Evening public ledger. [volume] (Philadelphia [Pa.]) 1914-1942, 1922-05-30
oIspIsased by Zander. .0ump Verdict
Philadelphia, May 90, 1922.
Mathematical and Nautical


Sir--I wish to call your attention to
quiz in last Tuesdays EVENING PuP-
LILO LEDGER. May 1G. under the head
Ing "What Do You Know?". Quiz
In travelling westward around the
world is a day lost or gained?" Under
Answers to Yesterdays Quiz print
cd in the edition of Wednesday, May
II. is the following:
In travelling westward around the world
line. the Tooth meridian near the middle Of
the Pacific Ocean.
Here ] wish to offer correction.
First. The day Is lost and not gained.
Second. The international date line
theoretically comedies with the 1SOth
meridian, and not the Tooth meridian,
as your answer states.
The date line Is purely an arbitrary
line and is not officially accepted by
any government, but its adoption has
been for purposes Of .practicability. Il
starts at the North Pole. passing through
Bering Strait. then slants to the west
70 clear the projection of the Aleutian
Islands and give them the same day as
the United States.
II then returns to the 1S0th meridian
and drops south irto the tropics. keep
Ing fRr TO the eastern Of the japanese
Archipelago and the Philippines, until,
soaring the latitude of the Fiji Islands,
1t makes another swerve to the eastern.
SC as not to conflict with the date in
Australia and the adjacent islands Of
Australasia.
1t at no time comes in close prox-
Unity to either Of the Tooth meridians,
east or west. Consult any reliable at.
las and you will see.)
The navigators' date line Is the 1SOth
In nf n
Pacific Ocean and exactly twelve hours
from Greenwich.
ship sailing westward lengthens it's
day BY one hour for every fifteen de-
srees Of longitude moving with the sun,
und by II certain amount corresponding
to the difference of longitude made
good BY the ships run, equivalent to
four minutes OF time for every degree it
steams. and by going westward entirely
around the earth will have lost one
day at the arrival at the starting point.
To this navigator the second of the
month would be the first, or Monday,
Sunday.
This is evident. since by going around
ing westward. our ship has in respect
to itself diminished by one the number
Of revolutions made BY the earth during
this time. (Remember. opposite direc-
tlon to the earth's rotation.)
Steaming to the eastern. the reverse
tskes place and our ship gains one day.
making one more revolution than the
earth does. (Same direction as the
earth's rotation.)
Now, let US get down to brass
tacks."
4 ship sailing westward through Sat
urday. May 90, 1929, finds itself in
longitude in 10 degrees 81 minutes 45
seconds west and the time II hours 80
minutes p. NJ.
This position would be approximately
one-quacter Of mile or fifteen seconds
OF are from or to the east Of the 16Oth
meridian and the time nearly midnight.
Say the speed Of our ship is ten knots
per hour. At this rate the intervening
distance from our position 40 degrees
90 minutes 45 seconds W. to the 1SOth
meridian would be consumed within l
minute 30 seconds.
We would now fiEd ourselves on the
date line, with Saturday behind us,
past, and Sunday A. NJ. beginning on
the eastern side Of the line or in west
longitude. On the western side of the
line, or In east longitude, Sunday would
be past and Monday A. NJ. beginning.
Thus we would be literally precipitated
into next week" losing one day Sun
day and starting our entrance into east
longitude with Monday.
The only length of day equivalent to
time that the ship would have of Sun
day would be thirty seconds.
ship In a similar position in east
longitude and sailing eastward would
haye just completed days run through
Sunday In east longitude, and after
crossing the line would find herself en-
tering the A. NJ. period OF another Sun
day in west longitude, thus gaining q
day and having two Sundays In making
the eastward passage.
Should we find ourselves at 8 A. NJ
Sunday. May 2l. 1922, In west longi
tude, with sixty miles to go to the date
hne. and arriving at 2 p. NJ. Sunday
we could still carry on with the same
day--namely, Sunday.
Having had meridian altitude that day
sun on the meridian) in west longitude
at our next or succeeding meridian al.
titgds on the day following we woult
call Tuesday, having lost Monday.
HOWARD i. HOZEY.
Philadelphia. May %, 1922.
r. 81 take much interest in tn
editorials. Peoples Forum and Wha
l. ne In NJ.