172 BRANNER— THE FLUTING AND PITTING [April 4. 



time to time been obliterated by the breaking clown of their lower 

 lips. 



Fortunately we have the records of the rainfall taken at Quixada 

 from 1 89 1 to 1906.'^ These records show that during those fifteen 

 years the total precipitation was 10,711 millimeters. Distributed by 

 months, the greatest rainfall was in February, March, April, and 

 May when it reached an average of 134 millimeters a month; the 

 minimum fell in August, September, October, and November with an 

 average of 17 millimeters per month. 



These figures taken alone, however, do not give a clear idea of 

 the climatic conditions in the semi-arid region about Quixada. An 

 important fact that bears directly upon the question of the origin of 

 these caldrons is that the rains are frequently torrential while they 

 last, even during the dry season, and that they are often followed by 

 periods of drouth during which the hot dry atmosphere quickly 

 takes up the water filling the caldrons. For example, the table of 

 rainfall shows that in October, 1894, there was a precipitation at 

 Quixada of 96 millimeters in a single day, and that too in the dry 

 season. In December of the same year 95 millimeters fell in two 

 days ; in July, 1904, the rainfall was 147 millimeters in two days. In 

 the last case this heavy rain was followed by nearly five months of 

 complete drouth. But even in the absence of long drouths, the rapid 

 evaporation and high winds and high temperatures would empty one 

 of these caldrons in a short time. The temperature at Quixada'^ in 

 1897 ranged from an absolute maximum of 36.2° C. to an absolute 

 minimum of 22.1° C. 



Statistics dating back to 171 1 bear out the generally accepted fact 

 that the interior of Ceara is a region of frequent drouths. In the 

 189 years from 171 1 down to and including the year 1900 it is 

 claimed that there have been thirty-one years of drouth.* But even 

 the years of drouth may have had rain enough to overflow the cal- 



" Thomaz Pompeo de Souza Brasil, " O Ceara no comego do Seculo XX.," 

 Fortaleza, 1909, p. 330. 



' F. M. Draenert, " Zum Klima des Staates Ceara, Brasilien," Meteorolo- 

 gische Zeitschriff, April, 1903. 



' Raymundo Pereira da Silva, " O Problema do Norte." Rio de Janeiro. 

 1907, p. 7- 



