_March 27th._—A good sleep has worked wonders. I find Grass Valley a romantic little mountain town, about 2,200 feet above the sea-level, on the western slope of the Sierra Nevada, owing its existence entirely to gold-mining. Visited Mr. A.’s mill—a magnificent quartz-crusher. Nine stamp-heads, each 900 lbs. in weight, are worked by one of Watts’ engines. The fine-dust gold is collected on blankets, or bullocks’ hides with the hair on, over which the water washes it, as it comes from the stamp-heads. Some of the most productive gold deposits in California were discovered in and about this quaint little place. I descend a shaft 240 feet deep. The gold is distributed through the mud and silt of what was clearly an ancient riverbed. _March 28th._—Ride on horseback to Nevada and Hunt’s Hill. Nevada is a clean pretty _city_, with gay shops, brightly-painted houses, and planked streets. Near it are the famed hydraulic washings. The gold is disseminated through terraces of shingle conglomerates, often three hundred feet in thickness. These terraces are actually washed entirely off the face of the country, by propelling jets of water against them, forced under great pressure through a nozzle. To accomplish this, the water is brought in canals, tunnels, and wooden aqueducts, often forty miles away from the drift. This supply of water the miners rent. As we near the washing-spot, in every direction immense hose, made of galvanized iron, and canvas tubes six feet round, coil in all directions over the ground, like gigantic serpents, converging towards a gap, where they disappear. On reaching this gap, I look down into a basin, or dry lake, 300 feet below me. The hose hangs down this cliff of shingle, and following its course by a zigzag path, I reach a plateau of rock, from which the shingle has already been washed. A man stands at the end of each hose, that has for its head a brass nozzle. With the force of cannon-shot water issues, in a large jet, from this tube; and propelled against the shingle, guided by the men, washes it away, as easily as we could broom a molehill from off the grass. The stream of water, bearing with it the materials washed from out the cliff, runs through wooden troughs called ‘flumes,’ floored with granite; these flumes extend six miles. Men are stationed at regular distances to fork out the heavy stones. Throughout its entire length transverse strips of wood dam back a tiny pond of mercury; these are called _riffles_—gold-traps, in other words—that seize on the fine-dust gold distributed throughout the shingle. The ‘flumes’ are cleaned about once a month, and the gold extracted from the mercury. Masses of wood occur, in every stage of change, from that of pure silica to soft asbestiform material, and pure carbon.