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intersected each other in certain lines or nodes, the varying position of 

 these nodes leading at certain (calculated) epochs to'such a conjunction 

 of the planets as we shall have at the forthcoming transit. He demon- 

 strated, in reference to these calculations, the importance of the great 

 third law of Kepler which was to the effect that the "squares of the 

 periodic times of any two planets are to each other in the same pro- 

 portion as the cubes of their mean distances from the sun." This was 

 expressed in algebraic formulae. He explained the importance of obtain- 

 ing as large a base as possible, combined with extreme accuracy in its 

 admeasurement, this base being the very foundation from which all the 

 various angles were to be taken. The refined nicety required in taking 

 these angles was shown by several results calculated by the Professor 

 which proved if a human hair were placed at a distance of half-a-mile 

 from the observer that a serious error would be the result if the line 

 of observation were carried to the right edge of the hair instead of 

 the left, or vice versa. A mistake of this magnitude however he thought 

 they were not likely to perpetrate ! Some of the phenomena more im- 

 mediately connected with the Transit itself, such as "irradiation," the 

 so called " black drop," &c, were illustrated and explained as far as 

 the black-board would allow. The nature of the various instruments, 

 telescopes, astronomical clock, &c, was briefly touched upon, as well as 

 the great results which were expected from the almost continuous use 

 of photographic illustrations during the entire Transit. By means 

 of a globe the portions of the Earth from whence the Transit 

 could be seen were shewn, and the localities best adapted for 

 the observations pointed out. Mention was also made of Hor- 

 rocks, Captain Cook, and other early observers. The learned Pro- 

 fessor having spoken of these and other matters, alluded to the impos- 

 sibility of giving anything but the faintest idea of the subject on this 

 occasion. His time was very" fully occupied and he had no leisure to 

 prepare a paper or formal address. Much he could have wished to 

 say was necessarily omitted as he had endeavoured to bring forward a 

 few of those points only which he thought would be of general interest, 

 rather than enter upon the more abstruse and scientific aspects of 

 the subject. 



Sir James Wilson, after referring to the great kindness of the 

 learned Professor in devoting to the lecture just given, a portion of 

 his time which was already so fully occupied, and congratulating the 

 Fellows on having had the deeply interesting subject of the Transit 

 brought before them in so clear and lucid a manner, proposed that the 

 cordial thanks of the meeting should be given to Professer Harkness. 



Mr. Justice Dobson seconded the motion, and after some remarks 

 complimentary to the lecturer, referred to the great credit which had 

 accrued to Captain Cook for his observations on the Transit in this 

 Hemisphere, and hoped Professor Harkness in his turn might also be so 

 favored in his observations as to gain a large share of renown similar 

 to that which had been obtained by his great predecessor in these 

 southern waters. (Applause.) 



The motion having been put from the chair was carried by acclama- 

 tion. The proceedings then terminated. 



