In the adoption of this plan, the writer has been chiefly influenced by a desire to illustrate the history, genius and character of the times, which his Memoirs embrace; together with the progress and improvement of literature, science and the arts, within the same compass, more especially in this country; and this consideration has obviously led him to introduce, in conjunction with those objects, as well as with the Life of the great American Philosopher, various notices of many persons distinguished for their talents and merit, not only in our own time, but at different periods in the annals of science. He has thought it right to rescue from oblivion—to commemorate in this way, if not to consecrate, the names of some men in this country, more especially, who deserve to be ranked among the worthies of America. All this the writer has done, too, in conformity to the mode prosecuted by some of the most judicious biographers and memorialists, together with other writers of the same class: It is believed to be a manner of treating the interesting subjects, on which the pens of such authors have been employed, which, while it renders their works more pleasing, greatly increases their usefulness.—If, therefore, some of the matter which has been introduced into the present work should, at first sight, appear irrelative, and even unimportant, the Memorialist nevertheless flatters himself, that, on reflection, nothing will be deemed really so, how remotely soever it may seem, on a transient view of the subject, to be connected with the principal design of the undertaking; provided it has a tendency to illustrate the great objects he was desirous of accomplishing.[I1] ----- Footnote I1: The biographer of RITTENHOUSE entirely coincides with the compilers of the _Encyclopædia Britannica_, in opinion, respecting the utility and propriety of giving an account, in such Memoirs as the present, of _things_ as well as _persons_, connected in various ways with the main object of the work. In the preface to that useful dictionary of arts, sciences and miscellaneous literature, are the following observations: the consideration they merit; is submitted to the good sense of the reader.