It has ever been expected of an author, that in presenting himself to the notice of the public, he should state his claims to the attention he seems to solicit, and afford the means of judging how far it is likely to be rewarded. Anticipating these reasonable expectations, he endeavours to satisfy them by a declaration of the motives which may have led to the undertaking, or influenced his judgment respecting any peculiarity of plan or execution, by which his work may be distinguished. By affording this satisfaction to others, he also consults for his own interest or reputation; being well aware, that it is only by a due regard to the particular ends and objects of the writer, it can be ascertained whether his efforts are called for, his methods well chosen; or, even after the perusal, whether the work itself is fairly executed. This first duty to the public and himself, the writer of the following Treatise shall endeavour to discharge as well as he is able.
Having been called to the chair of Natural Philosophy in the University of Dublin, he naturally felt it to be peculiarly his duty, in addition to his course of public lectures, to furnish a manual for the instruction of the students in his own department; the work long in their hands, consisting of lectures formerly delivered by Professor Helsham, being extremely imperfect, even as a system of Statics, to which branch it is almost exclusively devoted. In making this remark, it is not intended to cast any imputation on the memory of that writer. His volume conveys, in the most clear and familiar style, nearly all that was known on the subject when it first appeared. But whatever may be its peculiar merits, he who is aware of the vast improvements which have been made in the establishment and development of the principles of Mechanical Philosophy, needs only to be informed, that the work here spoken of appeared at the beginning of the eighteenth, and was probably written before the close of the seventeenth, century; and it is presumed that he will deem it unnecessary to inquire whether it contains, or not, a course of elementary instruction fitted for the present age.
Some attempt to supply the deficiency bad indeed been made by the late Bishop Hamilton, author of a work on Conic Sections, fit to be placed beside the most finished productions of the ancient Geometers. But Natural Philosophy is chiefly of recent growth; and Elementary Treatises are the latest which arrive at perfection. During the progress of science, the task of its cultivators is that of exploring some region of vast extent: and it is not until their discoveries shall have swelled so as to approximate, that the whole can be combined into one continuous system. It is not, therefore, detracting from the merited reputation of that writer to assert, that the four supplementary lectures, first published about fifty years ago, are now only fitted to satisfy the curious as to the state of the science at that period.
Such was the acknowledged character of the manuals from which the students were to be instructed in this department of science: and the tutors, generally too much occupied in the discharge of their laborious duties to engage in a work for which some leisure was essentially requisite, contented themselves with supplying the deficiency of written treatises by the oral instruction of their pupils in their respective courses; until Doctor Robinson, Professor of Astronomy at Armagh, and late Fellow of Dublin College, in addition to his labours as a tutor, kindly suffered himself to be charged with the task of furnishing a Treatise suited to the wants of this Seminary. And assuredly, the acknowledged talents of that gentleman, the ardour with which he was known to have proceeded in every scientific pursuit, the various information with which his comprehensive mind was known to be most richly stored, and which he never failed to communicate, when called on, in a manner the most happy and effective, fully warranted the expectation, that the work of such a writer would prove of the highest value. - This expectation was not disappointed. The volume, which he has presented, is a summary of all that is known relative both to the theory of Mechanical Philosophy and its application to the Arts. But the information it conveys is dealt according to the riches of the store from whence it proceeded, rather than to the wants of those to whom it is offered; and the very principles themselves are thrown off with the haste of an overflowing mind, rather than unfolded with the patience so requisite in him who would accommodate himself to the apprehension of mere beginners. Accordingly, the work, though of the highest value to a numerous class of students, has not been considered as fitted to satisfy the most pressing wants of the University
Of the scientific productions of the sister Universities, it was not the intention of the writer to make any remark which might seem invidious. Latterly, indeed, that of Cambridge has put forth her native strength, which appears still sufficient to replace her on the eminence she had formerly occupied. But the elementary works on Mechanics are those here to be spoken of; and it is presumed it would be admitted even there, that the work, hitherto in general use, belongs to the past, and not to the present state of science. Others, indeed, have since issued from her press of much higher pretensions; but none which would seem to have been written for purposes altogether the same as those here contemplated.
Such appear to be the imperfections of the works heretofore provided by the Universities for the instruction of their youth in the department of Mechanical Philosophy, and it would plainly be idle to look elsewhere for better. Those who concur with the author in this view, will also agree with him in supposing, that as the present attempt was not uncalled for, the only charge which can lie against him must relate to the quality of the work which he proposes to substitute for those already in use. For this indeed he has some apologies to offer, and a large share of indulgence to solicit. Such he hopes will not be withheld, when the purposes for which the work was more particularly intended are considered. Some explanation of these purposes may be requisite for the stranger to the plan of education adopted in the Dublin University. He is to be informed, that whilst it invites by honours to the highest attainments, and provides the most able assistance for those who may be so allured, it forbears from compelling attention to the subjects of its instructions beyond very moderate limits. The sound discretion manifested in this treatment of the younger members, is chiefly conspicuous in what relates to their mathematical studies. In a course of academic instruction, by which the youth of the country are to be qualified for the various professional duties of active life, and, therefore, necessarily embracing a considerable variety of subjects, it was not to be proposed that all should become profound mathematicians. Neither could it be deemed expedient to interfere with the tastes of individuals, by which they may be directed into some other of the many walks of literature, perhaps equally useful, and certainly to many minds more inviting. In a society so diversified by tastes and objects, the number of those who do not enter on the higher branches of Mathematics must, at all times, be considerable. The qualifications of such, as well as of those of higher attainments among the students of the University, were necessarily to be attended to in a work proposed for their general use. Accordingly, in the following Treatise, the mathematical reasoning is sparingly resorted to, and as much as possible confined to the mere elements. Writing under these restrictions, and, in a certain degree, obliged to forego the aids peculiarly adapted to the science here treated of, the writer is apprehensive that he may have afforded to the mathematical reader some ground of complaint; yet it is to be hoped that he will not be dissatisfied with those sections which are more particularly intended for his perusal.
Such were the views of the author, and such the modifications of character which he has endeavoured to give to his performance. Should it be favourably received by the University, as a work suited to the purposes for which it was intended, he shall feel encouraged to complete what is now done by the addition of a second volume: and for the judgment whereby it is to be decided, whether he is to proceed, or here to close his labours, he waits with some anxiety.
After explaining his views to the reader, the next duty of an author is to offer some acknowledgments for the aids he may have derived from his predecessors. Yet much in this way cannot be required from the writer of an Elementary Treatise, where there is little room for any pretension to originality. Most works of merit, wherein the writer could expect to find any thing connected with his subject, he has consulted j and by many of them he has profited. Among those to whom he is most largely indebted is Poinsot, whom he has followed by the adoption of his theory of couples, and his use of that doctrine for the establishment of the conditions of equilibrium. To this name must be added that of Poisson, an author not less remarkable for the depth of his views than for the elegance with which he unfolds them.