THE DECREASE OF THE NORTH AMERICAN INDIANS. 295 
EXPANSION OF CLAY. 
From proceedings of the Institution of English Civil Engineers, March 26th, 
1870: 
In railroad tunneling, timbers were frequently broken by the expansion 
of clay, although it appeared quite dry.—Hawkshaw. 
In Primrose Hill and the Kilsby tunnels, if the cutting was left a few days 
without completing the brick arching, the timbers were broken. The expansion 
seemed to be nearly the same, whether caused by the air as in the former case, 
-or by the water as in the latter instance.—J/7. Foster. 
That in the Box tunnel it was usual to leave six inches for expansion between 
the face of the work and the timbers, and that space was scarcely sufficient.—_M/, 
Thompson. 
Had seen, at Richmond, a well of four feet in diameter, completely closed 
in one night by the swelling up of the bottom, although there was not any water 
in it.—Mr. J. Simpson. 
The first stone bridge ever constructed in England was that of Bow, near 
‘Stratford, in 1087: the next oldest was London bridge, constructed in 1176.— 
Linglish Paper. 
hit OWOEN 
THE DECREASE OF THE NORTH AMERICAN INDIANS. 
It is an almost universally received statement that, ever since the first contact 
-of the whites and Indians, the latter have been steadily diminishing or disappear- 
ing. The matter has elicited repeated comment on the part of thinking men and 
philanthropists in this and other countries. It has furthermore formed no uncom- 
mon theme of earnest debate and somber prevision among the Indians themselves, 
And yet to ascertain the exact truth in the case is no easy task. Ignorance of 
the real facts has given rise to much of general assertion and idle sentimentation, 
and with the unthinking, careless or unmeaning generalities have come at last to 
be accepted as definite and indubitable data. A few additional words, therefore, 
upon this subject may not be altogether inappropriate. 
That there has been in case of perhaps every one of the best and longest 
known Indian tribes a decrease, in many instances startling in its apparent 
rapidity, no one attempts to deny. Still the true rate of decrease is generally 
greatly exaggerated. The number of the aboriginal population in earlier days 
has been 2imost universally overstated. In the mind of the European explorers 
dhe vast expanse of the country seemed naturally to corroborate the boastful 
