The field collection and investigation of building-stone samples have
developed some important facts which had not been considered previously,
relative to the effect of quarrying, in relation to the strike and dip
of the bedding planes of building stone, and the strength and durability
of the same material when erected in building construction. These
investigations have also developed certain fundamental facts relative to
the effects of blasting (as compared with channeling or cutting) on the
strength and durability of quarried building stone.

_Mineral Chemistry Laboratories._--Investigations and analyses of the
materials of engineering and building construction are carried on at
Pittsburg in four of the larger rooms of Building No. 21. In this
laboratory, are conducted research investigations into the effect of
alkaline waters and soils on the constituent materials of concrete
available in arid regions, as related to the life and permanency of the
concrete and reinforced concrete construction of the Reclamation
Service. These investigations include a study of individual salts found
in particular alkalis, and a study of the results of allowing solutions
of various alkalis to percolate through cylinders of cement mortar and
concrete. Other research analyses have to do with the investigation of
destructive and preservative agencies for concrete, reinforced concrete,
and similar materials, and with the chemistry of the effects of salt
water on concrete, etc. The routine chemical analyses of the constituent
materials of concrete and cement-making materials, are made in this
laboratory, as are also a large number of miscellaneous chemical
analyses and investigations of reinforcement metal, the composition of
building stones, and allied work.

A heat laboratory, in charge of Dr. J. K. Clement, occupies three rooms
on the ground floor of Building No. 21, and is concerned chiefly with