L18 The American Geologist. 
Feb. 1891 
Short plugs of one-fourth-inch iron bar forged into the ends of the 
pipes before they are threaded, greatly increase the strength of the 
instrument, for the greatest tranverse strain is at the couplings. 
Solid bar maybe used for the lengths hut the strength of the 
piping- with plugs is practically as great and the weight is much 
less. The coupling on an end of each length should he screwed 
on very tightly and galvanized couplings are preferable on account 
of their greater strength. The cross-bar should be forged from one- 
half inch iron bar with handles about a foot long on each side and 
the vertical stem about an inch long with a coupling screwed on 
very tightly. The adjustable gas tongs Xo. 1. are better than 
any form of pipe wrenches so far as my experience goes for they 
are highly effective and not liable to get out of order. A base- 
ball-bat hag is a satisfactory receptacle for the entire outfit for it 
"will hold from twelve to fourteen lengths without difficulty and is 
convenient to handle. 
Tn use the bit is extended b} r screwing on length after length 
until the desired depth is bored. Care must be taken to make 
the joints as tight as possible for it is frequently necessary to un- 
screw the bit from the material in which it is being bored and 
sometimes it becomes quite tightly wedged. Usually the instru- 
ment must he withdrawn from the hole at about each six inches 
and the borings removed. In very compact materials less, and in 
loose soft sands more, can be brought up each time. Below a 
depth of twenty-one feet the rod should be disconnected into two 
sections each time it is raised unless there are some convenient 
branches or projections overhead against which its upper part 
may lean. 
In pebbly materials progress is very unsatisfactory or impossible 
unless the pebbles are very small. Quicksand is another adverse 
condition, and of course no progress could be made in lithified 
materials of any appreciable degree of hardness. 
I have made borings down to a depth of forty feet but if the 
texture of the materials is favorable and the rod is disconnected into 
rhiee sections each time it is brought up, (every three to eight 
inches ) a much greater depth could probably he attained. The 
labor of working the instrument is not great if care be exercised 
not to bore too deeply at a time and although one man can make 
good progress in soft materials it is economical to have assistance. 
