SCIENTIFIC NEWS. 



[Nov. 1st, if 



Notwithstanding the expensive plant and material used in burn- 

 ing gunpowder, it is interesting to know that the g6o lbs. of this 

 fuel evolves no more heat than can be afforded by about i6o 

 kilogrammes or about 3^ cwts. of coal. 



The improved means by which motion can be converted into 

 electric heat may appear to justify the opinion of Dr. Lardner, 

 and encourage the hope, often repeated since his time, that this 

 agent may take the place of our coal after the exhaustion of our 

 beds of this mineral. If the object to be gained were the dis- 

 sociation of carbonic acid and the fusion of the separated 

 carbon into a diamond, instead of moving a railway train at the 

 rate of 50 miles an hour, at the cost of id. per train mile for 

 fuel, there might be room for argument. Clearly neither of the 

 instances just referred to affect the question before us, which in 

 point of fact is as follows : — We now possess coal occurring 

 under such circumstances that an acre may contain 20,000 tons 

 or more, out of which a collier can hew for his day's work as 

 much as will make two tons of pig iron, or move a railway 

 train weighing 300 tons over a distance of 300 miles at the rate 

 of 40 miles an hour. The problem therefore before us is to 

 estimate the position of a nation, no longer possessing a 

 material so easily obtained and endowed with so much poten- 

 tial energy as coal, compared with other nations having un- 

 limited resources of this mineral at their command. There are 

 those who attach some weight to chemical action as being able 

 to supply us with electric heat, and with it, electric power, when 

 our coal is exhausted. All this, however, as far as our present 

 knowledge enables us to see, means a previous expenditure of 

 heat. A common source of electricity generated by chemical 

 action is the oxidation, or burning as it may be termed, of some 

 of the metals, of which zinc is the one in most common use. 

 This as well as others, if ever they existed in nature in the 

 metallic state, have, since then, become oxidised. To fit them 

 therefore for undergoing this process a second time, heat must 

 be employed, and this is generally accompanied with great and 

 unavoidable loss, which, along with other expenses connected 

 with their production, forbids our looking for any assistance in 

 their direction. Quite as extravagant as the use of zinc was 

 Lardner's idea of employing the hydrogen of water as a source 

 of heat. Water, being simply burnt hydrogen, as much heat 

 would be absorbed in separating it from its oxygen of combina- 

 tion as it is capable of yielding by burning it a second time. 

 We might therefore as reasonably expect a wheel to raise to the 

 level of the buckets receiving the water all that which had 

 served to move it, as to obtain heat from the hydrogen of water, 

 or worse still from chalk, as was insisted on by the Rev. W. 

 Moule. What has been said in reference to the use of elec- 

 tricity as a source of motion, or even of heat, to which may be 

 added that of light, must not be considered as of universal 

 application. Thus there are situations in Alpine countries 

 where continuous supplies of water descending rapidly from 

 great heights could, by means of turbines, furnish enormous 

 power. This power could, by the aid of electricity, be trans- 

 mitted to a distance, as is now done by compressed air in our 

 coal mines, or still more frequently by hydraulic machinery, in 

 the manner first proposed by Lord Armstrong. For the utiliza- 

 tion of the power on the locality where it is easily obtained 

 from the fall of water, we need not wait for further discoveries 

 in electrical science to assist us in turning it to useful pur- 

 poses. It must always be more economical to employ the 

 power direct so as to avoid the loss, as far as possible, 

 arising from the friction which is inseparable from the delivery 

 of mechanical energy for actual work. 



There have been found in nature, as every one knows, vast 

 stores of liquid and gaseous hydrocarbons, which are being ex- 

 tensively employed as a source of heat. With these we need 

 not concern ourselves, because, so far as exhaustion goes, oil 

 springs and gas wells will be subject to the same laws as those 

 which obtain with coal. With the facts and figures just given 

 before us, instead of spending time and money in searching for 

 substitutes for the fuel now in common use, we would act more 

 prudently in looking for means to reduce a waste, which, when 

 mechanical power is the object to which it is applied, amounts, 

 as it often does, to 90 per cent, of the capacity of the coal. 



Not inferior as a national calamity to exhaustion of our coal 

 would be the want of iron. Without this metal, coal, at the 

 depths it is often found, would be beyond our reach; or, if 

 reached, we should frequently lack, commercially speaking, the 

 means of utilising the object of our search. That the loss of this 



mineral would extinguish the manufacture of iron is proved by 

 the experience of the last century; for in 1740, owing to the 

 woodlands near the works failing to afford the necessary sup- 

 plies of charcoal, the make of iron had declined until it did not 

 reach, in that year, the quantity produced in one of our modern 

 furnaces. From this threatened annihilation Abraham Darby's 

 success in the application of coke for smelting iron ore relieved 

 us. The production of cheap iron may, for some centuries, be 

 considered as dependent on our being able to command cheap 

 coal ; because the known deposits of ore are too extensive to 

 render it necessary to concern ourselves about their exhaustion. 

 The extent to which iron has assisted in the enormous develop- 

 ment of our national industry is evidenced by the large increase 

 in its use. Fifty years ago the annual consumption per head ot 

 our population was under 80 lbs. In the year 1884 it amounted 

 to nearly 290 lbs., while the average of the whole world was only 

 a little above 30 lbs., and among some hundreds ol millions of 

 people it is under half a pound. In the year 1837 the make of 

 pig iron in Great Britain was a little above 1,000,000 tons. Since 

 that date (namely, in 1883), it was close on 8i millions. This 

 great and rapid progress in production was not confined to our 

 own country, lor between 1879 and 1883 the world's output of 

 pig iron rose from 14,000,000 to 21,000,000 tons. Very great 

 changes in the processes connected with the manufacture of this 

 metal in its various forms have no doubt promoted its extended 

 consumption in recent years. At the same time it must be 

 allowed that our knowledge of the metallurgy of iron fifty years 

 ago was sufficiently advanced to have enabled us to supply the 

 metal then, of a sufficiently good quality, and at a sufficiently 

 low price, for any purposes for which it was wanted. In addi- 

 tion to the extensive but somewhat expensively worked deposits 

 of ironstone of South Staffordshire and South Wales, Scotland 

 had been proved to contain a large quantity of Black Band iron- 

 stone, while Cumberland and Lancashire gave good promise of 

 being able greatly to add to their yearly output of rich hematite 

 ore. In the works, the puddling process, although a laborious 

 operation, had been brought to a state of great perfection, and 

 the value of the hot blast in smelting had been sufficiently 

 demonstrated. 



The twenty-five years after 1837 added however greatly to our 

 information connected with the manufacture of iron. The exist- 

 ence of the great Cleveland bed of ironstone, and subsequently 

 that of Lincolnshire and Northamptonshire, had been discovered, 

 and the processes known as the Bessemer and Open-hearth for 

 making steel had been invented. During a few years following 

 1862 the Middlesborough ironmasters, by an enlargement of their 

 furnaces, and by raising the temperature of the blast from 315° 

 as recommended by Neilson to 537'^ C. (600 to 1,000° F.), added 

 to an extended use of the escaping gases, had effected a saving 

 of one-third of the coal required to produce a ton of pig iron. 

 Immense improvements in rolling-mill machinery and ameliora- 

 tions in the Bessemer process have so reduced the cost of mak- 

 ing steel rails, that this article, made from ore brought from 

 Bilbao in Spain, has been sold for what, sixty years ago, would 

 have been considered but a reasonable price for pig iron ob- 

 tained from native ore. Without troubling you with unnecessary 

 details in the manufacture of iron I may say that, within my own 

 recollection, to make a ton of iron rails, beginning with the ore, 

 about 7| tons of coal was consumed, and now a ton of steel rails 

 does not require above 3J tons of fuel for its production. This 

 great economy in the manufacture of steel, combined with its 

 superior strength and malleability, has led to its extensive use 

 for purposes in which wrought iron was formerly employed. At 

 present, nearly half the malleable form of the metal produced in 

 this country is obtained from the Bessemer converter or from the 

 Open-hearth furnace, and the change is one which is gradually 

 extending. The increase of strength in steel as compared with 

 iron, just referred to, has very much assisted in combining great 

 power with lightness in the construction of the modern steam 

 engine. A striking example of this is to be seen in the Exhibi- 

 tion, where the actual machinery, capable of developing an indi- 

 cated power of 1,750 horses, weighs something under 26 tons. 

 To this proof of power in resisting enormous strain may be added 

 that afforded by the use of steel in the heavy guns from the 

 Elswick works. On the other hand the malleability of this form 

 of iron, and its simplicity and consequent economy of manufac- 

 ture, are such that the large boiler plates, also to be seen in the 

 adjoining building, can be sold at about one-third of the price 

 charged for iron plates of similar dimensiohs. 



