On the Passage of the Moon across the Pleiades in 1839. 177 



chanical or vital forces. His legitimate object in the present 

 state of the science would seem to be that of analysing the 

 simplest operations in the human body: — to aim first at dis- 

 coverino- the innumerable important processes that are carried 

 on through the influence of physical agents, before he pre- 

 sumes to explain the higher and more mysterious principle 

 of life : neither should he hastily call the vital power to his 

 aid, to explain a phaenomenon, such as heat, that is known to 

 be common to every kind of matter, and which can be pro- 

 duced by a variety of physical forces totally independent of 

 life. 

 Truro, Nov. 8, 1838. 



XXXI. On the Passage of the Moon across the Pleiades in 

 March, August, September, and November 1839. Bij the 

 Rev. James Groob^, F.R.A.S. 



[With a Chart : Plate V.] 



To the Editors of the Philosophical Magaziiie and Journal. 

 Gentlemen, 



nPHE annexed chart, showing the apparent path of the 

 -^ moon's centre over the Pleiades in the months of March, 

 August, September, and November of the present year, might 

 perhaps prove acceptable to some of your astronomical readers; 

 but whether of sufficient importance to merit insertion in 

 your next Number, I must leave to your determination. The 

 occultalion on the 19th of next month (March) will be par- 

 ticularly interesting ; happening when the moon is only four 

 days old, the whole of her disc will be visible ; and as the im- 

 mersions take place on the dark side, I have little doubt but 

 that by excluding the enlightened part from the field of view, 

 and using a telescope of considerable power, most, if not all, 

 the telescopic stars which suffer occultation may be perceived, 

 and their immersions observed. I should mention, that as 

 astronomical telescopes, generally used in these observations, 

 exhibit objects in an inverted order, the stars in the accom- 

 panying chart are inverted also, for the sake of more readily 

 comparing them with the appearance in the telescope. In 

 laying down the places of the stars, the right ascensions and 

 declinations, as well as the numbers annexed to them, are 

 taken from the catalogue of M. Jeaurat, as given by Mr. 

 Baily in the Philosophical Magazine for September 1822, 

 page 189, with the exception of No. G, the declination of which 

 as there given appears to be about 1' 15" too small. Mr. Baily 

 in projecting his chart has made the degrees of right ascension 

 Phil. Mag. S. 3. Vol. 14. No. 88. Mar. 1839. N 



