312 



SCIENTIFIC NEWS. 



[Sept. 21, 1 1 



enable the plan of the ancient city to be to some extent 

 ascertained. 



The Hydrophone. — Commandant Banar6 has devised 

 an apparatus in place of the syren, and has named it the 

 hydrophone. It is well known that in foggy weather 

 ships make use of a deep whistling sound, produced by 

 a syren, to prevent collisions. This whistle is heard 

 very well at considerable distances, if the wind be not 

 contrary, but it is often insufficient. M. Banare collects 

 on one ship, by means of a special microphone, the 

 sound-waves transmitted by the water, and emanating 

 from a vibrating body placed on board of another ship. 

 Experiments have been made at Brest between two 

 ships, one of which was at anchor, and then between 

 two vessels, both in motion. In the former series the 

 noise of the screw of the moving ship was heard plainly. 

 In both series the success was decisive. 



Two Eclipses of the Moon Observed at Babylon. — 

 M. Oppert communicated recently to the Academy of 

 Sciences the translation of a cuneiform inscription narra- 

 ting two eclipses of the moon.observed at Babylon in the 

 year 168, of an unknown local era and in the year 232, of 

 the era of Arsaces, corresponding to the year 256 bc, 

 The inscription describes the two phenomena with every 

 detail. Two phrases relating to the planets Mercury and 

 Venus could not be deciphered. If we compare the 

 eclipse of the year 232 with one of the ancient eclipses 

 calculated by Professor Oppolzer, we find that all the 

 particulars related by the inscription are verified. 

 According to M. Faye, observations of this kind are 

 important for improving the theory of the movement of 

 the moon. 



The Effects of Coal smoke. — The injurious action of 

 coal-smoke upon vegetation seems to be the joint effect 

 of two factors which have not been separately estimated. 

 On the one hand there is the visible, opaque matter, 

 consisting of particles of carbon, which acts by obstruct- 

 ing the pores of plants and by diminishing the total in- 

 tensity of the sunshine. This factor can be reduced by 

 what is commonly called " smoke-consumption." On 

 the other hand, we have the transparent, invisible sul- 

 phurous acid gas, which blights all vegetation. Against 

 this part of the nrschief smoke-consumption is powerless. 

 The only hope lies in minimising the quantity of fuel 

 burnt. This may be effected in manufacturing establish- 

 ments by obtaining the full duty out of every pound oi 

 coal, and in households by the sacrifice of the open fire, 

 which wastes at the very least seven-eighths of the heat 

 generated. 



Chinese Cookery. — The Journal d Hygiene reports that 

 a missionary during his stay in China had often seen the 

 pupse of the silkworm used as an article of diet. He 

 has personally tried this dish, and finds it savoury and 

 nutritious, and well adapted for invalids. 



After having reeled off the silk the larvse are stoved to 

 free them from moisture. The outer coating is easily 

 removed, and there are then seen small yellow masses 

 resembling the ova of the carp. They are then fried in 

 butter, lard, or oil, and seasoned with chicken-broth. 

 When the whole has boiled for four or five minutes, it is 

 bruised with a wooden spcon, and kept well stirred to 

 prevent it from adhering to the bottom of the pan. 



The mandarins, and in general the wealthy, add yolk 



of egg in the proportion of 1 to 100 pupae. This addi- 

 tion causes it to exhale an exquisite odour, and to take 

 the colour of cream. The poor merely add salt, pepper, 

 and vinegar. 



Earthquake in Iceland. — Captain Brown, of the 

 Icelandic trading steamer Princess Alexandra, of Glasgow, 

 brings intelligence of a reported earthquake or volcanic 

 eruption in Iceland. Shortly after leaving Reykjavik on 

 the afternoon of August 24th, the steamer got into a 

 thick sulphurous atmosphere, which continued for three 

 hours, the distance run during the time being thirty 

 miles. After emerging out of this atmosphere, which 

 was very stifling, the steamer got into very disturbed 

 water, and the compasses on board became unsteady, 

 moving from point to point. The steamer then en- 

 countered a strong east-north east wind, with a clear 

 atmosphere, and her course was altered to a southerly 

 direction in order to get clear away from the effects of 

 the volcanic disturbance. This course was kept for 

 seventy miles, when the steamer got into smoother 

 water. Captain Brown is of opinion that the dis- 

 turbance of the sea, which resembled the waters of the 

 Pentland Firth during a storm, was caused by an earth- 

 quake, which had extended its influence seaward fcr 

 thirty miles. 



The Public Health — The Registrar-General's return 

 for the week ending September 8th shows that the 

 deaths registered during that period in twenty-eight 

 great towns of England and Wales corresponded to an 

 annual rate of 17 8 per 1,000 of their aggregate popula- 

 tion, which is estimated at 9,398,273 persons in the 

 middle of th's year. The six healthiest places were 

 Bristol, Brighton, Portsmouth, Nottingham, Wolver- 

 hampton, and Sunderland. In London 2,475 births and 

 1,316 deaths were registered. Allowances made forj 

 increase of population, the births were 264, and the^ 

 deaths 130, below the average numbers in the corres- i 

 ponding weeks of the last ten years. The annual death- I 

 rate per 1,000 from all causes, which had been 17-5 and 

 16 4 in the two preceding weeks, further declined last 

 week to i6'o. During the first ten weeks of the current 

 quarter the death-rate averaged 16-2 per 1,000, and was 

 4 - i below the mean rate in the corresponding periods of 

 the ten years 1878-87. The 1,316 deaths included 26 

 from measles, 39 from scarlet fever, 18 from diphtheria, 

 32 from whooping cough, 1 1 from enteric fever, one from 

 an undefined form of continued fever, 131 from diarrhcea 

 and dysentery, three from cholera and choleraic diarrhcea, 

 and not one from small-pox or typhus; thus 241 deaths . 

 were referred to these diseases, being 43 below the 

 corrected average weekly number. The death of a 

 journeyman tailor, formerly of Whitechapel, whose age 

 was stated to be 103 years, occurred on the 4th inst , in ^ 

 the Hand-in-Hand Asylum at Ha.kney. In Greater 

 London 3,249 births and- 1,630 deaths were registered, 

 corresponding to annual rates of 307 and i5'4 per 

 1,000 of the estimated population. In the Outer Ring-T ; 

 ^^ deaths from diarrhcea, seven from measles, six from 

 scarlet fever, and five from whooping-cough were regis- 

 tered. Of the fatal cases of diarrhcea, six occurred in 

 Stratford, four in Tottenham, three in Bromley, three in '• 

 Willesden, and three in Leyton sub-districts. The ) 

 deaths from measles included three in Tottenham and 

 two in West Ham sub-districts ; and four of the six fatal ' 

 cases of scarlet fever occurred in West Ham sub-district. 



