The Southwestern Historical Quarterly, Volume 29, July 1925 - April, 1926 Page: 88
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Southwestern Historical Quarterly
engineer, writing in 1767: he gives the location of the mission at
Orcoquisac in 300 23' north latitude and 283 52' longitude from
Tenerife.
The uncertainties of positions in longitude yielded before the
chronometer. New charts and maps were published. More skilled
cosmographers were attracted to America and among them an il-
lustrious one, Alexander Von Humboldt. He came almost as the
King's guest. His equipment was of the best and of the latest
design. An inventory of his instruments casts a light on the
technology of terrestrial measurement of his day. A partial list
follows :
(a) Time-keeper.
(b) Demi-chronometer for ascertaining longitude at short dis-
tances.
(c) Three-foot Achromatic telescope.
(d) Telescope with attachment for fixing it to a tree.
(e) Lunette d' epreuve for measuring very small horizontal
angles.
(f) Snuff-box sextant, two-inch radius, telescope four diame-
ters; useful for exploring in boats or on horseback.
(g) Reflecting and repeating circle.
(h) Theodolite, azimuth circle eight inches diameter.
(i) Artificial horizon.
(j) Quadrant, radius of one foot; levelled with plummet and
bubble.
(k) Dipping Needle.
(1) Variation Compass.
(m) Needle, twelve inches long with sight vanes.
Humboldt preferred to use the occultation of stars by the moon
for determining longitude, to using the chronometer. He says
that many ports in the New World were charted erroneously in
longitude through using a chronometer keeping incorrect time.
During his stay in Mexico, 1803, he prepared a map of the provinces
of New Spain. The result was an amplification of the Royal map
of this region, by the addition of all available geographic informa-
tion. The intention of the old map was to portray the relative
positions of natural objects and places, leaving to some future time
the correct fixing of the geographical co-ordinates. Hence Hum-
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Texas State Historical Association. The Southwestern Historical Quarterly, Volume 29, July 1925 - April, 1926, periodical, 1926; Austin, Texas. (https://texashistory.unt.edu/ark:/67531/metapth117141/m1/102/: accessed March 28, 2024), University of North Texas Libraries, The Portal to Texas History, https://texashistory.unt.edu; crediting Texas State Historical Association.