44S 



CATALOr.UE. TKUKESTEIAL iMAGNETISM. 



Hutchins on the dip in the north seas. Ph. 



tr. 1775. 129. 1776. 179. 

 Douglass's observations made about 1735. 



Ph. tr. 1776. 18. 



Known to Mountaine. 



Dunns magnetic atlas. Lond. 1776. 

 Legentil. A. P. 1777. 401. H. 5. 

 Diilryniple. Ph. tr. 1778. 389. 



Easrlndics. 

 Pickersgiil. Ph. tr. 1778. 1057- 



Davis's straights. 



Miller. Koz. XIII. 391- 

 Lacepede. Roz. XV. 140. 

 J?ode Jahrbuch. 1779. 

 VunSwindcn. S. E. Vlll. 



Thinks the diurnal variation owing rather to a change in 

 the needle than in the earth, the effects in different places 

 and with different needles varying considerably. The de- 

 clination increases before an aurora borcalis. 



Van Swinden on the affection of the needle 

 in the aurora borealis. A. Petr. J780. IV. 

 i.H.lO. 



Coulomb. S. E. VIII. ' , , . . 



Attributes the diurnal Tarijition to the action of»the 

 ,sun with his atmosphere, like the aurora bprealis, driv- 

 ing the magnetic fluid from the parts of the earth nearest lo 

 him : the action continuing in these climates an hour or two 

 after noon, till the sun reaches the meridian of the magne- 

 tic pole. 



runcks N. und S. Erdoberflache. Leip.z. 

 . 1781. 



Sho\vs the variation and the dip. 



Cassini on the dailv vaikition. Koz. XXIV. 



2.37. 

 Po'ister in Svvinbiirne's Travels. II. 

 Several observations of variation. Am. Ac. I. 

 Chart of the magnetic equator and meridian. 



A. P. 1786. 4:). Journ. Phys. XLVI. 84. 

 Silberschlag's theory. A.Berl. 1786.87. 



Makes the lines of equal dip parallel. 



Cavallo. Ph.tr. 1787. 6. 



Deduces the diurnal variation from the effect of heat. 



Btiffon Mineralosrie. V. 



Cotteonthediurnal variation. R02. XLr.204. 



Makes the needle undergo several vicissitudes in the year, 

 becoming four times stationary. From January to March 

 it retires from the meridian, then approaches it till May, is 

 stationary in June, retires in July, approaches till October, 

 and retires from it in November and December. 



Churchman's magnetic atlas. II. 1. 

 Churchman on the magnetic atlas. 4. R. I, 

 Dalton's meteor, observ. 61. 

 *llobison. Enc. Br. Art. Variation. Suppl. 



Art. Magnetism. 

 Macdonald on the diurnal variation of the 



needle in Sumatra. Ph. tr. 1796.340. 



The variation about 1° s' E. at 7 in the morning, 

 1" 11' at 5 in the afternoon; diminishing again till 7 the 

 next morning. Supposes the strongest pole to the south. 



Macdonald on the variation of the needle at 

 St. Helena. Ph.tr. 1798.397. 



Nov. 1796, the variation was 15° 40' 311" W.; in- 

 creasing 3' 55" from 6 in the morning to 8, then dimi- 

 nishing till 6 in the evening, and remaining stationary all 

 night. 



Haiiy on natural magnets. B. Soc. Phil. n. 



.5. Journ. Phys. XLV. (II.) ,'309. 

 Rennel's variation chart of Africa. Fark's 



travels. Zach. Ephem. IV. 192. 

 Harding on the variation.' Ir. tr. IV. 107. 



Thinks the change at Dublin is 1 2' 20 " every year. 



Nugent on the magnetic poles. Ph. M. V. 



378. 

 Heller on the magnetic effects of the sun and 



moon. Gilb. IV. 477. 

 Humboldt. B. Soc. Phil. n. 37. 



Found the number of vibrations in tqual times at Paris 

 245, at Valcntia 235, atCumanaSig. But what was the 

 temperature ? 



Humboldt. Ph. M. XI. 3.55. 



Finds the lanishing point of declination lat. 29°. N. Ions'. 

 .66° 40'VV. probably of Paris : this is further W. than in 

 Lambert's chart in Bode. 1779. 



Humboldt's letters. Ph. M. XVI. l65. 



Burckhardt on the law of declination at Pa- 

 ris. Zach. Mon. corn III. 161, 546. Note. 

 Ph. M. IX. • 



Gives for the declination at Paris T. dccl. = .449 Csin. 



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