284 SECTIONAL TRANSACTIONS.—A, G. 
Mr. R. GrirFitHs.—Some problems in the measurement of temperature in 
steelworks. 
With the increasing need for closer control over the temperature in the 
manufacture of steel and its products the development of special forms of 
pyrometers has become necessary. For example, in rolling-mill practice 
the time required for taking an observation is a determining factor. Experi- 
ments are described which have been carried out with the object of pro- 
ducing a pyrometer to satisfy the requirements. 
Mr. B. Lioyp-Evans and Mr. 5.5. Warts.—A contribution to the study 
of flame temperatures in a petrol engine. 
It has been recognised for many years that the calculated maximum 
explosion pressure in an internal combustion engine is far greater than the 
measured pressure. ‘The basis of this calculation is, that both pressure and 
temperature rise instantaneously when the piston is in its uppermost position, 
termed the T.D.C. (top dead centre). 
The authors have attacked the problem from the point of view of the 
temperatures produced, using the spectral line reversal system, developed 
recently by Dr. Ezer Griffiths and J. H. Awbery. 
In general, the tests showed that at the particular point considered in 
the engine, the temperature bore little relation to the pressure, this result 
being almost independent of the brand of petrol used. ‘The maximum 
temperature on any given temperature/crank angle curve was of the order 
of 2100° C. and lasted over a much longer period of time than did the 
maximum pressure. It was also seen that combustion as denoted by 
tongues of flame lasted down to at least crank angle positions of 70° to go° 
after T.D.C. 
As, however, the extinction of visible flame is not necessarily a criterion 
, V : 
of the end of combustion, curves of “a Were plotted against crank angle. 
Had T been the average temperature in the cylinder at the moment con- 
sidered, then = should have been constant. This was far from the case, 
and, in view of the turbulence in the cylinder, it can only be concluded that 
combustion was still proceeding. 
Dr. MArGarET FISHENDEN.—Radiation from non-luminous gases. 
As their temperature increases, radiation plays a more and more important 
part in the heat transfer from non-luminous gases containing water vapour 
or carbon dioxide. Methods of determining the radiation and convection 
from hot flue gases passing through a tube of internal diameter Io in. are 
described. 
Mr. E. G. Herspert.—Periodic hardness fluctuations induced in metals by 
mechanical, thermal and magnetic disturbance. 
A brief account is given of the experimental stages which led to the dis- 
covery of periodic fluctuations. 
Typical results are given, in which periodic hardness changes were set 
up in pure metals, nickel, iron and gold, by mechanical, thermal and magnetic 
disturbances, and the fluctuations were stabilised by application of a magnetic 
field. 
