The New York herald., 1878-12-16
VALUABLE TO NAVIGATORS.

HOW SHIPS POSITION MAY BE DETERMINED
OFF SANDY HOOK TO GEORGES BANKS BY sE-
GUINE's TEMPERATURES CHART
New YORK, Dec. s. 1873.
To THE EDITOR OF THE HERALD
During the summer months the heavy fogs that
prevail on the North Atlantic. and particularly on
that part of it lying north of the Gulf Stream and
extending from the Banks of Newfoundland to Sandy
Hook embracing within its limits uncertain currents
and dangerous shoals occasion the navigator no little
anxiety. The captains of steamships especially ply
ing between Europe and our Northern ports, and
who to satisfy the demand for quick passages must
make delay. have their judgment. skill and
durance often put to a severe test. The large num-
ber Of steamers passing over this dangerous
route, bound east and west, and the compare
lively few accidents by collision or strand
ing. is the best evidence OF the watchfulness.
skill and of their officers. Notwithstanding
all their care however, occasionally the captain finds
his ship among the dangerous breakers Georges
Banks Nantucket Shoals with the sand boiling up
around her. peril from which only thorough
man can extricate his ship At such time. when
made aware of his true position, he is surprised TO
find himself perhaps fifty miles north of his supposed
course; and in one notable instance the steamship
City of Washington was wrecked ut least $50 miles
north of her proper course But would he not have
kept his ship aoat il the lead had been used? asked
Perhaps he would. don't know that the lead
not used 1t is true that the soundings would have
warned him of his dangerous proximity to the bottom
but he had lost his way, and consequently
knew not in which direction to turn his
bow And even had no sheered off and
avoided the particular place where his ship was
wrecked he would have gone on and no doubt have
her ashore somewhere else. for soundings
would have convinced him he far off his course.
If remember rightly few years ago the captain OF
of the Liverpool steamers finding himself among
breakers, and thinking that his only safety lay in
sheerng off to the southwark. did and his ship
plump upon the shoals of the east end Of Sable Island
from which he extricated her only by the greatest
good fortune. leaving behind him officer and boats
crew. who had gone to the island for assistance. On
another occasion this captain would have run
his ship ashore Nantucket Shoals had not the fog
provdentally lifted disclosing to his astonshed gaze
the light Sanckety Head. And very recently the
steamer Scilian less than twenty -four ont from
New York ashore Nantucket Shoals. fortunately
escaping with only bad leak. which necessitated her
return port Many other instances Of escape
from shipwrcck could be mentioned, were il neces-
sary to prove that with all the admitted good judg
ment, skill and of the officers of steamships.
they often find themselves far asray in their latitude
during thick weather. when observations cannot be
had. In view Of these facts it is obvious that any
thing by which the latitude may be determined within
ten miles, without slowing the speed Of the ship. is
of great importance. This am confident is possible
along the route from Sable Island to Nantucket IA
very dangerous part, where, during the summer
months, heavy fogs are prevalent. My observa-
tions have extended no further than this
SURFACE WATER TEMPERATURE CHART.
The water reaches its highest temperature about
the middle of August for which time the chart is
marked For each month before and after substract
as follows May. six degrees; June. five degrees;
maximum 18th Of August; September, one degree;
October, three degrees, and November six degrees.
The symbol U denotes tide rips. where the tempera-
ture varies from to two degrees.
LATITUDE