82: 
experiments be made in this country by those having the 
requisite zeal and opportunities ; our architects will then 
know with certainty the qualities of the different kinds of 
woods they are using, and instead of working at hazard and 
in the dark, as they now too often do, they will be guided by 
the sure light of practical science to certain and definite 
results. If these experiments contribute ever so little to the 
attainment of so important a result, the object of their pub- 
lication will be fully accomplished.” 
A subject of such vital importance in the art of construc- 
tion as the composition of mortars could not fail to invite, of 
rather compel, the researches of Colonel Totten. No species 
of masonry is subject to such severe deteriorating influences 
as the walls and arches of fortifications, especially in our 
climate ; so severe, indeed, that they almost drive the engineer 
to despair. Next only to the importance of having the 
building stones or bricks of a suitable character, is that of 
uniting them by a Strong and durable mortar. Few persons 
Whose attention has not been called to the subject conceive 
its magnitude, the variety of materials it embraces, and the 
laborious investigations to which it has given rise. Colonel 
Totten commenced his researches at an early date, and con- 
tinued them actively during the whole period of his connec- 
tion with Fort Adams. 
His work ‘on “Hydraulic and Common Mortars” was pub- 
lished in 1838 by the Franklin Institute of Philadelphia. 
It contains, besides original experiments and observations 
on mortars, hydraulic cements and concretes, translations of 
essays by Treussart, Pitot, and Courtois, the best French 
writers on the same subject, and constitutes to this day an au- 
“thority relied on by American engineers. Colonel Totten’s 
experiments extend over the period from 1825 to 18383 
they are especially valuable for the variety of limes and 
