present moment. In the "Preliminary Observations" prefixed to the Report of the last census, Mr. Rickman, to whose care that great national work was entrusted, remarks:

"That it has been reasonably supposed that the first enumeration of the people in Great Britain, especially as it took place in time of war, was rendered somewhat defective from backwardness or evasion in making the answers required, in as much as direct taxation, and more obviously the levy of men in every place, might possibly be founded on the results of such an investigation. But as no such effect was perceived to take place, the returns of the year 1811 were in all probability more full and accurate than those of 1801; and the war having now ceased, there remains no reason to suspect the least deficiency in the return of 1821. Indeed, the voluntary return of the ages of persons, an enquiry of far more labour than that of the enumeration of houses, families, and persons, proves, by the extent of the answers, that the Population Act has been carried into effect, in the year 1821, not merely with willingness, but even with zeal, throughout the greatest part of the kingdom."

The natural inference, however, from this candid statement on the part of Mr. Rickman is, that the increase of our population, as denoted by the last census, is to a certain extent merely apparent; and perhaps we shall not be wide of the truth in estimating, as that gentleman himself appears to do, the actual augmentation of our people at two-thirds of the number by which the returns of 1821 exceed those of 1811.

Mr. Booth makes some sensible remarks on the extreme deficiency of our Registers, both of baptisms and burials, in the second part of his pamphlet, which he has entitled “An Examination of the Censuses of Great Britain." But we must remain satisfied with this reference, as it is entirely out of our power either to follow the author through the numerous details into which he enters, or to render them intelligible to the reader in a narrow compass. We therefore take leave of Mr. Booth with an expression of regret that he should have so completely marred his object by employing, on an abstract enquiry, an irritating style and a contemptuous manner; and turned against himself so pointedly the sympathies of his reader by attacking with abusive, wanton, and scurrilous epithets a writer who stands very high in the estimation of the public, and whose views, however much they have been misunderstood, are patriotic, wise, and essentially hu

mane.

ART. VII. Philosophical Transactions of the Royal Society of London, for the Year 1822. Part II.

THE Volume of the Transactions now before us contains many papers of considerable interest, though not above one or two which can lay much claim to novelty of subject, or peculiar importance.

Nos. 30 and 31 are contributed by J. Goldingham, Esq. F.R.S. and contain an elaborate detail of his astronomical observations for fixing with accuracy the situation of Calcutta, Madras, and Bombay. A discussion follows, on the comparative merits of the different instruments and methods employed. Much supplementary information is also given respecting several places on the coast of India, which the author thinks will be useful to navigation.

This, then, is all that the united labours of the scientific world have to display, in any way connected with mathematical research. A falling off not difficult to be accounted for, if, as it is natural to suppose, mathematical investigations of only ordinary merit, meet with no better reception, than some of very superior excellence have lately done, at the great tribunal of science; and on whose rejection we in a late Number made some remarks.

Next in order from subjects of mathematical science, we will take those belonging to natural philosophy. Under this head we will first notice No. 19, entitled, Experiments and Observations on the Developement of Magnetical Properties in Steel and Iron by Percussion, by William Scoresby, Esq. Jun. Communicated by Sir H. Davy.

It appears that the fact of magnetic powers being given to iron by hammering, &c. was known upwards of two centuries ago: the experiments having been tried by Dr. Gilbert. But Mr. Scoresby is of opinion, that, although the fact was known, it was only viewed in reference to the power of causing a deviation in a needle, and was never applied to the case of lifting a weight. Mr. Scoresby having in a former paper, (Edinb. Phil. Trans. 1821,) investigated the principal laws of this sort of action, devotes the present to the practical part of the subject, as it concerns the forming of artificial magnets. For the purpose of these experiments, several hammers of different known weights were employed, and the results were observed, both by ascertaining the deviation on a needle, and the weight lifted. The latter, Mr. S. considers, cannot be regarded as giving an accurate measure of magnetic force; the nature of the surfaces, and con

sequent degree of contact, obviously leaving much room for uncertainty. But the observed deviations, when sufficient precautions were taken for preserving the same distance and direction in the attracting body, he considers to be an unobjectionable test of the degree of magnetic force.

The following are some of the principal results which he obtained.

A cylindrical bar of soft steel, 63 inches long, and weighing 592 grains, lifted, after repeated hammering on pewter and stone, 6 grains, but could not be made to lift 11 grains.

The same bar, hammered vertically upon the top of a poker, after twenty-two blows, lifted with its lower end, which was a north pole, 88 grains. On using a larger hammer, the effect increased and produced a deviation in the compass of 34° at three inches distance. Further hammering diminished rather than increased the effect. The bar being next invert. ed, the magnetism was nearly destroyed by one blow; and two reversed the poles. Hammering the end of the bar in the plane of the magnetic equator also destroyed the polarity'; but the effect was not fully produced until many blows had been struck.

When the poker had been previously hammered in a vertical position, an increase of effect was obtained on the bar. A single blow now enabled it to lift about 20 grains: and, when the end was hammered into a kind of cup, so as to be easily bruised, the bar was by one blow rendered capable of lifting between 30 and 40 grains. After ten blows, the highest effect obtained in all the experiments was produced; the same bar readily lifting a nail of 188 grains, being nearly onethird of its own weight.

The length of the bar increased the effect. The shorter bar attained its greatest power with fewer blows. Thus, in twenty blows,

Deviation produced, at 3 inches dist.

13°

24°

33°

A strong magnet was injured by hammering, and especially if the north pole was upwards. After a time no diminution could be effected.

The effects of hammering on soft iron were much less than in the case just mentioned of soft steel. With cast iron the effect was greater, but still not equal to the former.

Mr. Scoreby's mode of applying the knowledge thus ac

quired to the formation of magnets, we will give in his own words,

"The strong magnetising effect of percussion on soft steel induced me to apply the property to the formation of magnets. For this purpose I procured two bars of soft steel, thirty inches long and an inch broad; also six other flat bars of soft steel, eight inches long and half an inch broad, and a large bar of soft iron. The large steel and iron bars were not however absolutely necessary, as common pokers answer the purpose very well; but I was desirous to accelerate the process by the use of substances capable of aiding the developement of the magnetical properties in steel. The large iron bar was first hammered in a vertical position; it was then laid on the ground with its acquired south pole towards the south, and upon this end of it the large steel bars rested while they were hammered: they were also hammered upon each other. On the summit of one of the large steel bars, each of the small bars, held also vertically, was hammered in succession, and in a few minutes they had all acquired considerable lifting powers. Two of the smaller bars, connected by two short pieces of soft iron, in the form of a parallelogram, were now rubbed with the other four bars, in the manner of Canton; these were then changed for two others; and these again for the last two. After treating each pair of bars in this way for a number of times, and changing them whenever the manipulations had been continued for about a minute, the whole of the bars were at length found to be magnetised to saturation; each pair readily lifting above eight ounces." P. 250.

Mr. S. then adverts to the precautions he adopted to guard against any accidental magnetic influence, and one curious circumstance deserves to be noticed, that any bars which had been strongly magnetised, and had had their magnetism destroyed or neutralized by hammering, beating, or by the simultaneous contact of the two poles of another magnet placed transversely, were always found to have a much greater facility for receiving polarity in the same direction as before, than the contrary. Hence it generally happened that one blow with the original north end downward, produced as much effect as two or three blows did with the original south end downward.

"I also observed," says the author, "that the polarity of pokers, generally supposed to be permanent and considerable in intensity, was rather transient and weak: for in no instance did I meet with a poker the magnetism of which I could not destroy by a blow or two with a hammer on the point; and, in general, two blows, even when the poker was held in the hand, and not rested upon any thing, were sufficient to invert the poles."

Upon the whole, we must express our recommendation of

this paper to the attention of our readers; for, if it does not possess any great claim to originality of invention, or novelty of combinations, it details a number of facts of considerable interest, as tending to make us better acquainted with the mysterious operations of the magnetic principle. Having said thus much, we shall not be thought to be depreciating the merits of Mr. Scoreby's experiments, if a comparison is forced upon our minds, on seeing their insertion in the splendid pages of the volume before us, between them and some other magnetic discoveries which we have lately had occasion to describe, but which, though distinguished by the most profound science, and most extensive utility, were not thought worthy a place in the Transactions.

We proceed now to the papers in the Chemical depart

ment.

No. 20. On the Alloys of Steel. By J. Stodart, Esq. F.R.S. and Mr. M. Farraday, Chemical Assistant in the Royal Institution.

This paper relates to various processes which appear likely to become useful in the Arts. The authors having gone through a course of experiments on a small scale, in the laboratory of the Royal Institution on the alloys of steel with other metals, particularly some of the newly discovered ones, proceeded to repeat them in a larger way so as to try whether the compounds thus obtained could be rendered useful to the Arts. For this purpose their operations were removed from London to Sheffield, where they could obtain a proper furnace and other conveniences for bringing the metal to a state suited for the purposes of trial.

One of the most interesting results was the combination of steel with rhodium, in equal parts by weight, which produced a compound, when polished, of the most exquisite beauty and admirably adapted for metallic mirrors.

Silver was alloyed with steel in a proportion of less than 1-500th of the weight of the steel, and a compound resulted, whose hardness was considerably greater than the best kinds of steel hitherto known. This, the authors think, will be of great use in cutlery, where a very fine edge is required. And the requisite proportion of silver is so small that the expence is not likely to operate as an objection.

An alloy with platina though it was inferior to the last în hardness, yet excelled it in toughness. This compound is therefore recommended for all purposes of the arts where tenacity as well as hardness is wanted.

The objection as to expence would operate against the combination with rhodium, &c.