has four openings through it, F F F F. An external elevation of this bush, detached from the rest of the pump, is given in fig. 16. D is a jacket, or casing, which surrounds the bush C with its four openings, F F F F, and communicates at one side with the water supply-pipe E. G is the outlet discharge-pipe, and H a ball clack valve, attached to it, which acts as a stopclack. The mode of operation will be Fig. 15.

obvious. On drawing up the ram B, the space between the bottom of it and the ballclack valve H is more or less exhausted of air; but as soon as the ram begins to pass clear of the openings F F F F in the bush C, the water rushes in from all sides into the exhausted space beneath it, and is by the return of the ram forced through the ballclack valve H, to a height proportionate to the force employed.

Fig. 17..

Fig. 17 is a longitudinal section of a double-acting lift and force-pump, on the same plan as the preceding, but with the jacket or casing in the centre; as in the case of the steam engine first before described. Fig. 18 is a cross section on the line o,p of fig. 17. A, is the barrel; B the piston, which is packed in the manner shown in fig. 17, and made of such depth in proportion to the length of the barrel, that at the termination of the stroke either way, the piston shall pass clear of the opening H. E E, a jacket or casing which surrounds the opening, H, in the barrel. F is the water supply-pipe, which terminates in a cistern or chamber F, which communicates with the jacket or casing E. G, is the deliverypipe; H1 and H2, the lower and upper ports of the barrel which lead to the delivery-pipe G; and I and 12, the clacks which com

mand these ports. As the pump is represented in the drawing, the piston is at the termination of its down stroke, and the upper part of the barrel filled with water, ready to be ejected through the upper port H2 and clack-valve 12. Supposing, therefore, the piston to be now drawn up, it will first close the middle opening H, and the space between the bottom of the piston and the clack-valve, I will be more or less exhausted; but as soon as the bottom of the piston begins to pass clear of the opening H, the water will rush in from all sides beneath the piston, while the piston, by its continued ascent, will expel the water in the upper part of the barrel through the port He and clack valve 12. On again depressing the piston, the reverse action will take place; that is to say, the upper part of the barrel will be exhausted; and when the top

of the piston passes clear of the opening H, water will rush in through that opening into the exhausted space, while the piston, on completing its descent, will expel the water in the under port of the barrel through the port H1 and clack-valve I1. And so the pump will go on working continuously, ejecting a body of water at every stroke, either from the upper or lower port of the barrel.

Should it be desired to obtain a continuous stream of water from a doubleacting pump, such as that just described, all that would be necessary would be to attach a short branch pipe to the delivery-pipe at K, and to mount an air-vessel thereon, in the same way as is done in the case of fireengines.

A

In both of the pumps which have been described, only stop-clack valves are used; but in figs. 19 and 20 a modification is represented, in which clacks are wholly dispensed with, and the inconveniences attending the use of such contrivances completely avoided. The pump here shown is supposed to be applied to a water-closet on board ship, in order to lift the water required and force away the soil, for which purpose it appears to be particularly suitable. Fig. 19 is a sectional elevation of the pump, and fig. 20 a cross section on the line, vw. and B are two barrels; the barrel, A, has two openings, Fi F2, on one side, at about the middle of its length, which are separated from each other by a partition, p. The opening, F1, is surrounded by a jacket or casing, E1, into which water is admitted by a pipe, O, from the outside of the vessel, whence it is forced into the basin, as afterwards explained. The opening, F2, is also surrounded with a jacket or casing, E2, which receives the soil, and from which it is afterwards ejected by the operation of the pump. A' is the piston of the barrel, A, which is made in proportion to the length of the barrel, of such depth, that whether it is at the bottom or at the top of the barrel, it shall cover only one of the two apertures, F1 F2. The barrel, B, is longer than the other, and fitted with two pistons, B1 B2, attached to one rod, and intermediately connected together in the manner shown. These pistons perform the office of two clackvalves, the upper one alternately opening and closing the top passage, H, between the barrels, A and B, through which passage water is forced from the barrel, A (through the barrel, B, and a recurved pipe, T, indicated in the figure by dotted lines), over into the soil-pan which is fitted upon the pipe, S; and the other one alternately opening and closing the passage, L, by which the soil which has been admitted

into the bottom of the barrel, A (through the opening, F2), is discharged into the river or sea. The piston rods of both barrels are connected to one crank-shaft, W, and so adjusted in respect to one another that as often as by the throw of the crank the piston, A1, is raised to the top of the barrel, A, it shall simultaneously open the passage from the soil-pipe, S, into the barrel, A, and force up a supply of water into the basin fitted on the pipe S; and as often as it is depressed (the piston of the barrel, B, being proportionately raised) shall close the passage, H, and open the passage, L, the soil being discharged at that instant through the nipe, M, into the sea. The pistons, B1 and B2, in order to answer the preceding conditions, must have a lap on each side equal to the depth of the ports or passage ways; and the proper depth to be given to these ports or passage-ways may be found by letting fall a perpendicular from the chord of 120° of a circle, whose diameter is equal to the stroke of the pump, which perpendicular (the sine of the chord) will be the depth required. The pistons also must be connected to the crank-shaft at an angle of 60°, and the connecting-rods, as also the throw of the cranks, must be of equal lengths.

ON THE FLAMBING OF SHIPS' BOWs. Sir,-The admission contained in the first paragraph of "B. I.'s" reply, is only what I expected from his candour, and he will permit me to trespass further upon it by asking him to read again attentively and dispassionately what I have previously written, together with this, as I am sure it will end our controversy.

In his second paragraph, alluding to my having said that the want of buoyancy was compensated for by the less weight and larger displacement of other of the foremost sections, he says, “this, I must confess, is contrary to my conceptions." Why, the very conditions of the question require that it should be as I state-that is, a certain waterline in each vessel is supposed, and does obtain, as the result of an equilibrium between the moments of the weights and the moments of buoyancy; the waterline being a condition, the weights can only be removed correspondingly forward and aft, and doing so, does not interfere with my position. True, if equal weights be moved equal distances in each vessel towards

their extremities then the total moments of inertia of their extremities will be increased equally; but the original difference in the amount of these moments will remain; that is, they will be greater in A, because of the greater displacement of the section for that from the centre of oscillation, and also the moments of inertia of the weight of hull will be greater in A, because of her wider decks, longer bow timbers, greater scantling of beams for equal strength with B, and greater area of planking. "B. I." says, "that B has the centre of gravity of displacement of the forebody nearer to the centre of gravity of the whole displacement, and that a greater force is necessary in order to lift or support the deficient section forward." Now, here it is, that "B. I." loses himself with respect to weightthere is no deficiency; were there so, there would not be an equilibrium-there would not be the given waterline, it would change; but a deficiency or excess arises the movement that equilibrium is destroyed by the water or by its absence, not by greater or less weight, but by greater or less buoyancy. The dimensions of the bow, A, above water, being greater, a greater buoyancy will be added by the wave, and because its dimensions are greater below the waterline, she will lose more buoyancy than B when this portion of their bows respectively, is in the hollow of an equal wave.

66

"B. I." says further, "When the crest of the wave arrives a little abaft the common centre of gravity, the falling moments, which are as the square of the distance from the centre of oscillation, will be much larger in the bow B." This is in direct contradiction of his statement just above, that B had the centre of displacement of her forebody nearer to the common centre of gravity." Now the moments of the weights must follow the moments of the water, or else we shall have a new waterline, and the moments of buoyancy of A being greater than the moments of her weights, must do so also; and therefore the moments of inertia, that is, supposing them equally well stowed, the form of B offers no difficulty to this, and, therefore, it is but rational to suppose an adherence to principles were possible; indeed, it is only the incorrect form that obliges a departure.

The following occurs in the fourth paragraph," The more sudden plungings, and very often entire burial of the sharp, yet heavy, bow in the waves." This is sheer prejudice; Sir William Symonds's latter brigs have had longer bows, and they have sailed better against a head sea. The Flying-fish, as compared with the Columbine or Pantaloon, further proves that which he states cannot be the case; with which, if he be not satisfied, I must recommend him a trip down the Channel in the Raleigh or Acteon, with a foul wind, a head sea, and a man of some nerve to put sail on the ship; if he be not bumped into a conviction, I would recommend the same trip, under similar circumstances, but in the Eurydice or Penelope-even the Constance.

Then " sharp yet heavy;" this is a contradiction-sharp, is of little displacement, therefore of little weight, and therefore not heavy.

"B. I." says, "F.' supposes the two

vessels under similar circumstances;" he should have added except form, and that difference involves a different position of the moveable weights; for where the greater displacement is, there must be also a greater amount of the disposable weights. I have already shown that the weight of the guns in a man-of-war is but a small item in the whole weight of a ship and lading, and yet it is only a very small portion of their weight that can be thought even to enter into this question.

"B. I." says, "the increased weight of hull being only as the increased breadth of decks;" this I have shown to be wrong-the overlooking the weight of hull, consequent upon change, of form has cost the country many failures. He makes a further statement, which is clearly an oversight, viz., "That the increase of displacement is as the cube of the breadth."

Again; "A sharper fore-body is believed to carry the centre of effort of the sails more forward." This has nothing to do with the question; for if the foremast be carried further forward, an equal weight must be carried correspondingly aft to preserve the water line. I deny, however, his position; the Navy affords as many proofs against as for the truth of his statement.

I may
take up this question as an im-

portant one, of which little or nothing is known in the Navy: our ships are masted, that is, the positions of the masts are chosen, by the Rule of Thumb-certainly nothing more intelligible.

"B. I." will allow me to thank him for his full admission that "the flambing form of bow is contrary to true principles;" but I cannot answer his question, "Are we not forced always to violate true principles in naval science, where so many opposite qualities are necessary?" in the affirmative; that which involves the necessity for a violation of principle does not deserve the name of science. I deny the position altogether, assured that if principles be violated, defects or failure will necessarily

ensue.

I am, Sir, yours, &c.,

F-.

LAW OF PATENTS.-REPORT OF THE COMMITTEE ON THE SIGNET AND PRIVY SEAL

OFFICES. (COncluded from p. 91.) | | It is impossible to ascertain with certainty when grants of letters patent for the sole use of inventions were first made in this country, but there is reason to believe that this prerogative of the Crown is very ancient.

The Crown derives this prerogative from the common law, and not from any statute. It is vested in the Crown as the depository of the supreme executive power of the State, to be exercised on the behalf and for the benefit of the public.

No statute is to be found relating to grants for the sole use of inventions prior to the statute of 21 Jas. I., c. 3, called the Statute of Monopolies.

That statute was passed for the purpose of restraining the Crown from making extravagant and illegal grants of monopolies. It declared all monopolies whatsoever to be contrary to law and void, excepting "letters patent and grants of privilege of the sole working or making of any new manufacture to the first inventor thereof."

The only other public acts relating generally to patents are the 5 and 6 Will. IV.{; c. 83; 2 and 3 Vic., c. 67; and 7 and 8 Vic., c. 69, which provide remedies for deficiencies in the old law.

The grants of the Crown must be made by charters or letters patent under the great seal, and the command given to the Lord Chancellor to make a patent for an invention is always by means of a writ, or bill, sealed with the privy seal, because the Queen cannot herself make her letters pa

tent except by means of her ministers, who act according to her legal commands; and therefore when the patent is written, the words "By Writ of Privy Seal" are inscribed, to show by what authority the Lord Chancellor seals the grant.

The present practice in regard to the granting of patents for inventions is, that, in the first instance, a petition to the Queen is left at the office of the Secretary of State for the Home Department. The Secretary of State refers that petition to the Attorney or Solicitor-General to consider and report thereon, in order that the Crown may be advised respecting the legality of the grant sought for, and the expediency of granting it. Upon the petition being left at the chambers of the Attorney or Solicitor-General, the title of the invention inserted in the petition is compared with the descriptions which are contained in all the existing caveats in the office. If the invention be not affected by any of those caveats, the patent is allowed to proceed; but if the title appears to relate to an invention which comes within the general description contained in any of the caveats, notice of the petition is sent to each party who has entered such a caveat.

A caveat against a patent is, in substance, a request in writing that a patent for a specified purpose be not granted without notice to the party who enters the caveat. Caveats may be entered at the chambers of the Attorney or Solicitor-General, at the Patent Bill Office, at the Signet Office, at the Privy Seal Office, and at the Patent Office of the Great Seal.

The following are the proceedings on a caveat before the Attorney or SolicitorGeneral at the report, or first stage :

The parties to whom notice has been sent are allowed seven days, within which they must enter their opposition, if they intend to oppose the patent. If no opposition take place within that time, the patent proceeds, as of course. If the patent be duly opposed, the proceedlings are arrested, and the applicant for the patent must obtain an appointment for a hearing before the Attorney or Solicitor-General, and a summons is served upon the opposing party.

After hearing the parties separately, if the Attorney or Solicitor-General be of opinion that the Queen ought to be advised to grant the prayer of the petition, he reports in favour of the petitioner, and the report is left at the Home Office in order to obtain the Queen's warrant. If the opposition be successful, no report is made, and the application drops.

The Queen's warrant contains Her Majesty's authority to the Attorney or Solici