SCIENTIFIC AND USEFUL

New Zealand Graphic, Volume IX, Issue 41, 8 October 1892, Page 998

SCIENTIFIC AND USEFUL

A SEW SPECIES OF CANDLES. A YOUNG Italian is reported to have invented a species of candles which produces a most intense light, and which is intended to be projected from a cannon and to strike the enemy’s works or that of the country where it is suspected they are. <>n striking any solid substance it breaks and the substance contained in it, taking fire, produces a light, estimated to be of the intensity of 100,000 candles, which illuminates the field for a great distance. FISH FROM VOLCANOES. Attention has recently been called to the fact that the volcanoes of the Andes eject large quantities of fish from the craters in the first stage of an eruption. The Indians hold that many of these fishes are alive when they are found on the sides of the mountain, and it is certain that few are either boiled or mutilated. The explanation is that during the long period of quiescence, extending even to a century, the crater becomes choked up and turned into the bed of a lake, with subterranean channels to other crater lakes, from which the spawn probably conies. The fishes are generally blind, showing that they are of an underground variety. MOSQUITOES. A correspondent suggests that one of t.he best methods of getting rid of mosquitoes is to stock the ponds and lakes with fish—carp is especially named as being one of the fish to feed on the larva of the mosquito. So far as this goes, it is undoubtedly a valuable hint; but, as the egg of the mosquito comes to maturity in a very short time, any small hole, even a cow track, in which water may lie for a week, is sufficient to bring forth the insect to perfection, so that after we get them from the lakes and ponds, there is generally enough left from swampy places in marshes to stock the country nevertheless.

LATEST PLANS FOR THE CHANNEL BRIDGE. Mr I’. Stanhope, who presided at the fourth annual general meeting of the Channel Bridge and Railway Company, read the report of the Council of Administration. As the result of careful soundings taken a couple of years ago a new route had been adopted, which would considerably shorten the distance. The number of piers would be reduced from 121 as originally intended to seventy-two, and the spans would be increased in size to 400 and 500 metres alternately from one end of the bridge to the other, while the work would be of such a nature as to obviate every possible risk. They would, at the same time, be of such a simple character that the time required for their completion would be only seven years, four of which would be occupied by operations in the sea. In consequence of the increased span adopted, and the new system ot lighting and buoying, navigation would be in no way impeded. The total cost of constrnction and interest till traffic could be opened was estimated at £32,000,000, while the anticipations of good returns to investors in the undertaking bid fair to be realised. All that was now required was the concessions which would enable them to begin work at once. Now that it had been demonstrated that the financial results would be satisfactory, and that there would be no obstacle to navigation, it was thought that, with the advantages which England and Europe generally would derive from this great work, these concessions would not long be sought in vain.

HOW LONG BEFORE THE END OF THE WORLD? There is a distinct limit to man's existence on the earth, dictated by the ultimate exhaustion of the sun. It is, of course, a question of much interest for us to speculate on the probable duration of the sun’s beams in sufficient abundance for the continued maintenance of life. Perhaps the most reliable determinations are those which have been made by Professor Langley. They are based on bis own experiments upon the intensity of solar ladiation, conducted under circumstances that give them special value. I shall endeavour to give a summary of the interesting results at which he ha a arrived. The utmost amount of heat that it would ever have been possible for the sun to have contained would supply its radiation for 18,000,000 years at the present rate. Of course this does not assert that the sun, as a radiant body, may not be much older than the period named. We have already seen that rhe rate at which the sunbeams are poured forth has gradually increased as the sun rose in temperature. In the early times the quantity of sunbeams dispensed was much less per annum than at present, ami it is therefore quite possible that the figures may be so enlarged as to meet the requirements of any reasonable geological demand with regard to past duration <>f life on the earth. It seems that the sun has already dissipated about four fifths of the energy with which it may have originally been endowed. At all events, it seems that, radiating energy at its present rate, the sun may hold out for 4,000,000 years, or for 5,000,000 years, but not for 10,000,000 years. Here then we discern in the remote future a limit to the duration of life on this globe. We have seen that it does not seem possible for any other source of heat to be available for replenishing the waning stores of the luminary. It may be that the heat was originally imparted to the sun as the result of some great collision between two bodies which were both dark before the collision took place, so that, in fact, the two dark masses coalesced into avast nebula from which the whole of our system has been evolved. Of course it is always conceivable that the sun may be reinvigorated by a repetition of a similar startling process. It is, however, hardly necessary to observe that so terrific a convulsion would be fatal to lite in the solar system. Neither from the heavens above, nor from the earth beneath does it seem possible to discover any rescue for the human race from the inevitable end. The race is as mortal as the individual, and, so far as we know, its span cannot under any circumstances be run out beyond a number of millions of years which can certainly be told on the fingers of both hands, and probably on the fingers of one.

PERHAPS no actress has ever been more truly popular than the lady whose portrait we this week reproduce from the old print which is bound in the extremelyinteresting account of her life, just issued. At the close of the last century, and the commencement of this, Dorothea Jordan was the darling of the stage ;] the favourite of the Royal House, the most courted, most popular woman in London. It was said of her ‘ that ‘ her face, her manners, her looks were irrestible ; her smile had the effect of sunshine, and her laugh did one good to hear it; her voice was eloquence itself ; it seemed as if her heart was always in her mouth ; she was all gaiety, openness, good nature ; rioted in her fine animal spirits, and gave more pleasure than any other actress, because she had the spirit of enjoyment in herself.’ Her temperament, like that of most high-spirited people, was mercurial, and Sir Jonah Barrington, who knew her well, and often saw her before going on the stage, relates that she was oftentimes in low spirits ; the sight of the crowded theatre, however, acted like a stimulant, and in a few minutes she would be the life and soul of the piece.

Dora was twenty-eight years of age when she attracted the attention of the Sailor Duke. This connection lasted twenty years, and the Duke treated her with so much respect, and she was so well received in certain circles, that it began to be whispered about that there had been some sort of private marriage ceremony. The lie was, however, given to this by the subsequent royal marriage, and the total absence of any claim on the part of the actress. A bitter controversy arose out of the terms of separation, some of her friends, amongst them Sir Jonah Barrington, considering she had been badly used. Nevertheless, an allowance of £1.500 per annum was made to her.

She had never left the stage, and still commanded popular favour, but the mortification she had endured preyed upon her. Her vivacity was no longer ‘ the riot of natural good spirits,’ but a tame imitation without the true ring. Moreover, a hoyden or country girl of forty-eight is not in touch with the audience. Miss O'Heill, too, a new star, had risen in the theatrical hemisphere, and all the world flocked to see her, and Mrs Jordan played to empty houses. The bright scenes of success, the triumphs which brought gratification to her vanity, were now to cease, and in the bitterness of her soul she would cry aloud that her sin had found her out. Debt and difficulties of all kinds surrounded her ; she had to fly from her creditors and find a refuge in France. She went from place to place until atlastshereached St. Cloud, near Paris. Here in this lonely deserted town she remained, anxiously waiting for remittances. There is a tragic element in the sad ending to so much brightness. She died literally of a broken heart. Her death is dramatically told by Sir J. Barrington, and reading through the lines of that not too veracious chionicler, we may gather sufficient evidence to be convinced of its truth.