Notes and Memoranda. 469 



made between London and Pekin in twenty-one days, the present 

 route requiring upwards of fifty. He also praised most warmly the 

 universal kindness and hospitality of the Russians. 



Mr. Lay, the Chinese Commissioner, stated that an expedition 

 was being organised in England to assist the Chinese government : 

 Prince Kung having expressed a wish to avail himself of the assis- 

 tance of Englishmen in suppressing the Taeping rebellion. This 

 expedition is to be placed under the command of Captain Sherard 

 Osborn. In connection with this movement it was proposed to 

 organize a system of emigration, by which the surplus population of 

 China could be located in some of the islands of the Indian Archi- 

 pelago. 



NOTES AND MEMORANDA. 



Magnetic Perturbations and Auroras. — The epochs of the appearance 

 of the Aurora borealis, and those of magnetic perturbations, coincide pretty 

 closely. Rarely are auroras exhibited without magnetic disturbances occurring at 

 the same time, and the agitation of the magnetic needle indicates the approach of 

 an aurora. The causes of the two phenomena appear to operate simultaneously, 

 and they are often accompanied by earthquakes in countries exposed to that clas3 

 of action. Magnetic perturbations, however, operate over a much wider range 

 than auroras. — Quetelet, Physique du, Globe. 



Vegetation and Temperature. — M. Quetelet says that careful observations 

 have convinced him that a plant develops much more rapidly during a mean 

 temperature, when this temperature varies, than when it is uniform, provided that 

 it does not fall below freezing. He is also of opinion that the effect produced is 

 equal to the squares of the temperatures. Thus, if the effect of an uniform 

 temperature of 10° Cent, be considered as 100, that of an average or mean 

 temperature equal to 10°, but varying between 6° and 14,° will be equal to 116. 

 6 X 6 + 14 X 14 _ 116 a 



2 



Growth op Cotton in France. — Cosmos states that M. Arnaud, of Remoulins-, 

 has demonstrated that cotton can be grown in the south of France. The expense, 

 beginningwith the preparation of the soil, and ending with cleaning andwarehousing 

 the cotton, is 800 frs. per hectare, which is equal to 24,711 acres. In Algeria the 

 return is 500 or 600 kilogrammes, each of which is rather more than 2£ lb. ; and sup- 

 posing 3001b. could be obtained in France, it would yield, at 6 frs. per kilogramme, 

 1800 frs., half of which would suffice for a good profit. The great objection is, in 

 the south of France the plant does not become quite ripe, and the capsules, after 

 being gathered in a closed state, require to be kept in a warm, dry place, until 

 they open of their own accord. 



76th Asteroid. — M. d' Arrest has discovered this body, which resembles a 

 12 magnitude star. He proposes to call it Freya. It is the first object of its 

 kind that has been discovered at Copenhagen. 



The Supposed Satellite oe Venus. — We learn from Cosmos that M. 

 Haase, of Hanover, called the attention of astronomers, by circular, to the advi- 

 sability of watching the solar disk towards the end of November and the beginning 

 of December, as he believes the body conjectured to be a satellite of Venus may 

 be a small planet revolving in an orbit, not differing much from that of the great 

 one. "When sufficient time has expired to collect the various observations, some 

 new light may be thrown on this curious subject. 



Age of the Pyramids. — M. Radau states that Mahmoud Bey, Astronomer 

 to the Viceroy of Egypt, has investigated the structure of the Pyramids, with a 



