840 THE POPULAR SCIENCE MONTHLY. 



always in good health, being "temperate in all things," and, 

 though often furnishing wine for his guests, declining the use of 

 it himself, as he said he wished to keep his head always perfectly 

 clear. To tobacco in all its forms he had a great aversion. One 

 of his theories was that human life was much too short, either 

 because of too much luxury and self-indulgence on the one hand, 

 or lack of proper sustenance on the other. By striking the happy 

 medium, he believed life might be indefinitely prolonged. His 

 last illness was of about three weeks' duration, and caused by a 

 carbuncle on the upper lip. After a time the brain became af- 

 fected and unconsciousness ensued, which continued uninterrupt- 

 edly until he passed away, having seen but fifty-five and a half 

 years. This early ending of his life seems like the irony of Fate ! 

 The many letters received by the family after his death, from 

 those with whom he had been associated in his scientific career, 

 filled with such heartfelt expressions of sorrow and regret for the 

 personal loss and the loss to science, attest to the estimation in 

 which he was held by them all. 



The original of the likeness accompanying this sketch was a 

 daguerreotype the only portrait of any kind ever made of Prof. 

 Vanuxem. This was taken in a group in 18-40, in the early days 

 of the art, when the arrangement of dress and pose was not 

 understood so well as afterward. Hence the eyes, said to have 

 been his best feature, are unfortunately cast down, as he was told 

 to look at the child seated on his knee. The portrait is like him, 

 but has not the pleasing aspect his countenance always wore. 



It appears from a discussion by Prof. Holden, of the Lick Observatory, of the 

 smallest object on the moon that can be registered on the photographic plate by 

 the three-foot refractor, that a crater on that star less than one tenth of a mile in 

 diameter will form an image that is about the same size as the grains of silver in 

 the photographic film, and can not in general be distinguished. Craters not more 

 than three tenths and fifteen hundredths of an English mile in diameter, however, 

 have been detected already. Prof. Holden concludes that for further advances in 

 lunar photography it will be necessary to employ plates of greater sensitiveness 

 so as to shorten exposure, and also plates in which the grain is finer. 



The "southerly bursters" of Australia are storms that occur very suddenly, 

 and mostly between November and February. A fresh northeasterly wind may 

 change in ten minutes to a gale from the south, doing much damage to vessels 

 that may be unprepared. The storms are always accompanied or preceded with 

 great electrical excitement, and cause a considerable drop in the temperature. 

 The wind velocity used to reach from sixty to eighty miles an hour, and on one 

 occasion attained the rate of more than a hundred and fifty miles an hour, in a 

 gust. Latterly, however, the wind seldom exceeds fifty miles, and generally 

 ranges between thirty and forty miles an hour. The average annual number of 

 storms is thirty-two. 



