of Columbia College, delivered an address on the subject of his
explorations in Utah and Arizona Territories. The speaker commenced
by giving a short history of the circumstances under which the two
government expeditions to which he was attached were organized. He then
confined his remarks to the subject of the latter expedition, no account
of which has yet been published. Its aim was principally to explore the
region embraced by what is known as the old Spanish trail from Santa Fe
to California. After giving an interesting account of the topography of
the region traversed, he proceeded to speak of the traces which were
found on every hand of a former occupancy by a numerous population now
extinct. These were most numerous near the course of the San Juan river.
There were found ruins of immense structures, a view of one of which he
exhibited, built regularly of bricks, a foot in thickness, and about
eighteen inches in length, with the joints properly broken, and as
regularly laid and as smooth as any in a Fifth Avenue mansion. This
structure he said was as large as the Croton reservoir. Inside were
rooms nicely plastered as the walls of a modern house. There were also
traces of extensive canals, which had been constructed to bring water to
these towns, which were received into large cisterns. The lecturer also
exhibited pieces of pottery which he said abounded everywhere, showing
that in a former age all this vast region had been inhabited. He gave it
as his opinion that the depopulation of this region was attributable to
the fact that both to the north and the south were warlike hordes, and
from the incursions of one and the other of these, the peaceable Aztecs,
who had been the former denizens of the country, had been gradually
wiped out. The only people left here now were the Mokies, who lived
in towns inclosed within high, thick walls, and who were almost
inaccessible. These people were visited, and the explorers were received
by them with great hospitality. The speaker concluded by giving a short
account of the manners of the people and their customs, as far as an