The development of the Canadian petroleum industry may be said to date from 1857, when a well dug for water was found to yield a considerable quantity of petroleum; but long previously, indeed from the time of the earliest settlements in the county of Lamberton, in the western part of the province of Ontario, petroleum was known to exist in Canada. In 1862 productive flowing wells were drilled at Oil Springs, but these wells, which were comparatively shallow, quickly became exhausted, and the territory was deserted on the discovery in 1865 of oil at Petrolia, seven miles to the northward, and about 16 miles southwest of the outlet of Lake Huron. Recently the Oil Springs wells have been drilled deeper, and are now producing 10,000 to 12,000 barrels (of 42 American gallons) per month. Petroleum has also been found at Bothwell, 35 miles from Oil Springs, but this district has ceased to yield. Quite recently a new territory has been discovered at Euphemia, 17 miles from Bothwell, where, at the time of our visit, there were four wells producing collectively 70 barrels per day. This territory is by some regarded as part of the Bothwell field. The present producing oil belt extends from Petrolia in a northwesterly direction, to the township of Sarnia, and in a southeasterly direction to Oil Springs, but in the latter direction there is a break of about four and a quarter miles, commencing at a point about two miles from Petrolia. At Oil Springs there appears to be a pool about two miles square. The extension of the belt then continues in the same direction, with another break of about nine miles, to the new oil field of Euphemia, the average width of the oil belt being about two miles. In all, about 15,000 wells are believed to have been drilled in the Canadian oil fields, and of these about 2,500 are now producing, the average yield being about three quarters of a barrel per well per day. The aggregate production is probably about 700,000 barrels per annum, the greater part of which is obtained in the Petrolia district, and the stocks were at the time of our visit stated to amount to from 400,000 to 450,000 barrels. In the Canadian oil fields the drilling contractor usually employs his own derrick, engine, boiler, and tools, furnishes wood and water, cases the well, and fixes the pump; the well owner providing the casing and pump, and subsequently erecting the permanent derrick.