The hand-dug wells in Roumania are highly interesting relics of a period which is now relegated to the past, though so long as the Roumanian petroleum industry exists, so long will the old hand-dug wells be associated with it. These wells are about 5 feet in diameter, and are sunk through alternate layers of clay, schisty clay, sandy clay, sandstone, and petroliferous sand to the more shallow oil horizons. They are dug by workmen who descend dressed with the minimum of clothing, usually saturated with oil, and wearing a tin hat to protect the head from falling stones, etc. The sides of the wells are lined with impermeable clay, which is protected by wicker-work. The man is lowered by a rope, air being supplied to him by means of bellows. At some places the rotary fan was employed more recently, but somehow it frequently happened that it was operated in the wrong direction, and the unfortunate digger was asphyxiated. These old wells have a depth of about 450 feet, and though their yield of oil is not considerable, it has for many years been a paying proposition to those engaged in this primitive method of petroleum production. The excavated earth, when digging these wells, was brought to the surface in buckets, lowered and raised by means of either manual labour or horse traction. When the first oil source was reached and the extraction of the crude oil commenced, this was accomplished by means of the use of wooden buckets or leather skins, one being lowered empty while the other was raised full. By this means it was possible to raise as much as 20 tons of the oil per day--quite a considerable amount, considering the primitive means adopted. Mechanical developments throughout the Roumanian oil-fields on a more or less serious scale began about 1898, as the result of the introduction of foreign capital, and, from that time to the present, the history of the Roumanian petroleum industry has been one steady period of continued expansion. Various systems of drilling have been introduced into the work of developing old fields or opening up new centres, but in regard to these I shall deal at length in another chapter. The advent of the rotary method of drilling, however, opened up a new era for expansion in 1912, and since that time Roumania has made more marked progress than at any time previously. The Roumanian oil-fields, as at present defined, cover a region roughly 20 miles in width, and extend to a length of between 300 and 400 miles, with, of course, numerous breaks. Of the numerous petroliferous regions in Roumania, those of Campina-Bustenari, Gura-Ocnitza, Moreni, and Baicoi-Tzintea among them provide about 95 per cent. of the total production, and, with the one exception of the Moreni field, all have been previously exploited by hand-dug wells.