142 
Session 1881, drawing attention, under the chief heads of the 
subject, to the facts and opinions elicited from the examination 
of a large number of competent witnesses. 
Experimental inquiries, which will be the subject of a further 
report, have been instituted for the purposes of testing the 
various safety-lamps in use, as well as the numerous modifica- 
tions recently proposed, and of determining the effect of coal- 
dust in causing or aggravating explosions. From time to time 
also experiments have been made with a view to substitute, in 
the breaking down of coal, some other means for the gunpowder 
shots which have so often, by their flame, caused the ignition of 
fire-damp. 
The presence of a powerful ‘‘ blower” of natural gas at the 
Garswood Hall Colliery, near Wigan, with the facilities offered 
by the proprietors, induced the Commission to erect suitable 
apparatus for a long series of these trials, and now that it ap- 
pears desirable to compare the results with what may be obtained 
in another district and with a differently constituted fire-damp 
the whole of the apparatus is in course of erection at a colliery in 
the Rhondda Valley, where a very permanent ‘ blower”’ offers 
similar advantages. 
In the course of the lamp experiments it came out very clearly, 
in confirmation of statements before made, that the greatly 
augmented ventilation in our larger modern collieries has put 
an end to the fancied security of the simple Davy and Clanny 
lamps. Their use in fact, unless they be protected by some 
farther contrivance, is attended with the most imminent risk 
when the velocity of a current liable to be rendered explosive, 
exceeds six feet a second. A high degree of importance thus 
attaches to the comparative trials of lamps in which the flame is 
sufficiently shielded against the impinging stream of air, and 
those which have the property when immersed in an explosive 
mixture, of rapidly quenching both the flame of the wick and of 
the burning fire-damp. 
The terrible disaster which occurred in September, 1880, at 
the Seaham Colliery, drew more anxious attention than ever to 
the question of the part played by coal-dust, and a special refer- 
ence having been made by the Secretary of State for the Home 
Department to Prof. Abel, C.B., the experiments at Garswood 
Hall were largely extended. Some of the results were very 
remarkable ; the proportion of fire-damp present with the air 
may be so small as to elude detection by the ordinary test of the 
carefully watched flame in the safety-lamp, and yet the presence 
of dust in suspension will cause rapid ignition, or even explosion, 
in a degree varying with the proportion of gas and the velocity 
of the current. Dust was employed from different parts of the 
works of several collieries where it was suspected that this agent 
had borne a serious part in intensifying and spreading explosions ; 
and it was found that some of the varieties were far more sensi- 
tive than others. Certain kinds of dust, in themselves perfectly 
non-combustible, were similarly tested, and proved to have an 
analogous effect in promoting explosion, even when the per- 
centage of gas was exceedingly small. 
It is obvious from these facts that under certain conditions it 
is very important that a satisfactory indicator of minute propor- 
tions of fire-damp should be employed ; and the further experi- 
ments proposed to be carried out by the Commission will include 
a particular inquiry into this subject. 
The question’ of the feasibility of the introduction of the 
electric light into the workings of a colliery has been partially 
solved. The Stanton Coal and Iron Company were induced by 
the Commission to make a trial of Mr. Swan’s lamps in their 
Pleasley Colliery, near Mansfield. Not only the inset and main 
road, but some of the ‘‘long-wall” faces of work, were 
brilliantly lighted in this manner, A second experiment of the 
same kind has been carried out at the Earnoch Colliery, near 
Hamilton. 
The use and abuse of explosives in mining operations have in 
the last few years formed a subject of much inquiry, especially 
with reference to the firing of shots in coal-seams liable to be 
invaded hy fire-damp. A return to mere wedging in all cases, 
as proposed by some officials, would be to ignore the advance of 
science as well as the necessities caused by competition ; and the 
Commission hopes by further examination, and especially by 
practical trials, to contribute useful information to the solution 
of a difficult but important question. 
Among the applications of scientific apparatus the employment 
of the ingenious protected lime-light lamp, and of the portable 
breathing arrangement of Mr. Fleuss, during the operations for 
re-opening of parts of the Seaham Colliery, deserves special 
notice. 
NATURE 
\ 
. Vs 4 2 : 
[Dec. 8, 1881 
UNIVERSITY AND EDUCATIONAL 
INTELLIGENCE 
CAMBRIDGE. —Messrs. W, M. Hicks and W. W. R. Ball are 
appointed Moderators in the Mathematical Tripos for the year 
beginning next May, The Senior Wranglership will in future 
be adjudged in June. ' 
The Examiners for the Natural Sciences Tripos in 1882 are Lord 
Rayleigh, Prof. W. J. Lewis, Prof. Morison Watson (Owens 
College), Drs. Gaskell, R. D. Roberts, and Vines, Mr. A. G. 
Vernon Harcourt (Oxford), and Prof. A. M. Marshall (Owens 
College). 
Mr. R. T. Glazebrook, Demonstrator of Experimental 
Physics, is approved as a Teacher of Physics, and Mr. A. S. 
Lea, Lecturer at Caius College, is approved as a Teacher of 
Physiology for the purpose of Medical Studies. 
Clare College offers a Natural Science Scholarship, examina- 
tion March 28 ; subjects: Chemistry, Chemical Physics, Botany, 
Geology. Candidates must give notice a fortnight previously to 
the tutor. 
Guiascow.—The matriculations forthe present session number 
2316, distributed among the various Faculties as follows, viz. :— 
In Aits 1327, in Medicine 624, in Law 211, in Theology 100, 
in Arts and Medicine 25, in Arts and Law 9, in Arts and Theo- 
logy 20. The total number of matriculations last session was 
2304, distributed as follows :—In Arts 1406, in Medicine 563, 
in Law 189, in Theology 85, in Arts and Medicine 29, in Arts ~ 
and Law 18, in Arts and Theology, 14. 
SCIENTIFIC SERIALS 
Sournal of the Franklin Institute, October.—Experiments on 
the strength of wrought iron and steel at high temperatures, by 
Mr. Roelker.—On the proper method of expansion of steam 
and regulation*of the engine, by Prof. Thurston.—On the last 
experiment with the Perkins machinery of the anthracite, by 
Ch. Eng. Isherwood.—Radio-dynamic facts, by Dr, Chase.— 
Universal energy of light, by the same. 
Annalen der Physik und Chemie, No. 10.—Photometric re- 
searches on absorption of light in isotropic and anisotropic media, 
by C. Pulfrich,h—On the vapour-tension of mixed liquids (con- 
tinued), by D. Konowalow.—On the heat of formation of water, 
by A. Schuller.—On the heat-conductivity of gases and its eon- 
nection with temperature, by L. Graetz.—Past observations on 
the expansion of water by heat, by P. Volkmann.—On the 
theoretical determination of vapour-pressure and volumes of 
vapour and liquid, by R. Clausius.—On heat-conduction in a 
system of cylinders, and on the experimental determination of 
the conductivity of water, by H. Lorberg.—On magnetic reac- 
tion, by F. Auerbach.—Application of the balance to the 
problem of gravitation, by Ph. v. Jolly.—On the spectra of 
hydrogen and acetylene, by A. Wiillner.—Some remarks on 
Herr Wesendonck’s experiments on spectra of carbon compounds, 
by the same.—The minimum of deflection of a ray of light in a 
prism, by K. H. Schellbach.—Contribution to history of natural 
sciences among the Arabians, by E. Wiedemann. 
La Natura, Nos. 21 and 22, November.—The Italian section 
at the Paris Electrical Exhibition, by R. Ferrinii—Thermal 
radiation of the sun, &c. (continued), by C. Cattaneo.—On the 
origin of electricity of storm-clouds and of the air, and on elec- 
tricity in general, by F. G. Nachs. 
SOCIETIES AND ACADEMIES 
LONDON 
Royal Society, November 17.—‘‘ Researches on Chemical 
Equivalence.” By Edmund J. Mills, D.Sc., F.R.S., and J. H. 
Bicket. Part IV. : Manganous and Nickelous Sulphates. 
The authors have examined the precipitability and precipita- 
tion of manganous and nickelous sulphates, alone or commixed, 
by means of sodic carbonate. The chemical events they de- 
scribe are represented in a series of four hyperbolas, whosé 
equations are given in the memoir. They sum up their results 
as follows :—(1) Precipitability is a linear function of mass ; (2) 
when the commixed sulphates are precipitated by sodic car- 
bonate, equal weights of them are equally precipitable, the 
attraction of one of them for the reagent being the inverse of 
that of the other; (3) when the sulphates are separately precipi- 
tated by the same reagent, they are equally precipitable, and do 
