till
lying in position. The backbone is being prepared for removal, the
sections each containing three vertebrae, partly cased in plaster
and burlap (see chapter XI.) The lower photograph shows a later
stage of progress, the blocks being undercut and nearly ready to
turn over and incase the under side. Strips of wood have been
pasted into each section to strengthen it.]

"It will appear, therefore, that the collection, preparation and
mounting of this gigantic fossil has been a task of extraordinary
difficulty. No museum has ever before attempted to mount so large a
fossil skeleton, and the great weight and fragile character of the
bones made it necessary to devise especial methods to give each bone a
rigid and complete support as otherwise it would soon break in pieces
from its own weight. The proper articulating of the bones and posing
of the limbs were equally difficult problems, for the Amphibious
Dinosaurs, to which this animal belongs, disappeared from the earth
long before the dawn of the Age of Mammals, and their nearest
relatives, the living lizards, crocodiles, etc., are so remote from
them in either proportions or habits that they are unsatisfactory
guides in determining how the bones were articulated and are of but
little use in posing the limbs and other parts of the body in
positions that they must have taken during life. Nor among the higher
animals of modern times is there one which has any analogy in
appearance or habits of life to those which we have been obliged by
the study of the skeleton to ascribe to the Brontosaurus.

"As far as the backbone and ribs were concerned, the articulating
surfaces of the bones were a sufficient guide to enable us to pose
this part of the skeleton properly. The limb joints, however, are so
imperfect that we could not in this way make sure of having the bones
in a correct position. The following method, therefore, was adopted.

"A dissection and thorough study was made by the writer, with the
assistance of Mr. Granger, of the limbs of alligators and other
reptiles, and the position, size and action of the principal muscles
were carefully worked out. Then the corresponding bones of the
Brontosaurus were studied, and the position and size of the
corresponding muscles were worked out, so far as they could be
recognized from the scars and processes preserved on the bone. The
Brontosaurus limbs were then provisionally articulated and posed, and
the position an