But a cameo need not be made of stone, for some of the finest that have come down to us were fashioned by the Romans by cutting layers of glass of different colors. It may seem strange to young readers to be told that although to-day we are very perfect in glass-making, there are a great many things the Romans could have taught us in this art. Now the reason why they were so skilled in glass manufacture was because they used glass as a substitute for porcelain, which was not then invented. The illustration which accompanies this article represents a very fine cameo designed by a very great English artist, whose name was John Flaxman. This cameo, which was cast, was made of white and blue porcelain, and was probably intended as a decoration for one of those beautiful urns which Wedgwood, the famous potter, manufactured in England almost a hundred years ago. To-day a great many cameos are made, but not out of hard stones. The shell of the conch, found in Florida and the West Indies, is the material used. The white surface is cut into the figure and left. The under layer of the shell, or the ground, which is of a brownish hue when polished, gives that contrast which a cameo should have. We do not take as much trouble to make a cameo as did the ancients. They cut the stone with tiny drills, the points of which are believed to have been diamonds. The shell cameo being much softer, can be scraped or cut with small chisels. Of the old cameos there are two famous ones, one cut on an agate, the other on an onyx. Nothing in modern art is as fine, and for the one on the onyx, which is known as the Vienna gem, as much as 12,000 gold ducats was paid by the Emperor Rudolph in the sixteenth century. By the study of ancient cameos a great deal is learned, for they show us the actual pictures of the dress and costumes of people who lived more than 1800 years ago. But more than that: on some of these cameos we have the exact likenesses of great personages, who as Roman Emperors once ruled the world. In ancient times cameos were used, just as they are to-day, as ornaments, only the Greeks and Romans, men and women, wore them set in gold on their shoulders, as they held together the folds of their flowing draperies. In the United States there are quite a number of cameo-makers, who cut good likenesses on shells; but the great art which existed in the time of Augustus has passed away. TIM AND TIP;[1] OR, THE ADVENTURES OF A BOY AND A DOG. BY JAMES OTIS, AUTHOR OF "TOBY TYLER," ETC. CHAPTER XII. TIP'S DANGER. [1] Begun in No. 92 of HARPER'S YOUNG PEOPLE, August 2. The work of preparing the dinner had occupied so much time that it was nearly the regular hour for supper before the last boy arose from the lowly table, and not one of them had any desire to fish or hunt. They sat around the fire, dodging the smoke as best they could, until the setting sun warned them that they must get their bedroom work done at once, or be obliged to do it in the dark.