Vol. XVI. No. 4 THE MAGNETIC DECLINATION AT OSLO OBSERVATORY 1843-1930 9 O'Clock 14 O'Clock D = 7°W + tabulated values in tenths of minutes. D = 7°W + tabulated values in tenths of minutes. (9999 = No data) 1931 Jan. Feb. Mar. Apr. May June July Aug. Sep. Oct. Nov. Dec. Jan. Feb. Mar. Apr. May June July Aug. Sep. Oct. Nov. Dec. 1 517 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 542 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 2 514 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 521 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 3 519 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 525 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 4 555 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 567 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 5 577 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 594 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 6 564 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 588 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 7 544 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 545 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 8 549 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 563 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9 558 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 604 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 10 567 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 549 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 11 570 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 537 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 12 516 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 522 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 13 536 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 539 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 14 533 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 533 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 15 535 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 559 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 16 577 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 563 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 17 551 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 566 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 18 554 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 556 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 19 494 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 510 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 20 518 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 508 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 21 514 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 514 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 22 526 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 528 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 23 525 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 543 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 24 468 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 494 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 25 526 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 525 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 26 555 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 501 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 27 522 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 531 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 28 492 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 528 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 29 514 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 572 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 30 529 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 571 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 31 507 9999 9999 9999 9999 9999 9999 546 9999 9999 9999 9999 9999 9999 Mean 533 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 543 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999 9999