OR, A TREATISE ON PILE. 57 
Description of an Instrument called a Trichometer,* designed & 
to measure the Ductility, Elasticity and Tenacity of Pile. —The } 
accompanying figure represents a brass plate, 3 and 58 inches } 
long and 1,45 ae A, is an inch seale divided on the margin rf 
into parts of an inch. By means of a slide and groove this scale 
can be moved up and down, not exceeding one inch, the parts of 
which are marked on the brass plate; B, is a permanent clamp, 
and C a moveable one; D, is a separate clamp, with a hook by 
which the scale disk is suspended. 
Modus operandi.—Having ascertained the state of the barome- 
ter, thermometer and hygrometer, place one end of a hair, some- | 
thing more than an inch long, in the clamp C, and the other |) 
end into clamp D; adjust, with the screw of C, until there is 
exactly one inch of hair from the points of clamp D, (between 
which it passes,) and the jaws of clamp B; close both these 
clamps. Having placed the instrument in a vertical position, | 
suspended the geal disk to the hook, and put into it as much | 
weight as will cause the pile to stretch, note the amount, as] 
indicated by the scale,t remove the weight, and ascertain toll 
what degree the pile returns to its original length by means of 
its elasticity. Repeat the experiment with gradually increased 
weights until the hair breaks. These results will show the ductility, elasticity and 
tenacity. 
Or tue Direction or Pite.—By direction we mean the course or path which a 
filament of pile pursues from the point where it pierces the epidermis to its apex. These 
directions are of three kinds, viz: Ist, the straight and lank;{ 2d, the flowing or curl- 
ing; 3d, the crisped or frizzled, which is generally spirally curled.§ 
The Laws Relating to the Direction of Pile. i Hair that is cylindrical must necessarily 
hang straightly and lankly from the head. 2. Hair that is oval must inevitably flow 
or eur 3. Wool that is eccentrically oa must always be crisped or frizzled, and 
sometimes spirally curled. 
The Reasons —Ductility and elasticity, (as before explained,) are essential properties of 
pile, and reside inthe fibres. A hair that is cylindrical has just as many fibres, on all 
sides, from the centre to the periphery ; and these fibres, being acted upon equally, when 
the hair is stretched or drawn up, the filament must necessarily stretch and draw up 
strarghtly, and the lankness be preserved. But an oval hair hasa greater number of fibres 
on its two flattened sides than upon the ellipses; when, therefore, the stretching power is 
* From “ trix,” a hair, and ‘‘metron,’”’ a measure. 
f The weight of the clamp D, and scale disk must be added. 
t “ Lank.”—We know of no word in the English language which gives a better idea of the peculiar direction of this pile. 
2 Query, whether crisped and frizzed pile is not spiral curls drawn out and combed separate? 
