249 
1897 | 1898 
Date ver Temp. Daaph- | Date OWES Temp. Dagon. 
gage anosoma | gage anosoma 
July 14 6.30 79 TOONS || Ira, 12 7.00 78 60 
21 5.20 81.1 960 ne LO 4.70 84 40 
30 4.60 84 4,720 AS 2.90 89 8,580 
Aug. 10 2730 80.8 7,600 Aion 2 2eihY Moe 6,960 
a | 1.90 79 7,120 9 320 83 360 
‘ 24 1.80 ts 5,120 | SCF A ALS) S10 77 60 
Sil Hal he f0) 80 11,000 OS) 4.20 82 1,020 
[= — — ———— PONE E10) 3.90 Siero 2,920 
Sept. 7 1.80 80 7,600 Sept. 6 4.70 79 240 
14 2.00 83 1,500 SLs) 4.20 (2 55) 1,800 
: 21 2.00 71 240 2X0) 4.20 43 960 
— = = => —— Cex 4.90 US 400 
the rise in river levels. Prior to that date hydrographic changes 
are slight. With falling levels and higher temperatures after 
September 7 there is a slight recovery in Diaphanosoma—trom 189 
per m.? on the 5th, to 1,053 on the 12th. 
In 1896 a well-defined heat pulse culminates August 10 at 86.5°; 
and Diaphanosoma,on August 8 at 14,260, with an abrupt depression 
from 7,440, on July 28, to 160, on August 3, in flood waters. The 
decline of this pulse from the maximum on the 8th to 440 on the 29th 
is attended by a uniform decline in temperatures from 86° to 74.3° in 
' fairly stable hydrographic conditions, that is, declining river levels. 
In 1897 there are two well-defined summer heat pulses, one 
culminating August 3 at 89°, and the other September 14 at 83°, 
separated by a depression to 77.5° on August 24. The crest of the 
Diaphanosoma pulse likewise has two apices, the first culminating 
at 7,600 on August 10, followed, during the decline in temperatures, 
