PREFACE. IN the preparation of a practical treatise upon the Locomotive Engine, the Author has had occasion to introduce a short chapter upon the action of Heat in the generation of steam. The prevalent hypotheses respecting the nature and precise mode of action of Heat appeared unsatisfactory; while the reasoning, indispensable to the proper statement of new views, was found likely to occupy a space far exceeding the limits which could be properly allotted to such a subject in a work intended only for the Mechanical Engineer. It was deemed best, therefore, to prepare a separate essay, the conclusions of which could be condensed within a small compass in the larger work, and to which essay those who might wish to pursue the subject could be referred. Hence the appearance of the following pages. But for the constant pressure of professional duties the Author would have extended his reasoning much further, and have devoted more time to the consideration of the terms best fitted to convey his meaning. The difficulties presented under every aspect of a question so vast as that of the nature of Heat may, possibly, procure for him some indulgence for the many deficiencies, of which, as existing in the following pages, none can be more deeply sensible than himself. 3, Upper Bedford-place, Russell-square, London, August, 1863. |