Among the new and most remarkable _placers_, are the gold bluffs, situated near the mouth of the Klamath river, about thirty miles north of Trinidad. The approach to them by land is over a plain of sand, into which the traveller sinks ankle-deep at every step. The bluffs stretch along some five or six miles, and present a perpendicular front to the ocean of from 100 to 400 feet in height. In ordinary weather the beach is from 20 to 50 feet in width, composed of a mixture of gray and black sand, the latter containing the gold in scales so fine that they cannot be separated by the ordinary process of washing; so that resort must be had to chemical means. The beach changes with every tide, and sometimes no black, auriferous sand is to be seen on the surface. By digging down, it is found mixed with gray sand, which largely predominates. The violence of the surf renders landing in boats impracticable. When the beach was discovered early in 1851, several tons of goods were landed from a steamer despatched thither, by means of lines from the vessel to the shore. The Pacific Mining Company have made good profits in working the bluffs and the sand of the beach. Tunneling has been carried on quite extensively in the mining region. Some of the tunnels through solid rock are wonderful achievements. At Duggan's Flat, a party bored 150 feet in the solid rock before finding the gold. Professor Forrest Shepherd, of New Haven, has made some remarkable discoveries of thermal action in California. In one place where there was nothing on the surface to attract attention, on digging down the heat increased so rapidly that at the depth of two feet he could not bear his hand in the earth, and the thermometer indicated a temperature of 130 degrees. At another place, after wandering for four days through dense thickets, he came upon a chasm a thousand feet deep, through which flowed a stream, the banks of which, on the 8th of February, were covered with vegetation. Following up the stream, the earth grew so hot as to burn the feet through the boots. There was no appearance of lava, and the rocks were being dissolved by a powerful _catalytic_ action. From innumerable orifices steam was forced to the height of two hundred feet. The number of spouting geysers and boiling springs, on a half mile square, exceeded two hundred. The Professor, in the course of a lecture delivered at San Jose, said he did not doubt that silver, lead, and iron abounded in California.