Correction of an Error in a Paper Published in the Philosophical Transactions, Entitled, "On the Parallax of the Fixed Stars"

X. Correction of an error in a Paper published in the Philosophical Transactions, entitled, "On the Parallax of the fixed Stars." By J. F. W. Herschel, Esq. F. R. S. Read February 22, 1827. In my Paper on the parallax of the fixed stars, published in the Philosophical Transactions for 1826, by inadvertence the letter \( l \) was written for \( \lambda \), in the formula for computing the most advantageous times of year for observations on the parallax of a double star. The mistake was detected, and rectified in an erratum annexed to the 4th Part of the Transactions for that year, but not till the table computed by the erroneous formula was printed off, and too late to cancel the sheet. The errors produced fall wholly on the 5th column of the table in pages 277, 278, of the volume for that year, headed, "Times of the year most proper for observation;" which column I have therefore had recomputed, and which is here subjoined. I am happy to be able to add, that except in a few instances, the differences are not so considerable as to render useless any observations which may have been made on the plan proposed, as in the great majority of instances the correct dates do not differ by more than a week from the erroneous ones; and about the times proper for observation, a week or a fortnight one way or the other is of no essential moment. | General Number in Messrs. H. and S's Observations | Star's Name, &c. | Times of the year most proper for Observation | |--------------------------------------------------|-----------------|---------------------------------------------| | 1 | 35 Piscium | June 27, December 27. | | 20 | γ Arietis | January 18, July 21. | | 25 | α Piscium | January 16, July 19. | | 38 | ε Eridani | February 13, August 17. | | 39 | ε Persei | February 13, August 18. | | 46 | 55 Eridani | February 6, August 10. | | 47 | ω Aurigae | March 6, September 8. | | 53 | Rigel | March 20, September 22. | | 55 | 118 Tauri | March 10, September 13. | | 56 | 32 Orionis | March 19, September 22. | | 59 | 33 Orionis | March 22, September 24. | | 67 | ξ Orionis | February 28, September 2. | | 366 | 41 Aurigae | March 23, September 26. | | 69 | 8 Monocer | April 2, October 5. | | 76 | 38 Gemin. | March 30, October 3. | | 80 | δ | April 6, October 9. | | 88 | 11 Cancri | April 18, October 21. | | 93 | φ² | April 18, October 21. | | 94 | 18 BodeHydræ | April 29, November 1. | | 96 | 144 of 145 | April 21, October 24. | | 98 | 57 Cancri | May 4, November 6. | | 99 | 17 Hydræ | April 28, October 31. | | 102 | Cancri 194 | April 30, November 2. | | 114 | Leonis 145 | May 24, November 25. | | 128 | 90 Leonis | June 5, December 6. | | 133 | 65 Ursæ | May 23, November 24. | | 134 | 2 Comæ | May 28, November 29. | | 147 | 118 of 145 | June 3, December 4. | | 152 | Struve 422 | June 27, December 27. | | 155 | 424 | June 30, December 30. | | 161 | 54 Virginis | January 14, July 16. | | 167 | 81 | January 12, July 15. | | 173 | 98 of 145 | January 20, July 23. | | 176 | Struve 456 | January 27, July 30. | | 177 | 457 | January 23, July 26. | | General Number in Messrs. H. and S's Observations | Star's Name, &c. | Times of the year most proper for Observation | |--------------------------------------------------|-----------------|---------------------------------------------| | 188 | 39 Bootis | March 22, September 24. | | 193 | 44 | June 25, December 25. | | 194 | Struve 474 | January 24, July 27. | | 201 | n Coronæ B | January 22, July 25. | | 205 | δ Serpentis | February 3, August 7. | | 206 | Libra 178 | February 12, August 16. | | 211 | II. 85 | March 4, September 6. | | 212 | III. 103 | March 10, September 12. | | 228 | g 5 Ophiuchi | February 25, August 30. | | 240 | μ Draconis | March 1, September 2. | | 242 | 39 Ophiuchi | February 8, August 12. | | 245 | 100 Herculis | March 8, September 11. | | 262 | I. 86 | March 19, September 21. | | 265 | 39 Draconis | March 29, October 2. | | 269 | | March 22, September 24. | | 271 | | April 15, October 18. | | 274 | | April 3, October 7. | | 280 | | March 28, October 1. | | 287 | | April 14, October 18. | | 295 | III. 57 | April 27, October 30. | | 306 | π Aquilæ | May 10, November 12. | | 311 | ε Draconis | April 20, October 23. | | 312 | ψ Cygni | April 18, October 21. | | 313 | I. 96 | April 20, October 23. | | 317 | II. 96 | April 6, September 10. | | 320 | I. 95 | May 12, November 14. | | 323 | ε Capric. | April 23, October 26. | | 326 | | April 27, October 30. | | 343 | Struve 751 | February 14, August 18. | | 349 | Aquarii 213 | May 28, November 29. | | 352 | | June 24, December 24. | | 354 | 94 Aquarii | May 21, November 22. | | 356 | | June 4, December 6. | | 359 | σ Capric. | July 16, January 14. |