344 OBSERVATIONS ON THE MAGNETIC DIP AND DECLINATION. 
October 21st, reversed the poles of needle No. 1, and observed as follows: 
| potarity of | Face of 
No. of 
Marked |Meansolartime| North end of Needle|South end of Needle} Mean of both ends| attached Name 
Needle. -|marked end Instrument. side ofobservation,| _—reada : reads of Needl Thermometer. of 
| of Needle, of Needle,| H. M. Deg.|Mins.§’Tenths, | Deg.|Mins.§Tenths./Deg.|Mins.§'Tentbs,| (Fahrenheit.) | Observer. 
| ee | E E | 4.15 p..l76. 15 75 . 52 76 . 03.5 53° |J.D.G. 
| bee “ WwW WwW 4.30 77. 30 77. 52 77.41 53 
«“ «“ | Ww E 4.38 |75.40 75. 55 15. 47.5 53 
LsBed. . Eeonh, Bee Wom| iby b> aa 8g 77. 35 77 . 36 58 
Needle. No. 1, with marked end south, gives, October 20th, ike |_| tbanamea 11.6 
Needle No. 1, with marked end north, gives, October 21st, . . . . . . 76°47 
Dip, by sixteen observations on neewle No. 1,°°° 3. Oe ee ce «=. EP BOS 
RECAPITULATION, 
Showing the result of all the observations on needles Nos. 1—3, 4, for the magnetic dip, 
at the first astronomical station of the north-eastern boundary survey, being four thou- 
sand five hundred and seventy-eight feet due north of the monument erected at the 
source of the river St. Croix; made on the 18th, 20th, and 21st of October, 1840: 
1. By sixteen observations on needle No. 3, October 18th, 1840,. . . . 76° 56'.75 
2. oe = “No. 4, October 20th, 1840,. . . . 76° 56'.43 
5. és “i He: Novi, October Silat, T5600 6°" “762 Gene 
Magnetic dip at station four thousand five hundred and seventy-eight feet due 
north from the monument, by a mean of forty-eight observations on needles 
os. 1, 3, and 4, October 15th, 20th, end 21st, 1840, 0. a  . 1. BP 87 a 
XI. November 27th, 1840,—Observations on the dip of the magnetic needle, at astro- 
nomical station, Park’s hill, on the true meridian of the monument at the source of 
the river St. Croix. Latitude 46° 06’ 40”, N.; Longitude 67° 46’ 45”, W. 
NEEDLE No. Be 
Polarity of No. of Time of 
Marked end. Readings. Observation, Dip observed, 
Ss 8 2h. A8m., P.M. 77° 03! 
N 8 3 57 ne 76° 55'.9 
Dip, by sixteen readings of needle No.3, . . . . . . 76°59'.4 
November 28th, 1840. At same station. 
Neepte No. 4. 
Ss 8 Ti CO.87 
N 8 76° 48/37 
Dip, by sixteen readings of needle No. 4, November 20th, 77° 05.87 
November 29th,—at same station as above. 
Neerpie No. 3, REPEATED. 
N 8 77° 03’ 
~ 8 1710156 
Dip, by sixteen readings of needle No. 3, November 29, 1840, 77° 02’.3 
Dip, by sixteen readings of needle No.4, November 28, “ 77° 05'.87 
Dip, by sixteen readings of needle No.3, November 27, “ 76° 59/.4 
