|
Abstract of Astronomic Work in Maine
November 1, 2002, Harold E. Nelson, Newport, ME
Longitude difference between Bangor and Halifax, Nova Scotia
Observation dates: 1851, December 16, 17, 19, 22
Western Station: Bangor, Maine (Coast Survey Observatory, Thomas Hill)
Observer: Sears Cook Walker
Instrument: Simms No. 5 Transit
Eastern Station: Halifax, Nova Scotia (Naval Yard Observatory)
Observer: Capt. Shortland, Royal Navy
Instrument: Troughton and Simms No. 4 Transit
Mean observed difference of longitude between reference points 0h 20m
46.557s
Probable Error: Plus or Minus .067s
---Though not used in later publications, Walker’s main accomplishment
here was to determine longitude differences between Bangor and Harvard
Observatory. As procedures improved in later years, the Coast Survey took
out the Harvard to Bangor connection and in 1895 observed between Harvard
and Calais Observatory directly. Coast and Geodetic Survey station
SHORTLAND is located on Trimble Hill, near Robbinston....perhaps named for
Capt. Shortland.
Longitude difference between Calais, Maine and Fredericton, New Brunswick
Observation dates: 1857, October 23
Western Station: Calais Observatory, Transit station of 1857
Observer: Edward Goodfellow
Instrument: Simms Transit No. 3
Eastern Station: Fredericton, New Brunswick, (Dr. Toldervy’s observatory)
Observer: J. Toldervy
Instrument: Troughton and Simms Transit No. 4.
Mean observed difference of longitude between reference points
0h 02m 34.73s
Probable Error: Plus or Minus.5s
--- This is the time Professor William Brydone Jack, first Astronomer of
British North America (Canada) of King’s College, now University of New
Brunswick, visited the men of the U. S. Coast Survey to view first hand
the "American Method" of telegraphic longitude determination. The
Americans had the chronograph register, but Jack, with his limited funds
only had the eye and ear method to time the star observations. Jack
reported his findings to Prof. G. B. Airy, the Astronomer Royal of the
Greenwich Observatory. Cloudy weather permitted only 3 star signals to be
exchanged with Fredericton, but the U. S. Coast Survey published the data.
Jack pushed telegraphic longitude through the Atlantic provinces and
Quebec. He was also in charge of calibrating surveyors compasses and
chains in British North America.
Longitude difference between Calais,
Maine and Heart’s Content, Newfoundland
Observation dates: 1866, December 11, 12, 14, 16
Western Station: Calais Observatory, Transit station of 1857
Observer: Charles O. Boutelle
Instrument: Simms Transit No. 8
Eastern Station: Heart’s Content, Newfoundland (Coast Survey Observatory
at HC)
Observer: Edward Goodfellow
Instrument: Troughton and Simms Transit No. 6.
Mean observed difference of longitude between reference points
0h 55m 38.00s
Probable Error: Plus or Minus .06s
Longitude difference between Calais, Maine and Cambridge, Massachusetts
Observation dates: 1895, August 21, 25, 27, 30; September 1, 2, 5, 8, 10,
13, 14
Western Station: Harvard College Observatory Dome
Observer: G. R. Putnam and A. T. Mosman*
Instrument: C & GS Transit No. 19
Eastern Station: Calais Observatory, Transit station of 1857
Observer: G. R. Putnam and A. T. Mosman*
Instrument: C & GS Transit No. 18
Mean observed difference of longitude between reference points
0h 15m 23.187s
Probable Error: Plus or Minus .007s
* Putnam and Mosman probably observed at each station, exchanging position
with one another, a common practice to remove any "personal error" of the
observer, in effect, canceling the errors out.
Longitude difference between Heart’s Content, NF and Foilhommerum, Ireland
Observation dates: 1866 October 25, 28; November 5, 6, 8
Western Station: Heart’s Content Transit Station of 1866
Observer: George W. Dean and Edward Goodfellow
Instrument: Troughton and Simms Transit No. 6
Eastern Station: Foilhommerum, Ireland Transit Station of 1866 (Valentia
Island)
Observer: A. T. Mosman and Benjamin A. Gould
Instrument: Troughton and Simms Transit No. 4
Mean observed difference of longitude between reference points
2h 51m 56.364s
Probable Error: Plus or Minus .029s
Longitude difference between Foilhommerum, Ireland and Greenwich, England
Observation dates: 1866, November 5, 13
Western Station: Foilhommerum Transit Station of 1866
Observer: Benjamin A. Gould and A. T. Mosman
Instrument: Troughton and Simms Transit No. 4
Eastern Station: Greenwich Transit Circle, Greenwich Observatory
Observer: Various
Instrument: Transit Circle
Mean observed difference of longitude between reference points
0h 41m 33.34s
Probable Error: Plus or Minus .06s
Latitude Observations at Bangor Maine
Observation Dates: 1857 September 7-10
Station: Transit Station of 1857
Observer: Edward Goodfellow
Instrument: Zenith Telescope No. 5
Observations: 213 on 41 pairs of stars near meridian
Latitude corrected to sea level and pole variation: 44d 48 12.89
Latitude Observations at Calais Maine
Observation Dates: 1857 September 2-29
Station: Transit Station of 1857
Observer: George W. Dean
Instrument: Zenith Telescope No. 4
Observations: 243 on 57 pairs of stars near meridian
Latitude corrected to sea level and pole variation: 45d 11m 09.39
Establishment of the Calais Observatory in 1857
On Monday, August 3, 1857, Professor A. D. Bache and his team reached the
east end of the Epping Baseline. On Friday, August 7th, 1857, Bache left
Epping for Bangor. Sometime between August 9, 1957 and September 18th
(when actual astronomic observations began), Assistant George W. Dean,
Sub-assistants Stephen Harris and Julius Kincheloe visited Calais,
selected the most prominent point nearest the Telegraph Depot, and
arranged with the Headmaster of Calais Academy for the establishment of
the observatory building, and also arranged for a telegraph wire to be run
from the Depot to the Observatory, and any necessary ground work for the
longitude observations with Thomas Hill. The observation station at Calais
was erected by Thomas McDonnell, artificer in the Coast Survey.
Magnetic Observatory at Calais
Location: About 400 feet south of the Astronomic Station (the
observatory). There are several ledges of granite and hornblende not far
distant; also many surface rocks of the same material. No local attraction
is suspected. Dip observed near Powder House, Calais, 76 degrees, 27.3
minutes.
Observation dates: 1857, September 16-23
Observers: Sub-Assistant Stephen Harris, Mr. Julius Kincheloe
Meteorological Observations at Bangor
The usual meteorological journal was kept, in which were recorded one
hundred and fifty readings of a standard barometer, and corresponding
readings of the thermometers for temperature and evaporating point.
Magnetic Observations at Bangor
Location: Six-hundred feet distant from the geodetic station (Thomas Hill)
in range with Mount Waldo. The geological formation is argillaceous slate,
apparently no indications of local attraction.
Observation dates: 1857 October 10-16
Observers: Sub-Assistant Stephen Harris and Aide Henry Wood Bache
Instruments: Declinometer D. 22 (C.S. No. 1) and Dip Circle C.S. No. 4
Meteorological Observations at Bangor
The usual meteorological journal was in charge of Mr. Henry Wood Bache,
one of the aides in my party. One hundred and seventy observations for
temperature, and an equal number for determining the evaporating point
were recorded. One hundred and seventy readings of the barometer
(Greenwich No. 910, and Dent’s aneroid, No. 8,580 ) were also noted, with
general remarks upon the winds, clouds, and other conditions affecting the
state of the atmosphere in the immediate locality of the station.
At the close of 1857, Assistant George W. Dean and Sub-Assistant Edward
Goodfellow are under instructions to organize parties for the telegraphic
determination of longitude between Mobile and New Orleans. Sub-Assistant
Harris has been assigned to the party of J. E. Hilgard in Section VII.
|