ab's being the direction of the cleavage, and all parallel or nearly parallel to each ather, dipping to the south; and, indeed, as well as in all other quarries which have been observed, with a bearing very nearly magnetic, east and west. It therefore appears clearly from this, that the cleavage can be in no way regulated by what appears to have been originally the strata of the slate rock material, as indicated by the stripes, and the great joints parallel thereto. Since this was observed, indications in other quarries have been perceived, from which it may be inferred that a like connection between the feet and the backs may ultimately be traced. From these and other appearances, perhaps it may be inferred that the slate rock material was once in a plastic state, and that the property of cleavage occurred subsequently to the period when the mass hobtained the position in which it is now found. In some of the feet an appearance has been observed as if the material in the plane of the stripes had moved while in a plastic or disunited state. This will perhaps be better understood by supposing a number of quires of paper, say, alternately a quire of plain and a quire of gilt edged and the gilt or plain having moved, they project one before the other, not unlike what in building is called The direction of the cleavage in some of the feet just alluded to is a little changed, although the general cleavage of a large block may be very nearly a plane, yet at every stripe a slight deviation takes place, forming a ridge. The material of the stripes is not only of a finer texture, but it is something harder than the other parts of the slate rock. The cleavage is also in some places altered by the nodules, and the occur rence of other harder or different material by which a carved and uneven surface is produced. The largest nodules that have been observed, are 2 feet long, 16 inches Fig. 4. D Fig. 5. 58 KIRKBY SLATE QUARRIES. broad, and 9 thick, with an appearance similar to the sketches, figs. 4 and 5; the transverse section being oval. The nodules are striped like the ordinary slate material in which they are found embeded; but they are either much harder than the slate, or otherwise they are as soft, and not unlike generally brown rotton stone. Indeed, one of the large nodules alluded to was partly sound and partly rotten. There is no reason, however, to suppose that the hard parts would, by exposure to the atmosphere for any known length of time, become soft. Side Seams. Besides the joints which are parrallel to the stripes, there are others which cross them. The greatest of these are called side seams, the bearing of which is nearly north and south, and the dip at a very considerable angle to the east. Whereever a side seam has been discovered, it has been found to extend through all the feet or backs as far as the quarries have been wrought; so the extent of these joints is not known. These joints have been observed to have nearly the same direction in both back and feet quarries. The distance they are apart in some places is not more than 20 feet, while in others, they are much more, and in some extensive quarries no side seams have yet been discerned. Some side seams are nearly planes, others differ from them in degree of roughness and irregularity, as well as in the material in the joints. It has been remarked by the workmen that when the side seams are the nearest to a plane, the cleavage also presents the evenest surface. This is remarkable as the plane of cleavage crosses the plane of the side seams. Ends. Each foot and back, or whatever other position the stripes or strata of the rock may have, are crossed by seams or joints called ends, the bearing of which is nearly north and south, or the same as the side seams, but the dip is generally nearer vertical. In some feet and backs the end joints are very close to each other; but in those which produce the largest material, they are at a much greater distance. One part of the same foot or back frequently contains more of these end joints than are found in an equal portion of another part. These end joints in a foot or back not only do not continue through into the adjoining feet or backs, but fre quently they only extend a little distance into the rock forming the foot or back, when they terminate. Some of these joints are by the workmen called sawgates, and indeed they very much resem ble the cut made by a saw in any material; the sides of the joints being parallel, and terminating as abruptly in the solid material as a saw-kerf in a plank, block of wood, or any other substance. Sometimes these joints are so close as not to be perceptible, and when they terminate, the workmen say the rock is grown together. These are nearly vertical, and their bearing varies from nearly north and south to north-east and south-west. These cross the direction of all the joints, and divide the slate back. Several of these have been observed at about 100 feet distance from each other. One of these veins, which has been more particularly noticed, is about two feet thick; and the corresponding feet on the east side are between two and three feet lower than those on the west side of the vein. Thus, either the rock has been raised on one side of the vein, or on the other side it has sunk. From the constant observation of the workmen, they find that the slate-rock, if not rendered quite useless, or poisoned, as they term it, by being near these ram bles, it contains a greater number of joints there than is found at a greater distance from those places. Hoping that I have described with accuracy, if not in geological terms, the several appearances to which I have al→ luded in these quarries, and that your readers, generally, will be able to understand what I have written, I am, Sir, Your obedient servant, JOSEPH JOPLING. THE NEW SAFETY-CAB. Public attention has been a good deal attracted by a carriage, built by the Safety Cabriolet Company, after Mr. Hansom's patent, as a specimen of those intended to be introduced into the streets of the metropolis. We are gratified to hear that the plan has been found to fulfil, if not exceed, the expectations of the inventor, and of the Company. For ease and safety to the passenger, it is unequalled; and for lightness of draught to the horse, far superior to any other vehicle yet invented. The position of the driver (on the top of the carriage) has been objected to as unsafe; but the men who have been engaged in this capacity are of quite a contrary opinion, in which we certainly agree: for facility of steering, it cannot be compared with the awkward one-sided position of the driver of the common cab; being elevated, the guide has a clear view of all around him, and can observe the signs of the drivers in the van without obstruction, a point of great importance in such crowded thoroughfares as Gracechurch-street, Cheapside, Fleet-street, and the Strand-the principal courses of cab-traffic. The safety and utility of the invention having been fully proved on the experimental carriages, by severer trials than it is ever likely a cab in ordinary use would be subjected to, the company are now building a number, to supersede the present dangerous and lumbering things-which will be in full operation about the latter end of May. It is almost needless to wish the undertaking success, we are confident the invention will mutually benefit the public, the shareholders, and the talented inventor. PROVINCIAL INSTITUTIONS, LIBRARIES, AND MUSEUMS. 66 Sir, I now proceed to fulfil my promise as to the public and permanent" provincial Institutions, most of which I find, upon further inquiry, have already been "recognised by the Government." In 1822, the Record Commission determined to transmit to each of the following Institutions (except those marked with an asterisk, which I have added to the list) a copy of every work published by them, on condition that they should be accessible to any person without difficulty; and the value of such books, including others given to other public libraries and to individuals, was stated in 1833 to exceed the sum of 35,000l.! Man of the libraries in the subsequent enumeration are public endowed Institutions; while others are "permanent," from the circumstance of their possessing vested funds sufficient to protect them from any chance of dissolution : Aberbrothock Subscription Library. Museum. Cork Royal Institution. Coventry Subscription Library. Dundee Public Library. E on College Public Library. *G asgow Museum. Gloucester Permanent Library. Halifax Literary and Philosophical *Hen'ey-upon-Thanes; Dr. Aldrich's Library. 60 PROVINCIAL INSTITUTIONS, LIBRARIES, AND MUSEUMS. Hull Subscription Library. Ipswich Corporation Library, for the use of the county of Suffolk. Leeds Subscription Library. *Leicester Public Library. Liverpool Lyceum Library. Royal Institution. Museum. Maldon; Dr. Plume's Public Li- Portico Library. cal Society. Montrose Public Library. Morpeth Public Library. Newark Stock Library. *Newcastle-upon-Tyne; Dr. Tomlinson's Public Library. Literary and Philosophical Society; possessing a MUSEUM, containing the finest collection of British birds in the kingdom. Norwich Public Library. Literary Institution. Nottingham Subscription Library. Stroud Institution. Sunderland Literary and Philosophical Institution. Taunton, Somerset, and Taunton Institution. Wight, Isle of, Institution, at Newport. Yarmouth Public Library. The Record Commission having set so good an example, why should the Trustees of the British Museum refuse to follow it? What objection can be raised to such an appropriation of a part of the 3,570 volumes of their own publications now remaining in store; to say nothing of the continual accumulation of other printed books, prints, coins, and objects of natural history? If it were not considered advisable to admit the whole of the Institutions I have enumerated to partake of this valuable privilege, a seIection might be made of the endowed and public and permanent ones. The different Provincial "MUSEUMS" would be greatly benefited by a share of the duplicate objects of natural history, coins, and prints. to 2 Although I may differ with your correspondent, P. P. C. R., on the expediency of an "Evening Reading-Room,' I consider his suggestion as to the exhibition of the coins (at least, of a part of them) as extremely valuable, and worthy of immediate adoption. There are duplicates enough, I understand, allow of this plan, without disturbing the continuity of the general collection." Some of the 20,000 MSS. might be exhibited under glass-cases; and a complete series of autographs of the kings of England, as well as MSS., with illuminations, from the earliest to the latest period, might be shown in this way.” Something of this kind is done in the Royal Library at Paris; why not in the British Museum? I am, Sir, yours, &c. T 1 W S. $ P.S-Any further hints or suggestions from your valuable correspondent, P. P. C. R., would, I think, be particularly ac ceptable at the present moment, as the Committee of Inquiry are still pursuing v their labours; and you, Sir, will confer a s lasting benefit upon the public by des voting occasionally some pages of your v widely-circulating Journal to subjects so intimately connected with its best inte, T rests the promotion of the cause of science and knowledge. I cordially agree with P. P. C. R. in his excellent, b observations on the very imperfect and unsatisfactory article in the Penny Cyclo pædia. Perhaps he does not know that Sir HENRY ELLIS is one of the COMMITTEE of the Society for the Diffusion of Useful Knowledge; but can the information in this article be entitled to such an epithet? To P, P. C. R. I would say, as it respects the present inquiry, unita vis fortior, and in future, if on some subjects we agree to differ," may we "differ to agree" on the principal one, "the necessity for an entire reform in every thing connected with the British Museum!"-S. S. 66 T to Candles, and in the Application of such Extinguishers to Candles and Candlesticks. Patent sealed July 3, specification inrolled Sept. 1835. After r this rigmarole title, it may be necessary to explain, that this patent is for a self-acting extinguisher. There is no improvement in the extinguisher itself as the title states; there is the self-same cone as has been used from time immemorial by every member of the save-all club; the improvement consists merely in an apparatus connected with the extinguisher and candlestick, which puts out the light after a given length of time has passed, or rather a given length of candle is consumed. The candlestick consists of a tube, covering the whole candle, which is inclosed therein with a cap, having a hole for the wick. A spiral spring in the tube under the candle continually presses it upwards against the cap, the same as in the carriagelantern. The patented improvement in the apparatus consists in attaching to the top of the candlestick an extinguisher, turning on a pivot and arm, to which is given a tendency always to close on the Candle by a spring coiled on the pivot. The extinguisher is held back by a catch, which communicates with a lever, having a chain and pin attached to it. There is a slit in the upper portion of the tube which is graduated with a scale of the hours and minutes the candle will burn. Tire pin is thrust through the candle at the required time it is wanted to burn indicated by the scale; and as the candle consumes, the pin rises till it comes in contact with the lever, releases the catch, and lets the extinguisher down. upon the light. The accuracy of the action of this machine, it will be seen, depends entirely upon equal portions of the candle being consumed in equal periods of time. All that can be effected is, an approximation to the desired measure of duration, which will be more or less near, as the candle is of equal quality throughout, and burnt in a situation free from draft or change of temperature. With respect to neatness this patent extinguisher is superior, but in utility only equal, to the simple selfacting one which has been in use for years, which acts by its own gravity, be ing released by the candle having burnt down to a pin which supports it. JAMES KEAN, of Johnston, Renfrew, Machine-maker and Engineer; Improved Throstle-Flyer, or a Substitute for an ordinary Flyer, employed in Spinning Cotton, Flax, Hemp, Wool, Silk, and other Fibrous Substances.Patent sealed July 3, 1835, inrolled Jan. 3, 1836. The patentee substitutes for the common forked-flyer a cylinder of thin sheet brass, copper, or tin, open at one end, and covering the bobbin. By this arrangement he says, that a swifter revolution will be made by the bobbin with the same power, or an equal swiftness with a smaller power; because at present the atmosphere greatly retards the speed of the bobbin, and the cylindrical flyer excluding the atmosphere, will allow the bobbin an unimpeded course. The exclusion of the air would certainly facilitate the speed of the bobbin; but the disadvantage is, that it will be difficult to get at the bobbin when the thread breaks to find the end and join it. The utmost facility should be given for this operation in spinning, which is of momentary occurrence, and the provision made by the patentee, we do not think sufficient to obviate the objection. The cylindrical must, we should think, be heavier than the forked-flyer, and this will consume a portion of the power saved; and a greater speed than is at present attainable is unnecessary, as it would cause an even more frequent recurrence of the before-mentioned disadvantage, that is, mending a broken thread. WILLIAM BUSK, of Bankside, Surrey, Engineer; Improvements in Propelling Boats, Ships, or other Floating Bodies.Patent sealed July 10, 1835; specification inrolled, Jan. 10, 1836. This invention consists in the application of the principle of Barker's mill to the propulsion of vessels. Water is pumped by a steam-engine into a tank, which is connected with trunks projecting over each side of the vessel. Each side of these trunks at right angles with the side of the vessel is provided with a sluice-gate; and the water being kept by the steain-engine always at the same level in the tank, has an equal pressure on every side of the trunk except where it is allowed to escape by the sluice; consequently, if the hind sluices be opened, the egress of the water that way will have a retroactive force on the trunks, and |