The fine sand from the first series of subsidences is placed in a
separate vessel, the washings are allowed to remain undisturbed for
twelve hours, the turbid liquid decanted and the sediment returned to
the cylinder. Water is then added to the mark, the whole shaken, and the
liquid drawn off at intervals of five minutes, as in the first series.
The sediment from this operation is placed in a separate beaker, the
washings returned to the cylinder, and again allowed to subside as
before; the sediment from this second subsidence is added to that from
the preceding operation, and the washings again returned to the
cylinder, the operation being repeated as long as any sediment can be
obtained from renewed treatment of the washings; the final washings are
then placed in a separate vessel for subsequent microscopic
measurements.
The collective sediments from the last series of operations are then
returned to the cylinder and allowed to subside with fresh additions of
water, as in the case of the first series; the fine sand thus obtained
being added to that from the first series, and the washings being
collected in a large beaker. The latter are left at rest for twelve
hours, and the sediment returned to the cylinder and treated as before
until no further separation can be effected. The fine sand resulting
from all of these operations is then dried, ignited and weighed; the
weight of the portion removed by the washing being determined by
difference, as it is, owing to its excessively slow rate of subsidence,
found impracticable to collect it for direct weighing. The size of the
particles of fine sand is then determined by micrometric measurement.
Similar measurements are made on the material obtained by long
subsidence from the washings from the foregoing operations. The average
diameter of the largest particles should not exceed 0.01 millimeter.
=204. Statement of Results.=—The results of the analyses on three soils
from the localities indicated in the table, and the method of stating
them, are given in the following table:
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Elsewhere in the archive
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account