252 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1911. 
The systems of time in various countries—Continued. 
Region or country. Meridian. Difference. Remarks. 
Masmania=o- st ete meee eee Ee Greenwich.......-. +10 0 0O Legal time. 
PRULK CYS ees ee ee ere eee oe Seen Rae seen s sete do. +2 0 O Railroads. 
United States: | 
Masternsfandardee le fs) a eat eS cpa Gobesttees. —5 0 0 Legal time. 
C@entralistandard 223222425 eee neace dowlP esse te —6 0 0 Do. 
Mountammistandarda:-- =) .25.2-Me oss eeeelcsees Got? s22:se6% —7 0 0 Do. 
iPacificistanGgand. sees seuss sates ore sees doses 55k —-s 0 0 Do. 
PAN ASR Se A ots arn iciraie Seige oes ae me | Seis dosfaasce see. -9 0 0 Do. 
EL Wal ew acc hs Mee Cs Pease a cad do —10 30 0 Do. 
ROLtOMRICOse ese chess eee ec aeeeee|aaeee GOSS AIUES eyo —4 0 0 Do. 
iphilippimesss = me Sie. ee eee ala St Dosserses ie ss =180 102-10 Do. 
ROU PUY ess heres = he Bae RS Bo Montevideo. ...... — 3 44 51.4 | Railroads. 
Weneziiela:< sateisaets Se sie MO. 2 Bre Caracas} 8282.52. — 4 27 43.6 
Wi CLOrIa tierce seers sos ace ae coe hear en oats Greenwich??: ..... +10 0 0 Legal time. 
This table makes easy not only the transformation of a given time 
to the corresponding time at Greenwich but also its conversion to 
that of any other place. For instance, when it is 6 hours a. m. in 
Chicago, in Manila it is 6-+6+8=20 hours, or 8 hours p. m. 
Upon the terrestrial map given here, the 24-hour zones have been 
indicated; the central line of the first passes through Greenwich, 
The countries and territories which have not yet adopted the inter- 
national system of time are tinted blue, the others rose. For great 
extents of country like the United States of America it is easy to see 
at a glance the time in each region. 
“THE INTERNATIONAL DATE LINE. 
Tt is well known that if we go westward from America to Asia, 
we find our date one day behind time when we. reach Asia; if we 
travel eastward over the same route we find our date one day ahead 
of time when we reach America. 
In order to avoid this confusion of dates, it is customary, in cross- 
ing the one hundred and eightieth meridian from Greenwich, to 
‘Sump’ a day, if traveling toward the west, and to repeat a day if 
traveling toward the east. However, because of geographical and 
political conditions, the international date line does not coincide 
exactly with the one hundred and eightieth meridian. It is an 
irregular line so situated that all eastern Siberia has the same date, 
the Aleutian Islands and Hawaii the same date as the United States 
of America, and, finally, the Fiji Islands and Chatham Island that 
of Australia. This line is shown on the accompanying map. 
