Annual Address by the President. 
9 
In many chemical lines the distinction between technical and scientific 
methods has either disappeared or is passing away, for, in many chemi- 
cal operations, the processes used require to be constantly regulated and 
controlled by laboratory analyses, and the pressure due to commer- 
cial work has, in many instances, given rise to methods that have been 
adopted in scientific laboratories in preference to those that have been 
there developed. 
Growth in any one branch of science is dependent npon growth in 
other branches, and this is particularly true of applied science. Con- 
sider the structures and machines of the engineer and note how they 
have gone on increasing in size and power in proportion to the improve- 
ments made in metallurgical methods. The problem of transportation 
across the North Eiver from New York City has presented enormous 
difficulty and several schemes for supplanting the method by barges, now 
in use, have been, proposed. One of these is for a suspension bridge of 
3100 feet clear span — almost three-fifths of a mile. In order that the 
structure be able to sustain itself and the several lines of railway that 
would cross it, this would require a very high working and ultimate 
strength in the material of which the bridge would be composed. If 
my memory serves me right the specifications called for an ultimate 
strength of 180,000 pounds per square inch in the material composing 
the cables. The longest clear span so far built is across the Straits of 
Carquinez, in California, where the Bay Counties Power Company’s 
cables that carry high pressure electric currents have a clear span of 4,427 
feet between towers. Because of their use as conveyors of electric cur- 
rents these cables had to have high conductivity as well as great strength, 
which made it more difficult to secure the proper material. Notwith- 
standing the two conditions that had to be satisfied, it is stated that the 
cables have a breaking strength of 192,000 pounds per square inch. A 
few years ago it would have been impossible to manufacture steel with 
anything like such high tensile strength. The constant increase in the 
size and weight of locomotives, and rolling stock generally, has neces- 
sitated material increase in the size and strength of bridges and the 
weight and strength of rails. Better alignment, easier grades, and 
improved roadbeds better maintained, have all contributed to make travel 
at high speed safer and more comfortable than it has ever been before. 
In bacteriology the last ten or a dozen years have witnessed the most 
wonderful advancement in consequence of which the whole subject of 
sanitary science has undergone remarkable changes, followed by similar 
changes in sanitary engineering. It is well that this is so, for there is 
nothing of so much importance to man as life and health, and recent 
advances in bacteriology have pointed the ways by which improved 
health conditions have been attained. Professor Wm. T. Sedgwick, at 
the meeting of the Society of American Bacteriologists, last December, 
