NORTH-WESTERN DISTRICT (No. 1). 23

gold and platinum, having greater specifie gravity than the mercury, will penetrate and remain in the mercury. In the case of clean gold it is quickly amalgamated thereby. Platinum and rusty or greasy gold will be retained against the wall of the bowl until the machine is brought to rest. The sand, being lighter than mercury, will pass over the surface and out of the bowl.

This machine had only been installed two days before my arrival and was given a test while I was there; it seemed to work perfectly, but it is still too untried to pronounce it an un- qualified success. My fear is that it may not have the capacity for a large operation, but this might be overcome in two ways, either by multiplying the number of machines or by first concentrating the sand by jigging.

Provided careful prospecting showed that there was a sufficient body of payable sand, the following plan would seem to lend itself to a large operation: Suitable ground having been found, the centre of this would be chosen for the gold-saying plant. A portable tramway with light cars would be run out to one side; these cars to be filled by a gasoline or electric small shovel and hauled to the plant by rope, carried up an incline, and dumped into a bin. From the bin the sand and gravel would pass to trommels, which would sereen out all over 40-mesh as being of no value; the trommels or screens would deliver to a Hancock jig, which for this class of work should have a capacity of 400 tons a day. The concentrates from the jig would pass to the Hanssen machine, where the values would be sayed. Such a plant would allow of a large daily tonnage being put through, thus very much reducing the values at which it would pay to handle the sand. Further, the plant would be of such a nature that it could easily be moved from place to place where the values proyed profitable.

If carefully thought out, both as to method of working and finance, I see no reason why some of the black-sand deposits of Graham island should not turn out to be paying ventures and hold good for a number of years, but it should be clearly understood that such undertaking must be approached with caution under expert advice and a thorough sampling of the ground made before any expense is ineurred for machinery.

Taking a number of samples here and there over a deposit and getting them assayed in the way that would be done on a lode mine will, in my opinion, give results which may be entirely erroneous, either too high or unduly low. The method that suggests itself would be to take a small self-contained Hanssen separator on to the ground and run through it a definite yardage of sand from representative sections of the ground, then retorting the mercury and weighing the resulting precious metals and calculating the yield.

Black Sand on Masset Inlet.

Peter Kay has a black-sand claim about 1 mile south of Masset wharf. The bank is 15 or 20 feet above high tide and some 50 feet back amongst the timber. Several test-pits have been sunk 8 or 9 feet deep, showing layers.of black sand from 1 to 12 inches thick; a sample of concentrates from this claim gave 0.6 oz. gold and 2 oz. platinum to the ton, but a general sample on assay gave no values. The southern end of the claim is cut by a small stream which has concentrated the sand; here two men were able to make good wages with a sluice-box, shovelling in the sand and pumping the water from the stream. Colours of gold can be got nearly anywhere by panning and some of the colours are a fair weight, by no means what is known as fine gold. This property is over 15 miles from where the other black-sand deposit is being worked and will serve to show the wide distribution of the values.

BELLA COOLA MINING . DIVISION.

During 1929 this area has been comparatively inactive. The usual assessment was carried out on sixteen claims only. The Division was also neglected by prospectors; less than thirty claims, some of which were relocations, were recorded. The cursory prospecting that has been carried out in this region in the past by hunters and trappers has disclosed evidence of minerali- zation, probably sufficient to warrant more intensive exploration. There are sections of the Division that are geologically favourable for commercial mineral oo :urrences.

The eastern margin of the batholith-contact cuts through the interior region of the Bella Coola valley, about 20 miles inland, and offers a likely section for prospecting. Several inclusion zones within the granitic rocks of the batholith on Dean and Burke channels deserve more than the superficial shore prospecting they have received. The interior regions of these localities

are admittedly rugged and rough, but their favourable aspects warrant the effort of intensive

prospecting.