Transit observations-Continued.

FORT YUKON, August 14, 1869.

Transit instrument, by Troughton & Sims-Sidereal chronometer No. 231, by Bond & Son-Observer, Captain Charles W. Raymond, United States Engineers-Recorder, Mr. J. J. Major.

Transit instrument, by Troughton & Sims-Sidereal chronometer, by Bond & Son-Observer, Captain Charles W. Raymond, United States Engineers-Recorder, Mr. J. J. Major.

Transit instrument, by Troughton & Sims-Sidereal chronometer No. 231, by Bond & Son-Observer Captain Charles W. Raymond, United States Engineers-Recorder, Mr. J. J. Major.

Transit observations-Continued.

FORT YUKON, August 22, 1869.

Transit instrument, by Troughton & Sims-Sidereal chronometer No. 231, by Bond & Son-Observer Captain Charles W. Raymond, United States Engineers-Recorder, Mr. J. J. Major.

FORT YUKON, August 23, 1869.

Transit instrument, by Troughton & Sims-Sidereal chronometer No. 231, by Bond & Son-Observer Captain Charles W. Raymond, United States Engineers-Recorder, Mr. J. J. Major.

xyt C Verror; p+qt=C'. Assumed values: p-14h 15m 008.20; q=—38.50
(x-p)+(y-q)t—C—C'—V - C'error=d+ error;
x-p=m; x=m+p; y—q=r; y- r+q
Conditional equation, m+rt-d

Normal equations, (1) Σdw-mΣw+rΣtw=-0.1092-5.84 m 4-47.64 r

(2) Edtw-mΣt wrΣ t2 w -2.7234-47.64 m +517.48 r

August 11.-Mean of two stars with smallest correction in azimuth and collimation gives 14h 14m 568 68. August 13.-Level interpolations unreliable.

August 20.-No level readings near time of reversal.

August 21.-Observations extend over 34 hours. Instrumental disturbance probable.

For errors of 08.10 and less, weight assumed, 1.00.

August 10, 11.-Weight assumed at 0.50 in consideration of large deviation in azimuth.

LONGITUDE BY SOLAR ECLIPSE.

FORT YUKON, August 7, 1869.

Zenith telescope, by Würdemann; and pocket glass; chronometer No. 1609, by Bliss & Creighton-Observers, Captain Charles W. Raymond, United States Engineers; Mr. Ferdinand Westdahl-Recorder, Mr. J. J. Major.

Zenith telescope, by Würdemann-Sidereal chronometer No. 231, by Bond & Son-Observer, Captain Charles W. Raymond, United States Engineers-Recorder, Mr. J. J. Major.

RECORD AND REDUCTION OF MAGNETIC OBSERVATIONS.

STATION, FORT YUKON, ALASKA-LATITUDE, 66° 33′ 47′′ NORTH--LONGITUDE, 145° 17′ 47′′ WEST FROM GREENWICH.

EXPERIMENTS WITH MAGNETIC DECLINOMETER.

Theodolite magnetometer No. 2, by William Würdemann.
AUGUST 12, (P. M.,) 1869.

The instrument was placed on a firmly imbedded spruce post, about fifty yards east of astronomical station. It was leveled, collimation examined, and "vertical" wire made vertical. The wooden box was used.

The instrument was then turned on a meridian-mark. Reading of the verniers, E. 29° 00'; W. 209° 00'.

The brass detorsion-cylinder was placed in the stirrup, and the torsion was approximately removed. (Stirrup suspended by two fibers, which were in position when the instrument was received, and had probably been used for several years.)

AUGUST 13, 1869.

The torsion-cylinder was removed, the declination-magnet was jammed, and the value of one division of its scale determined as follows:

Removed the declination-magnet, jammed the collimation-magnet, and determined the value of one division of its scale as follows:

Removed the collimator and suspended the declination-magnet; determined the zero of its scale as follows: