The boiling spring, or mud volcano, as such phenomenons are variously called, consisted, in the main, of a large pool of muddy colored water, lying at the foot of a hill. All around it were dead trees, and the smell of sulphur, though not so strong as at the first spring Fenn had visited, was plainly noticeable. The water had a dead, stagnant look, after the eruption, and Fenn was careful not to approach too close, for he could not tell when the spring would spout up again. He saw a number of turtles on logs and bits of wood that extended out into the pool, and others plunged from the bank into the water at his approach.