XX NOTES BY THE EDITOR. 



From the variation in the number of observed comets and the 

 poriodicitN' of shooting stars, it is concluded that during the inter- 

 val from 700 to 1200 the solar system was passing through, or 

 near, a meteoric cloud of very great extent ; that from 1200 to 

 1700 it was traversing a region comparatively destitute of such 

 matter; and that about the commencement of the 18th century it 

 again entered a similar nebula of unknown extent. 



The present Earl of Rosse has been engaged upon the determi- 

 nation of the radiation of heat from the moon. It appears from 

 his research that the greater part of the moon^s heat which reaches 

 the earth appears to have been first absorbed by the lunar surface. 

 The amount of lunar heat appears to indicate an elevation of 

 temperatnre for the moon's surface at full moon of 500° F. 



Full arrangements have been made in France and England to 

 observe the coming transit of Venus. Some constants in astro- 

 nomical science will be tested by these observations. 



The new facts in geography may be thus summarized : — 



The explorations and discoveries in South-eastern and East 

 Equatorial Africa. 



The additional and conclusive evidence now brought to light of 

 a climate in the ice-bound region of the Arctic, at a past and re- 

 mote period of time, resembling that of the countries lying near 

 the equator, v 



The marvellous results of the deep-sea dredgings of Profs. 

 Thompson and Carpenter, revealing the existence of animal life 

 at immense depths in the ocean, where it has been supposed to 

 have been impossible. 



The very general disturbance throughout this year of the earth's 

 surface by earthquakes, distinguishable not so much for the eftects 

 in particular localities as for the wide distribution of the phenom- 

 ena over the globe, and its appearance in parts of the world where 

 such disturbances have never been previously witnessed within 

 the memory of man. 



The attractive power of mountains, discovered in the pendulum 

 experiments made during the past year at the observing stations 

 upon the Himalayas, in India. 



The discoveiy of trees of enormous size in Australia, one of 

 which was found to be 69 feet in circumference; of great deposits 

 of valuable coal throusrhout the whole of New Zealand, and the 

 finding of coal upon the borders of the Caspian, verifying in the 

 last particular a prediction of Humboldt, made forty years ago; 



