264 Progress in Science. April, — 
The Cleveland Institution of Engineers has been lately engaged in discussing 
Mr. Wood’s methods of utilising blast-furnace slag. The slag is allowed to 
run from the furnace into water placed at the bottom of an iron drum rotating 
in a vertical plane. By this means the slag is disintegrated, and forms a 
powder called “ slag-sand,” which may be mixed with lime and used as mortar. 
The slag, in another of Mr. Wood’s processes, is received on a flat, circular, 
rotating table of iron, where it is suddenly cooled, and spreads out into thin 
layers, which may be readily broken up and used in the preparation of con- 
crete. Although there is perhaps no great novelty in Mr. Wood’s methods, — 
they are nevertheless likely to be of much value in using up a great deal of 
the Cleveland slag. In 1862 Mr. Gjers obtained a patent for running a stream 
of slag into water, but he allowed his patent to lapse. One great feature in 
Mr. Wood’s machine is its economy of water. Mr. Jeremiah Head calculated 
that the cost of water would be only about th of a penny per ton of slag 
disintegrated. 
To determine the elasticity of metals, two different methods may be em- 
ployed—either dire@& tra&tion or transverse flexion. The discrepancy in the 
values obtained by these two methods in experiments with steel have been 
theoretically investigated by M. Peslin, in a paper, ‘Sur la Ténacité de 
l’Acier,” published in a recent number of the ‘‘ Annales des Mines.” 
In connection with this subje& we may refer to a paper on ‘‘ Tests of Steel,” 
by Mr. A. L. Holley, read before the American Institution of Mining 
Engineers, in which the writer strongly condemns the practice of confining 
ourselves to mechanical tests, and staunchly advocates that all tested samples 
should be submitted to chemical analysis. In order that engineers may know 
what to specify, and that manufacturers may know what to make, a knowledge 
of the chemical composition of steel becomes absolutely necessary. 
We observe that a paper ‘* On the Molecular Changes produced in Iron by _ 
Variations of Temperature,” by Prof. R. H. Thurston, of the Stevens Institute 
of Technology, has been reproduced in “Iron.” : 
M. Pirsch-Baudvin has patented a new alloy, said to bear a strong resem- 
blance to silver in many of its physical characters. A very white metal, 
forming a good imitation of silver, may be made of—Copper, 71; nickel, 16°5; 
cobalt, 1°75; tin, 2°5; iron, 1°25}; and zinc, 7: about 1°5 per cent of aluminium 
may be added. In the preparation of this alloy certain precautions are neces- 
sary in the order and manner in which the constituents are mixed. The © 
cobalt is said to determine many of the characters of this alloy. 
The well-known ‘ Revue Universelle des Mines, de la Métallurgie, des 
Travaux Publies, des Sciences, et des Arts appliqués a l’Industrie”’ is about to 
appear in an English dress. The proprietors have arranged for an English 
translation of each number, which will appear almost simultaneously with the 
French edition. This ‘* Review” has recently contained a capital Report of 
the Liége Meeting of the Iron and Steel Institute. 
MINERALOGY. 
Corundum has been discovered, within the last two or three years, in 
deposits of considerable extent, and under conditions of unusual interest, at a 
locality, now known as Corundum Hill, in Macon County, North Carolina. 
Colonel Jenks, who discovered these deposits and has established workings 
for corundum at the Culsagee Mine, has recently visited this country, bringing 
with him a collection of specimens of great beauty and scientific interest. 
These have been submitted to the Geological Society, accompanied by notes 
on their mode of occurrence. It appears that the corundum is found in veins 
in a hill of serpentine, and is largely associated with chloritic minerals, such 
as ripidolite and jefferisite. Some of the crystals are notable for the intimate 
manner in which they are blended with these minerals, whilst others exhibit 
such brilliancy as to suggest that but little more is needed, in the way of purity 
of colour and freedom from flaws, to transfer them to the category of true 
gem-stones. It is hardly too much to expea& that sapphires, rubies, and the 
