《Letters on Different Subjects in Natural Philosophy, Volume 1 (Letters to a German Princess)》 - 免费有声读物

The Letters of Euler to a German Princess have acquired over all Europe a celebrity to which the reputation of the Author, the choice and importance of the several subjects, and the clearness of elucidation justly entitle them. They have deservedly been considered as a treasury of science, adapted to the purposes of every common seminary of learning. They may be studied to advantage without much previous elementary knowledge; they convey accurate ideas respecting a variety of objects, highly interesting in themselves, or calculated to excite a laudable curiosity; they inspire a proper taste for the sciences, and for that sound philosophy which, supported by science, and never losing sight of her cautious, steady, methodical advances, runs no risk of perplexing or misleading the attentive student. - Summary by Nicolas de Condorcet