migratory character of its meetings, which visit, for a week each year, place after place in succession, so as to indulge and stimulate all, without wearying or burdening any; in encouraging oral discussion, throughout its several separate sections, as the principal medium of making known among members the opinions, views, and discoveries of each other; in calling upon eminent men to prepare Reports upor. the existing state of knowledge in the principal departments of science; and in publishing only abstracts or notices of all those other contributions which it has not as a body called for; in short, in attempting to induce men of science to work more together than they do elsewhere, to establish a system of more strict co-operation between the labourers in one common field, and thus to effect, more fully than other Societies can do, the combination of intellectual exertions. In other Societies the constitution and practice are such, that the labours of the several members are comparatively unconnected, and few attempts are systematically made to combine and harmonise them together; so that if we except that general and useful action of the social spirit upon the intellect of which I have already spoken, and the occasional incitement to specific research, by the previous proposal of prizes, there remains little beyond the publication of 'Transactions,' whereby they seek as bodies to co-operate in the work of science."p. xlv. Sir William's first assertion we certainly shall not combat. Even an Irish meeting might well blame him for occupying their time in the "formal proof" of a proposition so very "evidently true" as that the Association "differs, in its magnitude and universality, from all lesser and more local Societies!" In his second, he is not so fortunate; he labours under a mistake in supposing that the Societies of London, for instance, confine their researches to matters within the compass of the bells of Bow-the "triple realm" is as much embraced by the plan of the Royal and other Societies as by that of the British Association, and there is scarcely any scientific Society of any pretensions in the kingdom whose 'gigantic arms" do not stretch to America and India, or even remoter portions of the globe. Does Sir William really' entertain the notion that all the F. R. S.'s (he is himself included) are dwellers in the land of Cockaigne-or that "Jemseetjee Jeejeebhoy," or the Pacha of Egypt (by way of example) are regular 66 metropolitan members' of the Asiatic Society? Assuredly not; a moment's reflection would have shown him that this peculiar characteristic of the Association is no peculiarity at all. The only real peculiarity is that next brought forward -the " migratory character of its meetings" and we have already seen how high a value is set upon this feature of the plan by no less competent judges than the Council of the Association; and, as to the "Reports on the State of Science," it is hard to discover in what especial manner the "principles of co-operation" has been exercised in their getting-up, seeing that each separate Report has been the production of one sole author, labouring in his own study, far away, both in time and place, from the social spirit-exciting meetings of which Sir William volunteers to be the chivalrous defender. Yet it is on these Reports, thus produced, that, singularly enough, the worthy President rests as the main strength of his defence. Returning to the charge, he observes: "We must still turn to this British Association, as the body which is corporative by eminence. The discussions in its sections are more animated, comprehensive, and instructive, and make minds which were strangers more intimately acquainted with each other, than can be supposed to be the case in any less general body; the general meetings bring together the cultivators of all different departments of science; and even the less formal conversations, which take place in its halls of assembly, during every pause of business, are themselves the working together of mind with mind, and not only excite but are co-operation. Express requests are also systematically made to individuals and bodies of men, to co-operate in the execution of particular tasks in science, and these requests have often been complied with. But, more perhaps than all the rest, the Reports which it has called forth on the existing state of the several branches of knowledge are astonishing examples of industry and zeal, exerted in the spirit and for the purpose of co-operation."-p. xlvi. It is even specially unfortunate that so much should have been said upon this topic in a speech which is made to take the place of a preface to the present vo. lume-since, as it happens, this "fifth Report" is remarkably deficient on that head. Both the third and fourth Reports included a considerable number of very valuable papers of this class, while this, with such a flaming panegyric in its 66 front, can only boast of three-and two of these are of such a nature as to reflect any thing but honour on a British Association." Desperate we may well suppose to have been the straits to which the Council were reduced, when we find they have procured only one original Report, that on the Recent Progress and Present Condition of the Mathematical Theories of Electricity, Magnetism, and Heat," by the Rev. W. Whewell-for insertion in a volume extending over a year in space. But nothing can justify the manner in which they have made up the deficiency, so far as it is made up; in the first place, by a Report "On the Phenomena of Terrestrial Magnetism, being an abstract of the MAGNETISMUS DER ERDE' of Professor Hansteen," by Captain Sabine; and, in the second, by a long essay wholly in the French language, and without a word of translation, "On the State of the Mathematical Sciences in Belgium !"-Aperçu de l'Etat Actuel des Sciences Mathematiques chez les Belges, par A. Quetélet, Directeur de PObservatoire de Bruxelles. Alas! for the British Association, if its most valuable feature be reduced to such a state of depression as this! What, has the wonderful co-operative tendency of its constitution so lost its power, that only one astonishing example of industry and zeal" can be produced in a whole year, after all the " working together of mind with mind" at the conversations in its halls of assembly-or has this "working together" so little to do with the matter, that, if the separate workers who have hitherto supplied this important department choose to stand aloof, the Council are forthwith compelled, for lack of better matter, to fill up their pages with a second-hand abstract of the investigations of a German professor, or, worse than all, with an essay by a foreigner, on a foreign subject, and in a foreign language? Is the " co-operative spirit" so weak, that it could not even produce a translation of this specimen of the labours of a British Association (represented in this instance by a sole and solitary alien) into the tongue of Britons? If this much-vaunted spirit be in so miserable a condition, in the name of British science let the Association drop this part of the plan at once, and not exhibit their pitiable poverty to the jeers of an unfeeling world. Ten times better would it have been, in the present instance, had pages 35 to 91 been left blank rather than occupied as they are; and, for the future, it would be far preferable to omit the "feature" altogether, rather than exhibit such a disfigured and scarcely-recognisable apology for it as disgraces the present Report. It is some consolation, under the circumstances, to find some improvement in another branch, counterbalancing in some degree the woeful falling off in this. Under the head "Researches undertaken at the request or suggestion of the Asso ciation,' we are presented with a considerable mass of information on a variety of subjects, offering altogether a complete contrast to the meagreness of the preceding section. We have to regret, as usual, that but too little attention is paid throughout to practical science; the only contribution to this department of any consequence in the volume is the elabo rate Report on the "Impact upon Beams," by Mr. Eaton Hodgkinson, who has performed a very extensive series of experiments on the subject at the desire and expense of the Association. The remaining principal papers in the division of "Researches" are, "On the Direction and Intensity of Magnetic Force in Ireland," (which is illustrated by several maps, which reflect the highest credit on the engravers of Dublin), by Dr. Lloyd, Captain Sabine, and Captain Clarke Ross, the discoverer of the Magnetic Pole ;"On the Radiation of Heat," by Mr. Hudson, of the Royal Irish Academy; "On Acrid Poisons," by Drs. Roupell and Hodgkin;" and two interesting collections of meteorological data" the Quantities of Rain falling at different Elevations at York," by Mr. Gray and Professor Phillips; and "Hourly Observations on the Thermometer at Plymouth Dock-yard," which have been procured by means of a small grant from the funds of the Association for that purpose, placed at the disposal of Mr. Snow Harris. We need hardly say that the contents of the concluding portion,-that on the proceedings of the sections, which is paged separately from the rest, are of little value. The notices are generally so short as to afford scarcely the means of even collecting what are the views and opinions advanced, and in many instances not so much as a word of explanation is given, -nothing more than the bare title of the paper read; such is the case with a paper which promises some interest to mechanical readers. "On Certain Points in the Theory of the Construction of Railroads," by Dr. Larduer and C. Vignoles, Esq. What these points were, and in what manner they were treated, must be gathered from other sources, for not a syllable is vouchsafed on the subject in the Report. TIMBER RAILWAYS. Oak and Screws versus Fir and Nails; and Concrete versus Loose Gravel. * Mr. Vignoles, civil-engineer, has published, in the form of a Report to the Directors of the Midland Counties Railway Company, a plan for making the upper works of railways; by adopting which he proposes to save, in two trackways, from 800l. to 2,2001. per mile. He might have said much more; and I fully concur in opinion with him, that "a more economical and better mode of construction might have been adopted by the Directors of the London and Birmingham, and other principal railways now in the course of construction," than that to which, despite the Report of Professor Barlow, and the other warnings they have had, they seem by some fatality resolved to adhere; in which opinion, I unhesitatingly assert, the shareholders in the London and Birmingham railway will also concur when, at no great distance, they will be informed that the Directors must have fresh powers, either to issue an additional number of shares, or to borrow additional sums on mortgage, either being to the manifest detriment of the original shareholders, over whom the money lenders, in whatever form they may present themselves, will have a decided advantage. It is now too late for the shareholders of the London and Birmingham Railway Company, and those of the other railway companies alluded to by Mr. Vignoles, to profit by his ju dicious, though sarcastic reflections; but other companies may take the hint, and avoid the rock on which their inexperienced, if not obstinate, predecessors have split. Mr. Vignoles, however, understands theories somewhat better than making calculations and estimates; for he writes *See Mechanics' Magazine, No. 701. down the cost of a stone sleeper, of five cubic feet, (which weighs from six to seven cwt.) 4s.; whereas the lowest price at which granite, or other equally hard and suitable blocks, can be procured at any quarry, is about 1s. per foot; and, whereas the cost of transport from the quarry to any spot on the London and Birmingham line, cannot, upon the average, be less than 20s. per ton, which is 6s. 6d. per block. I know that 7s. 6d. each is asked for Yorkshire blocks (not granite) in the River Thames; to which price are to be added lighterage, unloading into canal beats, canal conveyance to loading, and cartage to the railway, and the spot nearest to the railway; landing, hawling along it, (perhaps some miles,) to the place where the blocks are to be laid down. Mr. Vignoles' plan is to use fir planks, nine inches wide, and four and a half thick, bedded on ballasting, which is loose gravel, as a continuous support of his frame-work, on which are mounted rails, at the top resembling the rails at present in use, though their base is five inches, and they weigh 48lbs. per yard. Now, as this gentleman advocates the continuous support of the rails, and represents wood, even fir, to be a much better bearer for rails than stone blocks, it is singular that he should not have called the attention of the Directors of the company in question to my plan, of which these two objects form so promi nent a feature. Of its superiority over the existing mode of construction, we have (at least in reference to these objects) a decided confirmation, as Mr. Vignoles, in respect to theory, is held to be an authority. Mr. Vignoles intends to hold together the two longitudinal bearers for each track-way by wooden girders, at a short distance apart, so that the whole will form a frame, something like a huge ladder: and to secure the rails to the frame-work by nails or spikes; and if wrought-iron rails are used, each track-way, (that is two rails for a carriage to run on,) will, ac cording to his estimate, cost 22s. per yard, or 11s. for a single line of rail. Whether loose stones will constitute a continuous, solid foundation, especially on clay and other soft earth; and whether any dependance can be placed on the stability of the frame-work, that is, its continuing an absolute fixture, consider ing the nature of the trial to which it will be subjected, I must leave the public to judge, entertaining the opinion, that a decided preference will be given to bearers buried in and consolidated with a bed of concrete; two feet or more wide and deep, and which, for solidity, strength, and durability, will resemble a continuous rock, the whole length of the road. Then, the species of wood to be cmployed for bearers. Mr. Vignoles is for fir, which after being kyanized, he supposes will last seven years; but I am for oak, which after undergoing the same process, will last seven times seven years; and during this period no interruption be occasioned to the traffic, by taking up old bearers and putting down new ones. Again, Mr. Vignoles will secure, (that is, if wet, dry, and hot weather permit,) the rails to fir bearers by nails; but screws in oak bearers render my plan independent of the influence of the weather. Now, as to price: Mr. Vignoles' plan costs 11s. per yard; but I have made known that the maximum price of mine will be 10s., though in many, perhaps in most parts of the country, the price will not exceed 8s. per yard, even if it does 7s.; and were Memel fir to be used instead of oak, and nails instead of screws, a further diminution of 1s. per yard might be made. But who that reflects would thus economize? Mr. Vignoles' iron rail costs 5s. 7d. per yard, but mine only 1s.; and where he uses four feet of fir, I use only one of oak. He has no means for the bars to expand and contract, but upon my plan this advantage is enjoyed. In conclusion, I thank Mr. Vignoles for his publication, which, on account of its theoretical data, I deem of great value. THOMAS PARKIN. Patent Rallway Office, 31, Broad-street-buildings, Jan. 16, 1837. MR. PINKUS'S IMPROVEMENT (?) IN HIS PNEUMATIC RAILWAY. In our 612th Number we 66 nipt i' the bud" as promising a speculation upon the credulity of share-buyers as was ever advertised. It did not, however, come under our notice until the plausibility of a working model had worked upon the pockets of some, and the paid for opinions of certain opinion-giving doc tors upon those of others. The miniature railway was a good hit, and told well; there are so few who understand the relation between a machine and its model. Mr. Pinkus, convinced in spite of himself (whether by our remarks or not, we aver not), that his plan would not do; and seeing, also, that this began to be the opinion of some who had at first supported him, he bethought himself of another, and what he calls an improved plan, for which he forthwith took out Letters Faent. Upon this new plan a short experimental line has been commenced by the side of the Kensington Canal. The air-mains or tunnels, however, have been lying there some time, and are becoming rather rusty -operations having for some reason or other been suspended. We hardly know whether it be worth while to enter into the details of a plan, the foundation of which we hold to be absurd; but as Mr. Pinkus evinces considerable ingenuity in his improvement, we shall shortly describe it. He altogether dispenses with the travelling diaphragm, and diminishes the size of his air-tunnels to a fourth of what was originally proposed; in fact, the air-tunnel is the only feature common to the old and new plans. As we before observed, the travelling diaphragm is now altogether dispensed with. The railway is to be divided into sections of five miles length; at each of which lengths there is to be a fixed steamengine, working air-pumps. The diameter of the mile and quarter of air-main next each station is to be of 11 inches, and the middle 2 miles, to be of 9 inches. The pumps at each end act upon the air in the tunnel, continually rarefying it, as it is thrown in by the working of the locomotive-apparatus. The main is to have an opening in the upper surface two inches wide; on to the edges of this opening are to be attached plates, forming what Mr. Pinkus calls a "metallic valve," made of an amalgam of iron and copper, hard rolled to make it elastic, 4th of an inch thick at the lower edge, and that the upper (the insides of which are to be polished smooth), and four inches high. The annexed cuts will show the thing more clearly. Fig 1 is a plan of the valve, and fig. 2 a cross section of the air-main, with the valve attached, and the tongue (afterwards described) between the lips of the valve. In both figures a a are the lips of the valve, a Fig. 1. g Fig. 2. .... which it will be seen, in their undisturbed state, by their elasticity press upon one another and form an air-tight joint the whole length of the main. Working between the lips of this valve is a hollow metallic tongue (b, fig. 2,) the shape of which is seen in fig. 1; the sides of this tongue, in contact with the lips of the valve, are polished, and the tendency of the latter to collapse by their spring, pressing upon these polished sides, as they pass along makes the joint air-tight. This hollow tongue forms a communication through throttle-valves with a condenser or vacuum-vessel; and this vacuum-vessel communicates through alternating openings (somewhat similar to those used in steam-cylinders, and worked by an eccentric from the crank), with two cylinders, in which work pistons, whose rods turn cranks, which give a rotary motion to the wheels of the locomotive. The mode of action is as follows:-The air in the main is kept rarefied by the exhaustingengines at each end; a communication being made between it and the rarefied air or vacuum vessel, by opening the throttle-valve-and between the vacuumvessel and the cylinder by the sliding passage, a partial vacuum is formed under the piston, which the outward atmosphere forces down, giving half a turn to the crank; the alternating airpassages are then reversed-the other piston is acted upon in the same way— and a revolution of the crank, and consequently carriage-wheel, is completed. The cylinder-full of air, after having forced down the piston passes into the vacuum-vessel, and through the hollow tongue into the main, from which it is pumped into the atmosphere by the stationary-engines and air-pumps at each end of the five-mile section. As the tongue passes forward between the lips of the valve it will open a passage for itself, which will immediately close behind it by the elasticity of the plates. The tongue is prevented from becoming hot by friction by the current of cold air constantly passing through it from the cylinders. This, we believe, is all of Mr. Pinkus's specification, which is wanted to give our readers an idea of his improvement-there are several minor points which it is unnecessary for us to refer to. Our readers will perceive from the foregoing sketch that Mr. Pinkus's said improvement is worse than his original plan-inasmuch as he has added complication of parts and weight of machinery. We could suggest an improvement, whereby Mr. Pinkns would save air-pumps and steam-engines at each end of his five miles. Let him make his vacuum after Savery's plan, |