for the mimeograph may be appreciated
when it is stated that they bring annually an equivalent of three times
the amount realized from sales of machines. The manufacture and sale
of the mimeograph does not come within the enterprises conducted under
Edison's personal direction, as he sold out the whole thing some years
ago to Mr. A. B. Dick, of Chicago.

In making a somewhat radical change of subject, from duplicating
machines to cement, we find ourselves in a field in which Edison has
made a most decided impression. The reader has already learned that his
entry into this field was, in a manner, accidental, although logically
in line with pronounced convictions of many years' standing, and
following up the fund of knowledge gained in the magnetic ore-milling
business. From being a new-comer in the cement business, his corporation
in five years has grown to be the fifth largest producer in the United
States, with a still increasing capacity. From the inception of this
business there has been a steady and rapid development, resulting in the
production of a grand total of over 7,300,000 barrels of cement up
to the present date, having a value of about $6,000,000, exclusive of
package. At the time of this writing, the rate of production is over
8000 barrels of cement per day, or, say, 2,500,000 barrels per year,
having an approximate selling value of a little less than $2,000,000,
with prospects of increasing in the near future to a daily output of
10,000 barrels. This enterprise is carried on by a corporation called
the Edison Portland Cement Company, in which he is very largely
interested, and of which he is the active head and guiding spirit.

Had not Edison suspended the manufacture and sale of his storage battery
a few years ago because he was not satisfied with it, there might have
been given here some noteworthy figures of an extensive business, for
the company's books show an astonishing number of orders that were
received during the time of the shut-down. He was implored for
batteries, but in spite of the fact that good results had been obtained
from the 18,000 or 20,000 cells sold some years ago, he adhered firmly
to his determination to perfect them to a still higher standard before
resuming and continuing their manufacture as a regular commodity. As we
have noted in a previous chapter, however, deliveries of the perfected
type were begun in the summer of 1909, and since that time the
business has continued to