In our last example we have a succession of keys built up by interlocking the wards and bows one within the other, upon the summit of which may, by special care, be balanced a bottle or similar object. Where the bottle is added to the pile, it takes the place of the uppermost key shown in our illustration, and rests upon one taking a more gentle incline, as in the case of the one immediately below. This rather ambitious structure forms a fitting climax to our series, and may be left to the ingenuity of the reader, whose accumulated experience should by this time be good equipment for the negotiation of the difficulties to be surmounted. _Miss Cairn's Cough-Drops._ BY WINIFRED GRAHAM. I. Little Hal Court knew nothing of towns; he had been brought up in the solitude and beauty of Northern Ireland. The country had given to this small boy something of its own peculiar charm, a wildness wedded mysteriously to peace. He could be so still and thoughtful, or so full of life and movement, he might have borrowed his child's personality from the waves of the great blue sea. Nature made a bold nurse--a teacher who whispered to Hal of things intense, of stories wonderful, bringing him the funds of her vast wisdom, the fairy tales of a country-side teeming with romance. "I live with my grandmother," he told his new governess, "because I have a different kind of mamma to other boys. She isn't the ordinary sort that stays at home; she--she's a celebrity!" He paused before alighting upon the correct word, bringing it out with so grave an air that Miss Ainsworth could hardly repress a smile. [Illustration: "I HAVE A DIFFERENT KIND OF MAMMA TO OTHER BOYS."] "Yes," he continued, hugging his knee and gazing through the window at the turbid waves of the Lough, a lovely inland sea, sending its green waters brimming to the verge of Castle Stewart's old garden. "She sings, you know! She sings--well, just like an angel, people say; but the angels don't have to travel about and leave their little boys at home. Mother makes heaps of money when she sings a song. They send for her right across the world, and she travels like a Princess; the people crowd to see her get into the train. It's always that way if you can sing. Don't you wish you had a voice like an angel, Miss Ainsworth?" "Yes, indeed." A sudden, almost painful, longing rang in the reply, as the dazzling picture of a world-famed artiste was conjured up by the simple description of a child. "I expect," added Miss Ainsworth, "you miss your mother?" "Why, of course. I wear this picture of her round my neck, and I love her so much I don't mind when other boys call it girlish; one doesn't mind being girlish for her!" A throb as of martyrdom crept into the child's voice--an almost passionate hunger for the mother-love denied him.