tageously displaying his zeal and intelligence, the officers of the lancer regiments would very soon ask, as the greatest favour, to be allowed to lay aside the lance for the carbine, in order to obtain an equal chance of distinction with the rest of the cavalry. Now it may, perhaps, be answered that, as the lancer regiments are in all other respects admirably equipped as regards both man and horse for the purposes of light cavalry, it will be time enough when the day of trial comes to exchange the lance for the carbine, if the experience of service should prove the necessity of such an alteration. But this is a dangerous reasoning. The war in the Peninsula gave a very fair test of what is wanted of our cavalry; and would the Duke of Wellington at any period of that war have consented to exchange a regiment of dragoons, either heavy or light, for a regiment of lancers ? This is a proper opportunity, by the by, for calling the notice of our cavalry chiefs to a point which, in time of peace, is never sufficiently considered-namely, the great importance of giving more time and attention in our dragoon and hussar regiments to the use of the carbine on horseback. One of our hussar colonels has invariably followed the judicious practice of making all his men act in their turn as skirmishers at field days; but a great number of regiments content themselves with merely selecting in each troop a few of the most active men and horses as permanent skirmishers, to rush out from the ranks at full gallop for mere effect and display, and return, after firing off their carLines half a dozen times in the air, at the same unnecessary speed with which they went out. This method of skirmishing affords no instruction whatever towards making even the selected soldiers good shots with their fire-arms; and as in the riding-school the pistol alone is used in firing at a mark, the greater proportion of each troop may go on from one year's end to another without a single opportunity of even knowing whether they have any dexterity or not in the use of the carbine on horseback. There are, no doubt, a certain number of parades for ball-practice on foot, but a man who is a tolerably fair shot on his own legs, may find himself as much puzzled upon a shy or hot-tempered horse, as a horse-artillery-man would be perplexed to take a good aim with an 18-pounder in a heavy sea on board of ship. At many of our cavalry stations there is no ground where, even on foot, this ball practice can take place; but surely, wherever it is possible, the men should invariably fire at the target from on horseback, instead of being dismounted for that purpose. Some of our officers, who are anything but deficient in either theory or experience, have answered these remarks upon making the men marksmen with the carbine, by saying that the horses soon get steady enough after undergoing a few of the fatigues and privations of service, and the soldiers learn better from the enemy how to skirmish, and use their weapons, than they can possibly be taught at home; but surely it should not be forgotten that, from our situation as an insular nation, the campaigns of our armies most frequently begin on the very beach where our armies disembark, and that the first success, however trifling, is of the utmost moral value as regards its effect upon the troops in general. Now the outpost cavalry are in all likelihood the first who will be engaged; and to find themselves possessed of a decided superiority in skirmishing, from expertness previously acquired in the use of their fire-arms, must naturally be of the greatest encouragement to them; while, on the other hand, to find by an unpleasant sort of proof, that they have been neglecting a point of instruction upon which they now discover that so much of their success must depend, cannot fail to produce a disheartening effect. "Fas est et ab hoste doceri,” is a very wise maxim, no doubt; but to learn to shoot by being shot, is a kind of instruction mutuel which can never be made at all palatable. To return, from what it is hoped will be considered a pardonable digression, to the subject of lancer regiments, and their utility for general purposes of service, it may be well to notice, that suggestions have lately been made, by good authorities, of the propriety of supplying the lancers with a certain number of carbines to each troop, by which arrangement those regiments would certainly be rendered much more available than at present, and at all events would be able to protect themselves in marching through difficult or enclosed country, unaccompanied by other troops. Still this would not enable them to be as useful as dragoons or hussars, when forming part of an army in the field. It is not only necessary for cavalry to be able to take care of themselves, but their principal use is, after all, to watch over the security of the infantry, who look to the patrol and picquet of cavalry for relief from fatigue, and for repose from the harassing watchfulness which would otherwise be required of them, without any intermission, in the presence of an active and enterprising enemy. Before taking leave of a discussion which contains much of interest for the cavalry officer, there is one great merit of the lance which must not be forgotten. Of all the means of making a man active and wellseated on horseback, the use of this weapon in the riding-school is beyond comparison the best. A man who, without stirrups, and mounted on a horse with a fine mouth, can wield a lance with facility, and go through the exercise, without disturbing his bridle hand, or in any way agitating the animal by want of balance in his saddle, must of necessity be an excellent military rider; and yet it requires no very tedious process to bring a recruit to considerable proficiency in using the lance sufficiently well on horseback to make him derive great advantage from it in this respect. To alter this, or any other part, (except, perhaps, the slow canter,) of our present riding-school system, would be a great pity. Those officers who are either so prejudiced or so ignorant as to despise the art of military. horsemanship, are little aware of the astonishing improvements that have been produced by its study of late years in the British cavalry; improvements from which many excellent results may be anticipated whenever they again are summoned to the field, as well from a mild mode of treatment of the horse, which must greatly tend to his duration, as from the much greater steadiness in the ranks, and susceptibility of control, which is the consequence of giving the soldiers good hands and increased ease and readiness in the management of their horses. Both to Vanguard and the lancers some apology is, perhaps, due, for the freedom with which the remarks of the former, and the arms of the latter, have been discussed; but a moment's consideration will convince them that the views here offered to the military public, can only arise from a zeal of which they themselves so largely partake, for the advantage of one of the most important branches of the service. W. THE DRUMMOND LIGHT FOR ILLUMINATING LIGHT-HOUSES, &c. LIEUT. THOMAS DRUMMOND, of the Royal Engineers, has the merit of having discovered a combination by which a light is produced, so intense and pure as to promise the most fortunate results in its application to the important object of light-houses. This valuable discovery has been submitted to the test of experiment with complete success; its superiority to light produced by any previously existing process, as well as its practical effects, having been triumphantly established. In a paper submitted to the Royal Society by Colonel Colby, Mr. Drummond describes his invention, suggested by his previous attempts to produce a light sufficiently brilliant to mark distant stations in surveys, first tracing the various clumsy modes of illuminating light-houses, down to the improved method by MM. Arago and Fresnel, recently introduced in France. The latter plan consists of an octagonal arrangement of powerful lenses round a large Argand lamp, of four concentric wicks, the light of which, by means of a coping or roof of minor lenses in the form of trapezoids, inclining at angles till they meet above, is thus completely enclosed. We must repeat by the way, the just animadversion of that officer upon the retention of a defective principle in the solitary instance of the North Foreland Light, where the expedient of a glass lens placed before a parabolic reflector (or rather vice versa, according to the original device,) is still suffered to mar the intended result, the effect of the reflector alone doubling that of the reflector and lens united. After detailing the two methods at present in use-viz. 1st, Parabolic reflectors, illuminated by an Argand lamp, the process being modified to meet the construction of the light, whether fixed or revolving; and 2nd, the French mode of M. Arago, referred to above,-Mr. Drummond observes: "Such are the methods at present in use in the best light-houses of Great Britain or France. The third and last method is that which I have ventured to propose, and in which the light is derived from a source altogether different from the preceding two; a ball or cylinder of lime, intensely ignited," by directing upon it a stream of mingled oxygen and hydrogen gases, "being substituted for the Argand lamps. 66 Fig. 1. represents the lamp. The two gases, oxygen and hydrogen, proceeding from separate gasometers, enter at o and h, but do not mix till they arrive at the small chamber c, of which fig. 2. is a section: into this chamber the oxygen gas from the inner tube is projected horizontally through a series of very small apertures, and the hydrogen gas rises vertically through a series of similar apertures at d. The united gases then pass through two or three pieces of wire-gauze placed at e, and being thus thoroughly mixed, Fig. 1. issue through the two jets against the ball b. To prevent the wasting of the ball opposite the two jets, and at the same time to diffuse the heat more equably, it is made to revolve once in a minute, by means of a movement placed underneath the plate m, and with which the wire f, carrying the ball and passing through the stem, is connected. Notwithstanding, however, this arrangement, the effect of the heat is such as gradually to cut a deep groove in the ball, so that at the end of about forty-five minutes it becomes necessary to change it. In a light-house, where it is of essential consequence to maintain a constant light, it would be unsafe to entrust this to an attendant, and hence the necessity of devising some means for remedying this inconvenience." This has been done by an ingenious and effectual contrivance. Having described his apparatus, which is accurately designed to combine the mechanical action of his plan, Lieut. Drummond next details the results of experiments, made at the Trinity House, on the intrinsic intensity of the different lights. These highly favourable results,—deduced from exact comparative calculations, which are given, and from which we learn that the light emitted by a lime-ball only three-eighths of an inch in diameter, heated by two jets, is equal to thirteen Argand lamps "Were obtained by screening the different lights, and then placing equal apertures opposite each, changing the apertures and taking the mean to destroy the effect of any inaccuracy in size. The intensity of the lime-ball being therefore 264 times that of the Argand lamp, a single reflector illuminated by the former will be equal to 264 reflectors illuminated by the latter; but the divergence of the reflected light, depending upon the size of the luminous body in the focus, will be smaller with the ball than with the lamp in the proportion of about three to eight: hence, in such a light-house as that of Beachy Head, eight reflectors may be substituted for thirty, and yet an effect would be produced twenty-six times greater than that of the present light, the most perfect of its kind in this country. "By similar experiments it was found that the French lens was equal to 9.1 reflectors; and if the effect of the additional lenses and reflectors which ought to accompany it, and which has been estimated at one-seventh, be added, then the lens is equal to 10.4 reflectors. In like manner, therefore, the effect of a single reflector with a lime-ball would be equal to twenty-five times that of such a combination of lenses. "It may now perhaps be asked, at what expense can such a light be maintained ? Can the gases by which the requisite heat is produced be procured at such a price as to compete with oil or coal gas ? The data I possess for forming an estimate of the expense of the gases are very scanty, but the quantity consumed was accurately determined; at the same time the consumption of the other lights was also tried, and the results are as follow: : Consumption 1 gill 1 gill 2 qts. pt. Expense per hour. 0.69 penny 0.83 penny Is. 2 d. "The lime requires four cubic feet of hydrogen and two of oxygen per hour, and the probable expense is 5d per hour. "In a revolving light of the first class, containing thirty reflectors, the expense per hour would therefore be about 2s. 1d. If the French method were employed, the increase of light would be th, and the expense only 1s. 24d. per hour. If six reflectors illuminated with lime-balls were used, which would probably be sufficient, the probable expense would be 2s. 6d. per hour, and the increase of light twentysix times. "The experiments at the Trinity House being concluded, the whole of the apparatus was removed to Purfleet, where on a knoll of chalk about 100 feet above the river a temporary light-house had been erected, and being fitted with the requisite machinery, the different lights were made to revolve in succession, and the appearance which they presented, as well as the duration of the light, were observed from the Trinity Wharf at Black wall, a distance in a straight line of 104 miles. "The four faces of the revolving machine were thus occupied : "No. 1. A single reflector twenty-one inches diameter, three inches focal distance, with an Argand lamp. "No. 2. Seven reflectors, with ditto. "No. 3. French lens, with its lamp. "No. 4. Single reflector with lime-ball. "The respective lights were accurately placed in focus. "When No. 4, the reflector lighted with the lime-ball, was turned towards the Wharf, the light was so great that the shadow of the hand and fingers was distinctly visible even on a dark brick wall, while no such effect was discernible when the other lights were turned in the same direction. "In order more justly to estimate their comparative effects, No. 4, was removed to a temporary tent about twenty-five yards to the right of the light house, as far as the edge of the cliff would permit, and on the evenings of the 25th and 31st May regular series of experiments were made. Being engaged at Purfleet, directing these exhibitions, I never had an opportunity of witnessing their effects at Blackwall; but Captain BASIL HALL, R.Ñ., who from the interest which he took in these experiments was an attentive observer of all that occurred, has at my request kindly favoured me with the following interesting account : "My dear Sir, "4, St. James's Place, 1st June, 1830. "You wished me to take particular notice of last night's experiments with the different kinds of lights exhibited at Purfleet, and observed at the Trinity Wharf, Blackwall; but I have little to add to what I told you respecting those on the evening of the 25th instant: indeed it is not within the compass of language to describe accurately the details of such experiments, for it is by ocular evidence alone that their merits can be understood. "Essentially the experiments of last evening were the same as those of the 25th, and their effects likewise. The degrees of darkness in the evenings however were so different, that some particular results were not the same. The moon last night, being nine or ten days old, lighted up the clouds so much, that even when the moon herself was hid, there was light enough to overpower any shed upon the spot where we stood by your distant illumination: whereas on the 25th, when the night was much darker, the light cast from the temporary light-house at Purfleet, in which your apparatus was fixed, was so great that a distinct shadow was thrown upon the wall by any object interposed. Not the slightest trace of any such shadow, however, could be perceived when your light was extinguished, and any of the other lights were exposed in its place. "In like manner on the evening of the 25th, it was remarked by all the party at the Trinity Wharf, that, in whatever direction your light was turned, an immense coma, or tail of rays, similar to that produced by a beam of sun-light in a dusty room, but extending several miles in length, was seen to stream off from the spot where we knew the light to be placed, although, owing to the reflector being turned too much on one side, the light itself was not visible. "Now, last night there was none of this singular appearance visible; but whether this was caused by the presence of the moonlight, or by the absence of the haze and drizzling rain which fell during the evening of the 25th, I cannot say. I had hoped that the appearance alluded to was to prove a constant accompaniment to your light, in which case it might, perhaps, have been turned to account for the purposes of light-houses. If in hazy or foggy weather this curious effect of reflected light from the atmosphere be constant, it may help to point out the position of light-houses, even when the distance of the observer is so great that the curvature of the earth shall render it impossible for him to see the light itself. "The following experiments tried last night were the same as those of the 25th, and certainly no comparative trials could be more fairly arranged. "EXPERIMENT I. The first light exposed was the single Argand burner with a reflector. This was quite distinctly seen, and all the party admitted it to be a good light. After several minutes this was put out. "EXP. II. The seven Argand burners were next shown, each in its reflector : and this was manifestly superior to the first; but how much so I cannot say, perhaps four times as conspicuous. Both these lights had an obvious tinge of brown or orange. "EXP. III. The third light which was exposed, (on the seven Argands being put out,) was that behind the French lens; and I think it was generally admitted by the party present, that this light was whiter and more intense than that from the seven Argands, though the size appeared very much the same. The "EXP. IV. The fourth light was that which you have devised, and which, instead of the clumsy word 'Lime,' ought to bear the name of its discoverer. Drummond light, then, the instant it was uncovered, elicited a sort of shout of admiration from the whole party, as being something much more brilliant than we |