“_Je me suis proposé de grands desseins dans ce petit ouvrage_,” as Bernardin de Saint-Pierre says in the preface to his pathetic story of _Paul et Virginie_. I have sought to present to the great English-speaking world the work of a genius hitherto only known to a few men of science, and not well known, even among the people of France, for whose credit he has done so much. In placing before the readers of this translation his book—small of size but great in matter as it is—I feel that I have accomplished an easy task, but one of real importance. I have been asked, as Corresponding Member for the United States of the Société des Ingénieurs Civils de France, to communicate to my colleagues scientific and professional memoirs and whatever may be of interest to them—“_en un mot, que nous resserrions les liens qui font des ingénieurs en général une seule famille_.” That were a pleasant task; but a grander and a more agreeable one still is that of bringing “nearer in heart and thought” the members of that still larger community, the men of science of the world, and of weaving still more firmly and closely those bonds of kindly thought and feeling which are growing continually more numerous and stronger as the nations are brought to see that humanity is larger and more important than political divisions, and that the labors of educated men and of the guiding minds in the great industries are constantly doing more to promote a true brotherhood of mankind than ever have, or ever can, the greatest statesmen.
When the wonderful intellectual accomplishments of men like the elder Sadi Carnot become known and appreciated by the world, much more will have been accomplished in this direction. It is perhaps from this point of view that the importance of such work will be most fully recognized. When the little treatise which is here for the first time published in English becomes familiar to those for whom it is intended, it will be, to many at least, a matter of surprise no less than pleasure to discover that France has produced a writer on this now familiar subject whose inspiration anticipated many of the principles that those founders of the modern science, Rankine and Clausius, worked out through the tedious and difficult methods of the higher mathematics, and which were hailed by their contemporaries as marvellous discoveries.
