E. D. G. exuding commendation as smooth and free from aspe rity as olive-oil. But though the last-mentioned gentleman is almost wholly vituperative, his employer has by no means confined himself to sentiments of an opposite description. Hence I am under the necessity of attributing the unwonted mode of reviewing, which the conductor of the Gardener's Magazine has thought fit to adopt on this occasion, to an amiable desire on his part of concealing from his readers the praise which has unwittingly been elicited from him. The fact that he has placed E. D. G.'s lucubrations before his own, adds strength to an opinion, which is not rendered less probable by the odd reason which he assigns for the relative position he has given to the two parts of the review. His coadjutor's remarks are placed first, forsooth, because they came to hand after his own were written. Does Mr Loudon always act on the principle of making the "last first, and the first last ?"

With the remainder of my remarks I must be extremely brief. The worthy critic insinuates that certain chapters of the Practical Planter belong not to me, but to some Edinburgh editor. Something peculiarly attic about these chapters may have caused suspicion in Mr Loudon; but his surmise is nevertheless wrong, by the token that I can produce every fragment of them in the original blotted manuscript, which never saw Edinburgh. Some parts of my work appear to him to have a bookmaking character; and, in order to show that he has a right to judge on this point, he speaks of himself as knowing "something of the trade." If he means the trade of bookmaking, his pretensions, I make bold to say, are founded on a rock. But he talks too modestly of his science when he intimates that he knows only something; he might with perfect truth have averred that he knew an immense deal. I, for my part, have no hesitation in allowing him the praise of being the greatest bookmaker of the age. No one can read a few pages of any of his voluminous publications, without seeing at once that he is an adept in the business. His Encyclopædias show, that one who is a master in the craft may publish the most ponderous tomes without employing his brains at all, without even being at the expense of a pen, farther than is necessary for dashing off the title-page and preface. The scissars are the great instrument in the hands of such an expert

tradesman as Mr Loudon, and with these he can accomplish feats which are truly astonishing. By means of the scissars an author may be gutted of his choicest contents in a few minutesa labour which it might require days to accomplish, by merely copying with such a lubberly tool as a pen. By means of this instrument, a single bookmaker may keep a press going for years together, without the printer's devil being ever once sent away without copy. By means of it, in fine, any thing short of miracles in the way of authorship may be achieved. The scissars, however, sometimes commit sad slips in the hands of even the most skilful operators. Many examples of this occur in Mr Loudon's own works, but I shall only give two instances. In cabbaging an account of the boar from some naturalist, our author has allowed his instrument to intrude on a paragraph relating to the bear, a circumstance which may lead some of his readers to suppose that the two animals are one and the same. By a similar mistake, he has furnished sheep with an appendage which Nature certainly has not given them, namely, claws. Some people may think this strange in the editor of a Magazine of Natural History, but they should remember that the most expert tailor will at times cut his cloth a few inches longer than is necessary.

I have thus, Sir, endeavoured to do justice to Mr Loudon as a reviewer. Much more I might have said, but I was unwill. ing to incur the risk of being excluded from your pages, on the score of unreasonable length. Hoping that you will spare room for my remarks in your next Number, I have the honour to be, &c. THOS. CRUICKSHANK.

CARESTON, 22d Dec. 1830.

[We have afforded Mr Cruickshank the opportunity he has required of defending himself against what he conceives to be an unjust attack. In our former Number, we referred to his work on Planting, with the approbation which we conceived it to deserve, and with that feeling towards merit and talent like his, which it will, in all cases, be a gratification to us to evince. In the same review to which Mr Cruickshank objects, we find something like a reflection upon ourselves, on which, how

ever, as it is without any apparent cause, or even meaning, we need not make any grave comment. Mr Loudon accuses us of entertaining some "prejudicial feeling" connected with the subject of planting. We presume that either the printer or the scissars have committed some mistake. It is more pleasing to us to be able to state, that having apprized Mr Loudon that Mr Cruickshank had announced to us his intention to reply to the somewhat questionable criticism of himself and his friend Mr E. D. G., he offered at once to allow Mr Cruickshank to insert any answer he might think fit in the Gardener's Magazine itself—a trait of candour and good feeling in Mr Loudon, which deserves to be appreciated. We avail ourselves, at the same time, of this opportunity of correcting a misapprehension which Mr Loudon has pointed out to us. In our recent notice of Mr Macnab's work, we quoted that gentleman as commenting on certain absurd practices recommended in the planting of evergreens,—namely, that the roots should be well dried, and that the planters need not be too nice in the operation. Mr Loudon mentions, that this remark, which was contained in the Kalendarial Index of the Encyclopædia of Gardening, was meant ironically. It is quite fair to admit of this explanation. It is impossible to suppose that Mr Loudon intended this remark otherwise than as a hit at ignorant and careless planters.— ED.]

ON THE CLASS OF INSTRUMENTS TERMED GRUBBERS OR

CULTIVATORS.

IN a former Number of this work, we described the form, and explained the mode of action, of the harrow-an instrument in universal use in tillage, and of which the purpose is to pulverize the ground which has been turned up by the plough,-to disengage from it, and collect the weeds and roots which it may contain, or to cover the seeds of the cultivated plants. We showed that the common rectangular harrow is in this respect

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defective,-that the teeth do not indent the surface of the ground at regular distances; some of them following nearly in the same line, while, in other cases, the intervals are large and irregular. This indeed arises not so much from the form of the harrow, as from the manner in which the draught is attached to it. But even when the draught is attached in a proper manner, the rectangular form of the harrow, as we endeavoured to show, is attended with certain inconveniences in practice, which may be remedied by rendering its form rhomboidal, as shown in Fig. 1.

By adopting this principle of construction, it will appear that the animals of draught move abreast, and exert an equal force in pulling, while the teeth indent the surface of the ground at equal distances, as may be made apparent by drawing lines from the centres of the different teeth parallel to the line of motion.

The advantage of this form of the harrow, as compared with the common form, is, that the teeth penetrate more into the ground, and that the instrument is moved by a less force of draught.

It must at the same time be observed, that, in certain cases,

the more steady motion of the rhomboidal harrow is less suited to the operation to be performed, than the irregular motion of the common harrow, which being attached to the draught at one point only, is more tossed and shaken when passing over rough or uneven ground.

There are two cases in which this shaking or lateral motion is useful. The first is when the seeds of plants are to be covered. In this case, the object is to give as great an agitation as possible to the upper particles of the soil, and then it is not necessary that the teeth of the harrow penetrate far into the ground; but it is important that the different teeth pass over as much of the surface in the same time as possible. This will be illus trated by inspecting the following figure (Fig. 2.), exhibiting the different effect produced by the teeth when they have a steady, and when they have a lateral motion.

Fig. 2.

The second case where the lateral or shaking motion is useful, is when the surface is covered with large clods, bound together by the roots of plants. In this case the teeth, being constantly forced out of the direct line of motion by the obstacles which they encounter, and so constantly exerting a considerable force to regain the equilibrium, beat or strike the clods of earth upon the surface, and thus tend to break them, and disengage the roots and stems which bind them together. On rough, turfy, or cloddy ground, therefore, as well as when the sole purpose is to cover seeds, the lateral or shaking motion of the harrow is advantageous. But, upon the whole, as a general instrument of tillage, the rhomboidal harrow must be considered the more perfect and efficacious; and quite a sufficient degree