turning more rapidly than sixty or eighty times a minute.

However, speed in another sense, the speed with which the operation is
performed, is what especially characterizes centrifugal extractors. In
this particular a contrast between the old methods and the new is
impressive. Under the action of gravity, cream rises to the milk's
surface, but compare the hours necessary for this to the almost
instantaneous separation in a centrifugal creamer. The sugar
manufacturer trusted to gravity to drain the sirup from his crystals,
but the operation was long and at best imperfect. An average sugar
centrifugal will separate 600 pounds of magma perfectly in three
minutes. Gold quartz which formerly could not pay for its mining is now
making its owners' fortunes. It is boasted by a Southern company that
whereas they were by old methods making twenty-five _cents_ per ton of
gold quartz, they now by the use of the latest amalgamator make
twenty-five _dollars_. Centrifugal force, as applied in extractors, has
opened up new industries and enlarged old ones, has lowered prices and
added to our comforts, and centrifugal extractors may well command, as
they do, the admiration of all as wonderful examples of the way in
which this busy age economizes time.

* * * * *




A NEW TYPE OF RAILWAY CAR.


[Illustration: Fig. 1.--CAR WITH LATERAL PASSAGEWAYS.]