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PLAN OF WCIKING.- Cn the left headland is the Engine and Windlass, the Water-cart, and directly opposite to them the Anchor, and between these two the Plough is pulled backwards and forwards, one end of the Plough being alternately in the air and the other in its work.

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A FEW weeks ago we gave a description and illustrations of the main portions of Mr. J. Fowler's apparatus for ploughing land by steam power, noticing the successive improvements he has made in it from the time he first exhibited it, and the very great degree of simplification he has at preent attained in its construction. These improvements may be shortly stated to consist, first, of a better mode of applying the power; secondly, the lightening and cheapening of the apparatus; and, thirdly, the improvements made in its details, which cannot be separately enumerated, but which, taken collectively, are of vital importance, as upon the mode of carrying them out depend its durability and efficiency. The difference betveen

good and bad detail frequently constitute all the diference between a machine made orly to be looked at, and one which will bear to be daily worked. The great success of Mr. Fowler's apparatus at the trials which have been made during the present week at Warwick, induce us now to give yet a fuller description of it in its present

form.

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shown in the accompanying large illustration, the

plough being worked between

the engine and the anchor. Again, the ope

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cent construction. We are now enabled to give an illustration of the latter, which is shown in Fig. 1. The frame is made entirely of wrought iron, the winding-forward drum being placed upon an upright spindle; and the machine so constructed with shafts as to be capable of being worked round any ordinary bend in a hedge. The side strain is well borne by the cutting discs or

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engine, which, by aid of pitch wheels and chain, is made capable of moving itself by steam from field to field, only requiring to be steered by one or two horses, which is easily done, and avoids much of the complication attending ordinary steering apparatus.

FIG. 3.-ROPE PORTER.

In our former article we gave an illustration of being now passed over two grooves, instead an anchor used for some time by Mr. Fowler; of being wound on a barrel, as formerly, is another but, as was then stated, not one of the most re

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wheels fitted to

the machine, which is balanced by having a box filled with earth fixed at the side opposite that from which the wire-rope passes off. The forward motion is accomplished by the friction of the wire-rope on the four-feet pulley, to which is attached a drum for winding up a rope stretched along the headland and fixed to the ground.

The water-cart, which is drawn along with the engine, is made circular, and of wrought-iron, and is shown in Fig. 2. It is used also for

conveying the wire rope from place to place, and for this purpose is fitted with a fly-wheel and handle for winding the rope up upon it. The cart is made to contain about 150 gallons of water. Fig. 3 shows two of the rope "porters," with the rope running over the pullies, as it does when in use.

Several of these porters are used when the field to be ploughed is of great length, in order to keep the rope as much off' the ground as possible, thus to prevent unnecessary wear, and to econo

mise the power required to work the apparatus.

We have before illustrated Mr.

Fowler's balanceplough, but the accompanying illustration, Fig. 4, shows the application of scarifier irons to the same

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frame work, the plough bodies being removed. Instead of attaching scarifier irons, the breasts only may be removed and shut, and blunt mould boards

FIG. 4.-SCARIFIER PLOUGH.

FIG. 5.-TRENCHING PLOUGH.

substituted in their steads, when at one operation a perfect fallow may be made. Fig. 5 shows onehalf of a balance plough frame, with subsoil irons attached. We have now given illustrations of the whole apparatus used by Mr. Fowler, and which may be seen in operation at the Royal Agricultural Society's Show at Warwick, where agriculturists will have had an opportunity of verifying the statements we have made with regard to its simplicity and efficiency. The cost of ploughing by steam was stated in our last article, the results given being from trials by the Society's engineer. Estimates have, however, been made by several persons, and the several conclusions arrived at are that from 78. to 10s. may be fairly put down as the cost of steam ploughing for different classes of land, and from 9s. to 18s. for double trenching the soil. These accounts, be it remembered, include every expense, wear and tear, interest of capital, &c., and compare very favourably with home labour. We insist that after so persevering a course as that which Mr. Fowler has taken, he should at length reap the reward of his labours. They have been most arduous, very costly, and such as nothing but a firm conviction that success was attainable, and a determination to obtain it, would have enabled him to overcome.

BOAT-LOWERING APPARATUS.-Mr. Clifford has forwarded to us--but too late for publication this week-a reply to the letter of "Nauticus," which appeared in our last impression. This we hope to insert in our next, but in the mean time as the

letter of "Nauticus" contained a statement relative to an accident to a boat's crew of the Oracle, which, if not immediately replied to, might operate seriously to Mr. Clifford's injury, it is only right that we should state that Mr. Clifford produces in contradiction to the charge letters from Messrs. Green and the Captain, which affirm "that there was not the slightest blame attached to her lowering gear," and furthermore, "that where it has been fitted in Messrs. Green's ships it has given general satisfaction."

THE MAGNETISM OF SHIPS. By F. J. EVANS, Esq., Master R.N., F.R.A.S., Superintendent of the Compass Department, Admiralty. I HAVE to bring to your notice, and under review, the valuable labours, still in progress, of a committee formed at Liverpool by various gentlemen connected with the vast shipping interests of that port, and working also under the auspices of the Board of Trade, to collect observations and make experiments on the condition and distribution of magnetism in iron-built ships, and the general system of compass correction and management.

Two or three disastrous shipwrecks, clearly traced to compass errors, occurring about the time that the iron navy of Liverpool was rapidly expanding, gave rise to various conflicting opinions on the safety of their navigation, and particularly on the subject of compass-compensation by magnets; these questions were discussed in various periodicals, and also at the British Association for 1854: hence arose the formation of the Liverpool the Advancement of Science, held at Liverpool in Compass Committee.

The publication in 1857 of the first and second reports of that body to the Board of Trade, and presented to both Houses of Parliament by command of Her Majesty, enables the observations relative to the theory of the magnetism of ships to be extended, not only in confirming what has been already advanced, but in giving some more general views of its character and distribution, particularly in iron-built vessels.

A striking feature in these reports is, that the researches of the various authorities already quoted, and their exposition of the laws of magnetic action on ship-board, have received ample confirmation from the various observations collected and experiments undertaken by the committee. In the opening page of the second report they observe, that it has been "proved, too, most decisively, that the deviations of the compass on board iron ships, when properly ascertained, are

Portion of a paper recently read at the United Service Institution, and published in the Journal of that Society.

not of that irregular and erratic character which many cards of deviation might lead one to suppose, but that they accord most closely with the deductions of theory and experiment, as exemplified in the works of the Astronomer Royal and Mr. Archibald Smith." And again, at p. 24, in alluding to certain fluctuations in the amount and direction of a ship's induced magnetism, "These fluctuations do not appear, however, to affect practically an authoritative statement which has already been supported by the committee, and which, as it forms the key to the correction and calculation of compass deviations, cannot be too earnestly repeated; namely, that a a ship's magnetism for any given place may be very closely represented by a permanent polar magnetic force in combination with a quadrantal force, or one changing its deviation in each quadrant as a ship is swung round.""

Among the various philosophers who, during the present half century -a period noted for the progress of theoretical and experimental research-have grappled with the perplexing and, it may be said, uninviting science of magnetism, none more perseveringly worked for practical ends than the late Rev. Dr. Scoresby, and to him is due the enunciation of the notable facts, that the distribution of magnetism in an iron ship depends on the direction of the keel and head while building with reference to the magnetic meridian; and that this original magnetism is subject to great changes after launching, and also from other extraneous causes. The following from among the results of his investigations, as bearing on the subject, are worthy of extract. - (Magnetical Investigations, by the Rev. WM. SCORESBY, D.D., vol. ii. 1852, pp. 330-343.)

plank obtain necessarily an extremely high degree of 1. That ships built of iron in place of timber and magnetic development from the e'aborate system of percussive action, as well as from the bending of the plates and bars, during the progress of their con

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struction.

of the retentive quality, a quality remaining whilst 2. That the dominant magnetism thus developed is terrestrially sustained by consistency of position, and otherwise, also, in relations inaccordant with terrestrial influence, whilst the ship remains free from mechanical violence or other magnetically-disturbing force.

3. That in each iron ship there is a special individuality of the magnetic distribution, depending peculiarly on the deviations from uniformity in the essentially on the position-characterised by the direction of the keel and heac-whilst building, and placing of occasional heavy masses of iron.

4. That, after being launched, percussion, vibration, or the straining of the general frame of iron-built ships, must tend to equalise the relations of the ship's magnetisms with those of the earth; and that the state of equalisation or approximation thereto will be hastened and advanced accordingly as the quantity accordingly as the ship's head is kept pretty steadily or intensity of mechanica violence is increased, and in the same direction."

cording to Dr. Scoresby, the theoretic magnetic The accompanying diagrams represent, accondition of iron ships built in England, with the dip of the needle fron 68° to 70° N., previous to being launched.

The confirmation of Dr. Scoresby's views will be the committee no longer allow a doubt as to the seen from the following extract: "The records of connection which exists between the direction of a ship's original nagnetism and her position when upon the building slip. In all the ships which have been exanined, the north end of the compass-needle invariably deviated towards that part

of the ship which was farthest from the north while she was building, if the compass was placed in a central position, and free from the influence of individual masses of iron."*

The reports also further proceed to show that the characteristic features of the original magnetism of an iron ship, by which is meant the magnetism dependent on her direction when building, and the effect on a compass when she is swang, presuming that the needle is not influenced by iron bulk-heads, or proximity to the stern-post, rudder-head, or other masses of vertical iron controlling the magnetism of the hull of the ship, is as follows:

In an iron ship built with her head to the north, cr nearly so, there is no apparent attraction of the Leedle towards either side while she lies in a north or south direction: but with her head in all other directions there is a strong attraction towards the stern.

With ships built head to the south, the same principle will apply, the deviation being then towards the bow.

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from direct experiment; still there is a notable |
example deduced from the latter in the case of the
ship Royal Charter, which will be hereafter
alluded to. The conclusions arrived at are thus
given:-

This original magnetism of an iron ship is fre-
quently very permanent as regards direction, but is
believed to undergo rapid changes in its amount, both
in reality and in its apparent effect on the compass:
the most striking change being at and immediately
after launching, and during the first voyage. It is
usually more evident in a steamer than in a sailing
vessel. There are cases in which the deviations in a
steamer have changed so much as two points in the
first two days at sea, while afterwards the change has
not been more than 3° in as many months.
sailing ships the change is generally, but not always,
more gradual, and extends over a longer period. A
change of 10 to 15° is not infrequent."

In new

Again, Under some circumstances considerably more than one half of a ship's original magnetism, or rather that part of it which affects the compass, may be lost, or may become balanced in the course of a year.

And, After this early reduction of a ship's magnetism has taken place, the remaining portion, as far as may be judged from examinations made in the same place, and under the same circumstances, appears to be comparatively permanent.

In confirmation of this comparatively permanent condition of a ship's magnetism the committee give a striking example in the case of the ship Great Britain; and it may be permitted me of inspecting deviation tables of most of the iron to express my opinion, having had the opportunity vessels in H.M. navy, extending over many years' observations, that from this evidence also their permanent condition appears to be the rule.

When built with head to the east, the deviation
is towards the starboard side, (the south in build-
ing) and when built with the head to the west, to
the port side (the south in building): [this de-
viation must be considered as only due to a dif-
ferential action, for if a compass be placed near
the top sides of such ships either internally or ex-
ternally, the north end of the needle (in north
magnetic latitudes) is attracted; one side, however,
attracts he needle more strongly than the other,
and that is the side which was furthest from the
north when the ship was building, as above stated.]
In these vessels if placed in an east or west direc-
tion, the north end of the needle will tend to the
bow or stern respectively according to the direc-
This extraordinary ship has been stranded, and
tion in which lies the greater mass of iron.
strained, and altered; has traversed both hemi-
In ships built in intermediate positions the pre-spheres, and been very many years in active service:
ceding characteristics are combined; thus, if
yet her lines of no deviation are now much the same
built with head to the N.E., the attraction will be as Dr. Scoresby would indicate them to have been
aft and to starboard; with the head to the N.W., when she was upon the stocks. Yet how small is the
aft and to port. If the head be S.E. or S. W., the change! a proof, apparently, that no circumstances
attraction will be forward and to starboard, or can permanently conceal or greatly alter the direction
forward aid to port respectively.
of an iron ship's original magnetism.

The amunt of original magnetism appears to have relaton to the size of the vessel, or the quantity o' iron used in her construction, and is thus illastated:-" In a ship of 400 tons, built head to eas, if a compass be carried fore and aft on the midle line, about three or four feet from the deck, the deviation may be 10 or 12° when her head is north or south. In a ship of 1,000 tons it may under the same conditions be 25° or 30, or mor, depending to some extent on the breadth of the ship."

From a consideration of the foregoing illustrations, we ma; at once predicate the character of an iron ship deviation from a knowledge of the direction of ler keel and head when building, or, vice versa, from having her deviation table we may infer the direction in which she was built: the accompanyng table illustrates generally these conditions. Thus if

Approximate direc- Maximum Easter- Maximum Westerly deviation

tion of ship's ly deviation head (magnetic) when ship's head while building is, is near.

when ship's head
is near.
East.
S.E.

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South.

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S.W.

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S.W.

North.
N.E.

N.W. We have now arrived at an important feature of the inquiry-the ateration in the ship's mag

netism after launching-and which would still appear to require an extended series of experiments to elicit more precise information. Numerous examples are given by the committee, but derived more from informtion communicated than

This was exemplified b, diagrams, which represent the magnetic character of vabus vessels as determined by actual experiment at Liverpol while they were in dock,

The committee thus report on that well-known iron ship the Great Britain :

Liverpool in Sep-
tember, 1856,

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after alterations-0 19, + i 13, − °8 33, +6° 6, -8 19 Liverpool in Octo

ber, 1856... ...0 9,-4 55,-14 0, +6 41,-0 9 Enough has now been advanced to show the valuable nature of the investigations under review, but on the subject of the changes of original mag. netism in newly-launched iron ships there appears to be ample scope for further inquiry, both as to the possibility of there being some regular law of change, as also as to the probable time required for the development of its final permanency of character. The alarming change alluded to in the reports by the committee of "cases in which the deviations in a steamer have changed so much as two points in the first two days at sea, while afterwards the change has not been more than 3° in as many months," is from its amount and irregularity sufficient to embarrass the most careful navigator; it is certainly to be hoped that the cases on which the statement is based are excep. tional, and arising from the injudicious selection of a position for the compass (probably from close proximity to some ponderous mass, especially of vertical iron). I am certainly disposed to view them in this light from a consideration of the results obtained in the Royal Charter.

An important feature in the navigation of iron vessels, and one at the same time of a perplexing character to the navigator, are the changes of of some ships. deviation of the compass arising from the heeling

In wood-built vessels the errors from this cause

may be considered as in general too small in amount to be appreciable in practice, unless the compass is in close proximity to the guns or other masses of iron; but in iron-built vessels the results are not unfrequently of sufficient magnitude to call forth unceasing attention and vigilance. Our information on this head is for the present very incomplete; but some few leading points can be traced, sufficient to place the seaman on his guard and to draw attention to the general characteristics. Messrs. Rundell and Towson, the secretary and honorary secretary to the Liverpool committee, who have paid great attention to the subject, and made various experiments, are of opinion that

heeling affects to the greatest extent ships that are built with their heads to the north or the south; and that the effect on the former is to draw the north end of the needle to the weather side, the deviations reaching their maxima when the ship's head is north or south (by compass), and having little or no effect when the ship's head is east or west. In ships built with their head to the south, the north end of the needle will be drawn to the lee side, the maxima and minima deviations ob serving also the same conditions as those just described.

[Illustrations in support of these views are given in the Committee Reports of the lines as taken in a graving dock, January, 1856; again in December, 1856, after being for some weeks head N.N.E. in the same graving dock; as they appeared two days after with her head in the opposite direction; and again as determined twice in January, 1857, after undergoing constant hammering in almost every part for forty-three days.] The most instructive case of the rapid changes of magnetism in a newly-built iron ship is illus. trated in the case of the ship Royal Charter, whose deviations were carefully obtained prior to leaving England in January, 1856; at Melbourne in Australia, in May, 1856; and again on her return to Liverpool in August of the same year. These changes are well exemplified by a comparison of the values of the five co-efficients alluded to; the Much controversy has taken place on the proresults being selected from an extended series of priety and indeed safety of applying an antagoobservations, as made with an Admiralty standard-nistic force to neutralize that of the disturbing compass specially placed in aid of the experiments. effects of the iron in the ship: our highest magAt Liverpool in netic authorities differ on the point, though agreeing in the main theoretical principles as to The -027,-8 48,-19 42, +6 59,-0 52 the nature of the magnetic disturbances. Astronomer Royal is strongly in favour of correcting the deviation of the compass by opposing -127,-1 11, 859, +6 23,-0 26 forces of magnets and soft iron. Admiral FitzRoy,

Jan. 1856, pre-
vious to going
on first
Voyage
At Melbourne in
Australia, May,
1856

At Liverpool on
return, in Aug.
1856

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-0 3,1 6,- 322, +6 10, +0 56 the quadrantal deviation as represented principally We see here very distinctly the permanency of by the co-efficient D; and the gradual diminution of the sub-permanent magnetism, or polar-magnet deviation, in the co-efficients B and C.

Subsequent experiments in the Royal Charter indicate that the sub-permanent magnetism is approximating to its original amount; but, as some alterations have been made in the ship's fitments, the comparisons are not strictly identical;

and which will appear with the conclusion of this article, they are nevertheless well worthy of attention.

probably in our next number.

I propose now to enter somewhat briefly, as I have trespassed long on your attention, on the vexed question of mechanical adjustment for com

passes.

General Sabine, and Mr. A. Smith, supported by numerous nautical authorities, consider such corrections dangerous-except within certain limits, compass, to be considered a standard, fixed in an such as coasting navigation-and prefer a superior elevated position, convenient for careful bearings, as far removed as possible from the disturbing influence of iron, and using the binnacle compass merely as a guide to the man at the wheel.

The opponents of the system of compensation urge that it is defective in principle and dangerous in practice; defective in principle so far that it has not stood the test of experience in distant voyages to the southern hemisphere, and dan

gerous inasmuch as it inspires the unskilled and unwary seaman with confidence in the stability of that which is not proved to be stable, and places in his hand a power over the action of the compass-needle which he cannot control and of whose strength he is ignorant.

The advocates, on the other hand, contend that a fertile source of error in navigation arises from the unskilful use of the deviation tables, the corrections being frequently allowed the wrong way, by which the original error is doubled; also that the tables do not provide for changes of the ship's magnetism caused by change of geographic position or other circumstances; and again from the want of directive power of the needles under certain conditions of large deviation due to the ship's iron, combined with the earth's directive or horizontal force being small, as in the higher latitudes; which deficiency of directive power magnet compensation would remedy.

There are just reasons in all or many of these arguments, and the question appears more to resolve itself, as my subsequent remarks will tend to show, into one of application under varied but

certain conditions.

(To be concluded in our next.)

THE SMALL ARMS FACTORY AT
ENFIELD.

We record these facts because they are interest- | ship will be more exposed to submarine attack ing and satisfactory, and because we are anxious than any other large ship? And if not, would that in all cases there should be an appreciation not his argument have equal cogency if directed of services rendered by employés of the Govern- against the building of any and every kind of ment. It has been too much the practice hitherto large war-ship?-EDs. M.M.] for those in authority to becloud the merits of those beneath them, and in many cases even to decorate themselves with laurels earned by others.

Colonel Dixon, who is highly respected, and not more for his professional ability than his urbanity, has offered an excellent example in his late distribution of prizes at Enfield; and on behalf of all who are in positions similar to those of Messrs. Hayes, Hague, and Williams we desire to see that example followed largely. It is not improbable that ere long some particulars as to the rate of production at the Enfield Small Arms Factory may be given, with other facts in relation to the place.

DUNN'S PATENT CARPET CLOTH.
WE had occasion a short time since to allude to

this beautiful material, and the great interest which has been excited amongst manufacturers generally has fully corroborated our first opinion of it. That it will eventually supersede many of the articles now in use, from its great proximity to the appearance of carpet, in lieu of the present dirty substitutes, there can be but little THE very complete and extraordinarily interesting Messrs. Goodyear and Co., and now connected doubt. The patentee, who was formerly with machinery of the Small Arms Factory at Enfield Lock has been the theme of eulogium amongst with the eminent firm of Messrs. Blackwood and mechanical men for some little time past; and Co., of Bread-street Hill, has favoured us with anything in connexion with it cannot but be note- many details of this process, which is obviously worthy, in these times, to the general public. So destined to play a worthy part in the history of perfect are the contrivances there for the purpose It is certainly suggestive of a in view the rapid production of small arms of vast number of industries, as each individual inunerring accuracy-that it was thought by some terested in his own peculiar notions sees, even in that the force of invention could no further go. its present position upon the mere threshold of Every manipulative process, from the rough branch usefulness, some one or other profitable applicaof the tree and the crude product of the forge, to the finished stock and truly bored and rifled covered a mode of vulcanizing colours-a desidebarrel, together with all correlative details pertain-ratum which has occupied the attention for years ing to them, seemed to have been successfully past of some of the greatest chemists of Europe, and which, according to the scientific journals of provided for. Machines accomplished almost everything, whilst attendants but looked on, and the continent, was conceived to be unattainable.

visitors were amazed.

As it has been often said, however, "Nothing of human creation is quite perfect," so it has proved with regard to the machinery of the Small Arms Factory at Enfield. Improvements have been recently, and are now being made in the automaton machines at that place. There appears to be an emulative spirit at work among those engaged near them, which is sure to be productive of advantage, especially as it seems to be encouraged by those in power. There was one portion of the rifle which the manufacturers of Birmingham had pronounced beyond the reach of machine labour at all. This was the lock. Inventions and improvements, however, on the part of some of the foremen of Enfield have brought this important portion of the implement of war quite within machine range; and it is, indeed, completed almost without a touch from the hand of the mechanic. To Mr. C. F. Hayes, Manager of the Lock and Screw Department, belongs mainly the credit of this remarkable, and for the country very economical change; and certainly Col. Dixon, Superintendent of the Establishment, performed but a graceful act when, on Saturday, the 25th ult., he presented Mr. Hayes with a War Department prize of £30 for his ingenuity. The lock of an Enfield rifle is an intricate piece of work; the principal parts being the "bridle," the "swivel," the "tumbler," and the "hammer." It was in relation to these minute but yet consequential details that Mr. Hayes displayed his skill. On the same interesting occasion, we learn that Colonel Dixon, who was attended by J. Gunner, Esq., Inspector of Small Arms, G. Munro, Esq., Storekeeper, and Mr. Barnes, presented second and third prizes of £17 and £13 to Messrs. H. B. Hague and G. Williams, of the "Furniture" and "Sight" Departments respectively, for inventions in connexion with their branches of small arms manipulation.

manufactures.

tion. We are informed that Mr. Dunn has dis

THE STEAM RAM.

TO THE EDITORS OF THE "MECHANICS' MAGAZINE."
GENTLEMEN,-By the newspapers we are in-
formed that it is determined to build a monster
vessel, designated "The Steam Ram," which, from
the description of her, is intended to run over or
run down all swimming craft that she may upon
the ocean obtain sight of. Little short of £500,000
is to be expended upon her construction and equip-
ments. It may be presumption in me to question
the prudence of such undertaking, or the prowess
of this sea monster, but I would ask, How is she
to run, with a chance of swimming, among sub-
marine charges of gunpowder or explosive com-
position? Suppose, for instance, that she pursues
a steam-vessel-a mite of a thing in comparison-
armed with submarine explosive shells, suspended
by buoys at any desired depth below the surface
of the water; these shells may be regarded as
submarine vessels in tow. The steamer so armed,
upon being pursued, launches overboard one or
two more of her shells, towing them by suitable
ropes or chains. On comes the monster ram, and
runs into contact with one or more shells, which
are so constructed as to explode, by self-action,
only when in hugging contact with any vessel that
may be the object of attack or destruction. Now
the result of such a collision would, I confidently
predict, be the bilging of "The Steam Ram" to
an extent beyond repair; down she would, in
all probability, quickly go; and with her a crew
of not less, perhaps, than a thousand men In all
earnestness would I commend this matter to the
careful consideration of those whom it may con-
cern. I remain, Gentlemen, your obedient servant,

JOHN HARVEY, Captain R.N.

Sandgate, Folkstone, July.

[We do not quite perceive what conclusion it is towards which Captain Harvey would conduct us. Does he intend to imply that the new iron steam

SCREW PROPELLERS.

Captain Beadon, R.N., sends the following :TO THE EDITORS OF THE "MECHANICS' MAGAZINE." GENTLEMEN,-You remark in your magazine of the 1st instant in reference to recent experimental trials of screw propellers i H.M.S. Doris, that proof had been given that a blade formed of a fine flowing curve throughout would be more successful, as had been proposed by Sir Howard Douglas. I hope you will do me the justice to state that this is no other than the first and original form of screw propeller designed by me in 1834 to Captain Ericsson, keyed to a horizontal submerged shaft connected with steam power, and two years before patents had been obtained for the mangled principle either by Smith or Ericsson. On my return from China, in 1842, I again urged Messrs. Robertson and Co., whose opinion you its adoption. In 1845 I patented it through will see expressed in ten minutes reading, the last ten pages of which I devoted to illustrate the advantage of a curved blade, and its history, after exhibited the volute principle by a model at the actual experiment under steam power. In 1851 I Great Exhibition for six months, with a challenge I am, yours faithfully, appended. GEORGE BEADON.

Crichtarrow, Taunton, July, 1859.

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GENTLEMEN,-In your last publication I find two letters from Lord Carlingford claiming the merit of being the inventor of my patent screw propeller.

My first patent, including the large boss and tapered blades, was taken out in 1819; at that time I was not

aware there wis such a person as Lord Carlingford in existence, and if his lordship will read my specification of 1849 he may satisfy himself that I could not have taken any idea from him, and I am ready at any time to try the validity of my patent with him.

I am, Gentlemen, your most obedient servant, ROBT. GRIFFITHS. 69 Mornington-road, N.W., July 13, 1859.

THE GREAT EASTERN GENTLEMEN,-Your correspondent "A Reader," says that the employment of paddle wheels in this ship destroys her usefulness as a sailing vessel. This is erroneous. The paddle-whees are narrow, and small in diameter, in proportion to the vessel, and, being provided with disconnecting gear, I doubt whether two-horses power would be consumed in turning them when the vessel is going 10 knots under sail alone. The crew would consume a little more power, were it not provided (as I believe it is) with a small engine to keep it going just sufficiently to prevent drag. Although she will carry low rigging for her size, I think she will not only prove very hanly under sail, but will, as a sailing vessel, bea any other sailing vessel in existence. I am, Gertlemen,

Your very obedient servant,

1 Clifford's Inn, 12th July, 1859

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T. Mor.

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