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THE POPULAR SCIENCE MONTHLY. 



ation of his invention, which is that of fix- 

 ing the buoys so that they shall not be re- 

 moved by storms, but declines to make his 

 plans public on account of the defective 

 condition of the patent laws. He has, how- 

 ever, explained it to competent navigators, 

 and they are said to regard it as practica- 

 ble. 



American and European Palaeolithic Im- 

 plements. Mr. Henry W. Haynes has com- 

 pared the argillite implements found in the 

 gravels of the Delaware River at Trenton, 

 New Jersey, with the palaeolithic implements 

 of Europe, by a personal inspection of both, 

 to ascertain to what extent they correspond 

 in character as objects of human workman- 

 ship. He traces many striking resemblances 

 between the two groups. The argillite im- 

 plements are, indeed, of ruder workmanship 

 than the European flints, but that is because 

 the material from which they are made is 

 less susceptible of being finely worked. The 

 types of the two classes of implements are, 

 however, remarkably similar, and the Dela- 

 ware objects are equally well adapted to 

 any purposes to which the European imple- 

 ments are capable of being applied. Re- 

 garding the character of the formations in 

 which the implements are found, the general 



appearance of the country and the gravels 

 present a striking resemblance to what he 

 has seen in the places where the palasolith- 

 ic implements in Europe were found. He, 

 therefore, considers the argillite objects of 

 the Trenton gravels to be true palaeolithic 

 implements. 



Disease from Coal-Dast. M. Paul Fabre 

 has published some observations on the part 

 which coal-dust plays in the pathology of 

 coal-miners. The effects which result from 

 the accumulation of dust in the respiratory 

 passages are obvious and need no particular 

 description. Coal-dust does not exert any 

 special action on the skin. The parasitical 

 pests, the origin of which some authors 

 have attributed to coal-dust, never appear 

 except when the chambers of the mines con- 

 tain water holding some irritant in solution 

 or suspension. Coal- sorters, who work on 



the surface, live in an atmosphere contain- 

 ing coal, and handle as much coal as the 

 workmen in the mines, but do not suffer 



from eruptions. Nearly all miners are 

 marked with characteristic scars of a clear 

 blue color, which, indelible as real tattooing, 

 follow every wound produced by splinters of 

 coal. Coal-dust in the air in a state of sus- 

 pension may produce a slight degree of sim- 

 ple conjunctivitis ; affections of the cornea 

 and iris are also sometimes observed, re- 

 sulting from blows inflicted by fine frag- 

 ments of coal. They arc generally cured 

 after the irritating splinter has been re- 

 moved. Miners are frequently affected with 

 defective hearing and other troubles of the 

 ears, which most frequently arise from a 

 stoppage of the extreme auditory conduit 

 with masses of dust that have been cement- 

 ed into a wad by the ear-wax. This may 

 be easily removed, and the irritation of the 

 car-passages may be cured afterward by 

 washing. 



f 



What Perils might come out of a Tun- 

 nel. The scheme to tunnel the Channel has 

 excited great alarm, and called out formi- 

 dable remonstrances in England. The ob- 

 jection most prominently urged against the 

 proposed work is that it would expose the 

 country to a constant menace of invasion 

 or treachery. The French might fill the 

 tunnel at any time with soldiers in the guise 

 of innocent passengers, and seize the Eng- 

 lish approaches so firmly that it would be 

 impossible to shake them off, before the 

 people had begun to imagine that danger 

 was near ; and the Irish republicans might 

 form a league with the French, and, seeing 

 that the telegraph wires were cut, destroy 

 communication within the kingdom, thus 

 increasing the danger, which, as it was 

 previously presented, seemed as great as it 

 possibly could be. The single defense of the 

 English would be the power of blowing up 

 the tunnel suddenly and unexpectedly, " and 

 what would that power be worth ? The pre- 

 mier might think himself justified in destroy- 

 ing twenty millions of property and impairing 

 twenty-two millions more; . . . but also he 

 might not. He might be an undecided man, 

 or a man expecting defeat by the opposition, 

 or a man paralyzed by the knowledge that 

 the tunnel was full of innocent people whom 

 his order would condemn to instant death in 

 a form which is at once most painful and 

 most appalling to the imagination. . . . The 



