Ab hoc itaque tempore series observationum Coelestinm interrupta est, finisque impositus 38 annorum observationibus.
Nocte, quam ultimam habuit, per delirium, quo omnia suavissima fuere, creberrime hæc verba iteravit, quasi qui carmen texit.
Ne frustra vixisse videar.
Quem procul dubio ceu colophonem operibus suis addere, eaque his verbis Posteritatis memoriæ & usibus dedicare voluit.
E.—COMPARISON OF TYCHO BRAHE'S POSITIONS OF STANDARD STARS WITH MODERN RESULTS.
The following table gives the places for 1586 (anno 1585 completo) of Tycho's nine standard stars (Progymn., p. 204), and their positions for the same epoch, computed from those of Bradley for 1755, with the proper motions of Auwers (Neue Reduction der Bradley'schen Beobachtungen, vol. ii.).
| Observed AR. | Observed Dec. | Computed AR. | Computed Dec. | |||||||||
| α Arietis | 26º | 0' | 30" | +21º | 28' | 30" | 26º | 0' | 44."7 | +21º | 27' | 33".0 |
| α Tauri | 63 | 3 | 45 | +15 | 36 | 15 | 63 | 4 | 11.2 | +15 | 35 | 35.6 |
| μ Geminorum | 89 | 29 | 10 | +22 | 38 | 30 | 90 | 28 | 41.0 | +22 | 37 | 48.5 |
| β Geminorum | 109 | 58 | 0 | +28 | 57 | 45 | 109 | 57 | 47.9 | +28 | 56 | 19.1 |
| α Leonis | 146 | 32 | 45 | +13 | 57 | 45 | 146 | 33 | 19.7 | +13 | 56 | 56.9 |
| α Virginis | 195 | 52 | 10 | -8 | 56 | 20 | 195 | 52 | 36.4 | -8 | 58 | 22.0 |
| δ Ophiuchi | 238 | 11 | 20 | -2 | 33 | 15 | 238 | 11 | 9.8 | -2 | 33 | 21.5 |
| α Aquilæ | 292 | 37 | 20 | +7 | 51 | 20 | 292 | 38 | 36.2 | +7 | 50 | 35.8 |
| α Pegasi | 341 | 2 | 30 | +13 | 0 | 40 | 341 | 3 | 1.3 | +12 | 59 | 47.1 |
The differences between Bradley and Tycho are shown in the next table. The effect of refraction (which Tycho thought insensible above Zen. Dist. 70º or Declination -14º for Uraniborg), is seen at a glance, and I have therefore in the last column given the difference of declination corrected for mean refraction.
| Bradley minus Tycho. | ||||
| ∆ α | ∆ α cos δ | ∆ δ | ∆ δ' | |
| α Arietis | +14".7 | +13".7 | -57".0 | -17".4 |
| α Tauri | +26.2 | +25.2 | -39.4 | +9.6 |
| μ Geminorum | -29.0 | -26.7 | -41.5 | -3.6 |
| β Geminorum | -12.1 | -10.6 | -85.9 | -56.5 |
| α Leonis | + 34.7 | +33.7 | -48.1 | +4.4 |
| α Virginis | +26.4 | +26.1 | -122.0 | +0.6 |
| δ Ophiuchi | -10.2 | -10.2 | +6.5 | +88.1 |
| α Aquilæ | +76.2 | +75.4 | -44.2 | -19.5 |
| α Pegasi | +31.3 | +30.4 | -52.9 | -0.1 |
