will be between Regulus and Eta in Leo, and the latter just leaving the upper part of the left paw of that constellation. Jupiter will also be in opposition to the Sun on the 2d, and Mars on the 6th of February. Moreover, these planets, by converse motion, will be in ecliptic conjunction on the 26th; Mars N. of Jupiter 3° 17'. On the 19th of March Mars becomes stationary, and afterwards direct; when, meeting Jupiter, he forms a second conjunction with that planet on the 28th, passing N. of Jove 20 16'. After this they will gradually separate, and by the 26th of May Mars will again pass N. of Regulus, at about 10 from that star. Hence, during February and March, they will not only prove interesting objects for the telescope, but also for the naked eye."

In the propriety of these remarks 1 fully concur; and being also of opinion, that it must be difficult to form a correct idea of these phenomena without graphic assistance, I have formed a sketch of the apparent paths of these planets, which is herewith submitted to your readers. Although it possesses little noveltyf, I trust it will be found of considerable utility, there being no British celestial map extant on which the paths can be readily delineated, except the enormous sheets lately published by the Useful Knowledge Society, and even on these the representation would be a disjointed and incomplete one, in consequence of its falling near the borders of two maps, where the distortion is extremely perplexing.

When alluding to these maps, I feel much inclined (but forbear) to go into a long detail respecting them. They have been several years on the anvil, so that the public had imagined their appearance was altogether abandoned. Since I saw the proofs four years ago, many corrections and improvements have been made; and the maps have been ushered into the world under the care of Professor de Morgan, whose companion volume con

*The projection is that of which the construction is explained in vol. xxi. p 339. The position of the planets are marked on the apparent orbits for the first of each month. The magnitudes of the stars are inferred by subtracting the number of rays from 10.

My much respected friend, the author of "Evening Amuseinents," constantly inculcated the propriety of partial maps of this kind. He gave sketches of the paths of the three superior planets in many of his annual volumes. The phenomena of a conjunction of two bright planets very near to their opposites is of rare occurrence.

UNLOCOMOTIVE LECTURERS.

Another attempt has just been made by the Court of Common Council, to remove the Gresham Lectures from that snug corner, over the north-eastern gate of the Royal Exchange, to which they are so devotedly attached for the very good reason, that its obscurity prevents their being very often annoyed by the presence of visitors. It was proposed, on the present occasion, to remove the scene of their labours to the New City of London Schools, on the site of Honey-lane Market; but, as on all previous occasions, the worthy Professors resolutely refused to move an inch, with one exception, in the person of Mr. Pul len, the recently elected Professor of As tronomy; and measures are now being taken to compel the unwelcome migration, if possible. The Professors allege, that they would be degraded by being at. tached to a mere school, and adduce, in proof of their great popularity, that the lectures, during the past year, have been attended by no fewer than 1,900 persons, out of the million and a half composing the population of London! Certes, the number does not appear very astonishing, when it is considered that, by Sir Thomas Gresham's will, there are to be two lectures read every day, during each term. It is high time that something should be done to render the establishment of some service. Whether that purpose would be best answered by a removal to the City of London School, may admit of question; but any thing is better than that matters should remain as they are.

ON PROPER AND IMPROPER PHILOSOPHI

CAL TERMS.

"Spirit of matter! beautiful heat!

Who bid'st atoms scatter, and then again meet !”*

Sir, It has often been observed, and at the same time lamented, that in philo sophical as well as in religious opinions, the great and fruitful source of controversy, may be traced to the vagueness of the terms which are set forth to represent or embody the principles under consideration. The Stoics and Epicureans wrangled for ages about the summum bonum, its constitution, and the mode of its attainment; and after all, it has been clearly shown by modern writers, that the controversy was a mere war of words, -that, so far as ideas on bona fide principles were concerned, both parties were agreed that it could only be that principle, or mode of action, which secured to the whole body of the people the largest amount of happiness; in short, that happiness and the summum bonum were convertible terms. But the Greeks, from their quick and lively temperament, were fond of disputation; and the summum bonum being received as an abstract term, that neither had, nor could have, other than an ideal existence, it was admirably adapted to eke out the argument-to set aside the possibility of a settlement of the con. troverted points; because each individual of the two opposing parties asserted his right (which no one had the power to deny), to lay hold of the ideal entity, and to deck it out with contingent properties and circumstances drawn from his own imagination.Hence, every disputant had his own summum bonum, the offspring of his own creative fancy, ich had nothing that was discernible common with that of his neighbour, except the name; and hence the wordy war became interminable. The controversy never was, and there is good reason to believe never will be 'settled, unless the terms are more clearly defined and restricted within certain determinate limits.

It were needless to point to the mathematics, for the purpose of showing that controversy is shut out from that department of science, simply by the well-defined and restricted application of the terms.

These lines are from a beautiful and philosophic Ode, by Junius Rediyivus,➡Vol. 23, 391, Page Mechanics' Magazine,

This is so well known that it need not be insisted on.

But with respect to terms embracing subjects of a mixed or general character, it is difficult to confine their application within limits that shall preclude the pos sibility of misconception, or, what is worse, misrepresentation; and, at the same time, to allow them sufficient latitude to comprehend the whole subject. It must, however, be allowed by every one who has given an ordinary share of attention to philosophical subjects, that in this department there is much room for improvement, and that, therefore, something may be gained by the attempt. If our endeavours be rewarded with only partial success, we shall consider that our labour has not been thrown away. And first, our attention should be directed to the introduction of a more orderly arrangement of those terms which form the basis of the physical science of modern times, from which the fundamental principles of our philosophy are derived.

Words are the types of things; and if the type could be made to represent the thing typified, completely denuded of all extraneous circumstances of all contingent and accidental properties, the great and fruitful sources of misconception would be almost entirely removed. The first step towards a right notion of proper terms rests upon, or is derived from, the following consideration: Throughout the whole of nature, every 'condition, change, circumstance, or property, essential or accidental, of which we are coinpetent to take cognizance, whether in morals or in physics, can only be recognised and treated of in a relative sense; that is, by comparison with the conditions, changes, &c., of surrounding objects. It thus appears that those terms only can be accepted as faithful types, in which the thing typified is presented to our mind in this relative sense, because in this sense only can we take a proper estimate of the attributes or properties with which it may be clothed. Relative terms are, therefore, proper terms. There are no absolute conditions or properties, therefore absolute terms are improper; they convey to the mind an idea which has no foundation in nature. In the following table we have eighteen varieties, or forms of expression, under which are comprehended two general ideas those upon one side all spring from the same root,

XX

But let the repulsive and attractive forces act alternately and between the point A and the points B B, the two balls may continue in motion for ever.

This simple diagram illustrates and explains all the known motions on the earth, and, by analogy, may also serve to illustrate the motions of the whole material universe. The circumstances will not be changed, whether we conceive these two little balls to represent two atoms or two worlds. But we must bear one condition in mind, which the diagram does not represent, that from the angle of incidence of the two opposite forces, all bodies under their action must necessarily move from and to the centre, in circular or spiral paths, and not in right lines. Now a very little consideration will enable us to perceive that the motion of the balls from the central point A, or from each other, under the repulsive force, gives the idea of the expansion of matter in its simplest form, and also a fair illustration of the decomposition of matter. Therefore, these three terms represent the same idea of a repelling, expanding, or decomposing FORCE. The three terms may be accepted as synonymous, or, at least, as varied by very slight modifications. In the same way the contraction and recom

with attraction or the attractive force.

It is very plain that these attractions and repulsions do not furnish ideas corresponding with the common notions of heaviness or weight, nor their opposites, lightness or weightlessness, because we conceive of heaviness and lightness as absolute conditions, and therefore, when they are compared with a relative standard, we find them devoid of meaning; with respect to gravity, it is proper or improper according as it is given absolutely or relatively; if it is given and received as signifying attraction, it is a proper term but we must recollect, that under the influence of an attractive force only, motion could not continue on the surface of the earth; with this one force only, there could be no motion from the surface. But there is motion both from or to the earth's surface; if, therefore, it is contended that motion towards the earth's centre proceeds from gravity, it must be admitted that motion from the centre or upward motion, as we would call it, proceed from levity; and what is levity? Nothing. I presume that no one will be found sturdy enough to contend that levity is the representative of a force.

But it may be said, that referring the action of gravity to an horizontal plain, is giving an unfair view of its mode of action. Let us, therefore, turn to diagram, fig. 2. Here we find repulsion, expansion, attraction, contraction, apply with equal propriety, as in the former case. A repulsive force exerted between A, B B, and C C, represents the expansion of matter; and an attractive force between the same bodies represents the contraction of matter. Here our ideas are clear, if we know which of the two forces is acting between two or more bodies, we can tell at once in what direction the motion should proceed; but if we consider the bodies BB' and C C' as being influenced by heaviness or lightness, considered absolutely, our perception becomes confused, and we are at a loss to say in what direction the motion of these ought to proceed. In the same way (diagram, fig. 1), if we suppose one ball to represent the agent and the other the patient, their attractions and repulsions will give a fair representation of the mechanical forces, drawing and pushing, and will show that they are relative, and therefore proper terms.