eps in as close
touch with the plant as if he were there in person every day, and
is thus enabled to suggest improvement in any particular detail. The
engineering force has a great respect for the accuracy of his knowledge
of every part of the plant, for he remembers the dimensions and details
of each item of machinery, sometimes to the discomfiture of those who
are around it every day.

A noteworthy instance of Edison's memory occurred in connection with
this cement plant. Some years ago, as its installation was nearing
completion, he went up to look it over and satisfy himself as to what
needed to be done. On the arrival of the train at 10.40 in the morning,
he went to the mill, and, with Mr. Mason, the general superintendent,
started at the crusher at one end, and examined every detail all the way
through to the packing-house at the other end. He made neither notes nor
memoranda, but the examination required all the day, which happened to
be a Saturday. He took a train for home at 5.30 in the afternoon, and on
arriving at his residence at Orange, got out some note-books and began
to write entirely from memory each item consecutively. He continued
at this task all through Saturday night, and worked steadily on until
Sunday afternoon, when he completed a list of nearly six hundred items.
The nature of this feat is more appreciable from the fact that a large
number of changes included all the figures of new dimensions he had
decided upon for some of the machinery throughout the plant.

As the reader may have a natural curiosity to learn whether or not the
list so made was practical, it may be stated that it was copied and
sent up to the general superintendent with instructions to make the
modifications suggested, and report by numbers as they were attended to.
This was faithfully done, all the changes being made before the plant
was put into operation. Subsequent experience has amply proven the value
of Edison's prescience at this time.

Although Edison's achievements in the way of improved processes and
machinery have already made a deep impression in the cement industry,
it is probable that this impression will become still more profoundly
stamped upon it in the near future with the exploitation of his "Poured
Cement House." The broad problem which he set himself was to provide
handsome and practically indestructible detached houses, which could be
taken by wage-earners at very moderate monthly rentals. He turned
t