RESEARCH IN BRITISH WEST AFRICA, out 
1910. 
Geidam oe | —}] —} —] O11) — GOi50)| S:9bileadcOd ee s23) || 
Katagum ... —| —| —| 025} 1:49] 095) 502) 745) 3:05; — — | — 
Maiduguri ...| — {| —/] —] — J 2°80; 0°65| 664] 644} 300; —/] —] — 
Sokoto ee es a oso GDN 603i) 93:06) |) 0:06 i i 
Birnin Kebbi — | —]| —| 0°22} 2°32; 1:91| 7:78) 4:60} 8-21] 0:06 = 
Kano... we | —| —]| —] 0:02) 0:98) 4:12) 810} 897) 462; —|)| —|] — 
Nafada we | —| —]|] —] 0:43] 2°52) 4:73) 8:89) 13°04] 3:53) 0710) — |} — 
Molat-.. -- | —| —]| —| 2°36] 6:97) 10:19] 5:21) 8:06} 4:08) 1:80; —| — 
Bauchi See ees OOS OO lean larl 45 8:00) mice oko |e 
Keffi ... cen ee en LOL 72) 5:30) 15:28)) 4270 13:98) 9:30!) S10) | — 
| Lokoja we | — | 103) 0-26/ 445) 5:67) 8-:07| 10°66) 5°98) 5-76) 3:61) —|) — 
Baro ... cee en en Oa coo) 004691) Lor2Oi 12-23), 4515) Po sa lo i 
West Geo see = |) == 1) 0:02) 4539) 8583)" 5:56) 5:35)) 1124) 7-57) 6:67) — |) — 
Tlorin acon — | O03) 1°18) 4:88) 5:97 | 7:37), 6:60)" 6-53'| 14°71) 387) — | — 
Kontagora «... | — | — | 1:12) 0°44] 4:06] 4:17) 13°29} 16:91) 10°93} 209; —} — 
Zungeru... | — | —/ 0°83) 1:15] 669) 5:54] 7:09) 19:27) 10°82} 2:05) —| — 
Zaria we | — | —]| — |] 217] 3°78) 4°95] 11:28} 17:73) 13°08} 081) --—| — 
Ankpa | 1:34) — |} 1:02) 5:65] 10:04} 5:64] 9:38] 11-42} 5:60} 6°31) — | 0:04 
| | | 
In Table B is given the monthly rainfall for eighteen stations for the years 
1909 and 1910, and as these stations are scattered over the territory, it is 
possible to compare not only the extremes, but also the intervening portions of 
the country. The arrangement adopted is that of ascending annual maxima. 
It will be seen from Table A that, although there was a great difference in 
the amount of rain which fell during these two years, the total for each station 
bears roughly the same proportion to the total for the colony. The curve of 
rainfall has only one maximum, and that occurs in July and August, which 
months are therefore the centre of the rainy season. A rainfall of one inch 
or under is practically negligible, so that, with very few exceptions (which will 
be referred to later), November, December, January and February constitute 
the height of the dry season. 
Although July and August on one side, and December and January on the 
other, are the centres of the wet and dry seasons respectively, the duration of 
these seasons varies very markedly in different regions ; ¢.g., at Geidam, in 1910, 
the dry season might be said to extend from October to June, while in the same 
year at Ankpa the dry season can be reckoned only from November to March. 
It will be seen from the tables that, in spite of the difference in the rainfall in 
1909 and 1910, the stations are arranged in certain well-defined groups, ¢.g., (1) 
Geidam, Katagum, Birnin-Kebbi, Sokoto and Maiduguri; (2) Nafada, Bauchi, 
Yola, Keffi and Kano ; (3) Ibi and Baro ; (4) Zaria, Zungeru and Kontagora ; 
(5) Lokoja, Ilorin and Ankpa; and that these groups of ascending rainfall are 
disposed in order from north to south. 
In the northern stations, the dry season reaches its maximum, and may be said 
to extend from October to April, but at the same time, the monthly rainfall is 
never very great. The length of the dry season diminishes in the various groups, 
until (5) is reached ; for example, at [lorin, in 1909, rain fell during every 
month, and at Ankpa, in both 1909 and 1910, the only months in which there 
22036 C 
