5] PT1 U Bl B 26, [918] 



\ / i LIRE 



75 



de, W*', "i the tungstide, Fe t W, 01 in both 

 forms according to thi percentage of tungsti 

 carbon. In the normal state the tungsten carbide and 

 iron carbide exist as .1 double carbide, -tl' ' ' 



h hi. h has iis a itical point .11 |.n. I '- as 1 omp 

 with 7-\v ('. fur pure iron carbide. Above tin Ac, 

 poinl this double carbide dissociates into its com- 

 ponents, bul if the maximum temperature is not 

 high these recombini 'hum;; cooling, and are deposits 

 from solid solution .11 400' ('., forming :i eutectoid 

 with tin- ferriti Vbove 1100 C. the following re- 

 action '" I ui s, 



WC 1 sFe Fe C 1 Fe 2 W, 



ami ilmiiiL 1 . cooling tin' lowering of the transformation 

 points ni' 11- in consequence ol the dissolved tung- 

 stide in austenite. The greater the carbon concen- 

 tration in the system, however, the less .Iocs the 

 abo\ e 1 • action proceed. 



Thr lowering of the Ar, transformation due to 

 heating increases with maximum temperature, and 

 this depends on the tungsti n, but not on th.- carbon 

 content. Above 9 per cent, of tungsten, however, 

 ;ponding with the maximum solubility of this 

 metal in item, th. lowered \i point is constant at 

 about 440° ('. If, now, a specimen which has a 

 lowered Vr, point be reheated just beyond the V' 

 point (about 900 C I, and then cooled, the trans- 

 formation takes place at tin normal point. This is 

 due to the fact that tungsten carbide is formed in 

 the Ac, range according to tin reaction, 



Fe a C + Fe 1 W = WC + sFe, 

 and dining cooling the recombination of the tungsten 

 de with the remaining iron carbide occurs. The 

 author-, are to be congratulated on their careful mag- 

 netic and metallographic analyses, which have enabled 

 them to present .1 clear and very plausible conception 

 of the chemical, structural, and phase changes which 

 in tungsten steels both on heating and cooling. 

 H. C. II. 0. 



FUEL ECONOMY. 



TIM! economical use of coal has been referred to 

 frequently in these column-, but with all the 

 various proposals foi its mon efficient application For 

 powei production th< possibilities of effecting marked 

 economies with existing boiler-plants have not been 

 fully appreciated. In the columns of Engineering 

 (Jul} i_' and oil Mr. I). Brownlie gives data of the 

 examination of 250 boiler-plants, comprising tooo 

 boiler- and using annually mot.' than two million 

 ton- of coal. Seventy-six per cent, of the plants were 



hand-til • d. icj being 57 S pet 



cent. ; the remainder, mechanically fired, -bow 

 an efficiency of onl) '114 pet cent. Only 96 pei 

 pi ;n- show a higher efficiency than 

 70 per cent. Certainly tin— figures indicate very 

 !.ad practice, for a net working efficiency of 75 per 

 cent, may well b>- aimed at. Reorganisation of the 

 plant- 1 \. turned to reach this figure would alone entail 

 a saving of 4,0,000 tons of coal annually; throughout 

 tin- countrj it would possibh l< ad to a saving of 



15, inn-. \- Mt. Brownlie points 



out, " the question of ib. economical generation of -team 

 will always be a very important pari of the greatei 

 national scheme of coal ecoi 1 n if all the power of 



ountn i- generated bj gas-engines and the l>\- 

 products of lie' distillation of roal " As a large part 

 of ib.- power will undoubtedh be steam-generated in 

 ■ ^i-tins; plain- for ma.ni years to come, the impn 



ol these plants is urgently called 

 1. ii during the period which must elapse before the 

 general reorganisation of tin- whole system of power 

 I > r 1 duction can be 1 at ried out. 

 NO. 2552. VOL. I02] 



Furthei evidi m ■ onomj is contained in 



Bulletin No. 31, Circul; ol University of Illinois 

 1 ngineering Experiiro i his bulletin di il 



w ith th. operation - 1 d power plants, and 



ile- mattei i- presented in ■> n 1 adilj understoi d 



l>\ those who are not expei neers. About 



> tons ol i o.tl .11 e consum in. " m Illinois 



in operating hand-fired powei I it is be- 

 lieved to be within the limits p.1 ittain 11 



lo effect a saving of fi tun u to 15 j ||,js 



fuel. Descriptions and drawings no impli 



appliances and the methods of using lined, 



hereb) the men who lire the coal , btain 



; .risr information regarding the besi 

 conditions for given steam consumption 

 proper attention these appliances enabli 



reel working conditions lo be reproduced ui 

 time, and also give evidence which leads to 

 di t. 1 lion of defects in the plant which would not othi 

 wise be suspected. The section dealing with tin 

 -image of coal is of interest, and contains a verv sug- 

 gestive statement : — " Do not undertake to store coal 

 until you are sure you know bow to do it properh 

 and safely." The circular has been compiled by a 

 committee of the University authorities, aided b\ an 

 advisory committee including several well-known 

 names, and can be commended to the notice of all 

 who desire to introduce scientific control in their boiler 

 plants. 



SALARIES IX SECONDARY AND 



TECHNICAL SCHOOLS, ETCA 



^pHH chief duty of this Committee, as defined in 



-*■ the terms of reference, was "to inquire into thr 

 principles which should determine the fixing of 

 salaries for teachers in secondary and technical 



chools, schools of art, training colleges, and other 

 institutions for higher education (other than uni- 

 versit) institutions)." They were specifically asked 

 not "to consider the question of the amounts b\ 



which existing salaries should be improved." 



Progress in tin- hu-her education of the nation 

 depends, in the first instance, upon attracting and 

 retaining, by means of adequate salaries and suitable 

 salar) scales, tin services of the most capable and 

 high!) qualified teachers. The present rates of pay-? 

 ni'tit fail to secure this. The report states (p. 52) 

 that the average salan of 33.^0 full-time assistant 

 masters in 40J grant-aided boys' secondary schools in 

 England and Wales on January ,1. 1917, was only 

 1S7/. per annum. The average salary of 4-?<)4 

 assistant mistresses in similar schools was 130/. per 



annum. Out of 1050 sei la chools in England 



and Wales receiving grants from the Board of Educa- 

 tion, in only 4(10 of tins.' schools wen- salaries regu- 

 lated by definite scales in [anuary, 1917. Salary scales 

 were, in general, onl; shori scales covering a period 

 of five or sis vears the average maximum for 

 graduates (men) 1 onh tool. ~s. The informa- 



tion in the report respecting salaries in technical 

 -ib. ml-, pol; etc., is much less detailed and 



precise (p. 411 Ii would appear, however, that on 

 Match 31, 1014, the average salary of heads . 



department I assistant teachers in these institutions 



w a- about 1N.1/. per annum. 



In view ol the inadequate salaries just in 

 nh 1 be higher cost of living, 

 tnd the more generous remuni 1 

 . ffered b_\ commerce, industry, and the Sen- '-ices, 



it is no wonder, even allowing for cei nt im- 



rtents, notably in London, that - ; ommittee 



1 K.j.ort of the Departmental Committe n Rerordary 



. .Technical Schools, etc. (Cd. 911.. 1 (H.M. Stationery Office.) 



