300 Astronomical Society. 



1795; Callet, ditto, Paris, (tirage,) I8'25; Hobertand Ideler, Ber- 

 lin, 1799; Delambre, Tab. Dec. Paris, 1801 ; Hutton, 4th ed, Lon- 

 don. ISOl, 5tii ed. 1811 ; Vega, Leipsic, 1-20; Hutton, 6th ed., 

 London, ]8'-2; Babbage, London, 1827- — Mr. Babbage thinks that 

 the errors which he has detected can only be attributed to the uni- 

 versal system of copying which prevails in such works. 



The numbers and correct logarithms to seven places are as below: 

 Xuiiibers. Logarithms. Vlacq's last five figures. 



24626 3913940 39751 



38962 5906412 13420 



57628 7606335 35875 



57629 411 10436 



63747 8044598 97412 



67951 8321959 58424 



From these the several tables specified may readily be corrected. 



Mr. Babbage knowing that there was in the Library of the Royal 

 Society a table of logarithms printed in the Chinese character, and 

 which exhibits no indication or acknowledgement of its being copied 

 from another work, was naturally desirous to compare it with Euro- 

 pean tables. On doing so, he found that in the six cases above 

 noted, errors occurred precisely as in the European tables; thus 

 furnishing an irresistible proof that the Chinese tables have an Eu- 

 ropean origin 



There were next read two letters from INIr. Andrew Lang to 

 F. B-iily, Esq. : one dated St. Croix, 20th of March 1826 ; the other, 

 St. Croix, 30th of November J 826. The first of these transmits an 

 account of observations of the meridian transit of the moon's en- 

 lightened limb, and some stars preceding and following her, made 

 at St. Croix, lat. 17° 41' 32" north, assumed long. 64° 45' west, 

 between September 22, IS'jS, and March 15, 1826. These were 

 sent to Mr, Schumacher at the same time, and have been published 

 in No. 104 of his Astro)/. Nachrichten . 



Mr. Lang describes the climate of St. Croix as peculiarly favour- 

 able to astronomical observations, and speaks of the steadiness of the 

 terrestrial refraction there. The terrestrial refraction scarcely ever 

 varies perceptibly from the one-sixteenth part of the intercepted arc. 



In Mr, Lang's second communication he presents a further ac- 

 count of the meridian transits of the moon's enlightened limb, and 

 of moon-culminating stars, observed between March 30, and 

 November 21, 1826. He also gives a summary of his observations 

 of occultaiions of ^y.', and ju,-, Sagittarii by the moon, on the 9th 

 of September; and of 4' Virginia, on the 28th of October. 



Next, there was read a paper, " On a new application of the me- 

 thod of determining the time by observations of two stars when in 

 the same vertical, to the case o( Polaris when so situated with re- 

 spect to any other circumpolar star in the course of its diurnal re- 

 volution below the pole: By Dr. T. L. Tiarks. The author first 

 describes the peculiarities and advantages of this method, and then 



presents 



