within a few days made an examination of Casa Grande ruin with the
view of determining the need for further protection of the ruin by a
roof or otherwise.

There are in this office two series of photographs representing the
ruin. The first series was taken in 1892 before the protective works
authorized by the Congress were commenced; the second series
represents the work in progress. In the recent examination the
present condition of the ruin was carefully compared with the
condition represented in the photographs.

On comparing the profiles of the walls, it was found that in many
cases the irregular upper surfaces retain the exact configuration of
1892, even to the slightest knobs and rain-formed crevices; the
correspondence being so close as to show that the injury and loss by
weathering during the interim has been imperceptible. In some other
cases, notably along the southern and eastern walls, the profiles
are more extensively modified; some of the points and knobs shown in
the photographs are gone, some of the old crevices are widened and
deepened, and some new crevices appear; and in some parts it can be
seen that walls are lowered several inches. On the whole the
modification of the profiles of the walls is limited, yet such as to
indicate that destruction is proceeding at a not inconsiderable
rate.

On comparing the scars and crevices on the sides of the walls, it
was found that, while many remain essentially unchanged, most are
enlarged and deepened. This is particularly noteworthy on the
eastern and southern walls, which are most beaten by wind-driven
rains, and which are also most modified in profile. It would appear