256 



NATURE 



\yan. 16, 1890 



and it seems that the immediate cause was the contamination of 

 the water supply of Philadelphia, where he had been living, 

 and where about a thousand cases of typhoid fever appeared at 

 nearly the same time. Prof. Lewis was only in his thirty- fifth 

 year. An excellent portrait of him accompanies Mr. Upham's 

 paper. 



At the meeting of the University Experimental Science 

 Association, Dublin, on December 13, Mr. J. Joly read a paper 

 on a resonance method of measuring the constant of gravitation. 

 A simple pendulum of small mass is hung in a tall glass tube, 

 rendered vacuous. Inclose proximity two massive pendulums, 

 one at either side, are maintained in a state of vibration for any 

 desired period of time. The times of vibration of all these pen- 

 dulums are alike. The observations consist in observing the 

 amplitude, or the increase of amplitude, of the central pendulum, 

 after a known number of vibrations executed by the exterior 

 pendulums. Several modifications, carrying out the same 

 principle, were suggested. It is proposed to test the method in 

 the vaults of the physical laboratory. 



The Central Meteorological Observatory of Mexico, which is 

 situated at 7489 feet above the sea, has published a summary of 

 meteorological results for each month of twelve years ending 

 1888 (excepting January and February 1877). The coldest 

 month is January, the mean temperature of which is 54°, and 

 the warmest month is April, the mean temperature of which is 

 64°. The absolute maximum in the shade was 89°, and the 

 minimum 28° "9. The wettest month is August, in which the 

 mean rainfall is 5*4 inches, and the driest month is February, 

 with an average of 0-4 inch. The greatest fall at one time was 

 2" 5 inches. The prevalent direction of the wind is north-west. 



The Essex County Chronicle of January 10 says that on Tues- 

 day, the 7th inst., two slight shocks of earthquake were noticed 

 at Chelmsford. The first occurred at 12.30, when a low rumbling 

 sound like thunder in the distance was heard, accompanied by 

 a vibration of the ground and a rattling of the windows. The 

 ''hock was observed in several parts of the town. The more 

 pronounced shock was, however, at 1.25 p.m., when the rumbling, 

 moaning sound was intensified, there being a heavy throbbing 

 in the air like the pulsation of an engine. At many houses there 

 was a violent shaking of the windows, and two cases are reported 

 of things trembling on the tables. Some men working for Mr. 

 Norrington heard the sound, took it to be the rumble of a heavy 

 waggon, and went out to see it. Nothing was in sight. Several 

 people recognized the shock as being similar to the forerunner 

 of the 1884 earthquake, and rushed out of their houses. Mr. 

 Arthur E. Brown, writing to us from Brentwood, says that the 

 shocks were noticed there. They were attributed by the people 

 in his house to the firing of guns at Woolwich. They rattled 

 the doors violently. 



A CORRESPONDENT Writes that during the thunderstorm which 

 prevailed over the greater part of Scotland early on Monday 

 morning, January 6, a slight shock of earthquake was felt in a 

 district of Perthshire. " This," he says, "is somewhat similar 

 to what took place at Argyll on the evening of July 15 last year, 

 and might lead one to suppose that atmospheric influence has 

 something to do with the production of seismic disturbances." 



At a meeting of the Royal Botanic Society on Saturday, 

 attention was called to a specimen of the double cocoanut, or 

 cocoa de mer, now known to come from the Seychelles. For 

 some hundreds of years these nuts have been occasionally found 

 washed up by the sea, and their extraordinary appearance, large 

 size, and mysterious origin have given rise to many stories of 

 miraculous virtue in the cure of diseases. Some are even said 

 to have been sold for their weight in gold. This specimen 

 belonged to General Gordon, and was given by him to General 

 Gerald Graham, by whom it has been presented to the Society. 



The Transactions of the Congres pour I'Utilisation des Eaux 

 fluviales, held last summer in Paris, have just been issued. The 

 volume contains a great number of engravings. 



A BOOK on the Congo State, by E. Dupont, the Director of 

 the Natural History Museum of Brussels, has just been published. 

 He presents the scientific results of his travels, devoting especial 

 attention to geological questions. 



Messrs. George Philip and Son have published the 

 second issue of their valuable "Educational Annual." The 

 work has been enlarged, revised, and to some extent re- 

 arranged ; and it ought to be of great service to all who are 

 for any reason especially interested in educational institutions. 



Messrs. Perken, Son, and Rayment have produced a 

 projecting optical lantern, which is likely to be of considerable- 

 service. When enlargements are required, a condenser of 

 10 inch diameter is available ; but when a magic-lantern 

 entertainment is to be provided, a condenser of 4-inch diameter 

 can be substituted. The apparatus consists of a mahogany- 

 body lantern with a long bellows-camera adjusted by the patent 

 quick-action rack and pinion, and lighted by the refulgent 

 three-wick lamp. 



On January 21, and the three following evenings, Dr. E. 

 Symes Thomson will deliver, at Gresham College, a course of 

 lectures on influenza or epidemic catarrh. In the first lecture 

 he will present a historical sketch of the subject. The remain- 

 ing lectures will be on influenza as it affects the lower animals, 

 the causes and consequences of influenza, and diagnosis and 

 management. 



The additions to the Zoological Society's Gardens during the 

 past week include four Leopard Tortoises {Testudo fardalis), 

 three Well-marked Tortoises {Homopiis signatus), a Rufous 

 Snake {Ablabes rufuhis), six Gray's Frogs {Rana grayi) from 

 South Africa, presented by the Rev. G. H. R. Fisk, C.M.Z.S. ; 

 two Spur-winged Geese {Plectropterus gafnbensis) from West 

 Africa, presented by Mr. C. B. Mitford ; six Red-bellied Wax- 

 bills {Estrelda 7-ubriventris), five Crimson-eared Waxbills 

 {Estrelda phoenicotis), seven Grenadier Waxbills {Urcegintlms 

 grantinus, 6 cj i ? ), three Paradise Whydah Birds ( Vidua 



paradisea), three Weaver Birds [Euplectes ) from 



Benguela, West Africa, presented by Mr. T. W. Bacon ; a 

 Bluish Finch {Spermophila ccerulescens i ) from Brazil, presented 

 by Mrs. Mayne ; a Green Turtle {Chelone viridis) from the 

 West Indies, presented by Mrs. Harris ; a Chattering Lory 

 {Lorius garrulus) from Moluccas, presented by Captain Bason, 

 P. and O. s.s. Bombay; three Yellow-winged Sugar Birds 

 {Cmrea cyanea), two Yellow-fronted Tanagers {Euphonia favi- 

 frons) from South America, deposited ; four Tufted Umbres 

 {Scopus umbretta) from Africa, a Geoff'roy's Terrapin {Hydraspis 

 hilarii) from the Argentine Republic, purchased ; a Koala 

 {Fhascolarctus cinereus ?) from Australia, two Indian Cobras 

 {Naia tripudians), an Indian Python {Python molurus) from 

 India, received in exchange. 



OUR ASTRONOMICAL COLUMN. 

 Objects for the Spectroscope. 

 Sidereal Time at Greenwich at 10 p.m., January_i6 = sh. 

 4Sm. 8s. 



