11 



the declination of Gyniiiaslics ; and observed that had they 

 been properly pursued aud practised with due regard to the 

 system, they would ia all probability have been held in as 

 high esteem in England as they are on the Continent at the 

 present day. 



1829 — January 6 and 7. — Mr. Giles delivered Lectures 

 on Astronomy. He commenced his first lecture with a 

 definition of the science, its early history, and relative use- 

 fulness. He then treated of tlie doctrines of attraction and 

 forces, shewing how the orbitical motions of the planets were 

 produced, and accounting for their elliptical form. He 

 proved by a variety of considerations the earth's annual and 

 diurnal motions, its figure, and how computed by Sir Isaac 

 Newton by the oscillations of pendulums, &c. In the lunar 

 illustrations — the moon's phases, revolutions, the heights of 

 her mountains, with the method of finding them by the 

 micrometer and trigonometrical calculation ; and the diffe- 

 rence between a periodical and synodical month were ex- 

 plained. The sun — his spots, magnitude, distance, and the 

 method of finding it by his horizontal parallax, were next 

 dwelt on. The inferior and superior planets, their magnitude, 

 distance, and peculiarities, and the method of finding the 

 longitude by Jupiter's satellites were considered; and the 

 orbits, motions in consequentia and antecedentia, the pe- 

 rihelion and aphelion, distances, &c. of comets, formed the 

 concluding subject of the first lecture. 



In his second Lecture Mr. G. explained heliocentric and 

 geocentric longitudes; defined direct, stationary, and retro- 

 grade motions, and the conjunction and opposition of the 

 planets ; explained the harvest moon ; took comparative 

 views of the sun, earth, and moon, introductory to a con- 

 sideration of eclipses ; shewed how eclipses of the sun and 

 moon were produced ; the phenomenon of an annular eclipse, 

 the duration of eclipses, and the method of finding their 

 occurrence. Explained the moon's nodes, &c. ; the seasons, 

 and on what their variations depend ; the zodiacal signs ; 

 the method of calculating longitude at sea by lunar obser- 

 vations; and a diagram of the Chinese zodiac- He con- 

 sidered the theory of the tides under various theorems, and 

 explained the apparent anomalies in the Newtonian theory. 

 He treated on the various systems of philosophers from the 

 time of Pythagoras. The galaxy, nebula*, and theory of the 

 fixed iitars were next illustrated, and a calculation mentioned 

 of the time that light and sound would be in travelling from 

 Sirius to the earth. 



