NIPHER MAGNETIC DKTERMINATIONS IN MISSOURI, 79. I 25 



Station ^i— Lebanon, Laclede Co,, Mo. Lat. 37° 48'. ; Lon. 92° 42'. 

 On the commons to the S.E. and in front of the Laclede Hotel, and 150 

 yds. from the R.R. track. An observation on polaris was made from 

 the piazza of the hotel, no evening mark reading having been taken, and 

 a second observation was made in the yard of Josiah McKnight. These 

 determinations differed 3' , and the weights of the two were taken at i 

 and 3, respectively. In the absence of Mr. Shaub, I received very satis- 

 factory assistance from Master William Diffenderfter. 



Station 14 e—St. Louis. On the grounds of Wm. Glasgow, cor. Glasgow 

 place and Garrison av.; 31 yds. to the Sheridan av. fence and 59 yds. to 

 the centre of Garrison av. It was afterwards learned that a water main 

 3 or 4 ft. in diameter runs up the centre of Garrison av. As Station a 

 of last year and Station e are equidistant from this main, and on oppo- 

 site sides, the mean for the two stations will give the most reliable value 

 for declination, which is 6° 23.' g. Polaris obs. for meridian. 



Station ■^2—Colli?isville, Madison Co., Ills. About 9 miles from Wash- 

 ington University, and a little N. of E. Observations made in the yard 

 of Dr. J. L. R. Wadsworth, a few feet E. of the centre of the yard. No 

 gas pipes in the city and location favorable. Polaris observation for 

 meridian. At the two stations last named, Mr. E. A. Engler acted as 

 assistant. 



DECLINATION. 



Declinometer No. 3 of the Coast Survey was used. 



The new magnet, ''No. i," was used for all determinations 

 after July 11. Its axis was re-determined at nearly all stations, 

 and was found quite constant. The scale value of one division 

 of this magnet is i.'9o2- Some excellent silk furnished by the 

 Nonotuck Silk Company of Florence, Mass., was sufficiently 

 strong, so that a single (combined) fibre would carry the magnet. 

 This greatly simplified the determination of the torsion correc- 

 tion, rendering it much more constant, and reducing its value to 

 a minimum. 



The determinations were all made outside of the tent, and, in 

 order to protect against wind, a closely fitting hood of heavy mus- 

 lin was drawn around the magnet-house. The transit was also 

 kept covered by a cloth. 



The meridian determinations were, in three cases, made by 

 the method of equal altitudes of the sun. In all other cases, 

 the reading of true north was obtained by taking the reading of 

 the pole star when at its greatest eastern elongation, subtracting 

 the azimuth of the elongation as given in the following table : 



