a strength of about 40 per cent. over coal, being about one-half more efficient than Newcastle coal, and one-fifth better than Welsh coal. It consequently, when used, kept a steamer much longer at sea. In addition to this 1,5007. had been applied for the erection of a store-shed at Sheerness. In former years 3,000l. had been expended in cleaning out the harbour there; this by means of a new process which had been adopted would in future, he hoped, be wholly, or in great part, saved to the country. At Portsmouth it was proposed to have additional saw machinery. There was also another addition. At Pembroke it had been proposed to erect new slips for the building of first-rates, and accordingly the erection of four new slips had been resolved upon." In reference to the statement made upon the subject of Mr. Grant's composition fuel, a letter has been published in the daily papers from a Mr. Oram the patentee of an article of this nature, (the specification of which was published in our 30th vol. p. 365,) stating that Mr. Grant had applied for a patent, and that he had opposed the application, and that the At orney General had refused to report to the Crown in favour of the patent to Mr. Grant. The matter, however, remains for further consideration. We believe that Mr. Grant has been for some years experimenting upon the subject, and that the delay which took place in applying for a patent arose from Government refusing at first to allow him so to do, upon the ground that as he experimented at public expense, the result should be for the public benefit.

NOTES AND NOTICES.

Mr. Oldham, the late Engineer to the Bank, The Courier states that this gentleman was in his 61st year. Until his invention for checking the number of notes printed, and for preventing forgery, was adopted by the Bank of England, they had no positive means of effectually stopping the latter, or of telling the number of notes struck off by their printing presses. Mr. Oldham was in possession of a large salary, with the right of reversion of a portion of it to his son.

Iron Pyrites and Calumine.—This mineral, which is composed chiefly of iron and sulphur, and is produced in considerable quantities from some of the Derbyshire lead mines, promises, in consequence of the high price of sulphur, to be in some request. It has hitherto been considered as deads or rubbish, and has been thrown away as such. Some gentlemen have been making inquiries for the article (known here as brazil or mundic) at Matlock, and twenty tons have been forwarded to their works, selected from the old hillocks of the Oxclose mine, at Snitterton, and the company express themselves willing to take any quantity that can be collected. Inquiries have also this week been made after calamine (lapis calaminaris) and arrangements are in progress which may probably lead to a market being

azain opened for this once important article to the miner. Calamine is abundant in the neighbourhood of Bonsall and Matlock, and as much as three thousand pounds annually have been paid for the article in Bonsall alone; but, owing to the introduction of a foreign article, the price has of late years so much declined as to make it (except in a very few instances) no longer worth working for.Derbyshire Courier.

Parallel Motion in Steam Engines.-Among the many mechanical inventions produced by the fertile genius of Watt, there is none which has excited such universal, such unqualified, and such merited admiration as that of the parallel motion. It is, indeed, impossible even for an eye unaccustomed to view mechanical combinations to behold the beam of a steam-engine moving the piston through the instrumentality of a parallel motion, without an instinctive feeling of pleasure at the unexpected fulfilment of an end by means having so little ap. parent connection with it. When this feeling was expressed to Watt himself by those who first beheld the performance of this exquisite mechanism, he exclaimed, with his usual vivacity, that he himself, when he first beheld his own contrivance in action, was affected by the same sense of pleasure and sur. prise at its regularity and precision. He said that he received from it the same species of enjoyment that usually accompanies the first view of the successful invention of another person.-Dr. Lardner on the Steam Engine.

Launch of an Iron War Steamer.-On Thursday, February 6th, was launched from Messrs. Ditchburn and Mare's building yard, Blackwall, the Proserpine, wrought-iron steam-vessel of 470 tons. She has four sliding keels, nine water-tight bulkheads, two of which are longitudinal running the entire length of the engine-room-is armed with four long guns on non-recoil carriages, and will not exceed four feet draught of water when fully equipt for sea. The engines are two 45 horse, having the wheels to disconnect on a new and improved method to facilitate sailing, by Messrs. Maudsley, Son, and Field. This vessel is constructed for sailing as well as steaming. It is a fact worthy of record, and ought to be generally known, that Messrs. Ditchburn and Mare were the first who arrived at the hitherto deemed unattainable result of giving highly superior sailing qualities to iron sea-going vessels of shallow draught of water. Their application and improvement of sliding keels have been most successful, their simplicity is such that a boy can manage them. Every person conversant with the history of naval architecture is aware that Captain Shanks, R.N. was the ingenious inventor, and that he received his first idea of them from the Indian navigating his raft; but although Capt. Shanks, was aided by the government of his day, and made several attempts to establish their use in timber-built vessels, he failed, chiefly in consequence of the great difculty in making the well and aperture through the keel, through which the sliding keel works, permanently water-tight; this in an iron vessel can be most perfectly accomplished. They are of the highest utility in the prevention of lee-way, counteracting rolling motion, and the vessel can be steered by them without the help of the rudder.

Testing the Strength of Iron Boats.-On Monday, February 24th, as they were lifting from the wharf a 25 horse boiler of an iron boat, built by Ditchburn and Mare, the crane which was of cast-iron broke, when the boiler and crane fell a distance of eight feet into the bottom of the vessel, little or no damage was done, and fortunately no one was hurt. This vessel is named the Lee, and has the reefing wheels after Mr. Hall's patent, we believe this to be the first application of them-we wish them every suc cess. Civ. E. and Arch, Journal.

Extracts from Milton's Address to Light.

Paradise Lost. Magdalene College, Cambridge, March, 1840.

My dear Sir, I have carefully drawn the diagrams which accompany this letter, illustrating my principle of subaqueous, inwardly generated illumination of the parts in succession, of objects submerged in dark waters like those in which lies

sunk at Spithead, the wreck of the Royal George.

That majestic vessel was once_the roaming, Lightning-flashing Ocean Fortalice, but alas! "darkness and the shadow of death stain it" now-the sea has yawned around it, and it is the last lonely resting place, the dreary, watery sepulchre of the brave!

It is about fourteen years since at one of the meetings of the Institution of Civil Engineers, I developed my principle of submarine illumination in clear water, by means of a lamp with a concave reflector, &c., but it was not until the last winter that I turned my attention to the invention of means of generating irradiation, and the power of distinct vision in muddy, and even in very muddy water, dark as thick night; dark as the very sun itself when "the sun was turned into darkness," in the vision of the Apostle in the Apocalypse.

I have had very many, and most interesting conversations with those intrepid and admirable divers, the Messrs. Deane and Mr. Peter Tall, who was their assistant at Spithead, and they are all three in perfect accordance in describing the waters there in which the Royal George is engulphed, as being almost always so muddy and murky that the wreck is utterly invisible, and that they were consequently under the necessity of working, not by their sight and touch, but by their touch only,-viz: like the blind.

They grope in darkness having no light." By working in this deadly night-shade Mr. Tall's hands were frequently lacerated by pieces of jagged iron of the wreck, and he mentioned to

me last December in Liverpool, where he now resides, that only once out of seventeen times when he was down upon the wreck, had he a glimmering of light giving even a dim vision.

On one splendidly bright day, and when it happened that the water was much less muddy than usual, there was a faint pale shimmering lurid twilight around, and on the wreck, and he saw a human skeleton of which when he next ascended the ladder, he brought up one of the thigh bones.

But this was one of the very rare exceptions to the forlorn dismal darkness of that melancholy flood,-and even when lamps have been brought down burning, it may be truly said of their wan, and evanishing flames

"Yet from these flames No light, but rather darkness visible !" a kind of ghastly sepulchral light, glimmering in the watery grave of the gallant hapless Admiral Kempenfeldt, and of his gallant hapless crew.

The observations which form the subject of this communication, will, I hope add a fractional part of an atom to the science of submarine operations; as they are grounded upon diversified experiments; and I think I may add, on habits of most cautious contemplation before hazarding practical inference.

The divine telescope draws the intelligential essence of man in roaming flight through the abyss of celestial space, the Hyaline of heaven; and the effluence of the spirit of Watt moving with fiery energies upon the face of the billowy deep, tears in conflict the awful plumage of "the wings of the wind." But, the science of works to be effected beneath its great waters, is as yet but as the dreaming of a slumbering infant, in comparison with the state of science which has created the telescope and the steam engine, those twin annihilators of space, on this globe, and in the firmament!

From the following simple diagram illustrating one of my experiments (viz. that made at the bottom of Kingstown harbour on the night of the 31st of last December) the principle of powerful illumination of the parts in succession of objects in waters like that of Spithead, will be most easily understood, and then, the application of the principle to the construction of an instrument for divers in water-tight dresses and helmets.

and working "in that obscure sojourn," the darksome bosom of the briny deep, in their water-tight dresses and divinghelmets.

Omitting, for the present, practical details, however important, the following is in a general form, the application of the principle; and the construction of the instrument, follows directly from the experiment just described. Let us suppose the diver to be in his drear abode on the

bottom, and either standing or walking in the thick darkness, in the "gloom and the day of blackness," of water like that which, on the evidence of the Messrs. Deane and Mr. Peter Tall, I have already described.

The plate represents a horizontal section of the diving helmet, and also a horizontal section of the two wings of the illuminating instrument, combined and identified with the helmet, and having, consequently, their support on the diver's breast and shoulders.

There are to be two parabolic reflectors with radiants in their foci, and consequently because of the parallelism of the reflected rays, two perfect, lucid images of the radiants (of course inverted) will be formed in the principal foci of the two lenses, and let these foci, like dazzling gems in their setting, fall within the piece of strong glass, and in its centre,strong, and also to be as clear as crystal, with parallel surfaces as represented in the plate, and which is to be inserted perfectly water-tight in the instrument.

Let now some substance, for example, the diver's own hand, or a piece of white paper, or the bottom of a leaky ship, which it is necessary to examine in the muddy fluid, be placed at an extremely small distance from this glass, and it will be as utterly invisible as if the thin plate of interposed water, were a massive plate of iron, or vessel of mercury.

But, let the diver draw his hand, or the paper into contact with it; or if we take the bottom of the leaky ship as the illustration, let him approach it and place the glass in contact with it, and in this, or any case whatever, the moment actual contact is created, that moment a focal image of the lucid flame must burst upon his vision, playing upon his hand, or upon the paper, or the bottom of the ship; viz. the focal images of the radiants which are burning in the foci of the paraboloids, accurately taking their "form," and also accurately coloured by the effect of the

talismanic spell of the two double convex lenses.

It will not be actual flame, it will not be the Hrympther of the Scandinavian Edda, the spirit of fire; but the paper, or wood, or copper of the ship, or the hand, &c., as it may happen to be, will not merely appear illumined, however muddy and midnight-gloomy the water, but it will appear to be

"Clothed with flames and amber light," it will not be actual fire, but it will be

"Full many a fathom deep,"

in the dreary flood, like that which was seen by Ezekiel in his vision, a light like amber, and the appearance of fire," upon the object which was a quarter of a second before as viewless, and as little of "things visible," as the beings of the human species whom ages ago, eternity has overwhelmed in its awful tide!

To take another illustration of the nature of this illumination, let me suppose that the person who has descended, wishes to read a book in the night-shade tabernacle of waters by which he is enveloped; he may, if he choose, read adown the dark profound, that appalling effort of the creative inspiration of Shakespeare's omnific imagination, -"Clarence's Dream,"-that pure intensity of human pathos-of picturesque and solemn description of sub-marine scenery, and of wild, ghastly, heartfreezing preternatural dreary horror!

It will be eyident at a glance, (the primal principle being thus explained,) that a third branch of the instrument might be placed on the helmet, cresting it with light, and that even a third focal image might be projected on the glass. To use an expression in Spenser's "Fairie Queene," skruging" the rays of light, in dazzling condensation together, to add a deeper intensity to the focal irradiation. This irradiation it is quite manifest may be pased over the parts in succession, of objects in the water, of the nature and circumstances of which it may be necessary to have an accurate knowledge. Even the telescope, the telescope itself, with its gorgeous power, must work by a similar process of successive application; no telescope can grasp at once into its field of view, a hemisphere of the empyrean.

For the present I limit my practical observations to this, that the glass nust be kept constantly wiped by the diver,