.19 | 38.2
1841 |16.84| 14.19 | 84.2 ||15.26| 0.00 | 0.0 ||32.10| 14.19 | 44.2
1842 |14.28| 10.46 | 73.2 ||12.15| 1.30 | 10.7 ||26.43| 11.76 | 44.4
1843 |12.43| 7.11 | 57.2 ||14.04| 0.99 | 7.1 ||26.47| 8.10 | 36.0
-----|--------------------||--------------------||--------------------
Mean |13.95| 10.39 | 74.5 ||12.67| 0.90 | 7.1 ||26.61| 11.29 | 42.4
======================================================================
Legend: [%] = Per cent filtered.

"A soil that holds no water for the use of plants below six inches,
will suffer from drouth in ten days in June, July, or August. If
the soil is in suitable condition to hold water to the depth of
three feet, it would supply sufficient moisture for the whole
months of June, July, and August.

"M. de la Hire has shown that, at Paris, a vessel, sixteen inches
deep, filled with sand and loam, discharged water through the pipe
at the bottom until the 'herbs' were somewhat grown, when the
discharge ceased, and the rains were insufficient, and it was
necessary to water them. The fall of water at Paris is stated, in
this account, at twenty inches in the year, which is less than the
average, and the experiment must have been made in a very dry
season; but the important point proved by it is, that the plants,
when grown up, draw largely from the ground, and thereby much
increase the evaporation from a given surface of earth. The result
of the experiment is entirely in accordance with what would have
been expected by a person conversant with the laws of vegetation.

"The mean of each month for the eight years is:

==============================================
| | |Per cent
MONTHS. | Rain. |Filtration.|
| | |filtered.
-------------+---------+-----------+----------
|_Inches._| _Inches._ |
| | |
January | 1.84 | 1.30 | 70.7
February | 1.79 | 1.54 | 78.4
March | 1.61 | 1.08 | 66.6
April | 1.45 | 0.30 | 21.0
May | 1.85 | 0.11 | 5.8
June | 2.21 | 0.04 | 1.7
July | 2.28 | 0.04 | 1.8
August | 2.42 | 0.03 | 1.4
September | 2.64