DISTRIBUTION OF RAINFALL IN BRAZIL. 



311 



speaking of the dryness of the climate of the Amazon valley, says that 

 the forests of the Monte Alegre, Erere district, and of Santarem bespeak 

 " during the dry season a very dry climate and a fault of moisture."* 



My own observations show that the plains north and northeast of 

 Macapa are so dry and parched during a large part of the year that trees 

 grow only along the streams or in other favored places. 



The rains, even during the rainy season, have a decided torrential char- 

 acter. Pompeo de Souza mentions a rain at Ceara in 1855 when a rain 

 gage, 200 millimeters deep, overflowed, t 



Using Dr Draenert's table of mean rainfalls, compiled from all the data 

 obtainable at the time of its publication, in 1886, we find that the pre- 

 cipitation was distributed as shown in the following table : 



Distribution of Rainfall by Semesters. % 



No. of 

 years. 



29 

 15 

 15 



4 



1 



3 

 25 



2 



1 



11 

 4 



4 



28 

 8 



7 



Station. 



Kio de Janeiro 



Santos, S. Paulo 



Alto da Serra, S. Paulo 



Sao Paulo 



Alto Parnahyba 



TJberaba 



Morro Velho, Minas 



Gongo Soco, Minas 



Itabira, Minas 



Queluz, Minas 



Maniios, Amazonas ^ 



Pant 



Ceara 



Pernambuco 



Victoria, Espirito Santo . . . 



Colonia Isabel 



S. Bento das Lages, Bahia 

 Baliia 



Rainfall (in 

 millime- 

 ters). 



974.6 

 2,503.0 

 3,576.7 

 1,494.1 



965.6 

 1,560.8 

 1,637.0 

 2,939.3 

 1,303.5 

 1,453.1 

 2,340.4 

 1,788.7 

 1,491.5 

 2,971.7 

 1,050.5 

 1,037.0 

 2,179.5 

 2,394.8 



Six rainy 



months 

 (in millime- 

 ters). 



632.9 

 1,708.9 

 2,289.5 

 1,152.6 



748.0 

 1,292.5 

 1,457.0 

 2,510.1 

 1,120.8 

 1,251.4 

 1,675.9 

 1,426.3 

 1,347.4 

 2,453.0 



779.4 



839.8 

 1,562.4 

 1,795.2 



Six dry 

 months 

 (in millime- 

 ters). 



341.7 

 794.1 

 1,267.2 

 341.5 

 217.6 

 268.3 

 180.0 

 429.2 

 182.7 

 201.7 

 664.5 

 362.4 

 144.1 

 518.7 

 251.1 

 197.2 

 617.1 

 599.6 



By taking shorter periods — say three months- this contrast comes out 

 still more strongly. 



*Bul. Buffalo Soc. Nat. Hist., 1874, p. 227. 



t Ensaio Estatistico da Provineia do Ceara. Thomaz Pompeo de Souza Brazil, i, 1863, p. 116. 



J The totals are taken from Dr Draenert's Vertheilung der Regenmengen in Brasilien. Meteoro- 

 logisehe Zeitschrift, Sept., 1886. They cover a longer and fuller series of observations than that 

 given by Professor Loomis. Amer. Jour. Sci., vol. xxv, 1883, p. 3. 



§ Revista do Observatorio do Rio de Janeiro, vol. vi, 1891, p. 109. 



XXXIV— Bull. Geol. Soc. Am., Vol. 7, 1895. 



