Tables 742 and 743 



TABLE 742. — Horizontal Magnetic Intensity, United States 



593 



This table gives for the epoch January I, 1925, the horizontal intensity, H, expressed in 

 c.g.s. units, corresponding to the longitudes in the heading and the latitudes in the first 

 column. 



TABLE 743.— Secular Change of Horizontal Intensity, United States 



Values of horizontal intensity in c.g.s. units for the places designated by the latitude and 

 longitude in the first two columns for January 1 of the years in the heading. 



Lat. 



Long. 



1855 1865 1875 1885 1895 1900 1905 1910 1915 1920 1925 



.3064 .3054 .3034 .3003 .2968 .2946 .2916 .2870 .2805 .2749 .2704 

 3107 .3087 .3051 .3026 .3000 .2962 .2910 .2863 .2825 



3188 .3157 .3125 .3108 .3086 .3055 .3017 .2980 .2950 



.2652 .2650 .2644 .2624 .2606 .2591 .2567 .2526 .2465 .2419 .2382 



.2817 .2787 .2752 .2750 .2728 .2710 .2687 .2653 .2603 .2561 .2527 



.2922 .2887 .2852 .2838 .2816 .2802 .2784 .2755 .2720 .2688 .2662 

 .2963 .2933 .2903 .2876 .2855 .2847 .2832 .2809 .2784 .2760 .2738 

 .2184 .2187 .2197 .2189 .2182 .2177 .2159 .2130 .2086 .2049 .2022 

 .2332 .2314 .2292 .2302 .2292 .2284 .2266 .2239 .2198 .2167 .2142 

 2407 .2403 .2391 .2383 .2368 .2345 .2317 .2292 .2272 



2519 .2502 .2488 .2481 .2471 .2453 .2433 .2414 .2396 



.2612 .2602 .2592 .2573 .2557 .2553 .2547 .2536 .2522 .2506 .2492 

 .1612 .1631 .1654 .1667 .1682 .1689 .1692 .1680 .1662 .1644 .1632 

 .1682 .1682 .1692 .1710 .1718 .1718 .1710 .1693 .1667 .1647 .1632 

 1792 .1798 -1794 .1791 -1783 .1766 .1741 .1723 .1708 



1958 .1956 -1952 -1949 -I940 -1924 -1905 -1888 .1873 



2110 .2100 .2092 .2087 .2082 .2070 .2057 .2043 .2029 



2242 .2228 .2217 .2215 .2213 .2206 .2196 .2183 .2172 



•1365 -1372 .1381 .1402 .1424 .1434 .1444 .1443 .1432 .1422 .1415 

 1367 -1367 -1387 -1397 -1402 .1404 .1394 .1380 .1369 .1362 



1280 .1286 .1291 .1294 .1295 .1287 .1276 .1268 .1262 



1458 .1458 -1457 -1458 .1458 .1450 .1440 -1431 -1422 



1639 .1635 .1631 .1632 .1632 .1626 .1618 .1609 .1600 



1847 .1838 .1831 .1832 .1834 .1831 .1825 .1816 .1808 



Smithsonian Tables 



