which would
obtain largely for future building purposes on account of its stability.
More than twenty-five years ago one of the writers of this narrative
heard him remark during a discussion on ancient buildings: "Wood will
rot, stone will chip and crumble, bricks disintegrate, but a cement and
iron structure is apparently indestructible. Look at some of the old
Roman baths. They are as solid as when they were built." With such
convictions, and the vast fund of practical knowledge and experience he
had gained at Edison in the crushing and manipulation of large masses of
magnetic iron ore during the preceding nine years, it is not surprising
that on that homeward railway journey, mentioned at the close of the
preceding chapter, he should have decided to go into the manufacture
of cement, especially in view of the enormous growth of its use for
structural purposes during recent times.

The field being a new one to him, Edison followed his usual course of
reading up every page of authoritative literature on the subject, and
seeking information from all quarters. In the mean time, while he was
busy also with his new storage battery, Mr. Mallory, who had been hard
at work on the cement plan, announced that he had completed arrangements
for organizing a company with sufficient financial backing to carry on
the business; concluding with the remark that it was now time to engage
engineers to lay out the plant. Edison replied that he intended to
do that himself, and invited Mr. Mallory to go with him to one of the
draughting-rooms on an upper floor of the laboratory.

Here he placed a large sheet of paper on a draughting-table, and
immediately began to draw out a plan of the proposed works, continuing
all day and away into the evening, when he finished; thus completing
within the twenty-four hours the full lay-out of the entire plant as
it was subsequently installed, and as it has substantially remained
in practical use to this time. It will be granted that this was a
remarkable engineering feat, especially in view of the fact that Edison
was then a new-comer in the cement business, and also that if the
plant were to be rebuilt to-day, no vital change would be desirable
or necessary. In that one day's planning every part was considered and
provided for, from the crusher to the packing-house. From one end to the
other, the distance over which the plant stretches in length is about
half a mile, and through the various buildings s