Vol. XIII. No. 2 THE HORIZONTAL COMPONENT OF MAGNETIC INTENSITY AT OSLO OBSERVATORY 1843-1930 9 O'Clock H = 15000+ 14 O'Clock H = 15000+ (9999 = No data) 1875 Jan. Feb. Marz Apr. May June July Aug. Sep. Oct. Nov. Dec. Jan. Feb. Marz Apr. May June July Aug. Sep. Oct. Nov. Dec. 1 969 1297 939 951 950 967 965 962 955 964 973 967 965 1004 949 955 969 982 970 970 972 973 959 966 2 972 991 945 944 957 967 964 955 969 954 955 966 962 973 954 961 968 1015 989 991 979 960 944 966 3 975 988 947 956 952 964 946 966 950 969 941 991 979 985 951 959 977 982 993 998 988 964 941 975 4 964 993 958 956 964 949 975 966 934 962 935 976 962 985 951 970 983 987 997 979 974 965 958 970 5 972 992 953 960 920 967 984 968 962 956 971 969 973 984 958 970 951 981 991 974 988 958 968 976 6 984 990 953 959 945 965 964 978 962 948 982 980 978 977 970 977 980 971 982 989 984 965 974 987 7 985 990 960 902 940 972 962 971 963 956 980 961 985 981 955 987 983 977 975 990 998 953 981 967 8 981 979 920 905 943 969 968 961 967 953 979 975 968 984 958 963 977 990 977 972 984 962 994 967 9 977 986 960 958 967 951 960 975 940 956 983 981 983 994 971 967 972 976 974 989 945 950 976 971 10 982 976 964 957 957 954 971 968 954 965 981 970 982 974 967 970 983 986 983 977 976 977 981 974 11 989 977 970 960 916 939 948 976 985 959 980 968 981 978 972 964 976 973 990 1000 998 956 975 973 12 997 979 962 980 933 945 950 961 986 959 981 971 987 956 961 970 989 975 969 1002 979 973 970 974 13 997 961 979 965 968 957 949 973 964 967 975 980 985 976 978 984 979 986 962 993 989 969 974 978 14 985 971 954 954 956 967 938 982 970 967 979 969 989 971 971 965 961 978 958 1008 981 972 966 967 15 982 975 961 964 963 963 962 955 969 955 972 969 983 976 967 989 956 977 934 998 988 953 971 969 16 985 983 960 947 951 953 956 965 914 970 975 980 979 981 960 985 997 983 954 995 990 957 984 970 17 980 980 954 960 946 958 946 970 948 953 975 983 987 982 965 972 972 992 978 992 980 966 974 982 18 972 985 952 956 946 963 967 977 954 959 967 967 981 980 959 979 960 995 982 984 984 966 979 967 19 970 973 944 951 951 969 967 965 951 970 972 992 970 995 970 993 979 977 970 988 979 987 975 990 20 964 983 943 961 946 960 962 963 963 959 976 976 968 986 961 985 984 992 973 985 965 987 974 977 21 975 996 940 972 956 958 967 968 966 955 977 973 974 990 1001 959 975 978 971 1000 954 972 972 979 22 973 984 942 981 948 970 963 972 963 952 932 983 951 978 944 984 964 979 966 990 960 970 949 980 23 968 992 946 955 931 981 967 968 954 961 956 984 962 972 954 970 973 990 978 967 967 969 963 983 24 971 983 936 970 938 993 957 962 951 966 972 980 971 975 954 968 992 979 981 980 966 976 973 986 25 983 970 946 951 948 975 958 972 955 976 963 984 962 987 955 968 977 978 1002 981 968 963 931 990 26 961 971 959 956 943 979 977 978 959 958 969 978 952 980 977 960 975 981 1005 1003 954 982 967 976 27 968 921 963 950 948 970 961 982 955 955 973 981 968 969 943 957 980 1005 981 991 960 952 971 976 28 980 936 939 930 957 972 971 973 960 960 971 978 962 958 959 957 984 995 996 1007 963 971 972 977 29 986 957 950 955 976 951 961 985 962 979 980 996 933 996 982 958 991 960 975 967 978 979 30 982 969 938 962 949 957 964 967 963 964 985 984 959 960 983 985 986 1006 964 968 965 986 31 985 957 953 941 954 957 996 977 970 985 962 995 969 990 Mean 978 980 953 957 949 964 960 968 959 960 970 977 974 980 961 971 976 983 978 989 975 967 969 976