difadvantagés : oür coaft -is not qttlÿ extended' greatly in prpportion
to the area o f 5 land, but it has many promontories jutting'out on
each’ fide/'which neceffarily make-deep bays,'and unhappily^ augment
the diftreffes „of failors in ftormy weather^ another '.inConve--
nience o£ our Sea-fituation is, that thç laricTfooptingout fharp like
a wedge into the Atlantic Ocean, fhips oftentimes miftake one
channef fdr another, or are drawn afide from their, tm^ copfe.'by;
the inequality of the tides. Farther : TKe irregularity of ^ vvtides
fifing ffornrthe prominency of the 'head-lands, is alfo inèreàfed, ät
the extremity of Cornwall, by 'the -Scilly ïfles, :which narrow .the’
chanulh (whether the’tide fets to thte/forth,. or theSouth}-; sind cofT/
fequently, increafing the velocity of the current, promote a more
than ordinary indraught into both channels. The tide ofoftood at
the Land’s End riles on the top of a common fpring eighteen feet,'
and. from that t o twenty-four, according- t o wind andSweafher ;
infomuch, that in ftormy weather, from • the- South-Woft, • it has
rifen to toe height o f thirty feet;’ but at the commoj^tepp tides
only thirteen fe e tüfually, and at a very dead-neap -it has. not rifen
above ten feet; Düring the flood, the tide „àt .the.LandjS End
fete inward from* the South near nme hours; its•fG^feV'ejght
hours in moft places betwixt Scilly and the Lahd-sÆna; but the
ebb^continues only betwixt three and four hours, '^hist^s B^ery^
dangerous Angularity, if not known, and -properl-yiregàfdêd ; hùt
the greateft difficulty of all, which ôür maritime'fitoatiqn;.lie^widbra
is this; that an accurate furvey of our fhores, and a pr.ecil'eÿ&eteàj^
mixiation o f our latitude and longitude, has never yet- be„en ~taken',''
not fb much as of the Lizherd, the firft-land ufually iftäde by fhips’
homeward bound, and the Southernmoft pointiPôfe-England, from
which moft fhips outward-bound to tbefS&uthWafd’ begin their
reckoning : here a falfe ftep is made at firft’fetting out, and unlefs
rectified by repeated, obfervations, it may be of-fatal confequence.
T o have the longitude and latitude afcertained at the extremity of
the iff and where fhips begin and end their-reckonings, is certainly a
matter of the greateft. moment to .commerce', and fhould • be .performed
by a variety of the beft inftruments, at fubfequent times, and by-
more than on& fkilful hand. This has never yet been donc$/jfee~'
before, chap, i.) nor will be probably, but by the interpöfition of
the government, whofe attention and nomination of proper perlons,
and provifion of a-fofficient apparatus of aftronomical inftruments,
(an expence feldom within the reach of a private purfe) this matter,
I fpeak it with fubmiffion, feems to me exceedingly to deferve.
Another circumftance claims the attention of our countrymen ;
our harbours are gençrally at the mouths of rivers, and not very
diftant from the hills where they rife, and of courfe not fo long of
deep
deep as where the rivers and creeks run farther up into the land :
they are thererore more apt to be choaked with fends and rubbifh
than in other fituations. Too much care therefore cannot be taken
that/kps décharge not thdr balkft in improper places, fo as to obmany
intelligent
affedt-Qufi Stea-coaft^-rri' time
whe^i -a .remedy-;may nj/ cafily’bôÿ fourid^ out; i ■ The-higheft'1 tide5
iri equal d r ^ m fW è ^ a b q u é t y a days-aritf a h â f cfeati after the
.^ncp- md full moon, The^.tid^lhter than at* LondomBridge one
fifiy-ifo^jmihntesiii The variation dfe the needle; ét the
Land s Endhasjfor fopafyear^ beer| rckoneriabqve, eighteen degrees
Wefterly;| but in,the,month ofQcftober, Houfe,
op a one pf-the branches e^Fahn^itfo’ Harbour, l’t.vras^hyj.a ,nepdle of
ten inches and hall" Iq-ng^ found^tofiet nirtSfeen^dégreesé'Shelve minutes
Wefteriy.., Dr. Haftey % in .jh ^ y e a R j fc f f o ® it to be no
piqre., tiian feven degrees and a h a lf -Wefterly /^-/whether Ifo/
a been regular and gradual; fqfwant qf a],continued fériés*
'^(gt obfervaftions, I cannot determine. .. )i (
-in^Such’^S| the common, ordinary ftate q&our Sea in Cornwklf -as
to tides, ^creeks,'harbours, .ancf rpharfsi; but indeed, the tides- are
greatly accelerated of retarded, nofe only.fiÿ- the, prqjeriSoïi - o f fo
many'head-lands, the depths of bays^ and creeks, „and the indraught
^ orth ana SoüthChlftnels,^ But’Dy'jdSferenf winds,’aruf yet
^ - d i r r i i y phc^fioim^ncijn which hé^f^^{appeared on
thefe (Coafts, as far as I can learn, proceqdecffrom neither- ; GfÇ|thefe;,;
-caufes. On ‘the rft o f November, 1^55, abqut two o’clock in. the
afternoon, the Barometer being at,the higheftl have noted it for three
years paft, Farenheit’s Mercurial Thermometer a t54, the fane pointing
to.the Nprth-Eaft in a flat calm, : thé Sea,, about, half an hour
ajjter, ebb, was obferved, at the pier o f St. ^fichael’s Mount, to7 rife
fuddenly, and then to retire. „ This attrariedrihe attention of the
fpeéfatórs,, and to their great amazement, ten. miriufès* after, the
•%a rofe near fix feet,,,coming in from the Sodth-Eaft extremely
rapid ; it then ebbed away with-the fame rapidity to tiidWeftward
for about ten minutes, till it .was* near fix f|éido\yeï* thamBefore ; 4-
it then returned again; and fell again in the-feipe’ fpag/of time, and’
continued the agitation; ialternately riling., and falling^ each ’retrear'
an<^ advance nearly of the fpace of ten minutes, tih^fiv/hours and
a half-after it began. During' this,agitation,.the Seyn-boats, riding,
aV - o € ^ ^ B l . s l d e r , were whirled fomê.oii^way;' fome an-'
other ; and the flfoermen endeavouring tt>r^ing feme boats into the
pier, they were hurried in and duf qf the mouth’ of the pier,,as, the/
y * Letter to the autlior from Mr. Charles Heydori, Math, joftrumçnt-maker, Oftpber 3, 1754,
P * Sea'