OBSERVATIONS ON THE MAGNETIC DIP AND DECLINATION. 335 
Second, by compass No. 4, by W. J. Young, of Philadelphia, needle five and a quarter 
inches long. At 1h. 32mm., P.M. 
Vane A of compass to the north,— 
North and.of nepgis.teads, ........<< (gts wien os Pemereed, oy. ae. «8° AO Bae. 
South end of needle reads,. . . . ee ee 
Compass vernier reads, (with end of needle at 0 : ee a ee 
Vane A of compass to the south,— 
North end of weedie reads, ... J. a alhesw teeunibee: cucteisec. «if 8° ae 
South end of needle reads, .. ie ere ee 
Compass vernier reads, (with end of needle at 0, 7, 496 Se re ee 
Reversed the poles of the needle by means of bar magnets, when the readings were as 
follow. At 6h. 00m., P.M.: 
Vane A of compass to the north,— 
North end of néedie reads,~ 5 4 Oy: Fo.J00F MOF Tyeer Heodt 5 Ye .4).) ge Bo Bast. 
Bolthiendcot meetie readsys se. 44) wow baiwide dug: od). & 6 vie 8268 
Compass vernier, with end of needle at 0, reads, . . 2. . 1. . 4). 8° 47" 
Vane A of compass to the south,— 
Nott Gnd Of meedle reds; =... . teense Lin oijec.visese bere anole BOAT 
South end of needle reads,. . . . PO SN Se Oe ae 
Compass vernier, (with end of needle at 0 ) féhde PP he, J EGL. of ramet 
Result, by needle of compass No. 4, with poles direct, . . . . . . . 8° 42'.33 
with poles reversed, . . . . 8° 47.5 
Variation of needle of compass No. 4, ve amean of twelve observations 
BDO oy ere cee ts : ee Se ne ae 
Third,. by a small theodolite, a i. alent Philadelphia, Needle four and a half 
inches long. 
AS, P. my) north end of needle reads, © Fo . 88a" Bast. 
ROU Ghd Of HeEGIS TOGGS, % mem or ee PRPOY Spoon 1o Ogee ge 
North end of needle being at 0, vernier reads, . . . 2... . . , 8°84! 
South end of needle being at 0, vernier reads, . . . le ew ae.o 
Variation of needle of small “theodolite by a mean of four readings, ie eo OO. hy, 
This needle could not be conveniently taken out of the box, and therefore its poles 
were not reversed. 
SUMMARY. 
1st. Magnetic variation by twelve observations on needle of compass No. 3, 8° 39'.4 
2d. 2 ¢ by twelve observations on needle of compass No. 4, 8° 44’.9 
3d. - vk by four observations on the needle of the theodolite, 8° 36’.1 
Magnetic variation at Dr. Everett's house, near the entrance of the river 
Sabine into the sea, by a mean of twenty-eight observations on three 
needles). cOraary TOR ERI in os cies te be at Hi +s, . 8° 40. LE. 
VOL. 1X.-—88 
