218 KANSAS ACADEMY OF SCIENCE. 
COL. WILLIAM TWEEDDALE, 
Civil and hydraulic engineer, and for many years city engineer of Topeka, was 
born in Beith, Ayrshire, Scotland, in 1823, and came to this country with his 
parents when nine years of age. He entered the Rensselaer Polytechnic Insti- 
tute, Troy, N. Y., in 1850, and graduated as a civil engineer in the class of 1853. 
After one year’s practice in railway construction, he returned to the institution 
as instructor in field-work. In 1855 he removed to Chicago, where he engaged 
as a bridge engineer and contractor. 
At the outbreak of the civil war he raised a company of volunteer engineers 
at Dubuque, Iowa, and was subsequently breveted colonel of volunteers for his 
services in the ‘‘march to the sea’? campaign. In the New Madrid compaign he 
was in command of the expedition; designed the appliances and successfully 
constructed the New Madrid canal, which resulted in the reduction of Island 
No. 10. After the evacuation of Corinth he was given charge of the opening and 
maintenance of military railways. At Vicksburg he cut a canal by cutting down 
trees and sawing off the stumps four and a half feet below the surface of the 
water, through bayous, for the passage of transports from Ducksport to New 
Carthage, a distance of twenty-five miles. During the siege he was at Haines 
bluff, in charge of the construction of fortifications in the rear of the army, and 
in the campaign from Atlanta to Washington had charge of the bridge train for 
the army of the Tennessee. 
In 1867 he removed to Topeka, where he engaged in the practice of engineer- 
ing and as contractor for public buildings. Through his recommendation the 
Melan arch bridge spanning the Kansas river was erected. He was first elected 
to membership in the Kansas Academy of Science in 1872, and had been more or 
less active in it to the day of his death. 
At the time of his death he was engaged in introducing his patented process 
for the softening and purification of water, to the perfection of which he had de- 
voted thirty years of research and experiment. Among the last work of his life 
was the preparation of a paper on ‘‘ The Softening and Purifying of Water by the 
Tweeddale Process,’’ which was read before the Academy of Science at its an- 
nual meeting at McPherson, December 29, 1899. Colonel Tweeddale died in 
Topeka, November 4, 1900, at the age of seventy-seven years. He leaves a wife 
and one daughter (Mrs. W. C. F. Reichenbach). 
