JOURNAL OF AGRICULTURAL RESEARCH 
Vol. XIV Washington, D. C., August 19, 1918 No. 8 
INFLUENCE OF HUMIDITY UPON THE STRENGTH AND 
THE ELASTICITY OF WOOL FIBER 1 
By J. I. Hardy 
Assistant Wool Specialist , Wyoming Agricultural Experiment Station 
INTRODUCTION 
Much work has been done on the study of the fiber, the yam, and the 
finished cloth of wool. It has long been known that wool absorbs 
moisture from the air, but the first real research along this line appeared 
by Schloesing (7) 2 in 1893. This work was upon the relation of the 
moisture content of clean wool to the humidity of the air. In 1905 
Hartshorne (2) published work along this line, the results of which were 
in substantial agreement with the work of Schloesing. Hartshorne (3) 
formulated his results into the “The laws of regain in cotton and worsted/' 
using these laws in the construction of tables showing the moisture content 
of wool for a wide range of moisture and temperature conditions of the 
atmosphere. These tables show the great delicacy with which wool 
responds to the changes in the relative humidity of the air, and also 
makes it easy to find the moisture content of wool where the relative 
humidity of the air is known. He has continued his work upon the 
regain of worsted and of cotton and is to-day one of our greatest authori¬ 
ties along this line. 
The effect of moisture on the strength and elongation of yarns and 
fabrics was reported by Barker, Barbrick, and Pickles (r). In their 
tests on worsted yam they found that on increasing the moisture content 
from “absolute dryness" to saturation there was a decrease in strength 
but an increase percentage of elongation. They also found that when 
like patterns of worsted were tested in a room of 92 per cent humidity 
and then in a room with a humidity of 76 per cent there was an increase 
in'strength and a decrease in elongation. They further found that yams 
or fabrics made of cotton increased in both strength and elongation on 
the increase of the humidity of the surrounding atmosphere. 
1 Approved for publication in the Journal of Agricultural Research by the Director of the Agricultural 
Experiment Station of the University of Wyoming. 
2 Reference is made by number (italic) to “literature cited,” p. 394-295. 
Journal of Agricultural Research. 
Washington, D. C. 
Vol. XIV, No. 8 
Aug. 19,1918 
