» $84 OBSERVATIONS ON THE MAGNETIC DIP AND DECLINATION. 
(the computed azimuth of the star when observed upon,) was laid off to the east of the 
stake driven on the night of the 17th, by taking a mean of the readings of three verniers, 
each reading to fifteen seconds. This new direction, being that of the true meridian, 
was marked by two permanent stakes, three hundred and seventy five yards apart, the 
one being to the north, and the other to the south of the position occupied by the theo- 
dolite, 
These stakes were to be permanent marks, while this station was occupied, for use in 
observing the horizontal declination of the needles. 
February 18th. This night the star Polaris was again observed, when at its greatest 
western elongation, for the purpose of verifying the accuracy of the azimuth direction 
obtained by the observation of the 17th. The same means were adopted as before 
described, and the direction of the azimuth line corresponded with that obtained by the 
previous observation. 
February 19th, 1840. At Dr. Everett’s house, west shore of Sabine river, near its 
entrance into the sea; Texas. Latitude 29° 43' 54”, N.; Longitude 93° 51’ 30”, W. 
III. Magnetic bearing of the true meridian line, to ascertain the variation or horizontal 
declination of the needle. (Same station as IL.) 
First, by compass No. 3, by W. J. Young, of Philadelphia, needle six inches long. 
At 2h. 00m., P.M. 
Vane A of Compass to the north,— 
North end of needle gives the variation; ... «0 6b e5) 4.» oes 4%, 8° 37’ East. 
Pees Ole OF MOOUIO FIVER OSE) NOT ik bre ce te nn ORE 
The end of the needle at 0, the compass vernier gives, . . . . . . 8°85! 
Vane A of compass to the south,— 
Deere One OF eee Petre a te a te OTT 
South end of needle reads, . ney. einige’) sie Ont , 340g 9/ 
Compass vernier reads, (with aid of cavdle at 0, PHaistdo at rebi0 ai .apite oBs! 
Reversed the poles of the needle by bar magnets, when the readings were as follows: 
At 5h. 30m., p.m. Vane A of compass to the north,— 
North end iof.needlereadsed: 0.408104 ed}-of .golksewols jeatgete Jo-!ning 89144! dilsist. 
South end of needle reads,. . . aiit-boe bees eew ro Bede! 
Compass vernier reads, (with the pail of needle at 0 av odd cash Gt as avobe a 
Vane A of compass to the south,— 
North ng te meme Oe a ce se BP 4B 
South end of needle reads,. . -Ort np rolleyieadp 66? 45! 
Compass vernier reads, (with ae ait os eda inf 0 jel 2 bus ctleod Inigesgg! 
Result, by needle of compass No. 3, with poles direct, . . . . . . . 8° 34/.66 
with poles reversed, . 2.9... .. 8° 44".16 
Variation of the needle of compass No. 3, by a mean of twelve observations 
Memes to slags me pug MON IPOG™ 1QOR OF Bir al ANgISg: DOMED (OS esw ol gon Hh 
