64 



KNOWLEDGE. 



[Makch 1, 1899. 



Scicutc llotrs, 



A site has been secured at Kemp Town, overlooking 

 Queen's Park, Brighton, for the Gardens of the recently 

 founded Zoological Society for Brighton and Hove. 

 Some sixty years ago Brighton possessed a small 

 zoological garden situated north of The Level, on the 

 Lewes Road. The institution did not flourish owing 

 to the ignorance of its originators, who had no notion 

 of the proper method of dealing with captive specimens. 

 The consequence was a very high death-rate, and 

 a brief career for the institution. The new garden will 

 not be likely to fail from the causes which produced 

 the collapse of its predecessor, for it will be managed by 

 competent zoologists who have experience in the treatment 

 of animals of all kinds. Moreover, the encouragement 

 held out to the projectors by residents and persons of 

 distinction in Brighton is such as to warrant us in 

 believing that the undertaking will prove to be a success in 

 all respects. A special feature in the new institution will be 

 the regular delivery of courses of instructive popular 

 lectures for the benefit of the numerous schools in Brighton 

 and Hove. Among those who have enrolled their names 

 as patrons of the Society are several of the foreign 

 Ambassadors, the Duke of Fife, Sir John Lubbock, Sir 

 Edward Sassoon, the Earl of Chichester, and the Hon. 

 Walter Rothschild. The managing-directors are the Earl 

 of Landaff and Mr. F. W. Frohawk. 



Messrs. Taylor, Taylor, and Hobson have sent us an 

 improved circular spirit level. The spirit chamber, made 

 by squeezing from a flat sheet of German silver, being of 

 white metal sharpens the contrast between the bubble and 

 the surrounding spirit, and a compensating joint so eS'eets 

 the combination of the cover glass and spirit chamber 

 that expansion of the metal does not cause leakage by 

 rupture. Further security against leakage is effected by 

 an elastic guard ring compressed into the angular space of 

 the joint, and an outer jacket, separated from the spirit 

 chamber, protects the cover glass from injury. The instru- 

 ment is, indeed, a very compact, useful, and attractive bit 

 of workmanship. 



In our December number, 1898 (p. 275), we recorded 

 the fact that Prof. Howes had received some eggs of the 

 New Zealand hzard Sphenodon, and several of these which 

 were carefully kept have now hatched out. The young 

 lizards are in fine condition. 



The Marine Biological Laboratory, founded in Brittany 

 by M. de Lacaze-Duthiers, has been the scene of some 

 interesting experiments on the artificial formation of pearls 

 in Gastropods. The mollusc chosen by M. Louis Boutan, 

 who conducted the experiments, was Haliotis, of which 

 even the European species occurring in the English 

 Channel has a fine pearly inside surface to its shell. After 

 a series of unsuccessful attempts, some really fine pearls 

 were obtained by trepanning a small part of the shell and 

 introducing a foreign substance. 



* m t 



Our attention has been directed to a device for eflecting 

 a more complete combustion of coal or coke in the house. 

 The patent " Automiser " involves in its construction a 

 contrivance which is of great use in certain furnaces 

 for metallurgical operations, namely, hot-air chambers, 

 which augment in a remarkable degree the heating effect. 

 The " Automiser " is equivalent to a hollow brick open at 

 the bottom and having a tranverse slit across the front. 

 When this is put in the grate, in place of an ordinary 



fire-brick, the ah* enters the chamber from below, and, 

 becoming heated with the surrounding fire, is deflected 

 from the curved surface above, the hot air emerging 

 through the tranverse slit at such an angle as to impinge 

 on the fuel in the grate. 



Mr. Whymper has recently put the Watkin mountain 

 aneroid to a severe test. Travellers or surveyors raay be 

 led to exaggerate their altitudes in climbing through the 

 error caused by diminution of pressure ; thus, Mr. E. A. 

 Fitzgerald says, in the Geographical Journal, November, 

 1897, " Our aneroids played us some very curious tricks. 

 One of them, on being taken to a height of nineteen thou- 

 sand feet, registered twelve inches," that is to say, it indi- 

 cated an altitude of twenty-five thousand feet, and was 

 therefore about thirty per cent, in error as compared with 

 the mercurial barometer. This loss in the aneroid depends 

 (1) upon the duration of time it may be submitted to 

 diminished pressure, and (2) upon the amount of the 

 diminution in pressure. Colonel Watkin attacks the 

 problem of correcting this error by relieving the strain on 

 the mechanism of the aneroid and only permitting of its 

 being put in action when a reading is required. This is 

 effected by attaching to the lower portion of the vacuum- 

 box a screw arrangement, actuated by a fly-nut on the 

 outside of the case, which, when a reading is required, is 

 screwed up as far as it will go, thus bringing the instru- 

 ment into the normal condition in which it is graduated. 

 An inspection of the accompanying table, showing com- 

 parisons of the aneroid with the mercurial barometer at 

 different altitudes, ascent and descent, will indicate that 

 the error has been practically eliminated : — 



The instrument is made by Mr. Hicks, of Hatton Garden. 



To the account of sanitary Bibles for witnesses to kiss, 

 must be added the recent adoption by the Savings Bank in 

 Brussels of a process for sterilizing the bank notes which 

 pass through the establishment. This consists of exposing 

 the paper money to the vapour of formalin for several 

 hours. The Eevuf Scientijique, commenting on the fact, 

 calls attention to the necessity which exists for disinfecting 

 the books that are lent out from public libraries and 

 institutions, and which often pass through various dangers 

 of gathering harmful germs before being returned again. 



I 



and 



ELECTRICITY AS AN EXACT SCIENCE. 



By HowAKD B. Little. 

 IL— UNITS AND MEASUREMENTS. 



T is no doubt tolerably safe to assume that a bargain 

 of some kind was pending when primitive man 

 attained to his first notion of measurement. Probably 

 one of the high contracting parties (he of the keener 

 commercial spirit) demanded, in pre-historic word 

 tone, " more than that." Arbitration, or trial by 



