Here, in this tearful vale, where sorrow dwells And trembling mortals own the reign of fear, At his command, the sculptur’d tablet tells, Where hope exists, to dry the wand’rer’s tear. For, read his works, O man! and then believe, The mind that grasp’d at systems so sublime, Beyond the mortal part must ever live, And bloom, in sacred heav’n’s ethereal clime. Footnote 75a: The Port-Folio. ----- It being thus apparent, that not only Mr. Rittenhouse’s mother but her brother David Williams were persons of uncommon intellectual powers, the writer thinks it fairly presumable, that our Astronomer inherited his genius from his mother’s family.[76] His surviving brother has decidedly expressed this opinion: in a letter on the subject of the deceased, addressed to the writer of these memoirs soon after Dr. Rittenhouse’s death, he says—“I am convinced his genius was more derived from his mother, than from his father.” ----- Footnote 76: In order to gratify the curiosity, if not to remove the doubts, of such persons as are not disposed to believe in the reality of any thing like an hereditary power, bias, or propensity of the mind, the following memorable instances are selected from many others which might be adduced; to shew that mental faculties, as well as corporeal qualities and even mental and bodily diseases, are sometimes inherited by children from their parents: perhaps cases of this kind exist more frequently than is either observed or imagined. Mr. James Gregory, the inventor of the reflecting telescope in common use, called the Gregorian, was one of the most distinguished mathematicians of the seventeenth century. This eminent man, who was born at Aberdeen in Scotland in the year 1638, was a son of the Rev. Mr. John Gregory, minister of Drumoak in the same county: his mother was, moreover, a daughter of Mr. David Anderson, of Finzaugh, a gentleman who possessed a singular turn for mathematical pursuits. Mr. David Gregory, a nephew of the foregoing, was some time Savilian professor of astronomy at Oxford. This _Subtilissimi Ingenii Mathematicus_, as he is styled by his successor Dr. Smith, was born at Aberdeen, in the year 1661. Of the four sons of this celebrated mathematician,— David, a mathematician, was regius professor of modern history, at Oxford; James was professor of mathematics, at Edinburgh; and Charles was also professor of mathematics, at St. Andrew’s.