JANUARY 31, 1907 | 
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INVESTIGATIONS have shown that the yellow . crystalline 
substance deposited from solutions of ammonium molyb- 
date has the compesition H,MoO,,H,O. It was noticed 
as early as 1876, identified in 1882, and a crystal measure- 
ment made in 1903. The properties of this interesting | 
chemical curiosity form the subject of a paper by Mr. 
J. Hy» Graham in the Journal of the Franklin Institute 
(vol. clxiii., No. 1). 
In the Engineer of January 25 plans are given of the 
handsome and commodious new headquarters of the great | 
American engineering societies in New York provided by 
the liberality of Mr. Andrew Carnegie. The two top 
floors are devoted to the libraries of the several societies, 
and it is intended so to administer the library of each 
that by bringing them together there may be created an 
extremely complete and valuable library of engineering 
science and practice. 
STRIKING evidence of Japan’s native industrial capacities 
is afforded by an admirably illustrated 
description, by Mr. O. G. Bennett, ot 
Sumitomo Bessi, the great copper mine 
of Japan, in the Engineering Magazine 
(vol. xxxii., No. 4). Copper mining 
has been carried out for centuries at 
this peak of sulphide copper ore near 
the centre of the island of Shikoku. 
At the present time, 9000 tons of ore 
are raised daily by plant, modern in 
all engineering details, the transform- 
ation from the primitive methods 
having been wrought without the direct 
assistance of a single foreign engineer. 
Yue presidential address delivered by 
Mr. F. W. Taylor, of Philadelphia, to 
the American Society of Mechanical 
Engineers is | summarised in _ the 
Engineer and in Engineering of 
January 11. The author, one of the 
inventors of the modern high-speed 
steels, has written an address on the 
art of cutting metals that deserves to 
become one of the engineer’s classics. 
It is probably, both on account of 
its length and on account of the 
matter it contains, one of _ the 
most. remarkable that has _ ever 
been offered to a learned society. It contains the main 
results of twenty-six years’ study of the question of 
obtaining the maximum output from machine tools. As 
the best high-speed tool steel the author recommends a 
steel of the following composition :—vanadium, 0-32 per 
cent. to 0-29 per cent.; chromium, 5:95 per cent. to 5-45 
per cent.; manganese, 0-07 per cent. to o-11 per cent. ; 
tungsten, 17-81 per cent. to 18-19 per cent.; carbon, 0-682 
per cent. to 0-674 per cent.; and silicon, 0-049 per cent. 
to 0-043 per cent. He has succeeded in establishing 
formulze sufficiently trustworthy for the production of slide- 
rules by means of which it is possible to determine in a 
few minutes the best speed and feed to use in executing 
any given piece of work in any given lathe, and with any 
given set of tools. 
In one of the very valuable Bulletins (No. 275, 
Washington, 1906) recently issued by the United States 
Geological Survey, Mr. T. Nelson Dale describes the slate 
deposits and slate industry of the United States. It covers 
NO. 1944, VOL. 75] 
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| quarry in the United States. 
154 pages, with twenty-five plates and fifteen illustrations 
in the text, and deals with the origin, and 
structure of slate in general, and the slate deposits of the 
United States in particular. A full bibliography of slate 
and a glossary of geological and slate-quarrying terms are 
| appended. The classification slates adopted by the 
author is as follows :—I., aqueous sedimentary: A, clay 
| slates, B, mica slates; (4) fading: (a) carbonaceous or 
graphitic, (b) chloritic, (c) hamatitic and chloritic ; (2) un- 
fading : (a) graphitic, (b) hamatitic, (c) chloritic, (d) hama- 
titic and chloritic. II., A, B, dyke 
composition, 
of 
igneous : ash slates, 
slates. The scientific basis for these subdivisions is ex- 
| plained, and the microscopic and chemical’ analyses of 
typical slates are given. The Old Bangor quarry, 
Northampton County, Pennsylvania, is the largest slate 
The deposit measures 1000 
500 feet across it, and 300 feet in 
a close, overturned 
horizontal cleavage. The 
feet along the strike, 
depth. The general 
synclinal crossed by 
structure is 
almost 
thickest bed of good ‘slate is g feet thick. The product 
from the large beds is used for roofing, but that from the 
ribboned beds goes into mill stock. The value of the 
United States slate production in 1904 was 1,103,439l. 
A PAPER on internal-combustion engines for marine pur- 
poses, by Mr. J. T. Milton, was read at the Institution of 
Civil Engineers on January 22. The economy and _ the 
increasing use of internal-combustion engines on land has 
led to considerable interest being taken in their applica- 
tion to marine purposes, and already a large number of 
such engines have been fitted in small craft on the 
Continent, in most of which heavy mineral oil is the fuel 
used. On land, various fuels are used for these engines, 
namely, petrol, refined oil, heavy oil, coal-gas, producer- 
gas, coke-oven gas, and blast-furnace gas, but for marine 
purposes generally producer-gas and heavy oil are at pre- 
sent the only available fuels. The special conditions re- 
quired for a successful marine engine are :—(a) the engine 
must be reversible ; (b) it must be capable of being quickly 
