Part 81

Footnote 325:

A second edition of the first volume was published in the year 1789, in consequence of the extraordinary demand for that book, by reason of the very important papers respecting the Transit of Venus, contained in it.

Footnote 326:

Some further remarks respecting this comet, than those contained in Dr. Rittenhouse’s communication, here referred to, will be found in an extract which has already been given, of his letter to the Rev. Mr. Barton, under the date of July 30, 1770.

-----

5. An easy method of deducing the True Time of the Sun’s passing the Meridian, per clock, from a comparison of four equal altitudes, observed on two succeeding days; by David Rittenhouse, A. M. Communicated by William Smith, D. D. Prov. Coll. Philad.—Aug. 17. 1770.

-----

Footnote 327:

Mr. Francis de Zach (Astronomer to the duke of Saxe-Gotha,) in the explanation and use of his table, No. 38, entitled, “Correctio horæ meridianæ prodeuntis ex altitudinibus correspondentibus Solis,” says—“Tradit Clarissimus DAV. RITTENHOUSE, in Transactionibus Americanis (vol. 1. p. 155. edit. 2.), Methodum novum correctionis horæ meridianæ, absque tabulis, ex solâ observatione deducendæ; sed requiruntur, ad hoc, duorum dierum subsequentium altitudines quatuor æquales: id est, sub eadem altitudine manè et vesperi factæ, ad assequendam ex his, correctiones meridiei, Regulæ Clariss. Authoris sunt sequentes:” Mr. de Zach then lays down Dr. Rittenhouse’s Rules, which will be found in the Transactions of the American Philosophical Society, already referred to; and adds—“Exempla hoc perspicuum reddent:” he next states two examples, from which he deduces proofs of the accuracy of Dr. Rittenhouse’s method. See “Tabulæ Motuum Solis, novæ et correctæ, ex Theoriâ Gravitatis et Observationibus recentissimis erutæ, &c. auctore Francisco de Zach:” printed at Gotha, in 1792.

-----

6. Account of the Terrestrial Measurement of the difference of Longitude between the Observatories of Norriton and Philadelphia; drawn up by the Rev. Dr. Smith, in behalf of Mr. Lukens, Mr. Rittenhouse and himself, the committee appointed by the Am. Philos. Society, for that purpose, agreeably to the request of the Astronomer-Royal of England. Dated, Aug. 17. 1770.

7. The second volume, printed in the year 1786, contains—An Explanation of an Optical deception. Read, March 3. 1780.

8. An Account of some Experiments on Magnetism; in a letter from Mr. Rittenhouse to John Page, Esq. of Williamsburgh. Read, Feb. 6. 1781.

9. A letter from David Rittenhouse, Esq. to John Page, Esq. in answer to one from Mr. Page;) concerning a remarkable Meteor, seen in Virginia and Pennsylvania, on the 31st of Oct. 1779. Read, May 2. 1783. (N. B. Mr. Rittenhouse’s letter is dated Jan. 16. 1780.)

10. Observations on a Comet lately discovered; communicated by David Rittenhouse, Esq. Read, March 19. 1784.

-----

Footnote 328:

This Comet was observed by John Lukens, Esq. of Philadelphia, on the 20th of January, 1784. This respectable practical astronomer communicated his discovery of it to Dr. Rittenhouse the next day, on the evening of which, (“assisted by Mr. Lukens and Mr. Prior,”) he ascertained the then apparent place of this comet. Dr. Rittenhouse’s communication to the society, on this subject, gives also the apparent place of the comet on the 17th of February, being the last time the weather permitted him to see it: the result of his intermediate observations is also stated.

-----

11. A new Method of placing the Meridian Mark; in a letter to the Rev. Dr. Ewing, Provost of the University. Read, November. 1785.

12. An Optical Problem, proposed by Mr. Hopkinson, and solved by Mr. Rittenhouse. Read, Feb. 17. 1786. (N. B. Mr. Hopkinson’s letter is dated March 16, 1785: the answer is without date.)

13. Astronomical Observations; communicated by Mr. Rittenhouse. Without date.

-----

Footnote 329:

These observations were made in Philadelphia, by Dr. Rittenhouse, at sundry times in the years 1784, 1785, and 1786, on the new planet, or Georgium Sidus; and on the Transit of Mercury over the Sun’s disk, on the 12th of November, 1782. The same communication also states the geocentric places of the Georgium Sidus, at several different dates between the 1st of April, 1762, and the 14th of March, 1784, both included; as observed by Mr. James Six, at the city of Canterbury in England.

-----

14. The third volume, printed in the year 1793, contains—An Account of several Houses, in Philadelphia, struck with Lightning on the 7th of June, 1789; by Mr. D. Rittenhouse and Dr. John Jones. Read, July 17. 1789.

15. An Account of the Effects of a stroke of Lightning on a House furnished with two Conductors; in a letter from Messrs. David Rittenhouse and Francis Hopkinson, to Mr. R. Patterson. Read, October 15. 1790.