70 



SCIENTIFIC NEAVS. 



[Jan. 20, 18 



the sun-spot variation even more closely than the variations in 

 price. 



Following the regularitj' of each cycle there is some reason 

 for believing that the present period of low prices following 

 the last maximum of sun-spots which was in the end of 1882 

 and the beginning of 1883, will not last very much longer. 

 These are the simple facts, and the coincidence is so striking 

 that the subject is deserving of attention, and perhaps some 

 of your readers may be able to throw some further light on 

 the question. T. G. M. 



ELECTRIC SEWAGE TREATMENT. 

 "S.P.E."asks in your last number if anything has been 

 done for the purification of sewage by electric action. He 

 v/ill doubtless by this time, have seen mention of the novel 

 project for purifj-ing the sewage of London electrically. As 

 the general idea is not novel, I should like to ask if any of 

 the details of Mr. Webster's scheme have come to your 

 knowledge. W. 



THE LIFE-TIME OF THE SUN. 

 Some surviving opponents of Evolution seem to be 

 elated at the calculations of physicists, which seem to fix 20 

 million years as the maximum time during which the sun can 

 have existed. They would do well, however, to bear in 

 mind that geologists and naturalists, generally speaking, 

 attach very little value to such calculations ; which, moreover, 

 are sufficiently discordant. We see that the events which 

 have taken place since the origin of the sun cannot have 

 been compressed into such a comparatively short time. 

 However accurate the mere details of the calculations may be, 

 the fundamental assumptions are not proven, and there is 

 always the possibility of unknown factors intervening. 



Verax. 



Blow-Holes in Steel. — The presence of blow-holes 

 in steel was, at one time, generally attributed to bubbles 

 of carbonic oxide. More recently the investigations of 

 Mailer, Stead, and others have proved the cavities in steel 

 ingots to contain nitrogen and hydrogen. Mr. W. F. 

 Durfee has recently communicated to the United States 

 Naval InstitJte an ingenious and somewhat novel view of 

 the subject. He considers the blow-holes in ingots to be 

 caused by air carried down into the mould by the str ;am 

 of steel rushing out of the ladle. The action may be 

 illustrated by holding a glass of water under a running 

 tap, when the course of the bubbles may easily be seen. 

 When the tap is turned off, the fluidity of the water 

 instantly allows the bubbles to escape ; but if the experi- 

 ment be repeated with a more viscid liquid — melted 

 gelatine, for instance — some of the air will be unable to 

 escape. When the mass has solidified, the disposition of 

 the bubbles will be found to be verj^ similar to that of 

 the cavities in a soft steel ingot. The temperature of 

 molten steel is sufficient to expand air about seven times ; 

 while any atmospheric moisture would be converted into 

 gases with corresponding increase of volume. So that a 

 small quantity of air may produce a considerable degree 

 of porosity. Mr. Durfee proposes to overcome the diffi- 

 culty of producing sound ingots bj- making the steel 

 sufficiently fluid to permit the escape of the air bubbles 

 by the addition of a small quantity of aluminium. The 

 improvement in fluidity, and subsequent solidity, result- 

 ing from the addition of less than ot per cent, of 

 aluminium to melted wrought iron or mild steel has long 

 been known, and is practically taken advantage of in the 

 manufacture of Mitis castings ; but however beneficial, 

 its application to ingot steel must in the meantime be 

 limited to cases where cost is an entirely secondary 

 consideration . — Industries . 



RECENT INVENTIONS. 



The fallowing list has been compiled especially for the Sci'Rmi'Flc 

 News, l/y Messrs. W. P. Thompson and BouLT, Patent Ageitts, of 

 323, High Holborn, London, W.C.; Newcastle Chambers, Angel 

 Row, Nottingham ; Ducie Buildings, Bank Street, Manchester ; and 

 6, Lord Street, Livcipool. 



Preserving Milk. — A new treatment of milk to pre- 

 vent its turning sour has been patented by Mr. J. France, 

 of Marsden, Yorkshire. The milk desired to be pre- 

 served is charged with carbonic acid gas, in the same 

 way in which mineral waters are aerated,- and then 

 bottled. 



Ship's Log. — A log for indicating the speed of vessels 

 by registering the same on a horizontal plate, has been 

 patented by Mr. Rood, of Portswood, Southampton. It 

 consists of a single spring balance, and a line of from 

 twentj^ fathoms upwards. The plummet is towed in 

 the water, and the log placed under the deck with a 

 wire attached to it, leading to the trail line. 



Billiard Cue. — Messrs. Dress and Weber, of Frei- 

 berg, Germany, have patented a billiard cue. In order 

 that the cue may be able to retain its strength and 

 rigidity, a metal tube is used, inserted into a thin 

 wooden one of the proper size, the inner end of which 

 is turned down and let into a recess in an outer wooden, 

 stick of suitable dimension, the inner end of which is 

 itself inserted in a similar way and preferably screwed 

 into the outer end of the butt of the cue, which is made 

 hollow. Cues made in this way are not heavier than 

 the ordinary solid ones. 



Regenerative Hydro-carbon Lamp. — Messrs. Chandor 

 and Nolting, of Mark Lane, London, have patented a re- 

 generative hydro-carbon lamp. This invention is a 

 lamp, in which no glass chimney is employed. The 

 air requisite for feeding the flame is led to the same 

 from below in a highly heated state, while the 

 products of combustion pass off by a special tube, 

 which is so heated by the products of combustion 

 passing through it that it serves to heat the air fed to 

 the flame. By this means a pure white light is obtained 

 consequent on the perfect consumption of the hydro- 

 carbon employed. 



Application of Electricity to Coal-Cutting 

 Machines. — An apparatus for transmitting motion to 

 coal-cutting machines has been patented by Messrs. T. 

 and R. W. Bower, of Blackburn, and F. Mori, of AUer- 

 ton Main Collieries, Woodlesford. The improvements 

 refer to the employment of an electro-motor for im- 

 parting motion to coal-cutting machines. For this pur- 

 pose a dynamo machine of high tension is employed, 

 from which the electro-motive force is imparted to a 

 motor attached to the coal-cutting machine through suit- 

 able cables ; between the motor and the dynamo, and. 

 in connection with the cables, a cut-off is employed to 

 regulate the speed of the motor. 



New Gas Burner. — An apparatus for lighting by the 

 consumption of gas and air is the subject of a patent by 

 Mr. J. S. Sellon, of Hatton-garden, London. The gas 



