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THE POPULAR SCIENCE MONTHLY 



invader first attempted its conquest. . . . 

 An infinity" of mounds was found in one 

 locality, and twenty-four human figures in 

 wood in one of the temples, and golden 

 bells outside, " which gave out sweet chimes 

 in ever-varying tones." Some of the 

 mounds contained ornaments, in imitation 

 of every form of life, from the ant to a hu- 

 man being, and of every value from $10 to 

 $30,000. 



Waste of the World's Forests. When 

 the forests of such a country as Cyprus were 

 destroyed, said Mr. Thistelton Dyer in a dis- 

 cussion in the British Society of Arts, it was 

 like a burned cinder. Many of the West 

 Indian Islands are in much the same condi- 

 tion, and the rate with which the destruction 

 takes place when once commenced is almost 

 incredible. In the Island of Mauritius, in 

 1S35, about three fourths of the soil was in 

 the condition of primeval forest, viz., 300,000 

 acres ; in 1879, the acreage of woods was 

 reduced to 'ZO/lOO ; and in the next year, 

 when an exact survey was made by an In- 

 dian forest officer, he stated that the only 

 forest worth speaking about was 35,000 

 acres. Sir William Gregory says that in 

 Ceylon, the eye, looking from the top of a 

 mountain in the center of the island, ranged 

 in every direction over an unbroken extent 

 of forest. Six years later the whole forest 

 had disappeared. The denudation of the 

 forests is accompanied by a deterioration in 

 the soil ; and the Rev. R. Abbay, who went 

 to Ceylon on the eclipse expedition, calcu- 

 lated, from the percentage of solid matter in 

 a stream, that one third of an inch per an- 

 num was being washed away from the culti- 

 vated surface of the island. In some colo- 

 nics the timber was being destroyed at such 

 a rate as would soon lead to economic diffi- 

 culties. In Jamaica, nearly all the timber 

 required for building purposes has already 

 to be imported. In New Brunswick, the 

 hemlock-spruce is rapidly disappearing, one 

 manufacturer in Boiestown using the bark 

 of one hundred thousand trees every year 

 for tanning. In Demerara, one of the most 

 important and valuable trees, the green- 

 heart, is in a fair way of being exterminat- 

 ed. They actually cut down small saplings 

 to make rollers on which to roll the large 

 trunks. In New Zealand, Captain Walker 



says he fears that the present generation will 

 see the extermination of the Kauri pine, one 

 of the most important trees. All these facts 

 show that this is a most urgent question, 

 which at no distant date will have to be 

 vigorously dealt with. 



Professor Hoggius on Comets. Profess- 

 or Iluggins endeavored, in a recent lecture 

 on comets, to distinguish as clearly as pos- 

 sible between what we know about those 

 bodies, and what is only speculation. Some 

 comets have become permanent members 

 of our system, while others probably visit 

 us once only, never to return. It de- 

 pends upon a comet's velocity whether its 

 orbit shall take the shape of a returning 

 curve or not. If the velocity, at the earth's 

 distance from the sun, exceeds twenty-six 

 miles a second, the comet will go off into 

 space, never to come back to us. The small 

 portion of the comet's life during which we 

 are able to study it when it is in a condi- 

 tion of extreme excitement, in consequence 

 of its nearness to the sun is quite unlike 

 its ordinary humdrum existence, when it has 

 only a nucleus and no tail. Spectroscopic 

 observations of comets show that they shine 

 with an original light, the bands of which 

 indicate a composition of carbon combined 

 with hydrogen, and also with a reflected 

 light, the lines of which indicate the pres- 

 ence of a nitrogen compound of carbon. 

 Moreover, "certain minor modifications of 

 the common type of spectrum are often 

 present, and show, as was to be expected, 

 that the conditions prevailing in different 

 comets, and, indeed, in any one comet from 

 day to day, are not rigidly uniform." The 

 study of meteorites, Mr. Iluggins suggests, 

 may throw some light on the constitution of 

 the nuclei of comets, which are probably 

 similar to them, and therefore solid. The 

 tails have been supposed to be gaseous mat- 

 ter sent off by the sun's repulsive action. 

 The gases are probably not products of de- 

 composition, but matter that has been oc- 

 cluded. Experiments so far throw little 

 light on the question whether cyanogen is 

 present in combination or otherwise within 

 the comet, or whether it is found at the 

 time by the interaction of carbonaceous and 

 nitrogenous matter. In the latter case we 

 should have to admit a high temperature, 



