SCIENTIFIC NEAVS. 



[Dec. 1st, 1 8 



Gareloch, have a temperature which varies quickly with the 

 changing heat and cold of the year, and not differing more 

 than a degree or two from top to bottom ; deeper lochs, such 

 as Lochlong, Lochgoil, or Lochfyne, have a bottom tempera- 

 ture which is not at all affected by the changes of the year ; 

 and in them also it often happens that the coldest water is 

 not found at the bottom of the deepest part of the loch, 

 where the sun has least influence, but not very far from the 

 surface — water of different degrees of heat lying in layers, 

 the one superimposed above the other. Further, it is found 

 that the degree of saltness varies greatly in these lochs, the 

 deeper lochs having practically the same degree of saltness 

 as the ocean, while the shallow lochs have lost a good part 

 of their saltness. 



RoBURiTE. — Probably it is not widely known that roburite 

 is an invention due partially to the action of the Austrian 

 Government, who in 1882 offered prizes for the safest min- 

 ing explosives. Roburite, carbonite, and securite were three 

 out of twenty which were favourably reported upon, and the 

 former appears to be the most satisfactory, as it is only being 

 introduced into this country after English mining experts 

 have seen the three explosives used in Germany. It is said 

 that underground, both in coal and stone, it gives results 

 equal in power to ordinary blasting gelatine, while there is 

 not so much small coal produced as with gelatine and dyna- 

 mite. Some experiments made at the Monk Bretton Colliery 

 recently gave the greatest satisfaction. A shot containing 

 only 65 grm. was placed in the stone in the roof, in a 

 2 in. drill hole, 4 ft. 6 in. deep, and brought down about 4 

 ft. thickness of very strong stone. 



Nickel Steel. — According to the Mamtfaclurets^ Gazette, 

 nickel steel which is said to require no hardening is being 

 made by the Ferro-Nickel Societj'. It is composed of soft 

 iron, nickel, manganese metal or an oxide of it, aluminium, 

 wolfram, and ferro-cyanide of potassium. The steel is pro- 

 duced at one melting. After the iron and nickel are 

 melted, the manganese or its oxide and the ferro-cyanide 

 of potassium are added. After a few minutes' time, during 

 which the manganese with the other ingredients are melt- 

 ing, and the reaction is taking place, the mass is stirred 

 with a red-hot rod of graphite, whereupon the aluminium 

 is added, and the stirring is continued for a short time 

 longer. The alloy is well melted again, when it can be 

 cast into any decided shape in the usual way ; the precau- 

 tion being observed to paint the moulds with coal tar free 

 from water and ammonia, and to have them as free from 

 air as possible. 



Manufacture of Aluminium. — The Rhine Falls, situated 

 at Schaffhausen, form the largest cataract in Europe. 

 Some twenty miles below the point where it issues from 

 the Lake of Constance, the Rhine, with a width of 350 ft., 

 and an average depth of about 21 ft., plunges over a barrier 

 of rocks varying in height from 45 ft. on the right bank to 

 about 60 feet on the left. Including the rapids the total 

 fall, within a distance of a little over a third of a mile, is 

 estimated at 1 50 feet. The volume of water passing over 

 the falls per second varies from a minhmtm of 118 cubic 

 metres in February to a maximmn of 502 cubic metres in 

 July, when, in consequence of the melting of the snows in 

 the mountains and the rise in all the tributary streams and 

 brooks, the Rhine reaches its highest point. An applica- 

 tion has recently been made for a concession to utilise 

 these magnificent falls for the manufacture of aluminium, for 

 which it is estimated that 1,500 horse-power are required. 



Electrolysis of Sulphites. — Mr. R. Kennedy has con- 



verted sulphite of ammonia, obtained by mixing blast gases • 

 with sulphurous acid gas in a tower through which water 

 percolated, into sulphates by electrolysis. This was done 

 in the following manner : — Carbon blocks in porous pots 

 were used as cathodes. These were placed in tubs and 

 surrounded by carbon blocks used as anodes, and a large 

 current from a dynamo was turned on. At the end of an 

 hour sulphur began to form at the bottom of the anode 

 vessel, and in an hour-and-a-half no trace of sulphite re- 

 mained, the whole having been completely oxidised to sul- 

 phates. The curious result was the formation of pure 

 sulphur, and from this it was concluded that the conversion 

 took place partly by the sulphites dropping sulphur, and 

 partly by taking up oxygen at the anode. After the success- 

 ful conversion of the sulphites into sulphates by electrolysis 

 the liquor was filtered to secure the sulphur and then boiled 

 down to crystallise the sulphates. Experiments made on a 

 larger scale proved that this mode of recovering ammonia in 

 the form of sulphate was cheaper and better than the sul- 

 phuric acid and lime process, and that it might be adopted 

 profitably by gas as well as by iron works. 



Effects of Lightning on Railway Signals. — The effect 

 of lightning on electrical apparatus of all sorts is a subject 

 on which accurate data seem rather scarce, and its effect on 

 railroad signals especially, is a point on which more light 

 is needed. A cardinal principle in signals which are in any 

 degree automatic, is that they shall show danger in the 

 event of any derangement, and numberless ingenious 

 devices have been invented to provide against the possibility 

 of a signal standing at safety when it has not been intelli- 

 gently put in that position ; but lightning is such a lawless 

 element, and may influence electrical apparatus in so many 

 different ways, that the counteracting of the harm it may do 

 is not an easy task. It may make a ground connection, and 

 thus allow a circuit to appear all right when it is not, being 

 closed at one end, and open (without battery) at the other. 

 It may melt fixtures so as to permanently hold a signal in 

 the position it is in at the moment ; and again, it may charge 

 a wire with a current that will actuate the electro-magnets 

 and work the signal, when the signal-man has taken no 

 action whatever. While the chances of the signal being 

 held any length of time in the safety position from the 

 effects of lightning alone are very small, and while it is 

 probable that nearly, or quite all danger in this respect can 

 be guarded against by cautionary instructions to the 

 attendants, it is nevertheless well to make note of all 

 peculiarities noticed, that experience may be compared. — 

 Scientific American. 



The Electro Deposition of Iron. — Professor W. C. 

 Roberts-Austen, F.R.S., chemist to the Mint, has been 

 making some experiments on the electro deposition of iron, 

 a process which in Russia is used on a large scale for 

 making paper money. According to the Ironmonger, the 

 bath used is a solution of ferrous sulphate and magnesium 

 sulphate in equivalent proportion, of specific gravity I'lSS- 

 The solution must be so far neutralised by the addition ot 

 magnesium carbonate, that blue litmus paper scarcely shows 

 any acid reaction. A wrought iron anode about the same 

 size as the object to receive the deposit, must be employed, 

 and the best interval between the poles is found to be four 

 centimeters. Mr. Roberts-Austen finds that the current 

 best suited for an iron medallion had a strength of only 

 0-089 ampere. It was provided by two Smee cells, 

 coupled up for intensity. The adherence of the iron to the 

 copper on which it was deposited, was reduced by coating 

 the latter with a film of metal, but Mr. Roberts-Austen is 

 trying a thin layer of silver iodine on the copper moulds. 



