torial combat and bloody scenes of strife. The emperors looking always for some way to popularize themselves with the people found no other gift so acceptable as these gigantic open air places fitted to pander to their inhuman desire for witnessing contests in which suffering and death were essential elements. Accordingly buildings of this kind were scattered throughout the Roman world. Pompeii, Pola, Nimes, Verona, Constantine and many other cities were endowed with them, but the most gigantic and architecturally imposing of the series was the Colosseum completed in Rome by Titus (80 A. D.). This stupendous structure was nearly a third of a mile in circumference and one hundred and fifty-six feet in height. The interior had seats. for eighty-seven thousand spectators. The exterior façade was divided into four stories, the lower three of which were decorated with engaged columns of the Tuscan, Ionic and Corinthian Orders, and the fourth was relieved by the application of Corinthian pilasters. While but a portion of the original fabric remains, the ruin is profoundly impressive and the student can appreciate the overwhelming effect it must have had upon the war-loving Roman and how for the people of the dark ages it stood as a symbol of the past greatness of Rome.

"While stands the Colosseum, Rome shall stand,

When falls the Colosseum, Rome shall fall,

And when Rome falls, with it shall fall the World."

It would be impossible, within the limits of our space to enter into discussion or description of the myriad utilitarian works of the Empire. While expressing truthfully the character of the age, the Triumphal Arches, Aqueducts, Votive Monuments, Tombs, Theaters, Villas and the Palaces before Diocletian, do not illustrate any new significant phase of architectural form. Each of the constructions treated presents an architectural innovation, structural or decorative, which was continued by subsequent civilization and lives today, as elemental in our modern design. The

barrel vault of the Cloaca is reproduced in principle, in arcades, and tunnel construction, and the groin vaulted scheme that grew out of the simple vault has in a developed form made possible our great cathedrals. The continuance of the fundamental law of Roman composition, bilateral symmetry, is apparent in the inspection of the façades of our great public buildings. The Dome of the Capitol at Washington is a direct descendant of the Pantheon Cupola. It is true that it depends for its construction upon a steel skeleton and is supported above the square hall by pendentives, an innovation of Byzantine art, but the profile of the soaring dome and its circular encolumned drum below is the final expression in the architecture of today of the greatest of all Roman monuments. The Metropolitan Museum in New York possesses a most interesting reconstruction of the Pantheon. It is of such a size and so placed that the student is able to stand within the structure and by the exercise of a little imagination, visualize in the third dimension the splendors and wonderful effect of the Hadrian production. Our illustration reproduces a photograph of this model. (Fig 6.) The Roman method of concrete construction in many of its details may be seen in actual operation in the erection of our fireproof buildings, sewers or subterranean projects and the decoration of the core or ossature is duplicated in practically every building operation that the reader will inspect. The Roman Arcade is so frequently employed that no further specification of its use is needed. Regarding the orders, perhaps because there is a certain similarity between the conditions that govern our own and the Roman arts, the several column forms with their various details are popular in the same order as among the Romans. The Corinthian, more or less modified, according to the taste of the designer, has been greatly demanded in monumental work, although the Ionic has been introduced in a number of cases with signal success. The Doric is the most frequently employed of the classic orders in modern work. The Tuscan appears occasionally, the

most charming example of its use being in the decoration of the entrances to the Riding Academy in Brooklyn, N. Y. To even summarize the influence of the basilica plan, construction and decoration upon the architectural forms of later ages would be to outline the development of Early Christian and Medieval Art, a subject reserved for future treatment. It is sufficient to say that practically all churches are adaptations of the civil basilica. The Thermae are the prototypes of many of our great railroad stations, museums, galleries and government structures, their chief rooms being inspired, in decoration, lighting and general distribution by the tepidaria of the Imperial baths. The placing of the Roman temple upon a high podium and providing a monumental approach by means of a colossal stairway finds an echo in many of our modern works. At times this Roman stairway is combined with a Greek façade, as in the sub-treasury on Wall street, New York, and sometimes the designer builds the Roman pedimented temple front on the high base and leaves off the steps, as in the Broad street façade of the New York Stock Exchange.

If the student will go about with his eyes open and attempt to classify, relate and trace to their origins the architectural forms that he observes in his daily walks, keeping in mind the elements of the structural arts that have been treated in this series of nine articles, he will find that a new world of interest will be opened up. The present will be vitally related to the past. The ancient civilizations will constitute the frame for a living science. With the development of an increased faculty of observation, a greater fullness of life will be experienced, and art and its multiform expressions will be felt to be, not a thing mysterious and apart, but the sane and logical reflection of actual life, and as such the most certain expression of the character of a people.

SEARCH AND REVIEW QUESTIONS ON THE REQUIRED READING WILL BE FOUND IN THE ROUND TABLE SECTION AT THE BACK OF THIS MAGAZINE.

(End of C. L. S. C. Required Reading, Pages 310-399.)

I

By Frank Loxley Griffin, Ph. D.

Assistant Professor of Mathematics, Williams College.

T is not strange that the peoples of antiquity stood in great awe of comets, and saw no similarity between. these bodies and the planets, whose wanderings among the fixed stars were so well known. For, coming at irregular intervals and hence unexpectedly, comets appeared with startling suddenness, their long tails extending like streamers of light far out among the stars, and their heads often larger and brighter than the planets yet nebulous and shining with a strange diffuseness, showing sometimes a bright central nucleus of a fantastic shape. (The English na:ne for these bodies comes from the Latin coma, hair,—a name given because of the fancied resemblance to a terrible fiery mane.) The apparition might occur in any part of the heavens, followed by rapid flight past the sun, and early disappearance. Moreover, in the middle ages, superstition was enhanced through the coming of brilliant comets at several crises of history; for example, in 1066 just before the Norman conquest of England, and again during the Turkish invasion of central Europe in 1456.

Still, some of the ancients believed that these bodies are subject to definite laws; and Seneca is credited with this interesting prediction:

"The time will come when our descendants will wonder that we were ignorant of things so simple. Some day there will arise a man who will demonstrate in what region of the heavens comets take their way; why they journey so far from the other planets; what their size."

This prophecy was fulfilled in Sir Isaac Newton and his friend Edmund Halley. In the monumental work, "Philosophiae Naturalis Principia Mathematica," published in 1687 at Halley's expense, Newton showed why a comet must move in the curve it follows, and how this path may be ascertained from observations of the comet. Halley in turn applied the methods his friend had developed, making a laborious computation of many orbits, with a remarkable re

sult. Comets seen in 1531, 1607, and 1682 were found to have traveled nearly the same path; which fact suggested that these were in reality one comet on several returns from a long journey into space, and caused Halley to offer his famous prediction that the year 1759 would witness another return of the same celestial wanderer. On Christmas eve, 1758, the comet was indeed sighted, and in the following spring was generally visible, some seventeen years after the death of Halley, to whom thus belongs the credit of first foretelling the return of a comet. Later investigation has shown that this comer, which so properly bears Halley's name, has been observed on each return, at intervals averaging about seventy-seven years, since the date 11 B. C. It was seen in 66 A. D. before the destruction of Jerusalem, being mentioned by Josephus in his sixth book as a sign from heaven. Other appearances which caused excitement occurred in 451, when Attila the Hun was defeated at Chalons, and in 1066 and 1456; for the comets of the latter two dates, mentioned above, were none other than Halley's. In nearly every case, the European accounts are practically worthless for purposes of identification, as the Chinese observers alone had sense enough to record the course of the comet among the stars. Crude drawings of this comet at several appearances have come down to us, and more skilful ones by able observers in 1835, but of course no photographs.

On the present trip the comet was first detected photographically by Wolf at Königstuhl on September 11 last, and was first seen by Burnham at the Yerkes Observatory on September 16. The comet's westward motion together with the sun's eastward course brought the comet too near the sun to be visible to the naked eye until the end of April, after it had passed to the west of the sun. It will by May 8 be visible in the east for two hours before sunrise; but will soon be obscured by sunlight, passing the sun again on May 18, after which despite the moonlight for a few evenings just at nightfall it will be a conspicuous object in the west