The daily union. [volume] (Washington [D.C.]) 1845-1857, 1851-05-11

the keeper TO the TOP OF the house. and extending 300
feet northwest, or In direction directly Al right angles
the direction OF the sea- northeast had most Injurious
tendency, and that il was enough in ITSELF the
overthrow OF the light house. had the not reached the
body OF the structure II Is easy 10 perceive that the
inches must have been immense when that rope was
attached 10 the weakest part OF the building 10. the
lantern deck, 80 feet above the rock.
Since the destruction OF the Minot the question has
been several times asked, the structure built upon
principles, and such light house be made TO
stand there The answer. in my opinion, is this: The
base OF stone structure al that exposed situation should
not be less than has been adopted for the principal
on the coast of Great Baiian. The Bell Rock CARING
ford Skeryvore, and Menai, have base Of 40 feet the
least 10 AS The greatest The Eidystone Rock aboa, SO
feet low. line and the diameter Of the tower at
| high water line, 10 feet above is 70 feet.
AT the Mnot, circle OF 26 feet diameter AT low
water cannot be had There is not. fact much space
| 10 be had at low water the diameter Of the tower
should be at high water, while between the two tides
there is height OF 10 feet to be provided for
Without any reference 10 the cost OF stone structure
venture the opinion, after the experience had there that
be made to stand. even constructed upon
The principle OF the Ediys,one for II rs 10 be Iemem
bered that while the Eddystone Rock is bare at high
water spring tides, the Mlno is barely uncovered the
diameter OF % ieet at low water spring tdes Daring
the first sessions operations there, si7 from July 10
October three months, sixty hours was all the time that
the men could work upon the rock aud this under the
Eye OF most vigilant and energetic contractor, employed
TO drill the holes in the rock.
i A similar in lis general characteristics to the
iron pile light is alone suited TO the locaty,hat is to
| force OF the wave.
i The experiments of Mr. Stevenson at the Skerryyore
have established that the maximum force OF the
gale Of wind. determined by dynamometer, is about
5000 pounds per square foot or about AZ pounds per
square ncha pressure nearly double that exeTed upon
the piston OF an ordinary condenslng steam,engne
base OF larger than that afforded at The Mnot is
qLisle 10 resist such pressures as these The must
be allowed free passage, or there must be sufficient
weight in the tower 10 counterva the effect O the
To provide the necessary amount OF weight requires
base of large unless the tower be carried 10
due height.
BY suppressing the room, additional space oil
feet could be mad for The passage OF the IN gale OF
passed through; but conceive that greater heigh,
could safely be given TO the light house than that adopted
for the structure which put up theIesay So feet for
the top of the piles above the rock. the base being limited
space admitted should certainly have used il TO the ex
tent OF 80 40 feet The had been up three
winters, and but Tor this unpect dened gale would still
be up believe. The principle OF the iron pile ligh,
requires the solid part OF the building to be kept above
the reach of the So long this the case the
Nno resisted the storms and there several of great
violence within lis time but when The did reach the
keepers house, oil course destroy ed the entire fabric
Finally, the Mlno light had all The base that the rock
afforded; it had all the height that could saiey be given
to such base Spring tides rise there about Is eeI
cordng to the observations made by the coast survey
THIS left space between tie top OF high and the
bottom OF the Of IS feet for the unobs,ruced
passage of the notwithstanding this, the did
reach above this line, and the result is loo well known
enclose herewith report OF Mr. Dennson--a 81 etch
representing the present appearance OF the sumps of the
nine piles, varying IN length from inches to 10 feeand
the newspaper article which have referred in the body
of This report
I have the honor to be your obedent servant
w. n. SWIFT, Agent for IT, s.
Colonel J. j. ALERT. Chief Typographical Engineer
Washington