May 25, i88S.] 



SCIENTIFIC NEWS. 



501 



CORRESPONDENCE. 



Tke Editor does not hold himself responsible for opinions expressed 

 by his correspondents^ nor can he take notice of anonymous com- 

 inu7iicaiions . All letters must be accompanied by the name and 

 address of the writer, not necessarily for publication, but as a 

 guarantee of good faith. 



WILL MAN EVER FLY ?— LANTERN-FLY. 

 I have been much interested in the discussions in your 

 paper anent the question, " Will Man Ever Fly? " and with- 

 out expressing an opinion one way or the other, would like to 

 draw your attention to the manner of flight of a bird in this 

 colony called locally " Boonea." It is about the size of a 

 pigeon, and is coloured black and yellow; in fact, it is known 

 as the black and yellow boonea, in contradistinction to a 

 rather rare bird called the green and grey boonea. I have 

 no doubt but that Mr. J. J. Ouelch, the Curator of the British 

 Guiana Museum, would describe the bird to you and be able 

 to forward you a skeleton, as probably its formation has 

 something to do with its manner of flight, which strikes one 

 at once as being artificial or mechanical, and suggests almost 

 unconsciously that that is just the way man would fly. The 

 bird never soars or turns or sails, but just goes straight from 

 one point to another, be that a mile or a quarter of a mile, 

 with a regular and steady beat of the wings. The bird must 

 not be confounded with birds of imperfect or restricted 

 flight, such as the coot and Savanna chick and bush-fowl (the 

 latter called here Katakka), which only fly a short distance 

 and then drop. The boonea is a fruit-eater, and when feed- 

 ing is particularly active and strong, but when flying in his 

 artificial sort of way is sluggish, and appears to be calcula- 

 ting the chances cf his flying machinery holding good to the 

 end of his intended journey. I am no naturalist, but have 

 well observed for many years the ways and habits of birds 

 and animals in their free state, and feel sure that examination 

 and study of the flight of the boonea will give a leg-up to 

 the advocates of the theory of man being able to fly one of 

 these odd days. 



In your number of 23rd of March, i888, page 279, I am 

 sorry to see doubt cast on Madame Merian's account of the 

 lantern-fly. Very often I have one of these beetles in my 

 possession for several days and nights, and can speak posi- 

 tively of their luminosity. From the two constant lights on 

 the top of the head it is quite easy to read ordinary print by 

 passing the lights along the page. When they fly they give 

 a light from under the body also, just as the light is given 

 by the common firefly. 



The light of the lantern-fly (or La Belle, as they are 

 called in some of the West India Islands, where they are 

 more plentiful than in British Guiana) is of different colours 

 in different insects : in some it is green, in others red, and in 

 others blue. Readers of the Scientific American for the past 

 ten years or more will no doubt remember the numerous re- 

 discoveries that have proved Madame Merian right, and I 

 think she will be found to be right to the end of the chapter. 



British Guiana. T. 



SIR H. ROSCOE'S REPORT ON THE TREATMENT 



OF LONDON SEWAGE. 

 This report, of which you give an abstract on p. 457 of the 

 Scientific News, is in some respects disappointing. It 

 might have been hoped that a chemist of the indisputable 

 merit of Sir H. Roscoe would have thrown some new and 

 valuable light upon the sewage question, and perhaps 

 indicated some novel and feasible process. Such, however, 

 is not the case. Had he made himself fully acquainted with 

 what has been already done, he would have found that 

 materials can be added to sewage which remove, practically 

 speaking, the whole of the suspended solids and a large part 

 of the dissolved impurities in a harmless form. The volume 

 of the sewage does not come into account. If a certain 

 quantity of material will treat ten million gallons of sewage, 

 less than 20 times as much will suffice for 200 milHons. 

 There are several such processes in existence, all essentially 

 turning upon the use firstly of an absorbent, such as clay, 

 peat, carbon of various kinds, coke, etc., followed up by a 

 metallic salt. The first portion of these processes is, in fact, 



"inverse irrigation." In ordinary irrigation the sewage is puri- 

 fied by being passed through the land ; here, on the contrary, 

 the land is passed through the sewage with the same effect. 



Sir H. Roscoe is undoubtedly right in his condemnation of 

 the operations carried on by the Metropolitan Board of Works, 

 who attempted to deodorize the river or the sewage before 

 the elimination of the putrescible matters. Aeration is exceed- 

 ingly useful as a means of putting the " finishing touch " to an 

 effluent, but as a method of dealing with crude sewage it will, 

 I fear, be found too expensive. J. W. Slater. 



. — ■►^:»t^'^5<f-» 



RECENT INVENTIONS. 



The following list ha^ been compiled especially for the SciENTIFI 

 News by Messrs. W. P. Thompson and Boult, Patent Agents, o 

 TfiT,, High Holborn, London, W.C- ; Newcastle Chambers, Ange 

 Row, Nottingham ; Ducie Buildings, Bank Street, Alanchester 

 and 6, Lord Street, Liverpool. 



Egg-opener. — An egg-opener has been patented by 

 Mr. H. H. Lake, on behalf of W. R. Hartigan, United 

 States. A pair of curved jaws hinged together by a 

 spring joint are provided with spikes which perforate 

 the egg shell on pressing the handles together. 



Guns. — Mr. H. Crampton has patented a safety ap- 

 pliance lor guns worked with miniature ammunition. 

 The invention is designed to prevent the fire from doing 

 damage when they are trained into directions beyond 

 certain limits. Over the muzzle of the gun is mounted 

 a shutter which is usually held up by a trigger catch 

 leaving the muzzle free. The trigger is connected by 

 cords of determined length to fixed points one on each 

 side of the gun. So long as the gun is trained into 

 directions such that neither of these cords is strained the 

 muzzle remains open and the firing is not interfered 

 with, but if the gun is trained so that it strains either of 

 the cords, the trigger is withdrawn and the shutter closes 

 down over the mouth of the gun. If the firing takes place 

 the miniature projectile is arrested by the shutter and 

 cannot do any damage beyond. 



Fresh Air for Underground Railway Carriages. — 

 An apparatus for supplying fresh air to the carriages of 

 underground railways has been patented by Mr. A. A. 

 Clarke, of 348, Hackney Road, London. According to 

 this invention each carriage is provided either at the end 

 or underneath with a chamber charged with compressed 

 air, carried up from this chamber and running along the 

 top of the carriage is a pipe provided in the centre with 

 a gauge for registeririg the pressure of the air ; this pipe 

 is also provided with one or more short tubes which are 

 connected with a radiator for supplying air into the 

 carriage. An advantage claimed is that the same make 

 of cylinder as is at present used for holding compressed 

 gas on the underground system can be employed, and 

 also the machinery for compressing the gas into the 

 cylinder can be made use of for compressing the air. 



Aerial Machine. — An aerial machine has been 

 patented by Mr. H. J. Haddan on behalf of Mr. A. de 

 Bausset, of Chicago, U.S.A. The elevating force 

 necessary to float the apparatus is produced by an 

 aerostat from which about three-fourths of the air has 

 been exhausted. The aerostat is built up preferably of 

 steel plates with internal cross stays, is divided into air- 

 tight compartments, and provided with conical ends 

 pressed outwards by springs, and with sustaining or 

 steadying planes. The car, which is adapted for air, 

 water, and land transit, is suspended by jointed rods. 



