76 



The four boats having each performed a complete circuit are next ranged in 

 line abreast in the same manner as before, between the quarter and the half mile 

 buoy and each makes a second circuit. Tbe day's work is completed by a third and 

 last "circle, in this case between the buoys distant respectively half mile and three- 

 fourth mile from the ship. 



The four boats make a total of twelve concentric circuits, each boat making 

 three. The results shown upon the coxswains' diagrams — each of which has three 

 concentric circles drawn upon it (see plan No. Y) representing the three circular paths 

 covered — are transferred by the Inspector to a final diagram or plan furnished with 

 twelve concentric circles. When this has been done the distribution of old and of 

 young oysters is graphically shown for a circular area having a diameter of a mile 

 and a half (plan VI). 



After calculating in square yards the area occupied by oysters the approximate 

 number thereon may be estimated by taking the average number of oysters per dive 

 (ascertained by scrutiny of the divers' results) in conjunction with the average 

 amount of ground which a diver is credited with being able to clear at one descent. 

 Usually this area is considered on average ground to be from two and a half to 

 three square yards. By assuming the area per dive to be_ three square yards the 

 danger of an overestimate is avoided. 



(c) Purchase or charter of an inspection depot ship. — To carry out inspection 

 satisfactorily I recommend that either a schooner be built, purchased, or chartered, to 

 serve as the head-quarters or dep6t upon which the inspection staff of divers and boat 

 men may live. 



If purchased or built specially, the latter of which would be the more economical 

 and satisfactory plan in the long run, cooler and more commodious quarters could be 

 fitted up than upon a steamer, and being wooden there would be practically no 

 liability to error in the accurate taking of compass bearings. 



A steam vessel would be required for towing purposes. The tC Margarita " 

 might be used for the present and when it becomes necessary to replace her, the next 

 vessel should be a screw steamer built and fitted specially for dredging and towing so 

 that when not engaged in the latter duty, she might be used for the dredging either 

 of chanks or of fishable oysters for market and for valuation sample. 



Meanwhile the " Margarita " should be altered and fitted to serve dredging 

 purposes for which she is by no means unsuited. 



(d) Beacons to be charted and improved, — An improved scheme of landmarks 

 should be provided and the positions of the several beacons accurately fixed on the 

 chart. It is almost incredible that none are marked on the charts in use ; the 

 Inspector has to roughly guess their relative position to the headlands and indenta- 

 tions of the coast indicated on the chart. Even the Admiralty Chart, which is 

 wonderfully accurate in other respects, shows the position of but a very few with 

 precision — the others either being omitted or not defined with exactitude. In taking 

 bearings from the sea, it is of little value to see upon the chart a number of marks at 

 a certain spot indicating the presence of a conglomeration of buildings ; we require 

 the position of the most conspicuous one to be placed with precision. 



The beacon on Yantivu should be increased in height and an additional one erected 

 on one of the islands to the northward. 



(e) Improvements in recording the details of inspection results. — The officer in 

 charge of the Inspection of the Pearl Banks should be directed by the Government to 

 insert in the records kept in his office as well as in the report furnished by him to 

 Government at the termination of each inspection, the following details concerning the 

 condition and abundance of the pearl oysters and associated organisms met with on 

 each of the inspection sections, namely : — 



(I) The number of individual dives made upon each group of pars, and the 

 number of those where oysters were found, together with the average number of 

 oysters per dive over the whole of the productive ground. Not less than 300 dives 

 should be made upon each section, if a reliable conception of the character and condi- 

 tion of the area under examination is to be arrived at. The number of dives made 

 upon the banks in the past, even upon the important Tolayiram Par, have been 

 totally insufficient. The Tolayiram Par is of such large extent that four inspection 



