360 OBSERVATIONS ON THE MAGNETIC DIP AND DECLINATION. 
RECAPITULATION 
Of the observations made at Bangor, Maine, July 9, 1841. 
Magnetic dip, by forty-eight observations on needle No. 1, from 1h. 15m., 
ft a | ee 2 ee eee re women tS 
Magnetic dip, by twelve observations on the same needle, from 7h. 43m., 
A Gee 8 My otis snmyineer wtcasiy Gut pias, Aaetbone. sited 
Dip, by sixty.observations.on needle Now, oi: bcs ice eee ot pected ory (16124 
i forty-eight observations on needle No. 2,. . . . . . «+» 76° .10'.8 
Dip, by a mean of one hundred and eight observations on needles Nos. 1 and 2, 
ee Peer ee Rar OF me Rt OT LOE EEO Te Oe SS, Bias OO 
The weather was clear all day. 
A small white-oak tree marks the position of the instrument. From it the following 
magnetic bearings were observed, of conspicuous objects, viz.: 
To the steeple of the new Methodist Church, distant about 250 yards, 8. 74° W. 
To the dome of the Female Academy, S. 53° W. 
To the centre of the state arsenal, N. 4° W. 
The three bearings fix the point of observation independent of a measured distance, 
which could not conveniently be made here. 
XXII. Park’s Hill, August 27th, 1841. 
Astronomical station No. 2, on the true meridian of the monument at the source of the 
river St. Croix. Boundary of Maine and New Brunswick. Latitude 46° 06’ 40”, N.; 
Longitude 67° 46’ 45”, W. Same station as XI. in the preceding series. 
NeEDLe No. 1. 
Marked end. Readings. Observation. ‘Temperature, Dip observed. 
Ss) 24 12h, 00m., noon. 69°.5 772. 03.82 
N 24 00 51 A.M. 73.5 76° 57'.74. 
Dip, by forty-eight observations on needle No.1,. . . . . . 77° 00'.78 
Neep.e No. 2. 
S 24 lh. 51m., P.M., 74° 76° 59'.29 
N 24 2 48 x 75 77° 02°14 
Dip, by forty-eight observations on needle No.2,. . . . . . 77% 00°71 
Dip, by a mean of ninety-six observations on needles Nos. land 2,  . . . 77° 00'.74 
The observations were made in the shade of the forest: the sun somewhat obscured 
by thin clouds: weather pleasant: wind south south-east: nearly calm. 
Norz.—On the 27th, 28th, and 29th of November, 1840, I observed the dip at this station with the instrument 
by Troughton & Simms, of London, which I had used on the Texan frontier. ‘The result then obtained, with 
the needles numbered 3 and 4, was 70° 02'.5, differing 1’.8 from the result obtained now, with the Gambey 
instrument, in an elapsed period of nine months. See observation XI. of my preceding series. 
The difference of these two results is probably not more than should be attributed to the diminution of the dip 
during the elapsed time between the two sets of observations, being at the rate of 2’.4 per annum. ‘The results 
show a very satisfactory agreement in the two instruments, and seem to entitle the observations made on the 
Texan frontier and elsewhere, with the former instrument, to additional weight in regard to accuracy. 
