The morning news. [volume] (Savannah, Ga.) 1887-1900, 1893-08-20


ed such a state. material Of the same nature
may De- built upon lt with the same slope. Tor
hundreds Of feet without disturbing the base
upon which 10 rests. ANY material left 20
itself VIII assume such q slope in the course
ot tifuc-u FIRST by precipitation from ITS top
ana upper portions OF itself 20 its base; ana
second. 0y pressing up from its oaso-n such
base Is not solid one-other ma terial. until
10 has obtained its repOse, then IL becomes
inert or az q state OF rest.
sHRINNAGE OF ADJACENT SWAMP LAND.
Another factor entering into this calcula-
tion and which has 20 be taken into consider
alton is the general settlement OF the surface
OF the swamp land al accent to the cut on both
sides after drainage, That this settlement
has occurred in the present instance is true;
and IN order TO determine accurately the
amount of shrinkage IL would require several
weeks leveling, which expense, under the
circumstances, l thought unnecessary, as 1
could determine approximately what the gen
eral settlement was by comparison OF my
levels taken recently with those taken by
| your county engineer before the work of eX-
cavation had commenced. The amount l find
| to be inches.
Instances Of the settlement Of the surface
| of SwampS after drainage are numerous. Geo.
! r. Waring in his book on Drainage. states:
| In the drainage of peat lands, whether large
| or small, great allowance must be made for
| the shrinkage of the material as the water is
| WlJhdraWn. In one case IN nv own practlce
| the drainage of peat swamp to depth OF D
| feet left the surface year later less than
| foot above the surface of the water, or a
! shrinkage of feet"
The material at Cuyler swamp is of a some
| what similar nature, but will not shrink as
| much as peat soil
| CONDITION OF CANAL BED AT MERIDIAN
ROAD BRIDGE.
| would call your attention to the condition
| of the bed of the canal at the Meridian cross
! road bridge. The excavation, am informed,
| has been completed at this point about six
! months. and you can readily see where the
| weight of material contained in the abut-
| ments to the bridge has forced the soil to
| oOZe up from the bottom underneath the YER
| teal Sheathing and in from the sides. In this
| case the filling amounts to 1.5 on each side of
| the cut and about in the center, an average
| of about 40 per cent.
| REMOVAL OF DEPOSIT FROM COUNTY CANALS
AND DITCHEs.
| Your county trunks and bitches are cleared
! once or twice year OF silt and other material
| to an average depth of foot, deposited there
| by bank pressure, wash-in, and the trampling
| in of the sides by CATTLE
METHOD OF MEASUREMENT.
| The following is the method adopted by
| me in measuring the excavation of the Casey
| canal. 1 divided the entire length of the cut
| made into sections on the curves those sec
| lions were p feet, and on the tangentS 80 and
| 100feet in length, The elevation of the banks
| or surface level Of the swamps was taken on
| both banks,-four elevations to each section.
Elevations of depths we're taken six times to
! the section. and the width of cut was taken
| in three places. The mean of those measure
| ments was then taken and used in computing
| the cubical contents.
The grapple Of the dredge is suspended
| from a chain and when dropped falls perpen-
dicularly, hence the sides of the cut at the
| time of dredging were originally left approx
| mately vertical; that they are not in that CON
! dition now is evident from causes heretofore
| mentioned.
The depth measured at the center of the
| cut is more nearly correct for the entire
| width OF the cut dredged than any depths
| measured near what had been the vertical
| fall of the Sides and which, when now made,
.N,1~F vaFN1 g,raN
| The dredge could not have excavated on a
| slope, and would noturally have dug the cut
| approximately uniform throughout its width.
| The engineer having been instructed to
| dredge the cut to depth of B feet mark
| was placed on the grapple when open and
| lying at rest in the bottom of the cut, indi-
eating this depth.
An approximate estimate of what should
have been removed, according to the plans
and grades in the distance covered by the
dredge, is "a 600 cubic yards.
NV measurements of the dump-pile the
side Of the cut show l6,l279 cubic yards now
there: to this must be added 20 per cent for
shrinkage and settlement and 10 per cent, of
the amount first deposited in the dump-ptle
for wash-away by heavy rains. Sixteen thou
fand, one hundred and twenty-seven and nine
tenths Q6l27.9) cubic yards represent 7-l0 of
the amount deposited by the dredge. One
tenth G-l0) is II of this amout and 20 per
cent or 2-10, is 4607.8 cubic cards, making a
total OF 2o735.7 cubic yards. Ten lO) per
! cent of this-2 0T3.5 cubic yards,-is to be
of 2,S09.2 cubic yards removed.
| On the assumption that the center average
depth measurement is more nearly correct
for the mean width throughout the entire
length of cut at the time of dredging than the
average depths and widths at each section al
several places, the amount removed is 10, 62t
cubic yards. To this must be added /, Ia
cubic yards for a 3-inch shrinkage of the
swamp surface contiguous to the cut also
an average of 6inch deposit throughout the
entire length and width, which amounts tc
| a of nF
! cubic yards removed.
Taking the average depths and widths of
each section throughout the entire length OF
the cut, find total OF lS,3267 cubic yards.
| For a deposit of an average of 8 inches
| throughout the entire length of each section
there have to be added 3444.l cubic yards
also for 3-inch shrinkage of the surface of
the swamp, l. 1870 cubic yards. making a total
Of 2,9lS.7 cubic yards removed.
From the above results L would respect
fully state that as near can be determined
the amount of material removed by the
dredge in the time specified. viz. from be
| ginning of operations to July 1, 1898, was g.
9293 cubic yards. Respectfully submitted
X. S BURNETT, G. e
| Through Major r. A. Blandford engineer
Chatham county, court house, Savannah.
MAI. BLANDFoRD's STATEMENT.
Savannah, Ca, Aug. 19-To the Honorable
| Commissioners of Chatham county Georgia:
| conference.-the able report of Mr.. R. S Bur
| nett, consulting engineer clearly and forcibly
| explains to your honorable body the nature
| Vi tA6 material lnb CONDITION OF the Work,
| and the result of his measurements of the
| excavation made by the steam dredge in the
| new Casey canal
| can add nothing to this valuable paper
| but will briefly state that in making my esti-
mates of the cost per cubic yard of the ma
| terial eXcavated by the dredge, / have been
! conservative in the quantities measured from
time to time that the results of my estimates
| might be upon a strictly sound basis. Re
| spectfuliy submittsd,
| r. A BLANDFORD,
! County Engineer.
UMBRELLA DRUMMER'S FATE.
He is Said to be Dangerously Ill at
| Plant CitV.