434 FIRST REPORT UPON MAGNETIC WORK

advantageously have been a trifle larger, about 8x8 feet. A few
alterations had to be made, such as the substitution of all the iron parts
by copper, brass or wood. For the iron frame spreading out the tent
at the base of the pyramid on top, I substituted two light pieces of
wood fastened together in the centre by a brass screw, about which
the two pieces could turn and be spread out in the form of an X.
They were held in place by small brass hooks in each corner of the
base of the pyramid. The pine rod (2 inches in diameter) was some-
what over 8 feet long and consisted of two pieces which, when joined
together, were held in place by a piece of brass tubing. The rod
terminated in a copper tip which passed through the brass ring of the
tent on top. About the copper tip could be passed guy ropes to hold
the tent in time of strong winds or for the purpose of allowing the
centre pole to be placed at an angle from the vertical and thus to be
shifted away from the centre of the tent. With the aid of these guy
ropes the whole tent could be easily tilted back far enough to allow
making azimuth observations on the sun. The tent was held down by
seven light pegs (2x1/2x8 inches). Very often four—one at each
corner—were sufficient.

The conditions under which the magnetic survey had to be com-
menced were such that it was highly essential that the observer
should be as independent and as free in his movements as possible.
As stated, the funds had to be carefully managed, it was not known
how long the Coast and Geodetic Survey could spare its instruments,
and the time which the observer could devote to the survey was
restricted. As a first step, the amount of baggage to be transported
from place to place was reduced as much as possible and disposed in
such a way that no package would weigh over 30 pounds, and hence
could be easily handled. After a few trials, the instruments and
personal effects were put up in three packages, each weighing 25 to 30
pounds. The chronometer was always in the special care of the
observer. It fitted snugly in a leather case to which was attached a
handle for holding or carrying it. In traveling on the railroad the
packages could generally be safely entrusted to the baggage-master
when specially cautioned.

The special Theodolite No. 163 the observer did not carry along