210 University Geological Survey of Kansas. . 
5 OSREELESEEL EERE LIES 
ee IEEE IEEE DED LES IPED 
CSRS SESS: SSDs A 7 oe LEE eZ 
SEESSSSSSS SOS > OS Mi = 
Sox SSSOSD S> > 
3 SLOG SSS OD SOS OSS OSS OOS OOOO LS Pos COOK 
SSO SRS SO SOS CPS PROS LISS OS OSS SESS LOO 
PS RSS OOS SOD POSS ISS 
SO SSS SOS SIGOPS IES 
S 
SA PREKKSISS / Z S 
SSR Ss SSS SOOO SSDS SEIN 
, Peo SSS SSSR ER OI SOS SE 
OSE. SSESOSS BOSE BBEOR BLL 
Fig. 18. Longitudinal Sectional elevation and transverse section, showin method of 
apart on the caps and also nailed on the outside or inside of 
the posts. Sticks of wood in three or four foot lengths are 
placed crosswise on these and so on, forming a sort of cribbing 
until the space above the cap and the roof is filled. This ar- 
rangement of timbers is called ‘‘lagging’’ or ‘‘filling,’’ and 
is commonly employed where cavities or spaces occur between 
the walls and timbering. Tinally wedges are placed between 
the lagging and the caps, and the former is forced up against 
the roof, thus holding the whole construction firm and secure. 
Wood of stove lengths is also thrown in back of the poles 
nailed to the posts, which prevents the loose dirt or boulders 
from falling into the drift. Figure 20. 
A local weakening in the roof of an untimbered drift, due 
to a sand or clay pocket, may be remedied if the drift is used 
as a passageway by putting two sets, one on either side of 
the weak spot, and lagging as before described; but if the 
drift is not used as a passageway, it may be cogged or cribbed 
up, which would easily secure the roof, and yet not wholly 
impair the use of the drift as an air passage. 
Caps, posts and mud sills are usually made of round tim- 
bers, in the rough, with one side flattened and furnished with 
a shoulder or seat—the flat part of the cap facing downward, 
while that of the sill is placed upward. The posts have their 
ends squared and cut at an angle to fit the flattened portions 
of the sill and cap when standing in the proper position. The 
four pieces, when fitted together, form a very strong frame 
or set. Figures 20 and 21. Square timbers are sometimes 
used, but are generally more expensive, yet easier to handle. 
