394 



NATURE 



\Sept. lo, 1874 



much to effect economy in fuel as to prevent smoke; and although 

 the first cost was somewhere about 130/. per boiler, the proprietor 

 considers himself to be already more than recouped for his outlay, 

 as a saving of fully 12 per cent, in the fuel consumed was effected. 

 At the same works I have also seen in operation the method of 

 Messrs. Haworth and Horsfall, of Todmorden, which has, I am 

 told, in certain circumstances, some advantages over the other. 

 In this, as in the other, the coal is fed in uniformly by mechanical 

 arrangements. The mechanism is different in the two cases, but 

 the result in the motion communicated to the coal is very much 

 alike in both. The bed of coal, which is gradually supplied in 

 front, is caused to travel along the bars towards the inner end of 

 the furnace, and the combustion proceeds in a very uniform 

 manner in conditions highly favourable to economy of fuel, and 

 without the emission of almost any visible smoke. 



These two methods I liave mentioned because they appear 

 both to work very successfully in practice, while they both bring 

 into effect the principle of action of the fuel which has long 

 appeared to me to be the best that can be adopted for ordinary 

 cases of steam-engine boilers. 



I have now occupied, I think, enough of your time, and so I 

 will conclude. I have endeavoured to select out of the wide 

 range of subjects which fall within the scope of the Mechanical 

 Section of the llritish Association, a few which have come more 

 particularly under my own notice, and on which I thought it 

 was in my power to give intelligence that might be interesting as 

 to past progress, and suggestions that might be useful towards 

 extension of improvements in the future. 



SCIENTIFIC SERIALS 



Archives dcs Sciences P/iysiipies et A^attirelles, No. 198. — M. 

 C. Marignac contributes a paper On the simultaneous diffusion 

 of certain salts, and gives long tables of the results of his ex- 

 periments. — M. Marc jMicheli gives a note of eighteen pages in 

 length, On the Onagracea; of Brazil, of wliich the greater part 

 is taken up with the genus Jussia;a. lie sums up the distribu- 

 tion thus : — 



Pacific D— _:i 



N. America. Me.vico. Antilles. Guyane. 



Eujussieaea 23 

 Oligospermum 12 

 Macrocarpon 4 



— M. Maurice de Tribolet gives a concise history of the study 

 of the genus Neiintea, and gives analytical tables showing the 

 distribution of species in the Jurassic beds of the Jura. The 

 meteorological observations made at Geneva, under Prof. Pianta- 

 mour, during May, conclude tUe number. 



SOCIETIES AND ACADEMIES 

 Paris 

 Academy of Sciences, Aug. 31. — M. Faye in the chair^ — 

 Tlie following papers were read : — Astronomy at the Italian 

 Spectroscopic Society, by M. Faye. This was a reply to some 

 criticisms of P. Secchi. The author pointed out that P. Secchi's 

 theory of sunspots was a return to the idea announced by Galileo 

 in 1612, the clouds being buried in the body of the sun instead 

 of floating above it. The theory advanced by Ihe author on the 

 other hand had beeij pronounced by Mr. Langley to be a vera 

 causa. This vera causa, according to M. Faye, is nothing more 

 ihan a law of hydrodynamics, perfectly established! for tenestrial 

 air and water currents. — Remarks on the fish of the Algerian 

 Sahara, by M. P. Gervais. The remarks refer to species of 

 Coplodoii and Cyprinodoii, the former of which had been cited 

 liy M. Cosson as proving the continuity of the sheet of water 

 which extended over this region. — Note on the development of 

 the contractile coat of the vessels, an anatomical paper by M. 

 C. Rouget. New researches undertaken by the author on 

 amphibian larva; establish beyond doubt the contractibility of 

 the ramified protoplasmic cells observed last year in the vessels 

 of the hyaloid membrane of the adult frog. — On winged Phyl- 

 loxera and its ]irogeniture, by M. Balbiani. The author points 

 out the complete analogy between rhylloxera vastatrix and the 

 Phylloxera of the oak. — New observations on the migrations of 

 Phylloxera to the surlace of the soil and on the effects of the 



method of submersion, a letter from M. G. Bazille to M. Dumas. 

 The letter contained a note, published in the Messager du Midi. 

 — M. P. Mouillefert addressed also a letter containing observa- 

 tions on the employment of the chief insecticides from experi- 

 ments tried in the laboratory at Cognac and on the vines of the 

 neighbourhood. — M. P. Rohart addressed a letter on the action 

 exercised by the soil on insecticide gases. — Other communica- 

 tions relating to Phylloxera were received from MM. Delfan, A. 

 Richard, Gauthier, L. Rousseau, &c. — On a physiological phe- 

 nomenon produced by excess of imagination, a letter from M. 

 P. Volpicelli to M. Chevreul. Two experiments were made 

 with magnets upon nervous subjects, to see if the effects produced 

 were really magnetic or due to the imagination. In the first 

 experiment a piece of unmagnetiscd iron was shown to the patient, 

 who immediately fell into convulsions. In the next experiment 

 a magnet was placed in the hand of a nervous suljject, who at 

 the end of a few seconds became so over-excited that the magnet 

 was removed. That the effect thus produced was due to the 

 sight of the magnet was proved by hiding several powerful 

 magnets in the chair occupied by the same individual, who when 

 thus unconscious of their presence experienced no ill effect. M. 

 Chevreul made some remarks « propos of the foregoing paper on 

 certain other illusions, such as the divining pendulum and divin- 

 ing ring. — Remarks on recent researches concerning the explosion 

 of powder, by MM. Roux and Sarrau. The authors pointed 

 out the agreement between certain of the results obtained by 

 them and by MM. Noble and Abel in their recent communi- 

 cations to the Academy. — New note on the tail of Coggia's 

 Comet, by M. A. Barthelemy. The theory of a repulsive force 

 emanating from the sun requires, according to the author, that 

 the axis of the tail should always be a prolongation of the 

 radius vector. With Coggia's Comet, ho\\ever, as observed by 

 M. Heiss on Julv 5, the tail made an angle of 160° with the 

 radius vector. The facts appear to the author to be simply ex- 

 plicable by the hypothesis of an interplanetary medium submitted 

 to the attractive action of the sun, through which medium the 

 comet travels with an increasing velocity ; fans and jets are 

 supposed to be the result of the sun's attraction on the denser 

 portions of the cometary matter. — On a new theory of the forma- 

 tion of cornets and their tails, by M. Virlet d'Aoust. In 1S35 

 the author suggested the hypothesis that comets were nascent 

 stars — the internal and still incandescent portions shinuig through 

 cracks in the dark surface. This view was afterwards aban- 

 doned for Saigcy's hypothesis, which considered the tails of 

 comets as the result of the reflection of [their light on an atmo- 

 sphere which they drew after them. This opinion was again 

 modified to meet the researches of Weiss, Schiaparelli, Klinker- 

 fues, and Oppolzer, who showed the connection between the 

 comets of 1S62 and 1S66, of Biela and Pogson, and the annular 

 meteor streams which give us the August and November shooting 

 stars. The author then asked whether comets did not equally 

 belong to rings which had given rise to their existence, and if the 

 light emitted by their tails did not simply result from the reflec- 

 tion of light from the nucleus on to the cosmical particles which 

 constituted the rings on which they seemed to depend. The 

 recent researches upon Coggia's Comet confirm this view in the 

 author's opinion. — On a new model of prism for direct vision 

 spectroscopes, by M. J. G. Hofmaun. — On some points in the 

 anatomy of the common mussel (lilyliliis ediilis), by M. Ad. 

 Sabatier. 



CONTENTS 



Pack 



The Intern,\tional Congress of Okibntalists 375 



Anders Jonas Angstrom 376 



The Iron and Steel Institute 377 



Shahpe's " UiRDS IN THE British Museum " 378 



Our Book Shklf .,..,,,,.. 380 



A Remarkable 'I'hunderstorm — C. Wakefield 3S0 



The Exhibition of Specimeus and Apparatus at the British Associa- 

 tion.— Alfred W. Bennett, F.L S 3S0 



Photographic Irradiation.— \V. J. Stillman 381 



PHiiger on Ilie '-Salivary Glands" of the Cockroach.— Dr . W. 



AiNSLlF. Hoi LIS 3S1 



Conference FOR Maritime Meteoroiogv 381 



On Sewage and Sewage Farming, by Prof. Thomas Baldwin . 3S1 



NOTE-'S 382 



7"he Ruins of Trov : Recent Discoveries of Dr. Schliemann 



[ ll'itit I UtiUrations) 384 



The British Association 386 



Scientific Serials 394 



Societies and Academies , 301 



