Rensselaer Union, Volume 8, Number 17, Rensselaer, Jasper County, 13 January 1876 — MECHANICAL AND SCIENTIFIC. [ARTICLE]

MECHANICAL AND SCIENTIFIC.

—The French Government has sent Dr. Durand Fardel to China to study the subject of contagious diseases and obtain data for discussing the question of quarantine. ' f —The remarkable discovery.'of a 1 toiling lake in the Island of Dominica has excited much scientific interest, and investigations of the phenomenon, are Vi" Ikmade by geologists. It appears that a company exploring the steep and forestcovered mountain behind the town of Rosseaucame upon this ltoiling lake about 2,500 feet above the sea-level, and two miles in circumference!’ On the* wind clearing away for a moment the clouds of. sulphurous steam- with which the lake was covered a mound of water was seep ten feet higher than the general level of the surface, aud caused by ebullition. The margin of the lt*ke consists of beds of sufpbur, and its overflowing found exit bjt a waterfall of great height. —A valuable process for removing the hydrochloric acid nuisance from the air and rivers is described in the Ctunnical Newt. In the apparatus thus employed the chloride of lime produced contains 35 per cent, of chlorine ami the fuel consumed amounts to halt the weight of the finished product. The chlorine resulting from this process is so diluted with nitrogen and air that, lor perfect absorption, the surface covered with lime is six times larcer tiian in the ordinary chloride of lime works. The introduction of the process is rendered costly by the extensive chambers required; but, on the other hand, the advantages which present themselves are, that the amount ol lalwr is slight, the consumption of fuel moderate, and manganese is entirely dispensed l wuh; ; - wjb*. —M. Pupka, of Vienna, has published an account of his experiments in lining steam boilers with sheets of copper in order to hinder incrustation. He states that of the three plates which formed the bottom ot a locomotive boiler the two at the ends were covered with aslieetof copper .04 inch in thickness, the middle one being left bare, aud the machine was used steadily for two years, and in districts where .the water is of excessively bad quality. On removing the tubes a layer oi incrustation four inches thick was found on the iron surface, while a deposit varying from only .08 to 43 inch thick appeared on the copper. The iron" also was found corroded in many places to a depth of .02 inch, but the copper had remained perfectly clean aud bright. M. Pupka stales that the texture ol the incrustation showed*- grains of a larger size ou the iron than on the copper- . « —A little controversy regarding the relative strength of the lion and tiger has Ken sustained among certain correspondents to Nature. The latest writer—Mr. Haughton, of Trinity College, Dublin—declares that every person well acquainted with both animus will concede that the tiger is the stronger, Mr. Haughton states that the strength of the lion in the fore-limbs is only 00.9 per cent, of that ot the tiger,! and that the strength of the hind legs • is only 65.9 per cent, ot that of the tiger.' “ 1 may adu,” lie says, “that five men can easily hold down a lion, while it requires nine men to control a tiger. *>Martial also states that the tiger always killed the lions in the amphitheater. The lion is in truth a pretentious humbug, and owes his reputation to his imposing mane, and he w ill run away like a whipped cur under circumstances in which the tiger will beldlv attack and kill.”