riment; and first he spread it, without any addition to it, upon an iron plate over a strong fire, where he gave it a very powerful roasting, to try if by that means he could not relax, and loosen the component parts to such a degree, as to make the separation and reduction of the metal more easy, when he should bring it into the furnace. When he had so done, he mixed it up with a flux of a very peculiar but gentle nature, which he had before made use of for other purposes with great success, and committed it, as in the former experiment, to the furnace, where he urged it by a very strong fire for about 3 hours, and on taking it out, he found the event answerable to his most sanguine expectations; for in the bottom of the crucible he found, as near as he could remember, rather more than half of the sand he had put into the crucible reduced to a very fine malleable metal.

Being fully convinced, by the experiment, that this black sand was a very rich iron ore, he acquainted some of his friends with it, who being largely engaged in trade to those parts of the American colonies, where he was informed this sand was to be easily procured, and in very large quantities, he was in great hopes an account of this nature would have inclined some of the gentlemen in that part of the world, to have prosecuted so useful a discovery in a larger way; and he owns he had often wondered that an affair of such consequence should have lain dormant for so many years.

However he was a few months preceding the above date, pleasingly surprised to find in the hands of Mr. Collinson, not only a pamphlet, but a letter on the subject addressed to the Society for the Encouragement of Arts and Manufactures, by Mr. G. Elliott, who relates that, though previous to his attempt of making iron from this sand, he met with nothing but what was discouraging from the most skilful persons to whom he proposed his design, yet that he had such a persuasion in his own mind of the practicability of the thing, that he could not rest till he had made a trial, and the event proved encouraging much beyond his expectations, insomuch that he could scarcely believe the trial had been fairly made, till a 2d trial evinced with certainty, that 83 lb. of the sand would produce a bar of excellent iron weighing 50 lb.: a prodigious yield indeed, and far beyond what Mr. H. had ever heard of from the richest iron ores that are any where to be found; most of the ores he had ever met with or heard of, yielded little more than half in pig metal, and which suffered a waste of near part to make tolerable good, bar iron, and much more if he was rightly informed, when the iron was intended for more valuable purposes, such as being drawn into wire, &c. On this subject Mr. Horne received the following letter from Mr. Elliot; dated Killingworth, Oct. 4th, 1762.

I understand by Mr. Collinson, that you have seen, and greatly approve of,

the sample of sand iron which was sent; that you are desirous to know how it was made, and whether it can be made in large bars. The little bar you saw was cut off from a bar of 524 lb., the first that was made at my son's work, the first that was ever made in America, and probably the first that was ever made in the world, in that manner, and so large a bar. I never heard of any attempt made upon the iron sand till that of your's 20 years ago, of which Mr. Collinson gave me an account in his letter.

As to the manner of making the iron, it is wrought or smelted in a commonbloomary, in the same manner as other iron ore is smelted; excepting this difference, this iron sand is so pure, so clean washed, that there is not a sufficient quantity of cinder or slag to promote and perform the smelting, therefore we add either the slag which issues from other iron, or else add some bog mine ore, which abounds with cinder; in this way it is as capable of being wrought as rock ore or bog mine. I was in hopes that if this iron sand could be wrought at all, the particles being so very fine, it would smelt very quick; but herein I found myself mistaken, every particle has a will of its own, and must have its own particular smelting, for instead of its being performed in less time, it took more than common iron ore, but upon further experience, and more acquaintance with this sand, the workman has shortened the operation from 5 hours down to 3: if by any means it might be reduced to the same time with pig iron, it would be a most useful improvement. If you can afford any directions to hasten the operation, I should be greatly obliged for any instructions. There is so much of this sand in America, that I am apt to think that there is more iron ore in this form of sand than in mines.

I have written an essay on the subject, which I hope Mr. Collinson will let you see, as I hope to see what you are about to publish. My son has a steel furnace, which was erected several years before the act of parliament prohibiting them in the plantations: he has converted some of the sand iron into steel, of which I send you a sample; as also a sample of the iron. As my son had no instructions for making steel, we were forced to hammer out the skill by various trials as we could; so conclude that he is still imperfect, and wants your help and direction to bring it to perfection, in which art I understand you are a perfect master, and withal kind enough to offer your assistance; for which I am very thankful, and look upon it as an additional favour, if you will be pleased to indulge me with the benefit of your correspondence, for I live in a corner of the world where such information, as I trust you are able to furnish, will be highly beneficial. Previous to my attempt of making iron from sand, I proposed my project to those who were the most skilful in those affairs, but met with nothing but what was discouraging; yet after all had a persuasion of the practicability of

the thing to a degree next to enthusiasm, so that I could not rest till I had made trial. I am glad that the iron has such qualities as to meet with your approbation; I knew that the iron was good, but did not know that it was so good as your superior knowledge has found it. I want to know what such iron will sell for in England, whether it will be worth while to send it. This black sand is a treasure that has long lain hidden from the world, and is what may render the colonies more valuable to Great Britain.'

(P. S. The bars of iron which have hitherto been made of sand, are from 50 to 50 gross, hope in time to have them reach to 70 lb. weight each; experience: must determine that matter; we can do better than at the time the essay was written. We have been visited with a long and sore drought, have done nothing. for a long time for want of water.)

The samples which accompanied this letter were 2 small bars, weighing only a few ounces, one of the iron made from the sand, the other of steel made from the same iron. These bars Mr. H. tried, and found that the bar of steel worked extremely well under the hammer, was very pure and clean, and free from flaws. On the contrary the bar of iron turned out much otherwise, for though it appeared to bear the force of the hammer, as well as the steel, yet it was not near so pure, but broke out in flaws and hollows, almost through the whole of the bar, and which a welding heat would by no means bring into proper union; this however engaged Mr. H. to try a different method, which was, when the bar was reduced into a proper size for the purpose, to double it up 3 times, one part of the bar upon the other, and to try if it would then bear welding and become more consistent, and by this means he found the end perfectly well answered;: for it bore the force of the fire and the hammer, and became in a manner perfectly sound. This severe trial proved to a demonstration, that the iron possessed all that agreeable toughness and ductility, for which the Spanish iron is so. deservedly famous, without partaking of that vile red-short quality, for which, the latter is very remarkable, and manifestly tends to prove the excellency of this sand iron, when reduced into bar iron under proper care and circumspection.. This sand is so pure, and so clean washed, that their first method of reducing the sand to bar iron proved too tedious, for want of some of those adventitious materials, to promote and perform the smelting, and which always accompanies the common ore, whether it be of the rock or bog kind; which materials mixing with the matter, made use of by way of flux, and uniting with the ashes of the fuel employed in melting down the ore, is usually run into a thick opaque glassy substance, forming as it were a covering over the metal, which by its gravity naturally sinks to the bottom; this the workmen call cinder. Now the want of this matter rendering the operation too tedious, Mr. H. finds they had recourse. either to this cinder brought from other iron works, or to a quantity of the bog

mine, which he doubts not would abundantly furnish matter for cinder. If they had used only the first, and that properly chosen, it might very probably have been of some service, without doing any material injury to the metal; but if the bog mine is used, though the surface might be apparently more, yet in all likelihood the injury would be infinitely great; and he was inclined to believe that something of this kind occasioned the difference observed between the 2 bars above mentioned, viz. that the one might have been reduced by the help of more pure materials, and the other by the assistance of their bog mine, whose constituent parts abounding with many impurities, some of which, by mixing with the metal, may have occasioned the defects above complained of, and which required so severe an operation both of the fire and hammer to separate from it. He was therefore of opinion, that as the prosecution of this useful discovery deserved the greatest encouragement, if the Society of Arts and Manufactures should take it under their patronage, the premium they might think proper to propose should rather be given to the person who should produce the purest metal, than to him who should produce the greatest quantity; for otherwise he was afraid they would be deprived of what he should esteem the most valuable part of this discovery, he meant the obtaining a more pure, and better kind of iron, than any they had hitherto been possessed of.

XIV. On the State of the Cold at Berlin last Winter, dated Feb. 12, 1763. By Simon Peter Pallas of that place, M.D. P. 62.

We have had great frosts here, as indeed all over Germany. Dec. 27, a little after seven o'clock in the morning, the cold was excessive, the mercury in the thermometer of Fahrenheit stood at 4 degrees under O, which is 15 degrees under ✪ of Reaumur's scale, than which the cold in 1740 was but very little more intense. Mr. Euler, junior, observed the same day the thermometer at the same degree; about 8 and at 9 o'clock of that day, the mercury in the barometer stood at the height of 30" 1", the like of which never had been observed at Berlin before.

XV. Of a Remarkable Darkness at Detroit, in America. By the Rev. James Stirling. p. 63.

Detroit, 25th Oct. 1762.

SIR, Tuesday last, Oct. 19, 1762, we had almost total darkness most part of the day. The darkness continued till 9 o'clock, when it cleared up a little. We then for the space of about a quarter of an hour saw the body of the sun, which appeared as red as blood, and more than 3 times as large as usual. The air all this time, which was very dense, was of a dirty yellowish green colour. We were obliged

to light candles to see to dine, at one o'clock, though the table was placed close by two large windows. About 3 the darkness became more horrible, which augmented till half past 3, when the wind breezed up from the s.w., and brought on some drops of rain, or rather sulphur and dirt, for it appeared more like the latter than the former, both in smell and quality. Mr. S. took a leaf of clean paper, and held it out in the rain, which rendered it black whenever the drops fell upon it; but when held near the fire turned to a yellow colour; and when burned it fizzed on the paper like wet powder. During this shower the air was almost suffocating with a strong sulphureous smell; it cleared up a little after the rain. There were various conjectures about the cause of this natural incident. Some imagined it might have been occasioned by the burning of the woods; but Mr. S. thinks it most probable, that it might have been occasioned by the eruption of some volcano or subterraneous fire, whence the sulphureous matter may have been emitted in the air, and contained in it until meeting with some watery clouds, it has fallen down together with the rain.

XVI. Of a Remarkable Marine Insect.* By Mr. Andrew Peter Du Pont. p. 57. In a calm on his voyage to England, on board the Friendship, Capt. Thompson, two persons swimming took up this most singular creature floating on the surface. Its motions muscular. Its length a little more than 1 inch. Four small and short horns, probably its eyes. It protruded them in the water only; an orifice in the front part, seemingly its mouth. Two round spots opaque, possibly respiracula. The mid-line of the back part appeared through a common magnifier like a silver leaf, and was in continual undulating motion, either from the muscles or circulation of juices. Two side lines extending the whole creature's length, and ending in one in the tail of a deep blue. The claws, or tentacula, end in a deep blue; a silvery cast intermixed with the blue over the whole back, or upper parts, where the blue is lighter. It can turn itself on the back by a muscular contraction of the head part, the tail, and ramified arms inwards. The inferior parts are white. It died the third day, though the water was shifted once every day.

XVII. On the late Transit of Venus. By M. Wargentin, Sec. to the Royal Acad. of Sciences in Sweden. p. 59.

The observations on the last transit of Venus over the sun, made at the Cape of Good Hope, are excellent, and seem to decide, that the horizontal parallax of the sun is 8".1 or 8.3 at most. Mr. W. had before found it to be that quantity,

* The animal here described and figured by Mr. Du Pont is not an insect, but belongs to the Linnæan tribe of Mollusca, and is the Doris radiata of the Gmelinian edition of the Systema Naturæ.