easily moved by the lever either in the same or in parallel planes, but at right angles to each other; while if both be moved at the same time, a diagonal motion is obtained at the pleasure of the operator.

This plan of a traversing stage has many advantages, it is in the first place simple in its construction, and is very easily managed— and as the end of the lever to which the hand is applied moves in all cases in exactly the opposite direction to that in which the stage is moved by it; and as the compound microscope always inverts the image of the object under examination, the object will appear to move in the direction of the hand. But the great objections to this form of the traversing stage, are that the lever is very much in the way, and being attached to one of the extreme angles of the stage, when, it is in use, the strain is thrown more upon those parts of the stage in the vicinity of the lever, which wear away more rapidly than the others, and soon impair the correct working of the instrument.

The next mode of producing a traversing motion, is that usually known as Turrell's plan, and is described by that gentleman in the 49th volume of the transactions of the Society of Arts. In this mode the lever is entirely dispensed with, and the different motions are communicated to the stage plate, by two milled heads placed together, at the right hand side of the stage, and turning upon concentric axes. The motion of one of the plates of the stage is produced by turning one of the milled heads attracted to a pinion which works in a rack attached to the under side of the plate. The motion of the other plate is produced by the other milled head which works a screw, in a thread attached to the under side of the second plate; and by working the two milled heads at the same time, a diagonal motion is given to the stage. But apart from the complexity of this arrangement and its great liability to get out of order, it has several very serious defects, the greatest one being that in order to produce a diagonal motion in some directions it is necessary to use both hands, an objection which this form of stage was expressly designed to meet, but which it only partially removes.

In the microscope which I have now the honor to bring under the notice of the Canadian Institute, this difficulty is entirely overcome, and by a combination of the lever and the screw, the advantages, without the defects, of both Mr. White's and Mr. Turrell's plans are secured.

I have placed immediately under, and running the whole way across the stage, the lever f g Fig. 1. on which for about two inches

of it, is cut a spiral groove, h i. The fulcrum is at f on the left side of the stage in a small pillar rising out of a slight projection from the lowest plate of it, 3 and is so contrived, that

the lever can be easily turned on its own axis. On the other end of this lever at g a milled

head is fixed, by which the different motions are given to the lever. An enlarged representation of the adjustment for the fulcrum is given at Fig. 2., representing a small brass pillar, which passing through the under plate of the stage, is held down by a forked piece of brass screwed to the under side of the plate, and accurately fitting the neck cut in the pillar at o, so that the pillar can readily be turned on its own axis while firmly held in its place. The end of the lever having a similar neck, is shown at m; this fits into the pillar and is held in its place by a small forked piece of iron, n, passing down over the neck, and secured by the small screw p. The grooved part of the lever passes through a short brass tube, e (Fig. 1.,) (an enlarged representation of which is given at Fig. 3.) to this tube a small stem is attached, which screws into the under side of the upper stage plate by a left handed screw, a small steel screw 8 passes through the tube, the point of which fits into the spiral groove

Fig.2.

P

an

n

Fig.3.

r

hi of the lever. The upper stage plate slides in dove-tailed grooves made in a frame of brass, and this frame slides in the dove-tailed grooves at a b and dc but at right angles to the former. The arm which carries the compound body rises from the projection shown at k; by turning the milled head g the action of the spiral groove on the pin in the tube e moves it, and with it the stage to which it is attached, to or from the hand; while by moving the milled head backward or forward, a transverse motion is produced, and by com

bining the two, a diagonal movement at the will of the operator is secured.

The advantages of this plan are simply these: 1st, the lever is not in the way of the operator, yet very easy of access, and the power is applied as near the centre of the stage plate as it is possible for it to be. 2nd, only one hand can in any case be necessary to produce every motion that may be desired; and 3rd, it is very simple, is not liable to get out of order, and if it should happen to get out of repair can readily be set right again.

I may perhaps be permitted to point out another improvement in this instrument, which has lately been introduced in England, and I believe also in the United States. This consists of a new arrangement for the coarse adjustment of focus.

The rack and pinion movement which is always unsteady and works by jerks even when most carefully constructed, is here dispensed with, and instead of it a chain movement is substituted, which has the advantage of being much smoother, and more sensitive, of being less likely to become unequal by wear, and of being easily tightened if it should cease to act, or "loose time" as it is technically called, while its delicacy and smoothness admit of an exact adjustment being made by its means alone, even when using high powers.

REVIEWS.

Gales in the Atlantic: By Lieutenant Maury. U. S. N., Washington Observatory, May, 1857.

In extending a knowledge of the physical phenomena of the Atlantic Ocean, the publications of the Washington Observatory under the able superintendence of the author of the "Physical Geography of the Sea," stand deservedly pre-eminent. Lieutenant Maury's Wind and Current Charts-an annual volume of over nine hundred quarto pages accompanied by a large number of ingenious and elaborately executed maps-are universally allowed to have contributed the most essential aid to navigation. As Humboldt truly states, the shortening of many a dreary voyage may be cited as one of their results. In that valuable publication, the gales of the Atlantic are especially discussed; and various explanatory

diagrams are given in illustration of their peculiarities of occurrence. In the publication now under notice, this subject is still further elaborated; and we are presented with a chart of the North and South Atlantic Oceans, for each month of the year, shewing by an ingenious arrangement of colours, the comparative frequency of gales, over given areas, in the different months. Three facts are brought strikingly before us by an inspection of these gale-charts. First, the marked preponderance of stormy weather generally in the North, as contrasted with the South Atlantic, at least for the winter months; secondly, the scarcity of gales between the parallels of 30° north and south; and thirdly, the remarkable difference between the frequency of gales in the winter, as compared with the summer months, over that region of the North Atlantic lying more especially in the track of ocean travel between the United States and Europe. Whilst in the October, November, December, January, February, March, and April charts, an extended and unbroken line of colour stretches from the British Isles to the Atlantic sea-board of the States only varying somewhat in intensity and breadth-in the June, July, and August charts, merely a few limited patches meet the eye. In his brief explanation of these charts, Lieutenant Maury states that they were principally worked out with a view to ascertain the most tranquil and favorable time for laying the sub-Atlantic telegraph. This time, and necessarily also the most favorable season for passenger travel across the Atlantic, he shews to be about the end of July, or the beginning of August. "At no season of the year," writes Lieutenant Maury, " can the passage around either of the Stormy Capes,' as poets call them, vie for storms with the winter passage between England and America." And again, "this part of the ocean is most tranquil in summer. Taking averages, we have in it fewer gales but more fogs and ice in June than in July or August; but fewer fogs and least ice in August. The last of July and first of August appears to be the most favorable time for laying the subAtlantic telegraph. This information may be useful to invalids and others crossing the Atlantic, as well as to those engaged in this enterprize."

Although these gale-charts are intended to be considered in the light of approximations merely, some idea may be formed of the care bestowed on their compilation, when we state that they embody the results of no less than 265,292 days of observations.

VOL. II.-T

E. J. C.

Journal de l'Instruction Publique: Montreal, (Bas-Canada,) 1857.-Nos. 1, 2, 3 and 4.

Journal of Education: Montreal, (Lower Canada,) 1857. Nos. 1, 2, and 3.

We notice with great satisfaction the nearly simultaneous appear. ance of the two educational journals of Lower Canada: each, as we trust, and fully believe, the avant courier of a new era for educational progress in that part of the Province. They appear as the organs of the improved Common School system of Lower Canada, now established with its twin Normal Schools at Montreal, the McGill and the Jacques Cartier Schools; and at Quebec the Laval Normal School; all under the efficient control of the Hon. Pierre J O. Chauveau, Chief Superintendent of Education for that part of the United Province.

It argues well for the success of the newly inaugurated system that an honest attempt is thus being made to adapt the educational system, not only to the wants, but also to the opinions and prejudices of the two very diverse elements which constitute the combined population of that portion of British North America, instead of attempting any forced and unattainable theoretic uniformity. The two journals thus addressed to different sections of the population, who are being trained under systems diverse in some important respects, and with different languages, historical associations, and aims are designed each with a view to their own special readers; while, nevertheless, they have much ground in common, and cannot fail to exercise a beneficial and stimulating influence on each other. That they are to move in harmonious combination is the present purpose of their editors, and in this worthy aim we wish them all success. The editor of the English journal, after detailing the design and objects of the work, and stating the varied contents with which it is purposed to fill its pages, thus concludes his first leading article, speaking in part for both journals:

Every thing congenial with public instruction will find its place in our columns, varied we hope in the most pleasing manner. Poetry will now and then lend us its harmonious accents. Science in its innumerable departments will afford us amusement and instruction. History, and more especially that of Canada, will frequently unfold an interesting page to our young readers. The passing events of our day, without any allusion to local politics will teach us many a lesson, and finally Religion that aromat (as a great English chancellor had it,) without which all science would be putrified, religion we hope will pervade all our writings, and by its sacred influence will exclude from our columns anything that might offend the eye even of the most scrupulous of our readers. With the help of these power. ful elements, and we hope, with the assistance of all the friends of education, "Le