HOUTMAN ABROLHOS ISLANDS. 129 



this very cheap type of motor craft for use in sheltered waters such as those 

 of the lagoons. It was even possible to dredge with a small instrument 

 2 feet long and weighing, without sinkers, 12 lbs., in a most satisfactory 

 manner. Much more time was spent in dredging on the second expedition, 

 the small dredge being worked from the rowboat in the lagoons, whilst an 

 Agassiz trawl was used from the lugger in the more open waters. On both 

 expeditions the skippers and crew were Scandinavians and they helped 

 enthusiastically in the work. 



On both occasions we took with us camp equipment. The working plan 

 was as follows. The lugger was sailed to a convenient and sheltered 

 anchorage where we intended to work, and usually cpiite close to an islet 

 (large or very small as the case might be). A camp was then set up on 

 shore, where my colleagues and myself slept, whilst the crew remained on 

 board. Two or three days might be put in at one anchorage in this way, or 

 we might shift lugger and camp every day according to the work carried 

 out. On some occasions the shore collecting, surveying, and work in the 

 lagoons with the dinghy, occupied all our efforls, so that the lugger was left 

 undisturbed for several days. On other occasions when the weather was 

 suitable for dredging in the open sea, we would start early in the morning 

 and leave our camp on shore, to return in the afternoon with the spoil, 

 which needed sorting, labelling, and preserving. 



One of the great difficulties in connection with work at the Abrolhos 

 Islands is to find the right kind of weather. For the greater part of the 

 year the winds and sea are too unruly for continued work in these waters, 

 except from a large vessel, and a large vessel could not be used amidst the 

 coral islets. It appears that the best times are between the two well-marked 

 seasons, Summer and Winter (dry and wet seasons), i. e. the months of 

 October and November on the one hand and April and May on the other. 

 Both of our expeditions were carried out between winter and summer, but 

 we were not nearly so fortunate on the second occasion, although longer at 

 the islands. On one occasion we hunk' with two anchors out whilst a eale 

 blew for twenty-four hours ; a nasty coral-reef, just submerged, was situated 

 only about twenty feet behind our stern. No accidents happened, but our 

 work was delayed for several days owing to the bad weather. On another 

 occasion, however, the ocean swell was so reduced to leeward of one of the 

 islands that we were able to follow the outer reef and examine it from the 

 motor dinghy. 



Reversing thermometers were used on the second expedition in conjunction 

 with the Ekmann water-bottle, but we were too short of workers to initiate 

 a scheme for the complete oceanographical investigation of this region and 

 were forced to be as economical as possible. Our plankton hauls were made 

 chiefly with the object of comparing the plankton of the lagoons with that of 

 tin.' ocean outside, and for this purpose we usually aimed at taking hauls in 



10* 



