278 MR. SPENCER LE M. MOORE—PHANEROGAMIC BOTANY 
These winds bring moisture from the low-lying Amazonian region, moisture which is, 
however, largely intercepted by the high plateaux lying to the north of the province. 
On the other hand, south winds, generated in or having to pass over the dry Pampas, 
will not carry much moisture with them. To judge from our experience at Santa Cruz. 
and at Corumbá, there is much fine weather during the wet season, several days of 
brilliant sunshine sometimes intervening between the storms; and this is borne out by 
the observations of Lt.-Col. Americo Rodrigues de Vasconcellos * at Cuyabá, this 
observer recording for January and February 1889, the middle of the wet season, only 
11 and 15 rainy days respectively. 
The main feature in the temperature is its liability to great and sudden variations. I 
may cite in illustration the testimony of Dr. Joáo Severiano da Fonseca t, who accom- 
panied as doctor the Brazilio-Bolivian Boundary Commission of 1875-78. On June 19th 
of one of these years, on the Cuyabá river, he noted a temperature of 35°C. at 
2 o'clock ».«., and by 10 o'clock that night the mercury had fallen to 7^5 C.: that is, an 
oscillation of more than 50 degrees F. within eight hours! This is, of course, an 
extreme case. On another occasion he recorded a sudden fall, during a hailstorm, of as 
much as 18^7 C. In the highlands frosts are reported to occur sometimes, nearly every 
year, between June and September, and the Indians are occasionally frozen to death; 
moreover, the young coffee-bushes are then liable to destruction. Fonseca also says that 
one morning, near the 16th parallel of south latitude, he saw the ground covered with 
hoar-frost and the puddles frozen over, and this at the level of the river! During 
Dr. Morsback's three years at Cuyabá, the temperature varied between 41*9 C. and 
72.0. This temperature of 41”9 C. (upwards of 107” F.) is, so far as I am aware, the 
highest on record for the province. Our highest at Santa Cruz was 38^5 C. on Monday, 
Oct. 12th. 
As an instance of tho daily range of temperature, 1 take the opportunity of citing 
the following figures, deduced from De Vasconcellos’s observations at Cuyabá for 
July 1888 1 :— 
T A.M, 10 a.m, 1 P.M. 4 P.M. 
Average monthly temperature in the shade...... 19906 C. 25798 C. 30-63 C. 30781 C. 
The hottest period of the day is usually some time between 1 and 4 P.M. At Santa 
Cruz the maximum was generally reached at about 3 P.m., though exceptions often occur, 
the mercury at 6 o'clock sometimes standing higher than at any earlier hour of the day. 
Moreover, the morning hours are occasionally the hottest. 
The oscillations of the barometer are but slight ; the maximum monthly oscillation, 
as set forth in the tables to which I have had access, amounts to rather more than 
15 millimetres (Cuyabá, August 1888, De Vasconcellos), but this i is quite exceptional, as. 
the subjoined figures will show :— 
* * Revista do Observatorio, Rio, 1889, pp. 66 and 83. 
T ‘Viagem ao redor do Brazil, Rio, 1881. 
t ‘Revista do Observatorio, Rio, 1888, p. 185, 
