Drilling-tools, the chief novelty of which are the “jars”—a pair of sliding-bars moving within each other—have increased from two-hundred pounds to three-thousand in weight. George Smith, at Rouseville, forged the first steel-lined jars in 1866, for H. Leo Nelson, but the steel could not be welded firmly. Nelson also adopted the “Pleasantville Rig” on the Meade lease, Rouseville, in 1866, discarding the “Grasshopper.” In the former the walking-beam is fastened in the centre to the “samson-post,” with one end attached to the rods in the well and the other to the band-wheel crank, exactly as in side-wheel steamboats. George Koch, of East Sandy, Pa., patented numerous improvements on pumping-rigs, drilling-tools and gas-rigs; for which he asked no remuneration. Primitive wells had a bore of three or four inches, half the present size. To exclude surface-water a “seed-bag”—a leather-bag the diameter of the hole—was tied tightly to the tubing, filled with flax-seed and let down to the proper depth. The top was left open and in a few hours the flax swelled so that the space between the tubing and the walls of the well was impervious to water. Drilling “wet holes” was slow and uncertain, as the tools were apt to break and the chances of a paying well could not be decided until the pump exhausted the water. It is surprising that over five-thousand wells were sunk with the rude appliances in vogue up to 1868, when “casing”—a larger pipe inserted usually to the top of the first sand—was introduced. This was the greatest improvement ever devised in oil-developments and drilling has reached such perfection that holes can be put down five-thousand feet safely and expeditiously. Devices multiplied as experience was gained. The tools that drilled the Barnsdall, Crossley and Watson wells were the handiwork of Jonathan Lock, a Titusville blacksmith. Mr. Lock attained his eighty-third year, died at Bradford in March of 1895 and was buried at Titusville, the city in which he passed much of his active life. He was a worthy type of the intelligent, industrious American mechanics, a class of men to whom civilization is indebted for unnumbered comforts and conveniences. John Bryan, who built the first steam-engine in Warren county, started the first foundry and Machine-shop in Oildom and organized the firm of Bryan, Dillingham & Co., began the manufacture of drilling-tools in Titusville in 1860. [Illustration: JONATHAN LOCK.]