Asteroidea

Star-fishes; star-shaped Echinoderms having a central disc, from which project radially five hollow arms that contain lobes of the viscera. The integument is leathery and spiny. There is no dental apparatus to the mouth, which is central on the lower surface. The anus, when present, IMG:content-0347.png:[blocks in formation] Asteridæ ( Por cell an aster cærule us ). matism, or anything which throws a strain upon the accommoda- IMG:content-0348.png:[graphic] IMG:content-0349.png:[graphic] Astragal. In Cla ic architecture, projecting molding of half or more of a circle in section; one of the bars in which a window pane is set. IMG:content-0350.png:[graphic] IMG:content-0351.png:[merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small] been strange if some of these had not been approximately true. We are in fact told that Pythagoras secretly taught his disciples that the sun was the center of the universe, and not the earth, as commonly supposed. Aristarchus of Samos, 250 years later, seems to have proclaimed the same doctrine openly. With the advent of Hipparch us a new era began. Besides adding greatly to the existing store of knowledge, he performed the great service of uniting the scattered fragments into a consistent whole, thus raising astronomy to the rank of a true science. The system which he adopted, with its uniform circular motions in epicycles and deferents, though not the true one, as events afterward proved, formed a good working hypothesis, doubtle the best then available. That it answered its purpose admirably is sufficiently attested by the fact that it held po e ion of the field substantially unchallenged for 1,600 years. Usual Method, in drawing a Horoscope, of representing the Twelve Houses of Heaven.