(89 ) 



1903 I made here a new series of determinations of latitude by 

 means of zenith distances in the meridian. But I did not succeed 

 in securing new data with which to correct the determination of 

 the longitude, and at last I have entirely given up this plan, until I 

 should possess a telescope of the required dimensions for the obser- 

 vation of occultations of stars 1 ), because the observations of the 

 latter will certainly lead to a greater accuracy in the determination 

 of the longitude than can be attained by means of lunar altitudes 

 with my relatively small instrument. 



2. Determinations of astronomical coordinates at different stations 

 in the Chiloango district. On two journeys, one to N'Kutu on the 

 upper course of the Chiloangoriver from 22 to 31 December 1903 

 and a longer journey through Mayombe a ) in June 1904, I was 

 able to make determinations of latitude and longitude. The reason 

 why these could not be made oftener lies chiefly in the peculiar 

 difficulties attached to the transportation of the instruments especially 

 of the chronometers. The best way of transporting them is by water 

 by means of a canoe, and even then one must constantly pay 

 attention to avoid shocks caused by trees floating down the river. 

 When the chronometers had to be transported by land, I used a 

 hammock suspended from a long stick carried by two negroes ; while 

 mounting hills they tried to keep the stick as much horizontal as 

 possible. 



Another circumstance which makes it difficult to obtain accurate 

 results is that these excursions can be undertaken only during the 

 dry season, when the nightly sky is as a rule overcast, so that one 

 must take recourse to observations of the sun, and lastly in many 

 parts one meets with great difficulties in finding a proper dwelling place, 

 because prosperous negro villages, which formerly existed, are almost 

 entirely depopulated and turned into desert in consequence of the 

 trypanosomosis, which has raged there. 



On my journey in December 1903 the instruments were entirely 

 transported by water, first by steamer to Mayili then by canoe to 

 N'Kutu. At this latter station I secured determinations of latitude and 

 longitude. 



The journey through Mayombe in June 1904 also began by steaming 

 up the Chiloango- (or Loango-) river to Mayili. We there arrived on 

 June 2 and I made a time determination in order to control the 

 longitude determined previously. We then travelled by land to 



!) I received for some time past (1907) a telescope of Zeiss of 80 mm. aperture 

 and J 20 cm. focal length, with which I have already made some experiments. 

 2 ) The name of a part of the Chiloango district. 



