The Dorset County Express and Agricultural Gazette.
Dorchester, Dorset, England, 1880-12-21 00:00:00

DYNANIITR FOR THR HARBOUR BAR.

Some of the members of the Town Council being of
opinion the grab dredger cannot take up the hard stuff
on the Harbour Bar, experiment* have been made
with dynamite. Tome were conduct., 1 on Tuesday
morning last, by Mr. Benjamin Read, Portland arrant
for Nobel's Rxplosives Company, limited (formerly the
British Dynamite Company), the diver, Mr. Carter,
and apparatus being providod by Messrs. Comes and
C. 0., limited. While the diver was below, twelstrioli
the holes for depositing the cartridges, Mr. Ben. Read
distributed a pamphlet with extract. from the Blue
Book, for the recipients to read, si a• to remove any
fears thas. might be lelt as to the nature of the
explosive. Persons standing on the pier were favoured
thus, as well m tholes:Wally engaged about the experi-
ment. Mr. Read also placed a cart:idge in his hand,
I ignited, and showed how it burot away slowly. until it
reached hie fingers, wbeu he threw the remainder into
the water. He forth.* rxplained that he could throw
It against • wall without 'sager, and that the very
cartridge which he was hurling he could cut in half,
and the unborn% half couid be exploded with doe
effect. Several membenof the T.rvra Council were on the
pier; but the only councillor near, except Sir.kyle",
who was assisting the l,,roudi surveyor, Mr. Morgan,
was Mr. Curtis, who, we n -told, with due precaution,
withdrew before the lighting of the fame. The experi-
ment was made with cartridges about four inches in
diameter, and seven or eight inches long, and stated to
contain about 41b. of the explosive; these were placed
In water-tight bags, with fuses and lanyards, the end@
floating en the top of the water, with little red fl ige
attached, so that in cram either cartridge should not
explode, it could he pulled in by the cord, and nothing
be left to endanger • ship. The cartridges were
exploded by percussion caps inserted in the
fuse, and within the water - tight hag. The
diver's operations were completed after about
two hours' labour, during which he had
examined the bottom, and sunk two holm in the
clay found there; them were respectively 2 feet and
15 inches deep, and in these holm the cartridge* were
placed. Several boats were near with spectators
watching operatisna ; hut them were new requested to
withdraw before the cartridges were fired. Owing to
the surging of the boats, and the "slops," the fuses
had become wet, audit was necessary to cut the ends,
and am it was necessary the charges should be fired at
the same instance, one was held by Mr. Bead, the
operator, and the other by Mr. Morgan, assisted by
Mr. Ayes.. At this point we noticed the agility of
the men in the boats, who got out of the way as quickly
,asif • ratsmollector had been after their heels. Mr.
, Read, however, informed them it would take five
: minutes before the explosion could take place, and this
ufgwal2 feet or 13 feet In
t
31:fre't oved c°rAit ifeneettthhaboeafvmusemeothunsi'desoinrface ; but this was so
sodden that only attentive leokers-on caught the
appearance. The shock, however, was distinctly felt
on the pier. The diver then went down again, and
after examination reported that the explorioos had
made two holes in the clay, forcing it outwards, in
hollows about 9 feet diameter, and 3 feet underneath
the level of the ordinary surface, and had raised about
a foot high around the holes. The nature of the
harbour bottom was clay with streaks of sand, in
the part blasted, and, no doubt, says an operator,
the dynamite gas had forced its way into the
streaks of sand, and lifted them,,., The cartridges
were fixed on the south side of the harbour bar, out of
the main channel, it being feared lest a mound would
be created by the explosion. Mr. Read considers the
experiments very successful, and no doubt the success
will be still more marked when the dynamite is tried
against the boulders which are found near the Harbour
Bar. As illustrating the effect on fish. it MA noted
that a considerable number of smelts were thrown to
the surface after the explosion, and many were picked
up alive.