. Transactions of the American Philosophical Society. 20 VI. 0. 6. 5717- 591 8. 47 9. 19 12. 9710. \(\7- 053- 72 3- 39 4- 94- 344. 49 4- 363- 28 2. U * The right Afcenfion of this Star (Independent of the Ann. Var.) mud be incrcafcd by»n arithmetical progrellion, the firft term and common difference of which is , and thenumber of terms will be the years elapl^d fmce 1789 :—^as for example, let it be required tofind the Right Afcenfion of the Pole Sur, on the ifl of January iSoo. Then Ji = the lad term, and »• 01 = tlie fum of the extremes;—then X II = which
. Transactions of the American Philosophical Society. 20 VI. 0. 6. 5717- 591 8. 47 9. 19 12. 9710. \(\7- 053- 72 3- 39 4- 94- 344. 49 4- 363- 28 2. U * The right Afcenfion of this Star (Independent of the Ann. Var.) mud be incrcafcd by»n arithmetical progrellion, the firft term and common difference of which is , and thenumber of terms will be the years elapl^d fmce 1789 :—^as for example, let it be required tofind the Right Afcenfion of the Pole Sur, on the ifl of January iSoo. Then Ji = the lad term, and »• 01 = tlie fum of the extremes;—then X II = which is the fum of the X il= 20ij,83 = 33 33> ? added -then the Annual Variation OS. 12** 32 7. c6. will give01. 13 5 40. 39, and thisfum increafcd by the fum of the progrcfiion 1 6. 66 will giveOS. 13 6 47. 05, for the mean Right Afcenfion of the Star : but if the Right Afcenfionof the Pule Star is required before the beginniog of the year i68y, then the Ann. Var. andfum of the progreilion will be dcduftive. Account ?;*?^. ( ^19 ) NO. XIV. Account of ftveral Houses in Philadelphia, ft ruck innthLightning, on June 7, 1789. By Mr. DavidRiTTENHOusE,a?ii/Dr. John Jones. iT^;^? /^ N Sunday the 7th of June, 1789, wbllfl:\^J/ a thunder-gufl from the South-weft waspaffing over this city, a flafh of lightning ftrucfc two ad-joining buildings, the kitchens of houfes on the Southfide of Drinkers Alley. The annexed drawing reprcfents an infide view of partof the Souihend of thefe buildings. The funnels of thetwo kitchen chimneys, and thofe of the two chambersover them are carried up feparately by the fide of eachother. They had been originally of the fame height, butthat on the right hand nest the middle has been raifedfince about two feet higher. There was a fire burning atthe time in the two kitchen chimneys, whofe funnels arecarried up in the midft of the ftack. The lightning atthe fame inftant paffed through thefe two funnels, and byrarifying the enclofed. air, f
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