346 



SCIENCE. 



[Vol. VII., No. 167 



managing fishery affairs than a landsman who 

 happens to be master of the theory of navigation 

 is the right man to be trusted with steering an 

 ironclad. 



The whole lesson of my somewhat lengthy and 

 varied experience of fishery matters may be 

 summed up thus : — 



1. Don't meddle, unless you have good grounds 

 for believing that you know what the effect of 

 your meddling will be. 



2. Listen to all that the scientific men without 

 practical knowledge and the practical men with- 

 out scientific knowledge have to say, but give to 

 neither the power of directly interfering with such 

 a large and important branch of industry as 

 fishing. 



3. Collect all the information that is to be had, 

 so that the country may know year by year how 

 the fisheries really stand ; make that information 

 accessible to the people who are engaged in the 

 fishing industry ; inquire into real or supposed 

 grievances ; and regulate or restrict, experi- 

 mentally, on good cause shown. 



4. Let the department charged with these duties 

 obtain such scientific help as is needful from per- 

 sons of recognized scientific competency, who are 

 not under the control of the administrative depart- 

 ment, and are not responsible to any one for the 

 conclusions at which they may arrive. Moreover, 

 let all scientific inquiries thus undertaken be 

 strictly relevant, not merely to fishery matters, 

 but to questions with which the state may 

 properly deal as the representative of the general 

 interest. 



If the government is to be asked to give a body 

 of scientific men a roving commission to inquire 

 into the natural history of the seas and rivers of 

 England, let that issue be put plainly before the 

 minister to whom the application is made. But I 

 do not see what the board of trade has to do with 

 such ' aid to science ,' nor why it is desirable that 

 the gentlemen who are to be intrusted with this 

 very considerable enterprise should have the 

 1 management of the fisheries ' — which means the 

 power of meddling with a great industrial interest 

 — thrown in as a sort of hors d'oeuvre. 



T. H. Huxley. 



March 20. 



EXPLOSIONS IN COAL-MINES. 



Attention has been called to the connection 

 which exists between gas-explosions in coal-mines 

 and certain atmospheric conditions, which is ex- 

 pressed by saying that the number of such ex- 

 plosions is very considerably greater under low 

 atmospheric pressure (under so-called barometric 

 depression) than with a normal or high barometer. 



This is not a newly discovered fact, for it was 

 recognized by Dickinson as early as 1852 ; and for 

 nearly ten years past barometers have been used 

 in many English coal-mines for observing the con- 

 dition and changes of atmospheric pressure, and 

 estimating therefrom, to some extent, the danger 

 which may come from the latter source. But 

 there is a growing conviction that the whole ques- 

 tion needs further investigation, and particularly 

 that experimental tests are necessary. Such tests, 

 however, are very expensive, and for that reason 

 little has been done hitherto in that direction. All 

 the more noteworthy, therefore, are the numerous 

 experiments which were undertaken last summer 

 at the mines of Archduke Albert in Karwin, and 

 which were on such a scale that the working of 

 the entire mine was suspended at times in order 

 to give a free field to the scientific investigations. 

 Professor Suess has recently given an account of 

 these important investigations in the geological 

 institute at Vienna. 



The district in which these observations were 

 made comprises the greatest part of the archducal 

 Gabriela mine. This portion obtains its fresh air 

 from the Gabriela shaft, while the principal air- 

 shaft, 500 metres to the west, serves as the up-cast 

 shaft. At the latter a Quibal ventilator of 7.04 

 metres diameter was in operation during the whole 

 course of the experiments. A similar ventilator 

 of 12 metres diameter has been introduced re- 

 cently. 



The seams of the Gabriela mine belong to the 

 most easterly portion of the Ostran-Karwin dis- 

 trict, just on the edge of the Carpathian Moun- 

 tains ; and the mine joins the district of the 

 Johann-Schacht where the accident of March 6, 

 1883, occurred. The stratification is nearly hori- 

 zontal. On one occasion, after work in the mine 

 had been stopped for six hours, the freshly ex- 

 posed surface, where the miners had been at work, 

 gave a crackling, blowing, and slightly hissing 

 sound over its whole extent ; and the escape of 

 gas was detected not only by the lamp, but by the 

 ear. Many of the puddles of water on the floor of 

 the level were in slight agitation from the gas 

 bubbling up through them. The old surfaces, 

 however, were quiet, and experience has shown 

 that the portions of the seam lying nearest work- 

 ings lose their gas sooner or later, and cease to be 

 dangerous. For the reason above explained, also, 

 the working of drifts running directly into the 

 seam requires the greatest precaution, and in the 

 whole Ostran-Karwin district double workings are 

 carried on in the deep levels for the sake of venti- 

 lation. The escaping gas is carried along by the 

 draught produced by the ventilation, but local 

 accumulations are unavoidable. 



