com-
mon netting, will be drawn after this ship in cer-
tain latitudes, where small marine animals, not
known to us at present, may possibly be found.
Mr. M'Cormic, the surgeon, has a small printing-
press with him. Should the vessels be ice-bound
for a season, this will probably enable him to bring
out the Erebus Times, daily or weekly.”

The Iron Steamer, “Rainbow ’’—Sir.—Can any
of your readers inform me what has become of the
Rainbow steamer, built two years ago by Messrs.
Laird, of Birkenhead, for the General Steam Com-
pany? Last year she made several remarkably
i. passages to Antwerp, but now we hear no-
thing of her. There was some talk of her owners
having been paid not to run her, by the opposition
company;—if so, why is she not on some other
station? Is her construction bad? W.

Scientific Associations.—We are glad to observe
that Associations, similar in character to the British
Association, find increasing favour on the Continent.
A preliminary meeting of the naturalists and physi-
cians of the north hss been lately held at Gothen-
burg, for the purpose of establishing a like society,
to be called the Scandinavian Association. Eighty-
one scientific men assembled on the occasion, of
whom fifty were Swedes, twenty-one Danes, and ten
Norwegians. The Bishop of Agard was elected Pre-
sident, and Professors Schoum, and Halst, and M.
Fahraus, Secretaries, and representatives of the
three nations present. A council was then appointed
to draw up a code of laws for the future govern-
ment of the Society, which is to hold its first meet-
ing, next year, at Copenhagen, and of which Messrs.
Oersted and Schoum were chosen Presidents.-

Necessi'y of Innestigations in Acoustics.-Sir,
The report recently made to the Commissioners of
her Majesty's Treasury by Messrs. Barry, De La
Beche, W. Smith, and Charles H. Smith, on the
sandstones, limestones, and oolities of Britain,
forms with the numerous tables and results
of experiments by Messrs. Daniell and Wheat-
stone appended to it, one of the most va-
luable contributions to architectural science that
has been made in modern times. One hundred
and three quarries are described, ninety-six buildings
in England referred to, many chemical analyses of
the stones given, and a great number of experi-
ments related, showing among other points, the
cohesive power of each stone, and the amount of
disintegration apparent when subjected to Brard’s
process. It offers in consequence materials for de-
ductions of great practical importance beyond those
made or required to be made, in the body of the
report, and will lead, I hope, to the publication of
a comprehensive treatise on the subject by com-
petent hands. This being the case then, it must, I
think, seem desirable to all, that government
should continue the good work they have so well
begun, and that this report should be but the com-
mencement of a valuable series; and I would ven-
ture to suggest touching the next step to be taken,
the importance of appointing a committee to in-
quire into the most desirable forms of buildings
and the best mode of construction, in a phono-
camptic point of view, to investigate the science of
sound and to deduce principles to be hereafter ap-
plied in the erection of buildings. On this subject,
which is of the most vital importance to the ex-
cellence of new houses of parliament, we are con-
fessedly entirely ignorant, (and I speak not of ar-
chitects alone,) we do not know so much as would
enable one to say with certainty before a building
be finished, whether or not it will be well adapted
for oratorical purposes. Even in churches and
other edifices where the voice is to issue invariably
from one spot, many circumstances at present be-
yond our reach because not fully understood, may
have the effect, and every day do have the effect of
preventing persons in certain positions from hear-
ing; but in an apartment where, as in the House
of Commons, individuals will arise from all parts
indifferently to address the meeting, the difficulties
become much more numerous, the probability of
failure in some one respect or another, is neces-
sarily much greater. Sincerely therefore do I hope
that a commission will be immediately appointed to
collect information on the subject, and conduct a
series of experiments on a large scale, without
which, nothing effectual can be looked for. Inde-
pendently too, of the immediate occasion for this in-
quiry, the mass of facts that would be collected and
the truths obtained, would be a great boon to the
profession at large, and could not fail to produce
most advantageous results. –I am, &c. eorge
Godwin, Jun.—Civil Engineer and Architects'

Daguerre's Photogenic Process—Erratum.—
Page 466, lines 16 and 17 of second column, for
“diluted acid already mentioned,” read, “nitric
acid diluted with water in the proportion of one
part of acid to five parts of water.”

MECHANICS’ MAGAZINE, Vol. xxx1, is now
published price, in half-cloth, 8s. 6d., embellished
with a portrait, engraved on steel, by W. Roffe,
from a miniature by Chalon, of the late William
JAMEs, Esq., the Projector of the Railway Sys-
tem. Also, the SupplkMENT to Vol. xxxi, con-
taining Title, Index, Lists of Patents, and Portrait,
Price 6d. ComplktE SEts of the MEChANics’
MAGAzin E, thirty-one volumes, Price at 13 ls.

LONDON: Printed and Published for the Proprietor, by W. A. Robertson, at the Mechanics' Maaazine

Office, No. 166, Fleet-street.—Sold by A. & W. Galignani, Rue Vivienne, Paris.

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No. 844.] SATURDAY, OCTOBER 12, 1839. [Price 3d.

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18 cAPT. cARPENTER's vessel. PROPELLERs.


A vessel-propeller, the same, except in point of position, with that which is the subject of the present article, was brought before the public about a twelvemonth ago, having been patented by a Mr. J. J. O. Taylor. The extravagant statements put forth as to the powers of Mr.T.’s invention in comparison with the common and other paddle-wheels, prevented many from giving it much consideration—a glance being sufficient to convince any one at all acquainted with the subject, of the impossibility of its performing a tithe of the duty for which credit was claimed.

Capt. Carpenter, of the Royal Navy, subsequently improved upon Mr.Taylor's plan. Instead of one propeller under the dead wood of the vessel, Capt. Carpenter employs two, one on each side, near the stern. In this form, and as an auriliary power to that of the wind and sails for sailing vessels, it is well deserving of attention, and, in that character, we now lay it before our readers.

From a prospectus issued by Captain Carpenter, we extract the following statement of the advantages which he believes to be possessed by the plan.

“It has been the opinion of many distinguished naval officers, captains of merchant ships, pilots, and scientific engineers, that the principle upon which I propose to propel vessels, as exhibited on a model, would be of infinite service to navigation, if a similar effect could be produced on a large scale; I have, therefore, considered it my duty, as the subject lies within the precincts of my profession, to demonstrate that principle, so that it may not be lost to mankind. “The Euclid, an experimental vessel, 69 feet in length, has been fitted with this apparatus, from which it can be clearly proved that the propellers would be essentially useful to vessels under the following circumstances:— “l. To vessels that are tacking or veering in a narrow channel, amongst dangerous rocks and shoals, with light variable winds, and a strong current, and require to perform their evolutions with the greatest certainty. “2. To vessels that are becalmed near the entrance of a port, and are desirous of coming to a safe anchorage before dark, and only require to be propelled a short distance to accomplish their object. “3. To keep vessels clear of their anchor.

“4. To assist vessels in casting or winding, and backing astern. “5. To enable a vessel to be steered independent of the rudder, should it be disabled. “6. To assist vessels out of a dangerous position, should an accident occur to their masts or sails. “7. To Indiamen, transports, emigration ships, or other vessels that have many persons on board, this novel apparatus will afford the crew an opportunity of being usefully employed in propelling the vessel a-head during calms, and prevent that monotony, delay, and expense, which ever accompany distant voyages. “8. To vessels that are trading on coasts infested with pirates, and require, in a calm, to direct their broadside towards the enemy, to keep them off. “9. To vessels that are trading up rivers, such as the Gambia, where manual labour is cheap, and tedious calms are prevalent, when the use of the propellers would shorten the passage (probably many weeks), and be of great advantage to the owners. “10. To ships of war, in taking up an advantageous position in action, particularly if opposed to steam frigates in a calm, or concentrating their fire in breaching a fortification. “11. To ships of war, fitted both for sailing or steaming as may be deemed necessary, especially those that are stationed in a blockading squadron, and are required to intercept the enemy, if they attempt to escape in a calm, or in the event of the wind being favourable, possessing the means of topping up the propeller immediately out of the water, and making sail to economise their fuel. “12. To yachts that desire the means both of sailing and steaming. “13. To iron boats fitted for transporting troops across rivers or lakes, worked by manual labour, keeping the men safe under cover from the enemics fire, till they are ready to disembark. “14. To canal-boats for navigating in shallow water, and amongst weeds, where the propelling blades require to be readily cleared, and their action in the water directed so as not to injure the embankments. “15. To steam-vessels generally, that desire to do away with paddle-wheels, and to supply their place by a more safe and effective apparatus, that will give the same speed, and not incumber the vessel or alter the present mode of construction, that will remove the weight and inconvenience of the paddlebox, afford more room on deck, and allow boats to come alongside with safety. “The novelty of the invention consists in the position which has been selected for applying this peculiar propeller, and the manner in which it is affixed to a vessel so as to render it practically useful.” In thirteen out of these fifteen “circumstances,” we think that Capt. Carpenter's propellers would be useful auxiliaries. To the fourteenth and fifteenth, it appears to us they could never be advantageously applied. In canals (to mention one objection on this head) where the water is generally shallowest, viz., towards the sloping banks, it ought, to allow of this propeller being properly effective, to be the deepest. As to its application to steam-vessels generally, as a substitute for the paddle-wheel, we need only point out that the power is communicated to the propeller by a universal joint, and that the propeller acts at a considerable distance from any solid bearing, to convince marine engineers of the inapplicability of the plan. A model of a steam-boat, fitted with


this apparatus, has lately been exhibited working on the canal of the Polytechnic Institution. On this toy-like scale the }. works beautifully, but the idea of orming a judgment from such an exemplification is out of the question. A vessel suitable for canal navigation, we are informed has also been constructed, called the Aerolite, of the following dimensions, viz.: length of keel, 65 feet; draught of water with engine onboard, 2 ft. 2 in. ; extreme breadth, 8 ft. 11% in. The prospectus states, that “the efficacy of this principle of propelling has been well tested by manual labour, in this vessel, on the Thames, and on the City canal.” We have not, however, been favoured with any statement of the experimental working of this “test,” which would have given better data for observation than the action of the Polytechnic Institution model.

Fig. 1.

Description of the figures.

Fig. 1 is a view of the propeller; aa, the blades; b, shaft; c, iron brace; d, topping lift; e, universal joint; f, inner part of shaft.

Fig. 2 (front page) shows the position of the propeller when “topped” up, ready for immediate use.

Fig. 3 shows the position of the pro

eller when the vessel is in the act of i. propelled. Fig. 4 shows the position of the propeller when the vessel is at sea, and under sail. The mode of communicating the power is not necessary to be shown; as that will vary according to circumstances.


Sir, I submit to your numerous readers a few observations upon one of the properties of water, which may lead to

many practical and scientific improve: ments, particularly in the construction of The desiccation of many crystallized salts, for example, sulphate of soda, in a dry atmosphere, happens both at high and low temperatures, and, in either case, the transparent solid crystals, become a dry opaque powder. A remarkable instance of this kind also occurs if cream be frozen into thin sheets and exposed to a dry cold atmosphere, about zero, when the whole of the water of crystallization vanishes, and leaves a fine powder of dry curd and butter. This process is adopted in the higher Swiss Alps, where perhaps churning is found to be impracticable, by placing sheets of iced cream perpendicularly in a frame, like a plate rack, between two open windows, the desiccated cream falling down into a receiving dish, and forming a delicate substitute for butter.

hygrometrical instruments. 2 C



I have often noticed the rapid disappearance of snow during a dry black frost, and this seems to depend on atmospheric absorption, for it occurs during the night more than in day light. A fallowed field shall be wholly covered with snow so as to conceal the colour of the earth, and in one night of intense frost it disappears before the morning, without any intervening thaw.

I am, Sir,
Your obliged reader,

ANTHoNY CARLISLE. Langhorn-place, London.

IMPROVED MECHANICAL AGITATOR. Sir, Much diversity of opinion exists in the political world, as to the utility—as well as the best method of conducting— “agitation.” I trust, however, that few persons will venture to question, much less deny, the value and importance of agitation in the perfecting of many useful arts and manufactures; but for some most ingenious applications of this principle, I fancy I should hardly have obtained the paper whereon to write this communication, nor the little steel instrument with which it is penned. Now without the slightest wish to interfere with, or to rival Dan. O'Connell, Esq., M.P., the most celebrated agitator of the day— yet, have I, like him, been endeavouring to introduce “an improved system of agitation.” The accompanying camera-lucida sketch, represents a “mechanical agitator,” or “shaking machine,” which I de

signed between two and three months since, for a steel pen manufacturer. The action of the machine has been much admired, and it has been applied to some other useful purposes, besides that for which it was originally intended. In the manufacture of steel pens, there is always a slight bur raised on the edges of the metal, by the cutting-out process; in the subsequent operations of annealing, hardening, tempering, &c., the surface becomes scaly and discoloured, all which defects are very conveniently removed by shaking the pens together in large quantities; the effect being assisted by the presence of some abraiding substances, as sand, ashes, sawdust, &c. The old method of accomplishing this object was, by placing the pens and the polishing materials in a bag, and shaking them for an hour or two ; this, though a tolerably efficient, was nevertheless a very tedious operation, and it was soon superseded by a metallic cylinder or barrel, mounted upon two horizontal guides, which it was made to traverse backward and forward by means of a crank. In this machine, however, the motion of the pens was too rapid, and they struck against the alternate ends of the cylinder with great violence. An improvement upon this rude apparatus consisted in supporting the cylinder itself upon two cranks, which caused it to take an oval path, by which means the pens were turned over and over at each revolution. The extreme difficulty, however, of getting two cranks so accurately made as to work smoothly and evenly together, induced me to adopt the following method of obtaining the same beneficial results in a more simple manner. In the accompanying drawing AA represents a cast iron frame; B, is the cylinder (of tin plate) for holding the pens, &c., furnished with an opening at the top, closed by a screwed cap. Two iron rings, one at either end of the cylinder, terminate on the under side in square eyes, through which the bar C is inserted; this bar is prolonged to d, where it is connected with a crank, f, on the pulley-shaft, e. The bar C is pivoted on the top of a forked shaft or inverted pendulum, g, which moves upon two centres at the lower part of the frame, h; I is the driving wheel, a belt from which passes round the pulley, e, and gives

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