i6 



ITU RE 



[September 5, 19 18 



■ . . 11 1- checked a grow ing txpori 



nidi would probably, in time, haw 



ea consi qu< ni e to oui 1 n 



The window-tax was abolished in 1851, and house 



duty substituted for it. The tax no doubt affected 



oduction generally, but, in any case, il is 



quite timi that we made an endeavour to supph our 



|uin mi ins, and e\ ei j effoi 1 should 

 to assi - i m. mui. u iin ei s to attain that ab 



HIGH^TEMPER I 1 I RE APPL1 1 NCES. 



Dl RING the war period, when industries are 

 being conducted on more scientific lines, whert 

 in every detail of operation the utmost care must be 



1 ised, the exai 1 1 rol ol tempei atui e bi 1 01 u s 



imperative in processes • > f such paramount import- 

 as metal pouring, annealing, hardening, etc. 

 Within mi 1 in years the methods ol pyrometrj have 

 reached a high order of accuracy. Many pyrometers, 

 too, combine with moderate accuracy a simplicity and 

 a robustness "I construction which eminentlj adapt 

 them for works 1 use, and their rapidlj extending 

 application is as important a feature of modern pro- 

 as the attainment of the highest accuracy in 

 a limited number of instruments. In a works 

 recentlj instanced no fewer than 50,000 high-tem- 

 perature detcrminal ions are made weekly with elec- 

 trical and optical pyrometers, this work fully engaging 

 tin .11 tention ol sixty assistants. 



Progress of this nature can scarcely be adequately 

 reflected in an exhibition such as that arranged by 

 the British Science Guild at King's College, and the 

 pyrometer exhibits cannot be said to be fully repre- 

 sentative of modern work. The enormous demand 

 for sueh instruments no doubt precludes their avail- 

 ability for exhibition purposes. In every case their 

 installation results in a marked improvement in the 

 quality and uniformity of products, and economies 

 thus effected soon cover the cost of installation. 



Among the exhibits relating to the control of tem- 

 perature, one of some interest is an electrical thermo- 

 stat developed at the National Physical Laboratory by 

 Messrs. Haughton and Hanson. In this apparatus 

 an accurately controlled temperature may be main- 

 tained over prolonged periods, as is often required 

 in metallurgical research. Thus 1000 C. is main- 

 tained to within 1° C. 



Many industrial operations exceed temperatures at 

 .Il thermo-electric and resistance pyrometei 

 Me. Radiation and optical pyrometers are then 

 in demand. For works' purposes direct readin] 



mil this condition is easily attained. The 

 w.il: ometer exhibited by the Optical Pyrometer 



Svnd ca a simpli type, capable of being placed 



with safety in tin hands of an intelligent workman. 



if a small tell scope Hie image of i 

 l,ud\ emitting visible rays is focussed through a 

 wedge-shaped prism of dark glass, the prism being 

 i.d until the image just disappears. The instru- 

 ment is calibrated so that the position of the 

 jirisin indicates the temperature under observation. 



OrdinariK arrai a temperature differ 



of 400 C, a wider range t>f Soo° C. is possible. 



and thus a pair of instruments with ranges ,,l 



550 -] job l and- 12 ' respectively, safelj 



covei the temperatures of a wide range of operations. 



A gratifying feature of the pyrometers now in use 



; s the large proportion of British manufacture. This 



ichievement is due to the closi co-operation of those 



familiar with high-temperaruri research, thoroughly 



ted « iih the essi design and the 



- of the various types of instruments, with 



ifacturers who are responsibli foi tl urate 



NO. 2549, VOL. I02] 



'iion ol He designs ,,1 the exoerts. The time 



is surely not 1. n distant when the few special forms 



of instrument emanating 1 1 Germany will have 



been entirel) replaced b) improved Forms of British 

 manufactui ■ . 



Turning now to the range of furnaces in which 

 many types "I operation essential t < > technical work 

 il- carried out, the extensive use of gas heating is 

 well known. For fuel economy, clean ami perfei 

 combustion, and exact 1nui1.il of temperatu 

 heated furnaces present man) advantages for both 

 melting and tool-makers' purposes. I in latter fur- 

 naces an of the twin muffle type. One 

 example is shown by the Monometer Manufacturing 

 Co., and is designed for hardening high-speed steel. 

 \ feature ..l thi furnace is the patent automatic heat 

 regulator in give close and continuous control of the 

 temperature in both chambers. The furnace consumes 

 town gas with air al 2-lb. in t-ll>. pressure. The 

 same firm also shows a ladle furnace and i 

 die-casting machine, each fitted with a self-acting 



heat regulator, by which the desired tempera! an 



be controlled. Fuel economy is thus effected, and 

 the prevention of overheating and with it the mam. 

 errors consequent thereon- is ensured. The Davis 

 i'o. has on exhibit a portable tool-makers' 

 outfit, which includes an oven capable of attaining a 

 tempei ature of 1350° C. 



The requirements of modern thermal operations are 

 opening up the possibilities of electrically heated fur- 

 naces. These carry the advantages of compi 

 simplicity of design, and the great ease with which 

 exact temperature control can be effected. An 

 example is seen in the Wild-Barfield muffle furnace 

 manufactured by Messrs. the Automatic and Electric 

 Furnaces, Ltd., and used for hardening and similar 

 operations. Furnaces of the salt-bath type are also 

 in use, and are fitted with pyroscopic detectors, com- 

 pensators, and galvanometers. 



Among other exhibits of thermal interest may be 

 noted amorphous carbon electrodes of large diameter 

 and more than 6 ft. in length, with screwed , nds 

 which admit of a continuous feed. Electrodes of this 

 type in extensively used in electro-metallurgical 

 Operations such as (he manufacture of calcium carbide 

 and ferro-allovs. Messrs. Hadfields, Ltd., exhibit a 

 large temperature chart indicating manv of the im- 

 portant metallurgical temperatures based on Eh 

 available data. 



WATER-POWER AND ITS UTILISATION. 1 



7 HE World's Present Po^ci Demand, li is im- 

 possible in estimate, with any pretensions 

 accural . the power now being used in the various 

 countries of the world. 



Independent esiimntes, 2 based on such data as are 

 available, tend, however, to show that it is of the 

 order ,,l 126 million h.p., made up approximately as 

 follows : — 



World's factories, including electric 



lighting ami sinet railways ... 75 million h.p. 

 World's railways ... ... •■• 21 ., .> 



World's shipping 24 



Total 120 



This includes all steam-. u;us-, and water-power. 



1 Abridged from tin: Preliminary Report of the Committee of the Con- 



1 ieties appointed "to report on what is at 



ascertain the amount and distribution of water-power 



in the Briu-.li hi. 



- "The World's Supplies of Put! and Motive Power." Hawksley Lecture 

 Inst. Mech. 1 rs, Sil Dugald Clerk. "Natural Sources of 



Energy,' A H. Gibson : Cambridge University Press, 1914. 



