But though the power of ideas is a commonplace, and though psychologists tell us how much we may improve mental concentration by letting the words of any sentence call up each its own picture, what they a omit to do is to recognise the need of the human spirit for beauty. You can concentrate your thought on the list of pickles in a grocer's price list: it is doubtless a good exercise. But the same exercise directed to some great phrase, such as Emerson's _Trust thyself: ever' heart vibrates to that iron string_; or some vivid lyrical image such as _All the trees of the field shall clap their hands_, or even a complete poem of simple words but permanent beauty, such as that one of Wordsworth's beginning _I wandered lonely as a Cloud_; this will not only improve concentration and sharpen memory: it will enrich the mind with ever-available sources of inspiration, courage and joy. EDGAR J. SAXON. THE WORLD'S WANDERERS. Tell me, thou star, whose wings of light Speed thee in thy fiery flight, In what cavern of the night Will thy pinions close now? Tell me, moon, thou pale and grey Pilgrim of heaven's homeless way, In what depth of night or day. Seekest thou repose now? Weary wind, who wanderest Like the world's rejected guest, Hast thou still some secret nest On the tree or billow? PERCY BYSSHE SHELLEY. CLOUD-CAPPED TOWERS. Building castles in the air has always been one of the favourite amusements of mankind. To it we owe much, not only of the zest of life, but also of motive power for overcoming difficulties and reaching out towards new possibilities. Yet all literature, and tradition that is earlier than any written literature, is full of a deep note of warning; over and over again we see in the dim past the shadow of a tower that was built in vain, of walls that were piled too high and toppled into ruin, of crests that tapped the thunder-clouds and drew down lightning to their own destruction. Evidently man has seen danger in his own desire! The castle must be built with wisdom as well as with industry and boldness if it is to escape disaster and to become a storehouse, a safe defence or a vantage-ground for surveying earth and sky.