The western sentinel. [volume] (Winston-Salem, N.C.) 1887-1926, 1894-05-03
THE PILOT MOUNTAIN.
HOW FAR IS 1T FROM WINSTON
AND SALEM?
"A Davis School Man Tells How to
Solve the IrObiem-JuSt 20. IL
Miles From Here.

Written for The Sentinel
Having heard this question raised
frequently, l conceived the idea of de-
terinining the distance from Winston
to the mountain, by direct triangula-
ton. after the manner in which en-
ginecrs measure the distance across a
wide river or march. Perhaps it may
prove interesting to some Of your
readers, unacquainted with such
operations, to have short account of
our work.
In brief, it consists Of measuring
the lergth of line called the 'bas-,"
and measuring at each end Of this line,
the angle between it and tie line of
vision to the distant mountain
The problem is then very simple
one Of TrigonOmetry.
While this is an outline Of what has
to be done, there are many details in
Volyed in an accurate determination
of such distance, that require much
patience and time in their execution.
This work was incorporated in the
regular spring course OF field work for
the advanced engineering class at this
Institution, and from its members, /
received much valuable assistance.
We were several weeks in selecting
suitable stations for observation OF
the mountain, during which time
tried and found mpracticable. At
last two stations were selected, one
being on the site of the Zinzendorf
| Hotel, and the other near the end of
Fourth street. This base (62l feet)
was very short for determining SO
great distance, but with q very fine
| Gurley transit, and using every refine
II
| ed too short to DC serviceable
! Unfortunately it could not be meas
| ured directly, due TO the rough charac-
| ter of the ground, but had to be tri-
angulated from q secondary triangle,
! whose base could be measured. Such
| Il base EGO feet) was selected, and
measured ten separate times with the
! utmost Care.
| OF course all of these measurements
| differed slightly from one another, but
| very slightly, and by use of that. branch
| of Mathematics known as the Method
| of Least Squares" the most probable
| length was determined.
| The three angles were each repeated
| ten times, and the results reduced by
| d method that is thought to eliminate
almost entirely, all exceedingly small
errors due to imperfect grdduaticI
and centering OF the instrument
| errors of observation, etc
The test Of the accuracy is that the
| angles, when added together, should
give the theoretical amount, $50 de
| grees. Here much credit is due tC
Cadets d. w. Ihrower and II. w
BGtner, who having spent half day
on two OF these angles. succeeded il
closing within u seconds of the theo
retical result. From these data we
| could obtain our principal base, fal
more accurately than if we had actu-
| ally measured it.
Ear more care had to be exercised
| in the measurement of the principal
angles. The attempt was abandoned
once on account OF wind, producing an
unsteadincss in the Instrument, and
| again on account OF the light, for
light coming from a remote object
| across hill and plain, forest and field,
is subject to many slight disturbances
from its true path, causing ripple OF
| scope of the Jransic.
At last suitable day was found,
and each of these important angles
| was measured ten times and reduced
by two independent calculations, ano
| the final result was obtained by absO-
lutte agreement of two independent
lines of calculation. The distance
was thus found to be 20.12 miles, while
the writer has heard it estimated as
low as Is miles, cand as high as 25.
j. n. AMBLER, D. M. S.