2. Painting.
(a) Paint a characteristic December land-



170 NATURE STUDY FOE

scape. Compare carefully with Sep-
tember colors.
XXII.
ASTRONOMY FOR DECEMBER.
QuEEY : What is the heat and light value of
sunshine received during December f
Make use of the skiameter, and

Consider :

(a) The area covered by a given beam of

noon sunshine.
(b) The slant of the beam at the solstice.
(c) The heat and light value compared

with that on corresponding dates of
previous months.
(d) The relative value of the noon sunshine

on the parallels 0°, 20°, 40°, 60°, 80°
north latitude.
(e) The causes which modify the direct

value of the sunshine at three differ-
ent places.
NUMBEE WOEK.
1. Compare the area covered by a given
beam at the solstice with that covered by the
same beam on corresponding dates in the pre-
vious months studied.
2. What is the ratio of the area covered by.
THE GEAMMAR GEADES. 171

a given beam at your place of observation at
the solstice to the area covered by the same
beam at St. Petersburg ? at London ? at Chica-
go? at New Orleans ? Mexico? Quito?

3. Find the area covered by a given beam of
noon sunshine at different points on the most
southerly zero isotherm for the month; the
most southerly 32° isotherm for the month.
4. The quantity of noon sunshine which
covered a 10-acre wheatfield on September 23d,
north latitude 45°, now covers how much
ground?

5. Compare the heat and light intensity of
noon sunshine at the various places mentioned
in (2) for each of the months studied.
