Henry C. Adams
Capitolo 20
indeed, the tide turned in front of the tide.
Whence of wind they are only movements of the surface of the water, and
doesn't extend for a greater depth under the trough of generally
the wave that the crest is above it, but how they can strike the
movement of the afloat particles of sewage to a considerable
extension is necessary to record the direction and strength of
the wind.
The strength of the wind is suitable wind to sometimes the
time to make some observations of the tide. From reference to the
Beaufort Scale that it is a graduated classification he/she adopted from
Admiral Beaufort around the year 1805. The following table gives
the general description, the speed and pressure of the wind
corresponding to the tabular numbers on the staircase:--
[The illustration: the Flat III
PERIOD OF SIX MONTHS.
To face page 20]
The figures that point out the pressure of the wind in the
preceding table is low comparative with those determined by other
authority. From the formula of Meat of ram, the pressure against a
normal plain surface to the wind 0.97 lbs would be for sq. foot,
with a middle speed of 15 miles for now (22 fts for according to.),
comparative with o.67 lb given by Admiral Beaufort, and for a
the speed of 50 miles for now (73.3 fts for according to.) 10.75 lbs,
comparative with the formula of 7.7lb Semitones that frequently it is
used, it gives the pressure as 0.005V^2 (miles for now), so that
for 15 miles for now the speed the pressure would be 1.125 lbs,
and for 50 miles it would be l2.5 lb that must not have forgotten,
however, that, even if on one period of of a times the wind is able
_average_ this speed or pressure, will vary notably
from moment moment, being far in excess to a duration, and
practically calm to another. The speed of the wind is
usually taken by an anemometer of cup that has four 9 in cups on arm
2 long fts. The factor to reduce the records varies from 2 to
3, according to the attrition and lubrication the middle being
2.2.
The pressure is gotten multiplying the number of Beaufort
raised to the cube within 0.0105; and speed is found multiplying the