— 3 — 



At the end of March we left Siam in the Danish steamer 

 „ Cathay" for Copenhagen , where we arrived on June l s i 1900. 

 Our collections have all been placed in the Botanical and Zoo- 

 logical Museums of the University of Copenhagen. 



The island Koh Chang (Elephant Island) is situated in the 

 northeasterly part of the Gulf of Siam about 80 miles from the 

 boundary between Siam and Cambodia 1 ). A strait, 2 l /2 — 10 

 miles broad, separates the island from the Siamese mainland. The 

 area of Koh Chang is about 7 0 square miles and it is the lar- 

 gest Siamese island in the Bay. Consequent to its position in 12° 

 lat. N. the climate of Koh Chang is entirely tropical, the year being 

 divided in a rainy and a dry season, the former during the 

 blowing of the damp south-west monsoon (generally from 

 May to August) the latter in the other months where the dry 

 north-easterly winds are prevalent. The heat is most ex- 

 treme in spring, in March, April and May before the south- 

 west monsoon sets in and after the cessation of the north-east. 

 The coolest season is the autumn- and win ter- months. At 

 Bangkok 2 ) the annual average temperature is 26,7 ° C. (80,1° 

 F.), Decembers 24° C. (75,2° F.) and Aprils 28,5° C. (83,3° F.). 

 The annual rainfall amounts to 1670 mm (65,7 inches) of which 

 about 4 /s during the months from May to October. 



The times of tides in the Gulf of Siam are very irregular 

 and the rise also varies along the shores from 4 to 9 feet. In 

 the Inner Gulf the principal of the two tides occurs in the south- 

 west monsoon at night, but in the north-east this gradually 

 alters and the high tide will be found in the daytime. 



Koh Chang is a mountainous island and ranges of peaks 

 separated by valleys occupy its whole area especially running in 

 the direction from NW to SE and growing in height and impor- 

 tance as they go south. The highest point is found in the southern 



1 ) The more exact position is given by the following indications : Northern- 

 most point in 12° 10' lat. N. , southernmost in 11° 57' lat. N. , westmost 

 in 102° 14' long. E., eastmost in 102° 25' long. E. 



2 ) Bangkok [13° 88' lat. N., 100° 34' long. E.) is the nearest place, from where 

 some meteorological facts are present. During my stay in Koh Chang I 

 made some measurements of temperatures and the degree of moisture, which 

 later will be published. 



1* 



