Iowa County democrat. [volume] (Mineral Point, Wis.) 1877-1938, 1880-10-01
Sun SIGNALING.
Work OF the United states Ge0detic
survey in Nevada Reflections from
Mirror Distinguished for DIs-
tancc OfTwo Hundred Miles.


Mirror Distinguished for a DIs-
tancc OfTwo Hundred Miles
The Eurek0 New Ledt}er gives some
interesting intelligence concerning the
work Of a party connected with the
Y United states coast and geodetic sur
vey, now ut work in that vicinity. un-
der the direction of joseph Davis. The
Leacicr says The present working
headquarters Of tho survey Is at Arch
Dome peak, ncas the head Of Reese
river, in Nye county. From this point
tho entire adjacent country for radi-
ii Of two hundred miles i being trian-
gulatcd, by means Of heliotropic signal
lights placed on Ill prominent peaks
4 within the range I'll observation. Ii is
for the purpose Of establishing i hello
tropIc station ON Diamond peak that
i Mr.. Davis visits Eureka. and he will
4 leave tomorrow for that point. where
/ he Will IL stationed for four or five
weeks to- come. The heiotropc is an
instrument used for signaling to an OBJ
server at il distance by measure Of the
suns rays reflected from mirror The
instrument in itself is quite simple. IT
consists Of Il telescope mounted the
same is IN ordinary surveyors transit,
adjustable To any ycrticlc or horizontal
angle thus making it capable of being
accurately directed to amy determined
point. On the top Of the telescope
there are two signals, much resembling
Il globe sight on rifle, but considera-
bly, larger. Back of these sights
small, adjustable platcglas, mirror,
three or four inches in diameter, is
placed, and the suns rays. caught by
this, are directed toward an observer at
rays from the mirror are seen
by him, and ii has been dem
onstratcd that this reflection can
be distinguished on clear day for
Il distance Of two hundred miles. mi
the use Of the hcliotrope by the coast
survey I'M exploring party is first sent
.ahrad 10 determine prominent peaks
that may be observed from great dis
tanCC from the home station. and ON
these hcilotropes are stationed with
their lights until the locality, latitude,
longitude and altitude of the peaks are
definitely determined by triangulation
lIplll viz llNllll' 7ltlilN'ils ~ ll''lll WV
coast survey has one Of these hello
tropes ON almost every prominent
peak in this section of the country,
among which are White Pine and Hot
Creek peaks, Mount Jefferson, Diamond
peak and number Of others that we
do not recall They have also monu-
mcnt ON Prospect mountain for the
purpose Of establishing the exact Iong- |
tudc for the United States geological
survey, whose workings centre ut that
point. Mr. Davis will have his station
established Oh Diamond peak in Il
couple of days, when he will commence
Il system of signaling, with hcadquar-
tiers Ut Arcdomc peak, 4 distance Of
nincty-nincm miles. BY means Of Il pre-
arranged system of signals, the hello
trope is used as Il sort of tclcgraphic
communication and Mr.. Davis move
mcnts and work VIII lie entirely di-
rectcd by means of these sun dispatch
es from headquarters. When viewed
from 9rFfiAtt fSia"@ hgS9 hsI %I bn3
do an immense blazing star just rising
over the peaks ON which they are sta
toned. There is not Il boy i'll the coun
try who has Nut. at some time or other,
eXactcd il vast dead Of amusement from
the eyes of parties Mt Il dis
tancc with the suns rays reelected from
il bit Of broken looking glass and upon
the same principle Observation-Disclosures
We have Just described is constructed.
Tive heilotropc of the lofty summit of
II high mountain IN the same manner
daazIcs the eyes of the fal-distant OBJ
server with Il bit of looking glass no
larger than your hand. 1t does not
seem possible that 50 small i rejecting
surface could be seen ut such great
distance, but ii is clearly diScernille,
and at n distance of forty or fifty miles
ii is % dazzling rs 70 hurt the ewes.
The United States gcodetic survey IS
engaged in running on the thirty-nlnth
parallel. from SAN Francisco to New
Work Taking 4 strip of country
straight through, Of nm average width |
of two or three hundred miles. The
survey is u most thorough and com
plctc one and will establish tho line Of
its work with such precision as to make |
il the authentic data for all subsequent
astronomical and geographical calcnla-
tion III the United states The survey |
is moving eastward ut Il very slow rate,
and will probably he several years be-
fore the Rocky Mountains are reached
Il point whore the eastern division 81
the survey will he met Mr.. Davis i'll |
forms us that So far they have been
engaged nearly three wears in the state
of Nevada This seems an unusual
LENGTH Of time Ia accomplish the sur |
vev of So smalla section of country but
when the extreme accuracy Of the work |
is taken INTO consideration II will be
better understood. The simple topo-
graphy Of the country is not the only
thing 10 be determined by this enter
prise, hut the longitude and latitude
will bc So precisely arrived at rs not to
vary even half IN inch at amy given
point upon the line.
An Odd Custom in HE Island OF Jersey.
~