amount of wages paid or proposed to be paid. But strikes very seldom achieved the object sought; and it became their duty to inquire if, in the few cases where success was possible, that success could be equally secured without resort to this terrible engine of strife and suffering. Examples were then given of eight unsuccessful strikes, which represented the amount of wages lost at £1,082,650, profit lost £210,602, subscriptions £270,617, making a total of £1,563,869. All these strikes have terminated unsuccessfully; so that there has been no compensation for the loss. If these sacrifices were necessary, the endurance of the working-classes would command admiration; but he could not admit the justice or desirability of a restriction which prevents a parent and an employer from mutually arranging to bring up a youth to a good trade; he could not admit the wisdom of shutting out an efficient workman because he had not been apprenticed; nor could he see why any society should dietate the price of labour. With regard to the establishment of an arbitration court for the settlement of disputes, he suggested that it should be honorary, that the parties to the dispute should each name an equal number of jurymen, that the County Court judge for the district should be president or umpire, and that the business of the Court should be conducted without lawyers. A bill giving power to the Lords of the Treasury to arrange such courts on petition would restrict them within useful limits. Adverting to the establishment of cooperative societies and manufacturing companies with limited liability, he said the prospects they held out ought to stimulate prudential habits, and so improve the moral tone of working men. The operations of such societies would also supply a sort of wages barometer, showing what amount it is prudent to pay, because the conductors could have but small interest in paying too low a wage, since what is not paid in wages will be in profits, and the amount of profits declared would, in times of steady trade, also influence wages for the next half-year. If these societies prospered, we might see individual employers in self-defence constituting their workpeople partners in profits. But they had still to stand the test of "hard times," and they could not be expected to pass scatheless through a crisis. He concluded that strikes to restrict the number of workmen in a trade ought not to succeed, and that strikes against improved machinery were attempts to prevent the development of human intellect and the progress of civilization; and generally he concluded that strikes were wholly injurious, an entire waste of effort, to the extent of not less than a million of pounds sterling annually, or the bread of 38,460, with 4000 to 5000 additional who would be required by the profits lost through strikes. Improvements in the constitution of trade societies would, he thought, prevent many strikes, and would secure the support of employers for these societies; that cooperative societies, by teaching prudence, will be useful aids; and that an honorary and voluntary court of arbitration would amicably settle such disputes as might remain.

MECHANICAL SCIENCE.

Address of J. F. BATEMAN, C.E., F.R.S., President of the Section. To those who favour us with their attendance for the first time, it may be sufficient to say that the object of the Section is the promotion of mechanical science in a wide sense; for to this Section also stands referred all questions of civil engineering, which, although they may in themselves be only remotely connected with mechanics, yet depend for their successful issue upon the proper application of mechanical knowledge. Indeed, it would be difficult to say to what material pursuit in life mechanical skill is not of primary importance. In Manchester especially this Section should be well supported; for in this district have been born or have resided some of the most distinguished projectors and inventors of the age-men whose ingenuity and labours have conferred incalculable benefit upon the world-such men as the Duke of Bridgewater, Sir Richard Arkwright, and Samuel Crompton, in days not long gone by, and whose places have been well filled by the inventors and mechanics of our own time. Amongst the questions which have recently attracted popular attention, and which are specially deserving of the consideration of the mechanical men of the day, are the improvements

which are taking place in the construction of artillery, and in the antagonistic work of protecting the vessels of our navy from the terrible destruction to which they are exposed by the superior power and longer range of the guns which can now be brought to bear against them. It seems, at first sight, almost a matter of regret that our inventive faculties should be strained to the utmost to produce the most deadly weapon, and to ensure the most certain and extensive destruction of human life; but there is no axiom more true than that of a late great commander, that "the best security for peace is to be well prepared for war." On the subject of gunnery and ship-armour, we shall be fortunate in having the presence of many of those who have taken leading parts in their construction or improvement, and in the experimental and scientific investigations of these important questions; but I am sure that the Section will join me in the expression of deep regret that one amongst that number, second to none in mechanical skill, in successful results, and in indomitable perseverance, no less a man than that distinguished Manchester citizen, Mr. Whitworth, is prevented being here by serious illness. I trust it is only temporary, and that he will yet live many years to enjoy the profits and honours of successful enterprise. In the model-room, however, will be found one of his powerful and beautiful pieces of ordnance, and an armour-plate, four inches in thickness, pierced by the bolt discharged from his 12-pounder cannon. We are also to be favoured with some of the plates and other illustrations of the recent highly-important experiments at Shoeburyness, which, I trust, will be accompanied by explanations by our President, or by other members of the Association who have taken part in conducting these experiments. The respective merits of the various inventions which are now exciting attention, and the various modes of constructing ordnance and ship-armour will thus, I hope, be brought fairly and fully before the Section. The anxious attention of those most interested in the management of railways was, during the late very severe winter, when the thermometer fell in some places 10° or 12° below zero, unexpectedly directed to the sudden and numerous fractures in the tires of the wheels of the carriages and engines. The cause of these fractures, and the best mode of preventing similar occurrences in severe cold are matters of public importance, and fit subjects for notice and discussion in this Section. But serious as were the dangers resulting from the intense cold of last winter, they are as nothing to those which appear to attend the benefit of railway travelling by the excursion trains of the summer. Within the last few days we have been horrified by the accounts of two of the most disastrous accidents which have occurred in this country. As to the cause of one of these we have as yet but vague particulars. The other seems to have resulted from a failure in the working of the signals, and from a want of perfect understanding between two signalmen. Another subject which has recently attracted attention, through the terrible and disastrous conflagration in Tooley-street in London, is the extinction of fire. The powers which now exist for this purpose, with the methods which are adopted, would form useful topics for consideration; and such notices as will illustrate the most approved methods of preventionwhether by the adoption of plans of fireproof construction, or by the judicious application of water-could not fail to be both interesting and instructive. Manchester has fortunately been comparatively exempt from calamities of this nature; and there are peculiarities in the means adopted for their prevention which are deserving of attention. In those parts of this city in which protection against fire was most important, the dimensions and arrangements of the pipes were determined with special reference to these circumstances. In place of the old wood plug, a simple fire-cock, by which almost instantaneous communication could be made with the water in the pipe, and to which a hose and jet could be attached, was adopted, and the fire-engines were rather used as carriages or omnibuses for the conveyance of the firemen and their implements, than for actual use at a fire. Nearly every block of building in Manchester is commanded by at least a dozen fire-cocks within 100 yards. The question of the patent laws, and their bearing on the encouragement or discouragement of mechanical invention, will be prominently brought before the Section, and, I doubt not, very ably discussed by some of our most eminent men, who have specially considered the effect of protection. It is proposed to devote, if necessary, the whole of Friday to this important and interesting question. Many other matters of interest and importance will, I hope, be

brought before the Section; and in the discussion that may arise on steam, on the best form of vessels, on the ventilation of coal mines, navigation, and the other subjects to which the papers before us promise to draw our attention, I trust we may all derive instruction and advantage, and find that the bringing together of people from all parts of the country for friendly discussion, and for the mutual interchange of knowledge, fully carries out the object of the Association for the Advancement of Science.

On the Patent Laws. By Sir W. G. ARMSTRONG, F.R.S.

Several instances within the author's experience were referred to of the obstructive operation of the law which enables an individual, before he has put his invention into a practical form, to obtain a monopoly of the idea and then put a stop upon all others who are directing their attention to the same subject. The obstructive tendency of the Patent Laws is aggravated by the fact that, in addition to the patents which are legally valid, there is an enormous number incapable, if properly opposed, of being enforced at law, but to which people quietly submit in preference to troublesome and expensive litigation. This is a necessary consequence of the patents being indiscriminately granted to all applicants without investigation; and it would be difficult to remedy this evil by any practical preliminary inquiry. The number of patents, valid and invalid, is perfectly frightful; and it is impossible to make out with any certainty what one is at liberty to invent or use. The author pointed out the difference between copyright and patent-right: though both ought to protect the product of a man's mind, copyright neither created impediment nor injustice, while patent-right did both. It could not be disputed that the Patent Laws, in restricting the free use of ideas, obstructed invention, if, on the other hand, they encouraged it by holding out rewards. Thus the most that could be said was that they pulled opposite ways; and this could be no warrant to justify arbitrary interference with liberty of action. Although the Patent Laws ought to be discussed solely in reference to public policy, it would be harsh to exclude from consideration the interests of the inventor. He contended that as a rule an inventor would obtain sufficient reward without giving him exclusive rights. If the monopoly were withheld, the inventor got the start of all others; and the presumption was, that, understanding his subject better than others, he would keep the lead. The public have great faith in a name; and a reputation duly earned is not easily lost. Under any state of the law, hardships of inadequate reward must occur; and these cases he considered should be met by grants from the State. He instanced the inventor of the screw-propeller, who was unable to obtain any advantage from the law, whilst another person, who conceived the simple idea of enabling postage-stamps to be easily separated by punching a series of small holes between them, was placed in a position to obtain an exorbitant recompense from the Govern

ment.

The author, whilst he admitted that the law was capable of amelioration by having special tribunals for the grant and trial of patent-rights, compulsory licences, and the abolition of the right to patent foreign inventions, yet he regarded the whole system as unnecessary and impolitic, and could see no other complete remedy for its evils than its entire abolition.

Railway Accidents, from Trains running off the Rails. By G. ARNOTT, M.D. Inasmuch as the inertia of moving bodies causes them to continue in a rectilinear direction, and when revolving in a circle this inertia produces what is termed centrifugal force, the flanges of the outer wheels of a locomotive, in rounding a curve, are by this force necessarily brought in contact with the outer elevated line of rail, the projections of the tires or flanges forming the chief resistance to their tendency to move off at a tangent. When in this relative position, however, should any disturbing force exist or arise, particularly one which produces a "jumping" or rebound of the moving body, such as will elevate the flange to the level of the rail, a catastrophe, if the train is going at ordinary speed, becomes inevitable.

Now, as the safety of the train so materially depends upon the flange, this should be considerably deepened, and the rails also, where necessary, in a corresponding

degree. If a flange of ordinary depth is occasionally dangerous, one of double the depth, of proportionate strength, will prove in comparison more than doubly safe; and in case even of a defective condition of a sleeper or rail, the more powerful gripe of an enlarged flange will most materially lessen the risk of diversion.

On Elongated Projectiles for Rifled Fire-arms. By T. ASTON. After alluding to the improvements that have been made in war projectiles, which have resulted in the elongated form, he proceeded to notice the advantages which it possesses over the old spherical shape. The elongated projectile, presenting to the resisting atmosphere a sectional area considerably less than the spherical of the same weight, is less retarded in its progress through the air. It follows, therefore, that, although the spherical projectile with a similar charge of gunpowder is more easily set in motion, and has a greater initial velocity than the elongated form, and to that extent has at the outset an advantage, the elongated form is much better able to overcome the resistance of the atmosphere, and, owing to its superiority of momentum, preserves its progressive power for a much longer period; at the same time, it is less disturbed by the varying conditions of the elastic medium through which it is propelled. In short, it has a longer and truer flight. The essential condition to the efficiency of the long projectile is, that it shall move onwards with its point foremost; if it turns over in its path, it presents a large surface to the action of the air, its flight at once becomes irregular, and is rapidly retarded. The action of the common spinning-top suggests at once the idea that the best mode of making the elongated projectile move steadily through the air with its point foremost is to give it rotation round its axis of progression. The rapid revolution of the body causes its inherent inequalities to be rapidly carried round a constant axis in regular order, and a kind of balance is thereby established, which gives the body a steady motion. Various plans have been from time to time tried with the object of imparting to long projectiles a steady flight; they have been made with spiral grooves cut externally on their periphery, or internally from front to rear, in the expectation that the resisting action of the atmosphere acting on the inclined surfaces would give the requisite spinning motion. Again, they have been made very long and furnished with fins or feathers, in order that they may be propelled on the principle of the arrow, but no practically successful results have as yet brought projectiles of this kind into use. The required object is, as is well known, readily and successfully effected by propelling the elongated projectile from a rifled barrel, that is, a tube having its interior made of such a spiral form that the projectile while it is propelled from the breech to the muzzle is turned round its axis of progression: a rotatory motion is thus imparted, which is retained by the advancing projectile and gives it the required steady motion. The elongated bullet was first used with rifled small-arms, either poly-grooved or fluted, or, like the Enfield, having three grooves. The length, however, was limited; and various attempts were made to fire longer projectiles compounded of various metals and of various shapes, so that by changing the position of the centre of gravity they might be propelled point foremost. But, if made beyond a certain length, they were always found to turn over at moderately long ranges. Mr. Whitworth was the first to enunciate the principle that projectiles of any requisite length could be successfully fixed by giving them rapid velocity of rotation, which should be increased in proportion with their increased length. He, as is well known, uses rifles having a spiral polygonal bore, in which all the interior surfaces are made effective as rifling surfaces. The success of the elongated projectile having been established in the case of small-arms, their employment with ordnance followed as a natural consequence. Rifled ordnance were, therefore, called into existence to meet the requirements of the time. In fact, the rifled cannon may be considered as a rifled musket made with enlarged proportions. Directing our attention more particularly to the two systems of Armstrong and Whitworth, we see in the former the coiled barrel and fluted bore formerly used for the rifled small-arm, applied on an enlarged scale. In the Whitworth cannon the same system and form of rifling are used which are employed for the Whitworth musket. There is, however, a change required for the projectiles; they cannot, like the small-arms bullets, be made of lead, for obvious reasons, such as the cost of the metal, its liability to distortion of

form, and unsuitableness for shells. Sir William Armstrong uses a compound projectile, formed of an iron case surrounded with a leaden coating-the rifling being effected by the force of the explosion in the barrel, which is thus partly expended in forcing the lead through the grooves. Mr. Whitworth uses a simple hard-metal projectile, made of the requisite shape to fit the rifled bore by machine labour in the manufactory; so that the whole force of the explosion is employed to propel the projectile. After giving a description of the two projectiles, and pointing out that the Armstrong projectile necessarily required a breech-loading cannon, and that the Whitworth is used at pleasure for muzzle-loading or breech-loading cannon, Mr. Aston proceeded to notice the external shape of the projectiles. The importance of giving to ships intended for high speed the shape best suited to facilitate their progress though water is now universally acknowledged; and Mr. Whitworth considered that it was necessary to ascertain, by reasoning upon similar grounds, and by experimental research, what was the proper shape to give to his projectile, so that it might be propelled through the air under conditions most favourable to precision and range. He, after numerous corroborating experiments, decided that the projectile of the form exhibited to the Meeting was the best. It has a taper front, having nearly the external section of what mathematicians term the solid of least resistance, the curve being somewhat rounded; the rear is made to taper in such proportion that the air displaced by the front is allowed readily to close in behind upon the inclined surfaces of the rear part. The middle part is left parallel to the required distance, to provide rifling surfaces and obviate windage. The results of long and repeated trials show that this form of projectile gives much greater precision and a superiority of range, varying from 15 to 25 and 30 per cent. (according to the elevation and consequent length of range), as compared with a projectile of the common rounded front and parallel rear end. At low elevations, where the range is comparatively short and the velocities great, the difference in the result of the taper and non-taper rear is not so marked as at the higher elevations, where the mean velocities of the projectiles are reduced. But at all ranges the superiority exists both in precision and velocity, as the elongated projectile at no practical range has a mean velocity so great as to prevent the atmosphere closing in behind it. One of the most important advantages attending the use of the taper rear is, that it gives a lower trajectory, which renders errors in judging distance of minor importance, as the projectile which skims along near to the ground is more likely to hit a mark, especially a moving one, than a projectile which, moving in a more curved path, has to drop, as it were, upon the object aimed at, whose distance therefore must be accurately guessed. The taper shape of the rear is peculiarly well adapted for the proper lubrication of the gun, which is most essential for good shooting. With the Whitworth gun a wad made wholly of lubricating material was introduced; it obviates the necessity of washing out the piece, and the subsequent adoption of a similar wad for the Armstrong gun enabled that piece also to be used without washing out, which was at first necessary and found to be a very inconvenient operation for a service gun. Various forms of elongated Whitworth projectiles suited for special purposes were described: tubular projectiles for cutting cores out of soft materials, as the sides of timber ships; flat-fronted hardened projectiles, first used by Whitworth and afterwards by Armstrong, for penetrating iron plates. It is found that these projectiles penetrate, when fired point blank, through iron plates inclined at an angle of 57° to the perpendicular. The edge of the flat front, though slightly rounded, takes a hold, as it were, as soon as it touches the plate, and the resistance met is merely that due to the thickness of plate measured diagonally. Official experimental trials made on board the Excellent,' at Portsmouth showed that these projectiles penetrate readily through water, and would go through a ship's side below water-mark. The new American floating battery, which is submerged to protect her sides during action, would find no defence in that plan against these projectiles. Shell and shrapnel having the elongated form and taper rear were also described; and to show the suitableness of that form for ricochet firing, tables were read, from which it appears that the mean results of a series of six shots, making many ricochets within a range of 2400 yards, gave the greatest mean deviation of about 75 yards from the straight line. In considering the probable result of the contest now going on between armour-plates and projectiles, it should be borne in mind that the limit