Apri 5, 1912] 
problems in relation to plant breeding and 
adaptation, problems dealing with the trans- 
portation, handling and storing of fruit, rural 
sanitation, road making, rural social surveys 
and rural festivals as agencies for social con- 
tact. 
THE department of electrical engineering of 
the Massachusetts Institute of Technology has 
under way an important investigation on the 
adaptability of electric vehicles for trucking 
purposes, more especially with reference to the 
conditions in Boston and its vicinity. Mr. H. 
¥F. Thomson, the research associate, in carrying 
on this work, is making substantial progress 
in the inquiry. The inquiry is directed along 
several particular lines, including cost of the 
service, convenience of the service, difficulties 
and expenses due to the delays in loading and 
unloading at freight houses and the like, de- 
lays caused by drivers, and corresponding 
matters. The railroads entering Boston are 
cooperating with the part of the investigation 
relating to time occupied in loading and un- 
loading trucks at the freight houses, includ- 
ing the time occupied in getting tc the load- 
ing platform. The freight house conditions 
are being investigated by students of the de- 
partment under the direction of Mr. Thomson. 
An appropriation for this work was made to 
the institution by the Edison Electric Ilumi- 
nating Company of Boston. The research was 
begun about the middle of the year 1911 and 
is expected to extend beyond the year. It is 
expected to result in a report or series of re- 
ports on the relative merits of electric vehicles, 
other mechanical vehicles and horse vehicles 
for city and suburban delivery, for trucking 
and for the other purposes for which vehicles 
are used in the city and its suburbs. The 
department has had erected in Brookline a 
700 foot span of number two naught bare 
stranded wire to represent a‘transmission span 
on towers, and has had this span under ob- 
servation during the severe weather of this 
winter. The object is to learn more exactly 
the effects of ice, sleet and wind loads, and of 
temperature effects on the stresses imposed 
upon the wire and its supports. This research 
is being carried on by two students under the 
SCIENCE 
535 
direction of Professor Harold Pender. There 
are now a larger number of candidates for 
advanced degrees in electrical engineering 
than the department has ever previously seen, 
and the various branches of research which 
are being carried on are being constantly en- 
larged. This is in addition to the extended 
undergraduate work for which the depart- 
ment is notable. 
THE copper mines of the United States have 
produced more than fifteen and a quarter bil- 
lion pounds of copper, and of this total twelve 
mining districts have produced in excess of 
100,000,000 pounds each, according to the 
United States Geological Survey. These 
twelve districts, located in eight states, have 
yielded 94.69 per cent. of the total output of 
the country since 1845, when the total prod- 
uct of the United States was but little more 
than 200,000 pounds. These districts are 
Butte, Mont., which has yielded 5,315,000,000 
pounds, or 34.75 per cent. of the total produc- 
tion; Lake Superior, Mich., which has yielded 
4,756,000,000 pounds; Bisbee, Ariz., 1,285,000,- 
000 pounds; Morenci-Metealf, Ariz., 882,700,- 
000 pounds; Jerome, Ariz., 570,000,000 pounds; 
Bingham, Utah, 465,000,000 pounds; Shasta 
County, Cal., 336,000,000 pounds; Globe, Ariz., 
334,700,000 pounds; Ducktown, Tenn., 211,- 
700,000 pounds; Ely, Nev., 125,000,000 pounds; 
the foothill belt, California, 104,000,000 
pounds; and Santa Rita, N. Mex. (where min- 
ing is believed to have been begun as far back 
as 1800), 103,000,000 pounds. All other dis- 
tricts have produced 804,300,000 pounds. It 
is interesting to note that the first ten of these 
districts are also the first ten largest producers 
to-day, although the order is slightly changed. 
These ten districts yielded 93.84 per cent. of 
the production for 1910. The United States 
is by far the greatest copper-producing coun- 
try, our smelter output of copper in 1910 being 
56.75 per cent. of the total for the world. 
Nearly every one of the leading copper-pro- 
ducing districts of the United States, accord- 
ing to the Geological Survey, made a record 
output within the three years preceding 1910, 
and nearly every one of them could have donz 
so in 1910 so far as the ability of the mines 
