SCIENTIFIC TRANSACTIONS 
OF THE 
IRO WAI IDUISIAIIN 7 SOOIi ay 
VOLUME VIII. 
Te 
ON THE MAGNETIC AND ELECTRIC PROPERTIES OF AN EXTENSIVE 
SERIES OF ALLOYS OF IRON. Parr III. 
By W. F. BARRETT, F.R.S.; W. BROWN, B.Sc.; ann R. A. HADFIELD, M.Insv. C.K. 
(Puates I.—IV.) 
[Read January 22, 1902.] 
Tue first and second parts of our researches on the above subject appeared three 
years ago in the Transactions of the Society,* having been read in February and 
May, 1899. The present part deals with 
(A) alloys of iron which we have found to be non-magnetic, or nearly non- 
magnetic, even in strong magnetic fields ; 
(B) alloys of iron which within a certain range of magnetic field we have 
found to be more magnetic than the purest iron obtainable in commerce. 
It is obvious that these two classes of iron alloys or steels are of permanent 
interest and importance both from a theoretical as well as from a practical point 
of view. 
In our previous paper a full description was given of the process of manu- 
facture and the method of testing these alloys. Here we will only state that the 
alloys were all made and analysed at the Hecla Steel Works, Sheffield, of which one 
of the authors is Managing Director, and the magnetic and electric measurements 
were all made in the Physical Laboratory of the Royal College of Science, Dublin. 
The specimens, many of which are entirely new metallurgical products, were 
rolled into the form of cylindrical rods 102 ems. long and about 0°5 cm. diameter 
(No. 5 B. W.G.); they were then very slowly and carefully annealed from a white 
heat. Duplicates of a few specimens were made which were subjected to different 
*See Vol. vii., Part iv., p. 67. 
TRANS. ROY. DUB. SOC., N.S., VOL. VIII., PART I. B 
