mething
positive for posterity, and leave the ages to come some certain and
abiding legacy of our treasures of art and learning?

It may be that human progress will go on and on to the end of time
without a break; that in the course of centuries mankind will surpass
us in civilization, knowledge and power, as much as we surpass the
earliest and rudest men we have yet found traces of: maybe infinitely
more.

In such a case, what would not the scholars of, say the year 5000
A.D., or any other future age, be willing to give for a comprehensive
picture of humanity as it exists to-day--for a reasonably complete
library of our literature, science, and art? We may safely assume
that nothing of the sort will be possible if matters are left to take
their natural course. By that time every structure, every machine,
every book, every work of art, now in use or stored away in our
libraries and galleries of art, will have disappeared, a prey to time,
the elements, or the more destructive violence of man.

On the other hand, it may be that, through repeated disasters of one
sort or another, mankind, three thousand years hence, will have lost
all the knowledge men ever possessed, and be slowly struggling upward
for the hundredth time from inherited barbarism. In such a case, what
enormous benefits might not accrue to man from a fortunate opening up
of the wealth of knowledge we possess!

In any supposable case between these extremes of progress or
degradation, a legacy of art and learning, such as we might easily set
apart for remote posterity, would certainly be acceptable, perhaps
extremely useful. Besides, it might be possible for us to set such a
worthy example to those who shall come after us that, come what might,
humanity would never be left absolutely void of the means of
instruction, nor any worthy human achievement be absolutely lost or
forgotten. The experience of these later years has demonstrated the
value of such legacies even when unintentional, unselected, and
wretchedly fragmentary. It has made clear also how a legacy
deliberately made may be indefinitely preserved.

Roughly outlined, the carrying out of such a truly philanthropic
enterprise would involve nothing more difficult than--

_First_. The construction of a practically indestructible treasure
chamber in some secure place; and

_Second_. The preparation of a library well calculated to withstand
the corroding tooth of time.

Two kinds of structures w