Page 101 - 1915, Springs of CA.

HOT SPRINGS. 95
other radicles, it indicates probable contact with magnesium-rich
rocks. As its name implies, the Arsenic Spring contains an exception-
ally large proportion of arsenic and its content of aluminum is also
uncommon for an alkaline water. All the springs contain iron in
unusual proportion.
Shale that dips at steep angles is exposed on the hillsides near
Harbin Springs, but about 25 yards above the springs a belt of
amphibolite schist appears. Its observed thickness is about 25 yards
and its lower side apparently crosses the ravine very near the point
at which the springs emerge. As the high tilting of the sediments
is the only other geologic feature noticed that might account for the
springs at this place, it appears probable that the schist at least
furnishes a point of escape for deep waters, and it possibly also aids
in giving the water its abnormal temperature. The conditions pre-
sented by this rock cutting through the sediments just above the
springs may be similar to those at Mercey Hot Springs, in Fresno
County. (See p. 78.)

HOWARD SPRINGS (LAKE 51).
About 9 miles southwest of the town of Lower Lake a group of
mineral springs (PL VI, C, p. 92), several of which are notably warm,
issue in a line about 50 yards long at the base of a slope that borders
the south side of a drainage course. A number of seepages have been
dug out and cemented to form drinking basins, so that about 26
improved springs may be counted, although the group is said to
include 42 springs. Of the 8 springs that are of chief importance 5
are used for drinking and have been named Bohemia, Neptune,
Lithia, and Magnesia Twins. They have observed temperatures,
respectively, of 66°, 70°, 73°, 71 °, and 100°. When the writer visited
it in 1909, Bohemia Spring discharged about 1 gallon a minute,
while the other three rose in basins from which there was no appreci-
able overflow. The largest three springs are used mainly for bathing.
Of these, the Hot Soda or Hot Sulphur Spring has a temperature of
110° and discharges approximately 125 gallons a minute into a plunge
bath. Excelsior or Borax Spring, with a temperature of 95° and a
flow of perhaps 5 gallons a minute, also supplies a plunge bath.
Water from Eureka Spring is piped to tub baths, its temperature
being 107° and its yield perhaps 2 gallons a minute. The available
analyses of several of the springs are here given in form convenient
for comparison. 1
i The analyses of Lithia Spring and Bohemia Spring, published in advertising matter, have not been
reproduced, as they appear to be incorrectly stated.