In scientific circles there is some interest taken in the fact that the soundings of the Challenger expedition shows that down in the deep water of the Pacific and Atlantic Ocean there are many places where the water is but little above the freezing point, Gardeners accustomed to the circulation in hot water boilers can easily understand this, as well as why the Gulf Stream flows towards the poles and other similar phenomena. As the water on the surface at the tropics is warmed and light. ened, the colder from the poles flows down and re-places it, and the warm lightened water, of course, flows over the surface to take its place.