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If you have a dog it will be very interesting to find out in what way he knows you. Mr. john Burroughs says he appeared one day before his dog· in a new outing suit of khaki. The dog eyed him suspiciously and backed away. Threatening him with a stick, the animal became excited and angry. When he spoke in his usual tone the dog came to him and smelled him. He acted very much ashamed for not knowing his master. A dog trusts his nose more than he does his eyes. When a shaggy dog is clipped close for hot weather, his dog friends think him a stranger. They jump out and bark at him. But when they come close enough to smell him they look very foolish over their behavior. A good house dog knows the members of the family and all the friends who come about the place by their smell. A stranger he detects instantly in the darkest night. Next to their sense of smell is hearing. Dogs know familiar voices. They trust their eyes the least of all and are thought to be near-sighted. For odors they have wonderful memories. It is this that enables many lost dogs to find their way home over long strange roads. While all dogs have keen scent, the bloodhound and other hunting dogs have it to an astonishing degree. Descended from breeds of wild dogs, that had to hunt distant and unseen prey, they learned to follow the scent of one animal through a confusion of other smells and to pick up a trail lost in running water. By their sense of smell collie and other shepherd dogs trace and find sheep lost in storms. The St. Bernard dogs in the Alps Mountains find travellers buried in the snow. Terriers have keen noses for rats, and other burrowing rodents. Try your dog by changing clothing with a little friend. He will jump first on one, then on the other, and show plainly that he is puzzled. You may have to speak to him before he is sure which is his master.

That depends upon the kind of fuel that is burned. Smoke from a fire of dry hard wood, from anthracite coal or from a gas flame is chiefly a column of hot air. Often it cannot be seen. There is very little solid matter in it. The thick, black smoke from locomotives, factories and house chimneys is made by burning soft coal in a wasteful way. If you will turn back and read the little story of how gas is made, you will understand the changes that take place when coal is heated. In making gas, the coal is not burned but is