Sacramento daily record-union., 1882-01-19
DEBRIS.
roRrY-FIFrH DAY OF THE sLIcKENs
CASE IN COURT.
Interesting Testimony by Prof. Davidson
Concerning the Bay Of San Francisco
and the Wearing Away Of Soil
by Action of Water.

The trial of the case of the People vs. The
| Gold Run Ditch and Mining Company was
resumed in the Superior Court yesterday,
Judge jackson Temple presiding.
Witness Lewis, on cross-examination, was
examined at length by Mr.. Oadwalader rela.
tive to the creeks between San Francisco and
San Jose-Alameda creek, Los Gatos creek
and others.
Professor George Davidson sworn for
defense Ito Mr.. Wilson Am Assistant
United States Engineer of the United States
Coast Survey and Geodetic Survey, and
have been in that service since 1S45. Came
to California in 1850. Early studied
the harbor formations, and deposits from
rivers, and the Instructions to navigation,
etc., as part of my duty. Made the sub
ject of irrigation study, as United States
Commissioner appointed BY the President.
for the San joaquin, Sacramento and Tulare
valleys, from Shasta in the north, to San
Miguel in the south. In that duty he ex-
amined works of irrigation in Japan, China,
India, Italy, and other parts Of Europe.
Was in Japan in 1874, to observe the transit
of Venus, and after that examined into the
subject of IRRIGATION there. In connection
with the State HARDER Commission, was one of
the Advisory Commissioners to examine the
harbor of San Francisco. Have inspected
jacent to San Francisco, the Golden
Gate, the heads to the Farallones,
and San Pablo bay. In the ofice
OF the United States Coast Survey
are all the maps of surveys, while
copies of many are in the subj flee at San
Francisco, and are the basis of constant &C.
tion by the officials. The earliest maps of
the bar we have are, think, of 1855. Willis
work is dated 1841. but our work dates from
1854 and down to 1873. Know Beechy's
map of 1928 (of the English Admiralty
and have studied it and consulted it relative
to the harbor of San Francisco and entrance
to the Columbia river. That chart has been
used by the English up to recent years
seven or eight years ago. Know the officers
of the ironclad ship Jealous of her Majesty's
service used it, and she draws twenty-seveu
to twenty mine feet of water. This map
(showing) appears to be copy of it. The
Jealous came into and went out of the harbor
by that chart. Witness identified copy of
the charts of the bar in 1855 and 1874, be,
fore referred to- Both are coast surrey maps.
Superintended all the details of the work for
the chart of 1855. The witness examined the
charts again, and explained how he had de-
tailed knowledge of them and CT the surveys
on the bar from 1855 to 1873, and says there
has been no change of depth on the San
Francisco bar since 1856. The survey of
1873 developed the existence Of living shells
on the bar of San Francisco, which must live
on the surface of the bottom, and which
il covered with deposits, must die. One of
ha ut the formation Of tho har
of San Francisco is the moving of the sand
along the southern coast line moving to the
north another is the material carried by the
waters moving down the channel with the
tide. A great stream runs down the coast,
but along shore is narrow eddy current,
working along the whole Califorria and Ore
gon coast northward. 1t is shown by the
action on the southern sides of the points,
and the sands moved on to them. The sur
plus drainage of the waters of California into
the bay presses these sands in this eddy eff
shore, and hence the bar. II this surplus did
not exist the sands would form close in, and
soon close up the entrance to the Golden
Gate. The first movement of this surplus
and its material, is TO shoot out over the bar
but the final movement is to the north.
The amount Ct tide water going out of the
harbor, reinforced by the drainage into the
bay, tends to push all material off into the
out than comes in. The tidal prism coming
into the bay is over 400 square miles, at an ay-
erage of 6.10 feet. That is the average rise
and fall of the tide. The tides are peculiar
on this coast-a large and small high, and
large and small low tide. This action is favor.
able to the pushing of the bar out and the in
crease of the depth. Compared with the
channels of other hsrbors, that over the bar
of San Francisco is all channei-vessels come
In tha off Of ba CT
survey there are charts of the survey Of San
Pablo bay, three in number. We have the
-tracinSs cf two here. One of part of the bay,
and one of Ell OF the bay. Oae was made in
1868 and one in 1889. The surveys subse-
quent to the first were made to see il any
changes had occurred in the channel for nav
igation. A vessel can take the same depth of
water in the places of the survey of 1859
that she could in 1856 and 1868, but she would
have narrower channel-way. OFF Point
Pinols the deepest water in 1886 aud 1868 was
33 feet, and in 1873 o, 80 feet. The charts do
not show there ever was IL fathoms off Point
Pinole. The material coming into San
Pablo bay must come from the streams
emptying into it-Petaluma, Sonoms, Napa,
San Pablo and other creeks and all streams
that empty through Carquinez straits. Know
the Mare Island straits, and have since 1857
known them. Examined them to see if any
deposits had been ma1e. Found deposits
had been made on the fats wherever strucs-
ures had been carried out or wharves
or vessels and hulks moored in one. place fer
long time. Napa creek, l think, sent in
most of the material that aided in the filing
in at Mare Island straits. Have not so much
kno Wedge Of Suisun bay as of the others.
The streams to furnish material to Suisun
bay are Montezuma slough on the north,
two or three streams on the south, Suisun
creek on the north, and finally the two main
rivers. The width Of CaiquineZ straits at
the upper end--the beginning of Suisun bay
lie, generally speaking, about haf mile,
and is very narrow compared to the expanse
of water either side of the strait, which is
narrow neck, with high lands on either side.
l measured the square feet in the straits (rot
for this case) recently, and found 2O9.-
600 square feet (taken by cross sectieD)
Suisun bay, on account of the
character of the straits, is really
settling reservoir for all the heavy material
brought TO it by the streams enptying into it,
and new lands should be made more rapidly
row entrance is a throttling of the great
channel-way to the ocean. High water.tides
act as barrier to the water coming down,
and as the current is retarded deposition
takes place more rapidly in Suisun bay.
The acts of man aid these processes by the
cultivation OF the sill, the denudation of
lands of trees, the placing of animals to tread
up the ground. by mining, and in any other
way Of disturbing the soil and all tend
to accelerate the action of nature !;
accelerate the action of streams, and the
movement Of soil into the streams.
Great forest fires expose the soil largely,
and aid the movement of the soil under rains
and other waters, toward the streams. The
drier the soil. the thicker the underground,
then the greater the fire effects, as it is car
| ried by the roots deeper into the soil.
Wherever the soil is exposed, and washed
away from a rock by the act of man, the more
likely is that rock to move, and the more
| easily does that active agent. frost, operate.
As soon as the earth's soil is moved the rains
| act on the lighter matter, and the heavier is
left. which requires heavier waters and longer
periods to move. San Diego river, which 1
| have known Familiarity since 1851, and where
| little artificial action beyond grazing formerly
went on, has brought down great quantities
of material. In the Los Angeles plains, we
see the effect of material coming down
| rivers and changing their courses, as in
| the cases, too, of the San Pedro and San
Gabriel. SO we have the instance of the Pa-
| checo creek, where a very large deposit has
been carried down by reason of the tilling of
the soil. This deposition that / saw was
over six feet in recent years; and ! saw
fences covered up by the sediment, and new