who are fond of nature and ambitious to discover fresh secrets. In
furtherance of this purpose their Majesties, the King and Queen of Norway,
the Norwegian Geographical Society, the Royal Geographical Society of
London, and Koninklijk Nederlandsch Aardrijkskundig Genootschap,
generously assisted me with grants, thus facilitating my efforts to raise
the necessary funds. Subscriptions were received in Norway, also from
American and English friends, and after purchasing the principal part of
my outfit in London, I departed for New York in the autumn of 1913, en
route for the Dutch Indies. In 1914, having first paid a visit to the
Bulungan, in northeast Borneo, in order to engage the necessary Dayaks, I
was preparing to start for Dutch New Guinea when the war broke out.

Under these changed conditions his Excellency, the Governor-General,
A.W.F. Idenburg, regretted his inability to give me a military escort and
other assistance needed for carrying out my plan, and advised me to await
a more favorable opportunity. During this interval, having meanwhile
visited India, I decided to make an expedition through Central Borneo,
large tracts of which are unexplored and unknown to the outside world. My
project was later extended to include other regions of Dutch Borneo, and
the greater part of two years was spent in making researches among its
very interesting natives. In these undertakings I received the valuable
assistance of their Excellencies, the governor-general and the commanding
general, as well as the higher officials of the Dutch Government, to all
of whom I wish to express my heartfelt thanks.

Through the courtesy of the well-known Topografische Inrichting, in
Batavia, a competent surveyor, whose work will later be published, was
attached to my expeditions. He did not accompany me on my first visit to
the Bulungan, nor on the second occasion, when I went to the lake of
Sembulo, where the country is well known. In the map included in this book