GEOLOGY AND MINERALOGY. 483 
the Mersey, on Port Frederic, the seams being from two to three feet thick. On 
the River Don, in the same neighbourhood, it crops out of the earth in many 
places from twenty-six to thirty inches thick, and this coal is stated by Mr. Sel- 
wyn to be the best in the island. In two places where shafts have been sunk, 
twenty-seven inch seams have been found less than twenty feet from the surface. 
For many of these particulars we are indebted to the official colonial reports of 
Dr. Milligan and Mr. Selwyn, both eminent geologists. 
An extensive bed of shale has been found at the great bend of the River 
Mersey, near La Trobe, which is estimated to cover 490 acres, and to have a 
depth of from eighteen to twenty feet, equal to a quantity of 20,000,000 tons. 
Making, however, a liberal allowance for waste, and for walls to support the 
ground in mining, it is calculated that at least 10,000,000 tons might be quar- 
ried and mined with ease. This shale is found close to the surface. Where it 
has been exposed to the atmosphere it is of a light brown colour, but taken 
from a greater depth it is of the colour of dark grey; and a small piece of it 
the flame of a candle lights easily and burns brilliantly. The extraction of oil 
from shales and coal has been largely extended of late years, not only in the 
United Kingdom, but in France, Germany, and the United States. The demand 
for lubricating oil on railways, and in machinery, and for many manufacturing 
purposes, is constantly increasing. Its great recommendation consists in the 
fact that it remains limpid and pure after exposure to the atmosphere, and never 
thickens or clogs on the machinery, as ordinary oils do. The manufacture of 
this oil is not attended with any difficulty that would prevent its becoming a 
colonial industry. The process is very simple, at least as much so as the manu- 
facture of gas. 
In New Zealand much enterprise has lately been displayed in coal mining, a 
matter of some importance now that there are so many coasting steamers, inter- 
colonial steam-vessels running to Sydney and Melbourne, and that a Pacific line 
is projected thence to Panama by the Otago Government. At the Motupipi coal 
field the fuel improves as the seam is worked ; the coal is rather sulphurous, and 
burns rapidly, leaving a good deal of ash, but does well for steamers, if mixed 
with an equal quantity of English coal. At Pakawan coasters can load coal, 
but vessels above 200 tons have to load in the offing, or at the Pata Islands. 
The preliminary step to all manufacturing enterprise is the development of 
the coal beds where they exist. The furnace and the steam-engine are the great 
industrial forces of the age; and to these coal is the staff of life. That many 
of our principal colonies possess this substance in abundance, should satisfy 
them more than if they had great gold fields. With it they can create gold by 
direct exchange, and by manufacture. Both by exporting the produce of their 
mines, and by using it in the creative processes of manufacture, they have it 
in their power to make a vast addition to their public wealth, and greatly 
augment their capability of supporting an industrial population. The collection 
of samples or foreign coal may be made one of the most interesting in the 
Exhibition, having regard to its important uses. Full details with respect to 
the seams, accompanied by maps and geological sections and reports, statistics 
of production, existing for land transport or shipment, and authentic analyses, 
