594 
would be possible to get five times as much light for a sovereign 
as could be done now. At present electric lighting would suc- 
ceed commercially where other considerations than cost had 
weizht. Improvements in the lamps were certain, and there 
was a probability that these improvements might go so far as 
to reduce the cost to one-fifth of what it now was. He left the 
meeting to judge whether or not it was probable, nay, almost 
certain, that lighting by electricity was to be the lighting of the 
future. 
HARDENING AND TEMPERING STEEL 
@R= of a series of lectures to the Liverymen and Apprentices 
of the Company of Cutlers of London was delivered on 
Thursday last by Prof. W. Chandler Roterts, F.R.S., ‘On 
some Theoretical Considerations connected with Hardening and 
Tempering Steel.” 
The Master of the Company, Mr. J. Thorne, presided, and 
the Lecturer observed thit the phenomena with which they had 
to deal, although admittedly as interesting and remarkable as 
any in the whole range of metallurgy, are but little understood. 
If the fact that steel can be hardened had not been known, 
the whole course of our industrial and even political history 
would probably have been widely different, and the dagger, 
which occupies so prominent a place in the armorial bearings of 
the City of London, would have represented a survival of imple- 
ments made, not of steel, but of copper hardened with tin. 
It has long been known that there are extraordinary differ- 
ences between the properties of wrought iron, steel, and cast 
iron, but our knowledge that these differences depend upon the 
presence or absence of carbon is only a century old, for it was 
not until the year 1781 that Bergman, Professor in the Uni- 
versity of Upsala, showed that wro ght iron, steel, and cast 
iron, when dissolved in certain acids, leave amounts of a 
graphitic residue, varying from 7 to 23 per cent., which are 
essential to the constitution of these three varieties of metal. 
Bergman’s work led many early experimenters, notably Clouet in 
1796, to attempt to establish the importance of the part played 
by carbon, and Clouet converted pure iron into steel by contact | 
at a high temperature with the diamond, which was the purest 
form of carbon he could command. Prof. Roberts said that this 
experiment had been repeated by many other observers with 
varying success, as in all the earlier work the furnace gases, 
which had not been excluded, might have converted the iron | 
into steel without the intervention of the diamond. It remained 
for a distinguished Master of the Cutlers’ Company, Mr. W. 
H. Pepys, to repeat Clouet’s fundamental experiment under 
conditions which rendered the results unequivocal, by ea ploying 
electricity as a source of heat. This experiment, which had 
been communicated to the Royal Society in 1815, was performed 
in the way Pepys had indicated. 
It was then shown that in soft, tempered, and hardened steel 
respectively the carbon has a distinct ‘‘mode of existence,” as 
is indicated by the widely different action of solvents on the 
metal in these three states. 
The evidence as to whether carbon in steel is comdined in the 
chemical sense, or is merely disso/ved, was then considered at 
some length, special reference being made to the results obtained 
by various experimenters, from Berzelius and Karsten to Sir 
Frederick Abel of the War Department. 
Prof. Roberts stated that the researches of Troost and Haute- 
fenille afforded strong evidence that in ‘‘ white cast-iron” and 
steel the carbon is merely dissolved, a view which he adopted, as 
he did not consider it to be atall in opposition to the facts 
recently established by Sir Frederick Abel, who had shown that 
the carbon may be left by the slow action of solvents on soft 
steel as a carbide of iron. f 
The various physical, as distinguished from the chemical 
theories that had been propounded from the time of Réaumur, 
(1722) to that of Akerman (1879), to account for the ‘intimacy 
of the relation’”’ of carbon and iron in hard as compared with 
soft steel, were then described, at some length, and the remark- 
able experiments of Réaumur, who cooled steel slowly in a 
Torricellian vacuum in order to show that the absorption of gas 
did not take place during cooling, was illustrated. 
In recent years much importance has been attached to the 
physical evidence as to the peculiar constitution of steel, and it 
has been shown that there is a remarkable relation between the 
amount of carbon contained in different varieties of steel and 
their electrical resistance. Some of the very interesting experi- 
NATURE 
| April 19, 1883 
ments of Prof. Hughes on this point were then exhibited and 
described, and Prof. Roberts concluded by saying that the value 
of the early work by Bergman and Réaumur had rather been 
lost sight of in recent discussions, Bergman’s work being 
specially remarkable, as he attempted, by thermometric measure- 
ment, to determine the heat equivalent of the phlogiston he 
believed iron and steel to contain. 
The importance of the degree of carburisation of steel from 
the point of view of its technical application was illustrated by 
reference to a series of curves, and it was incidentally mentioned 
that, in the case of the variety of steel used for the manufacture 
of coinage-dies, the presence of 75 per cent. of carbon more or 
less than a certain standard quantity makes all the difference in 
the quality of the metal. 
"NIVERSITY AND EDUCATIONAL 
INTELLIGENCE 
OxFoRD.—The new Board of the Faculty of Natural Science 
has issued its first list of lectures this term. The lectures are 
divided under the following heads :—Physics, Chemistry, Animal 
Morphology, Geology, and Botany. No lectures are scheduled 
this term under Mineralogy or Physiology. 
In Physics Prof. Clifton lectures on ‘‘Instruments and 
Methods of Measurement employed in the Study of Optics.” 
These lectures are given in the Clarendon laboratory, where 
practical instruction in Physics is given by the Professor, 
assisted by Messrs. Stocker and Heaton. At Christ Church 
Mr. Baynes lectures on Electrokinematics and Electrodynamics, 
and gives practical instruction on Electric and Magnetic Mea- 
surements. At Balliol Mr. Dixon gives a course of experimenta 
lectures on Elementary Heat and Light. 
In Chemistry Dr. Odling lectures at the Museum on the 
Composition of Air and Water; Mr. Fisher lectures on 
Inorganic Chemistry ; and Dr, Watts on the Cyanogen Series. 
At Christ Church Mr. Harcourt has a class for Quantitative 
Analysis, and Mr. Dixon a class for Ga+ Aualysis. 
In Animal Morphology Prof. Moseley lectures on Comparative 
Anatomy, and gives practical instruction to his class after each 
lecture; Mr. Hickson lectures on the Development of the 
Chick, Mr. Hatchett Jackson on Mammalian Osteology and the 
Principles of Embryology, Mr. Poulton on the Di-trioution of 
Animals, and Mr. Lewis Morgan on the Vertebrate Exoskeleton 
and on Human Osteology. 
In Botany Mr. Chapman gives practical instruction on Vege- 
table Morphology at the Botanic Gardens. 
In Geology Prof. Prestwich will give a series of lectures on 
Friday afternoons on the strata and fossils to be visited on his 
Saturday excursions. 
On June Ig an examination will be held in common by Mag- 
dalen, Merton, and Corpus Christi Colleges for electing a 
Scholar in Physical Science at each College. At Merton and 
Corpus the chief subjects will be Chemistry and Physics. 
Jesus College offers a Welsh Scholarship in Natural Science. 
The examination will be held on June 14. 
Examinations for the degree of Bachelor of Medicine (both 
First and Second) will be held this term. Candidates are to 
send in their names before May 1. 
CAMBRIDGE,—Prof. Huxley’s Rede Lecture at Cambridge 
University will be given on June 12, at 3 p.m., in the Senate 
House. The subject is not yet announced, 
Dr. Michael Foster leaves the Lectures on Elementary Biology 
for this term in the hands of Dr. Vines and Mr. Sedgwick, and 
will hold Catechetical Classes in Physiology for the Natural 
Sciences Tripos. 
Dr. F, Darwin will give six Demonstrations on the Physiology 
of Plants (Growth, Movement, &c.) at the Physiological Labora- 
tory on Saturdays at noon, beginning April 21. 
Prof. Liveing will lecture on the Chemistry of the Heavenly 
Bodies, beginning May 1. 
Lonpon.—Mr. A. H. Keane has been 1ppointed to the 
Hindustani Lectureship at University College. 
THE Winter Session at the College of Agriculture, Downton, 
near Salisbury, ended on Monday, when the certificates and 
prizes were presented to the successful students by Archdeacon 
Sanctuary. The certificate of membership, obtainable on 
examination after completion of the two years’ course of study, 
was granted to Mr. Arthur Herbert Kerr, Crookham, Farnham, 
. 
