he sun is withdrawn, so
will it come back to a suitable point, when the plants are watered and the
floors are wetted for the night. Remembering then, the variableness of our
climate, I candidly admit that I consider any precise directions of very
little value. None can be given that shall be implicitly followed, or on
which success shall certainly attend. Horticultural practice should be
made dependant upon ever-varying circumstances."

Mr. Belville, of the Royal Observatory, has constructed the following
Table, from a series of observations made with Simmons' hygrometer in
connexion with the dew point, as obtained by a Mason's hygrometer, or a
dry and wet thermometer.

+------------------------------------------------------------------+
| Range Mean | |
|of Simmons' Humidity of| |
|Hygrometer. the Air.| |
+--------------------------| |
| 20 deg. to 30 deg. 1.00 |Extreme saturation; air precipitates |
| | moisture at a fall of temperature. |
| 30 .. 40 0.96 | |
| 40 .. 50 0.89 | |
| 50 .. 60 0.81 | |
| 60 .. 70 0.77 | } |
| 70 .. 80 0.72 | }Ordinary fine dry weather. |
| 80 .. 90 0.67 | } |
| 90 .. 100 0.59 | |
|100 .. 120 0.50 | Air contains one half of the moisture |
| | it is capable of holding in solution;|
| | in England very dry weather. |
+--------------------------+---------------------------------------+

Example:--Suppose hygrometer read 45 deg., the mean humidity
corresponding is 93. Again, if hygrometer read 90 deg., the mean
humidity corresponding is 59 deg.

_Mushrooms._ (See p. 22.)

Convenience for growing mushrooms may always be planned in a cucumber
house; and as these excellent fungi are universally approved, it may be
useful to append an epitome of the mode in which they should be
cultivated.

The best, or, at least, most convenient situation for the bed, would be
be