but by chemical decomposition, though the action of fire and water, no smoke is created and thus none is seen escaping from the valley; but the deadly gases, all the more poisonous because of their temporary confinement, are constantly exuding through the earth-covering, having no connection with any active geyser through whose vent they might escape. ------------------------------------------------------------------------ [Illustration: A HARVEST FIELD IN DAKOTA.—Such a harvest scene as this can be seen nowhere else in the world except upon the broad and rich prairies of the Northwest, and in a few localities in California. Eight self- binding reapers are at work in the field so accurately photographed before us, requiring an army of workmen in the proper handling of the golden grain. In California, where the climate is dry and the rain falls only at certain seasons, the harvesting is done with heading machines, and the grain is cut, threshed and sacked all at the same time. But more care is required in the Dakotas, where the rainfall is more frequent and uncertain. ] ------------------------------------------------------------------------ [Illustration: THE BLACK GROWLER GEYSER.] Yellowstone Park has many natural curiosities which entitle it to rank as the greatest museum of wonders in the world; but it is to be doubted if the geysers, formations of silica, and awe-compelling cañons can equal the marvel of Death Valley and the evidence which it supports of the glacial deluge that converted a sea of fire into a charmingly diversified wonderland. There is a grim connection between the fossil district in which the bones of so many extinct animals have been found so plentifully, and Death Valley, in which the remains of existent creatures attest the continued destructive result of the ice-flood. Truly, the ways of Providence are ways of mystery; and the more we contemplate them to satisfy the ambition of curiosity, the more we realize the incomprehensibility of the infinite, and that every advance step is an interrogation point in our lives. [Illustration: LITTLE FIRE-HOLE FALLS.] ------------------------------------------------------------------------ [Illustration: AN ENCAMPMENT OF SIOUX INDIANS, DAKOTA.—This is a war-camp of Sioux Indians, photographed during the hostile era of Sitting Bull and his band of desperadoes. It shows the camp deserted by the warriors, and left in charge of the women, children and old men. Photographic reproductions of such scenes become more interesting and valuable as time goes by, for they will never again exist in reality. The hostiles have been driven to the Government reservations, and the places once occupied by their villages, and the prairies over which they roamed in quest of game or the trophies of war, are now covered with homes, farms and cities. ]