14 



Herman Schultz, 



In these calculations, as has already been intimated, all the instrumen- 

 tal corrections — with exception of those for the screw of micr. II — were 

 negliged as imperceptible; and the reductions for the rest, performed in a 

 manner analogous to that employed for 20 Vulp. (1. c, § 5). These reduc- 

 tions were always carried out with 3 and 2 decimals in the numbers of 

 reduction for Act 4 and A^" respectively, and also the original uncorrected 

 media of Act 5 were calculated with 3 decimals of the second, although in the 

 present table (col. 3) only two decimals are given. In the few cases, in 

 which the comparison-star showed a sufficiently proved proper motion, such 

 motion was duly taken account of in ' the reduction to the general epoch 

 1865,0 in th 5 Ul and 6"' columns of the tables of observation. 



As the zero-points of the micrometers were usually left untouched for 

 considerable times, and as the apparent variations of the coincidences of 

 the wires were indeed in general so small, that they evidently must princi- 

 pally depend on the uncertainty of the single coincidences; I have in the 

 reductions not employed the coincidences obtained immediately on every 

 single night, which are given in note III below, but instead of them the 

 coincidence-means, which are communicated in the here following list. Du- 

 ring the spring 1863 (nights 1 — 18), as in these months the zero-point was 

 several times changed , the original coincidences were nevertheless immedi- 

 ately employed. Concerning the coincidences of micr. I it is first to be re- 

 marked, that, as this micrometer has no ocular-slide, it was, in order to 

 render it possible to measure distances exceeding half the field, furnished 

 with 3 moveable wires (A, B, C); and secondly, that up to the autumn of 

 1865 two fixed wires (I and II) were employed alternately. These last dis- 

 tant about 16" from each other formed the system, that was employed in 

 the observation of Mars during the opposition 1862 and was retained un- 

 changed during the next following years. The coincidence-numbers for micr. 

 I, corresponding to the position of the screw above the centre of the mi- 

 crometer, are in the following list marked with an asterisk. In the case of 

 micr. II such discrepancies between the coincidences, depending upon the 

 positions of the micrometer-screw, never occurred (1. c. , p. 20). The num- 

 bers enclosed in parentheses express the number of nights, from which the 

 single coincidences are taken, where also in many instances coincidences 

 of nights are used , when nebulse were not observed — thus for example is 

 explained the coincidence of 1870 Aug. 8, which reposes on coincidences 

 from 36 evenings, although during this period nebulse were on no other 

 evening observed. The coincidences of micr. II were always taken with 

 m. p. 320, those of micr. I often also with m. p. 210. 



