300 ANNUAL OF SCIENTIFIC DISCOVERY. 



SUMMARY OF FACTS IN ASTRONOMY AND METEOROLOGY. 



Local Attraction. — Colonel Sir Ileniy James, Director-General 

 of the Ordnance Survey, reports that (.lining the past year 

 inquiry has ^cen prosecuted into this very remarkable phenom- 

 enon, lie observes that the rehitive extent to \vhi(;h \\w, plumb 

 line and tiie levels of our aslronomieal instruments are all'eeted 

 in a country where there is nothinj^ on the surface of the ground 

 to account for it, may be judged from the fact that it is nearly 

 double the amount of the dellection on Sehehallion mountain, 

 3,oi7 feet high, with the instrument placed on the sides of the 

 mountain itself, at one-third of its altitude, the position to pro- 

 duce the greatest elfeet from the mass of the mountain on the 

 plumb lines. He considers that we have very decided indications 

 that the cause is in the granitic rocks which extend in a soulh- 

 Avest direction from the Cowhythe through BanOshire, and which 

 are highly impregnated in some parts with magnetic iron in a 

 nietaliic state. The range of mountains on liie south-east of 

 Banil'shire culminates in Ben Muieh Dhui, 4,^05 feet i)igh, 

 whicli, after Ben Nevis, 4,3G8 feet high, is the iiigijest mountain 

 in Scotland. The great amount of the attraction at Cowhythe, 

 ami along the coast to the east and west of Portsoy, cannot be 

 explained by anything visible on the surface, and ol)lig<,'s us to 

 imagine the existence of some large and very dense mass of 

 matter underneath it. Sir H. James hopes to resume this im- 

 portant inquiry this season ; and the geological structure, as well 

 as the mineral character of the rocks, will be carefully investi- 

 gated by the Director of the Geological Survey of Scotland. 



The Captive Balloon. — Mr. Glaislier narrated the results of some 

 meteorological experiments maile in the car of the Captive Bal- 

 loon. The principal fact was, that often, when the air near the 

 ground is quite still, and the smoke from the chimneys of the 

 houses rising vertically, a hard gale is blowing alott, and thai at 

 a height of less than 1,000 feet. — Dr. Mann pointed out that 

 meteorological observations between the surface of the ground 

 and moderate elevations, such as 1,000 iaot, are of more practical 

 value than those taken higher up, esj)eeially during the rapid 

 motion of a free balloon. Professor Newton said that he thouirlit 

 it important to learn everything possible about the atmosphere, 

 even at the highest altitudes. Observations made in the United 

 States on the motion of the smoke left l)y meteors had proved in 

 some instances that gales in opposite directions occurred, even so 

 high up as 50 or 60 miles. 



M. Janssen, in a letter dated from Darjoeling, Sikim, British 

 India, 2l^I May last, says that the spectra of some stars, which 

 are rather ruddy colored when not disclosing the presence of hy- 

 drogen, do positively disclose the presence of :iqueous vapor. 



The Liijlit of Uranus. — This planet emits light which dift'ers 

 from that of anv other of our svstem. According to Father 

 Secihi, its spectrum exhibits broad alisorption lines. The surface 

 modifies the sun's light which it rellects, in the same mauner as 

 do colored bodies. 



