82 
The line of tin-bearing country extends in a North and South direction, and 
it has been found in places across the country as far North as the Preston River, 
and South beyond Bridgetown. 
Tin in the North-West. 
Tin has also been found in the alluvial workings at Pilbarra, but could not 
be worked for some time, as the Mining Regulations for working gold and tin clash, 
and no larger area than an alluvial digger’s area could be granted on a goldfield, 
A very rich deposit of coarse stream tin occurs near Mr. G. and J. Withnell’s 
station on the Shaw, which assayed 71 per cent, of metallic tin; the only draw¬ 
back to the working here is its distance from the coast, but should a good lode be 
discovered, there is not the least, reason why it should not be profitably worked. 
Prospects are obtained in many places between Pilbarra and the Nullagine, all 
of which country is of a highly Metamorphic character, very favourable for deposits 
of tin. 
COAL. 
The Irwin Coalfield. 
In the year 1846 Gregory discovered some coal seams in the bed of the North 
branch of the Irwin River, which were shortly afterwards reported on by Dr. Yon 
Sommer, who stated that there were two seams, 6 and 8 feet thick respectively, and 
a reserve of 10,000 acres was declared, but nothing further was done for many 
years until at last the Government decided to send the Rev. C. G. Nicolay to 
report on the value of these seams. That gentleman found that there was so much 
water to contend with in sinking, and that the coal raised was of such a poor 
quality, that the field was again abandoned till the year 1888, when Messrs. Bell 
and Eliot found in the bed of another branch some better specimens. These they 
traced up to their source, which they found to be a seam in the cliff 4ft. thick and 
dipping towards the North; into this they drove a distance of 150ft., but it did 
not prove of sufficiently good quality to induce further work. There are also six 
other seams of smutty coal; a portion of one of these proved to be of a lietter 
quality and ten tons were raised, but, owing to a division in the company, nothing 
more was done. Several seams have also been opened up on Gregory’s branch, but 
none have at present been shown to be of any commercial value. All the upper 
tributaries of this river pass through carboniferous shales and limestones, con¬ 
taining lower carboniferous fossils, and some poor coal seams. 
The coal itself occurs in thin seams mixed with coaly shale; it is dirty to the 
touch, and contains so much water that it falls to pieces on exposure to the 
atmosphere. 
Two assays made in London gave the following results (No. 1 was by Mr. 
Harland, and No. 2 by Mr. Wingham) : — 
Water ... ... 1704 
Volatile matter 28*61 
Fixed carbon ... 41*29 
Ash . 13*06 
100 
12*4 
32*2 
43*5 
11 9 
100 
Sulphur . 0 . 83 
The large amount of ash 'may iu part be due to extraneous earthy matter 
The coal cannot be utilised for gas making, as it does not cake, and the coke 
