NOTE ON AN AMERICAN EXAMPLE OF A "ST. GILES STAIRCASE." By S. EDWARD WARREN, of Newton, Mass.

THE St. Giles staircase is one of the most complicated conceivable constructional features in architecture and engineering. Therefore, as a visit to Marblehead promises to be in order during the present session of the Association, a note upon the construction may interest those visitors who are interested in such matters.

In popular language, the structure is a winding stairway, arched overhead as it winds; the whole, steps, walls, and spiral arched covering being in cut stone. It will be found in the old abandoned fort at Marblehead, garrisoned, when last seen, by one man in working dress, and armed only with a wooden rake.

To those who are unfamiliar with the construction, its essentials can be made intelligible, step by step, without model or diagram, as follows:

1. Hold a rod vertically in the left hand.

2. Hold a second rod horizontally in the right hand, one end of it meeting the first rod.

3. If the second rod be moved upward, keeping it parallel to itself, it will sweep over, that is, generate a vertical plane area.

4. If, instead of this upward motion, this same second rod be revolved about the vertical rod, keeping it horizontal, and meeting the vertical rod at a fixed point, it will generate a horizontal circular

area.

5. If both the motions just described be combined, and if both be uniform, the horizontal rod will have an ascending spiral motion, always in a horizontal position, around the vertical rod, and will generate the spiral surface of a square-threaded screw, the same as is seen on a larger scale in the plastered under-side of circular stairs winding around a cylindrical central post or pit, and called a helicoidal surface.

6. But now substitute for the horizontal moving rod a semicircle, having that rod for its diameter, and in a vertical position; that is, so that the vertical rod shall be tangent to it at one extremity of its horizontal diameter.

7. Now give this semicircle the same compound or spiral motion that was given to the moving rod in the last case, and it will generate what may be popularly termed the cylindrically spiral surface, which will be the arched ceiling of the staircase.

8. Finally, the joints between the stones of a semicircular arch being radial, the joint surfaces of the spiral overhead arch of the St. Giles staircase may be generated by radii of the generating semicircle of its arched ceiling. In this case, these joint surfaces will be heliocoidal, of the kind called oblique; that is, like the surfaces of the threads of a triangular or V-threaded screw. These straight lines produced will everywhere intersect the vertical rod or axis, and hence will be in vertical planes. They will also intersect the helix or spiral line generated by the centre of the moving semicircle. These properties facilitate the construction.

9. But such joint lines are not perpendicular to the arched surface, that being not over a horizontal circular passage, but over an ascending one. But, in making them thus perpendicular, we fall on niceties of description, which would require diagrams and models, and on niceties of construction, which are expensive and difficult. Wherefore I stop, only directing inquiry for the stone-winding stairs in the Marblehead fort, and adding that a model in plaster of the like construction will be found in the Institute of Technology.

TITLES OF OTHER PAPERS READ IN THE SUBSECTION OF ANTHROPOLOGY.

EXHIBITION OF STONE IMPLEMENTS FROM THE RIVER DRIFT OF NEW JERSEY. By C. C. Abbott, of Trenton, N. J.

INDICATIONS OF A PRE-INDIAN

OCCUPANCY OF THE ATLANTIC

COAST OF NORTH AMERICA, SUBSEQUENT TO THAT OF PA-
LEOLITHIC MAN. By C. C. Abbott, of Trenton, N. J.

ANTIQUITIES OF ONONDAGA COUNTY, NEW YORK. By W. M.
Beauchamp, of Baldwinsville, N. Y.

ETHNOLOGY OF AFRICA, ILLUSTRATED BY A LARGE MANUSCRIPT MAP. By A. S. Bickmore, of New York, N. Y.

IMPROVED STEREOGRAPH FOR DELINEATING THE OUTLINES OF CRANIA. By A. S. Bickmore, of New York, N. Y.

OCCURRENCE OF EXOSTOSES IN THE EXTERNAL AUDITORY CANAL IN PREHISTORIC MAN. By Clarence J. Blake, of Boston, Mass.

REMARKS ON THE MOUND-BUILDERS. By J. F. Everhart, of Zanesville, Ohio.

CONTEMPORANEOUS EXISTENCE OF MASTODON AND MAN IN AMERICA. By R. J. Farquharson, of Davenport, Iowa.

THE PROBABLE EXISTENCE IN AMERICA OF THE PREHISTORIC
PRACTICE OF TREPANNING, IN THE CUTTING OF RONDELLES

OR AMULETS FROM THE SKULL. By R. J. Farquharson, of
Davenport, Iowa.

ON STONE AXES. By S. S. Haldeman, of Chickies, Pa.

REMARKS ON ABORIGINAL POTTERY. By S. S. Haldeman, of Chickies, Pa.

ANCIENT MOUNDS IN VICINITY OF NAPLES, ILL. By J. G. Henderson, of Winchester, Ill.

SIGN LANGUAGE AND PANTOMIMIC DANCES AMONG THE NORTH
AMERICAN INDIANS. By J. G. Henderson, of Winchester, Ill.
TEXTILE FABRICS OF THE ANCIENT INHABITANTS OF THE MISSIS-
SIPPI VALLEY. PT. I. MATERIAL. PREPARATION OF MATE-
RIAL AND SPINNING, ILLUSTRATED WITH SPECIMENS OF BARK,

SPINDLE-WHORLS, MODELS OF SPINDLES AND DRAWINGS. By
J. G. Henderson, of Winchester, Ill.

TEXTILE FABRICS OF THE ANCIENT INHABITANTS OF THE MISSIS-
SIPPI VALLEY. PART II. THE LOOM AND THE FRUIT OF THE
LOOM, ILLUSTRATED WITH MODELS OF LOOMS, MODELS OF
SHUTTLES, AND DRAWINGS. By J. G. Henderson, of Win-
chester, Ill.

TEXTILE FABRICS OF THE ANCIENT INHABITANTS OF THE MISSIS-
SIPPI VALLEY.
MOUND-BUILDER, STONE-GRAVE AND

PT. III.

CAVE FABRICS, ILLUSTRATED WITH SPECIMENS OF CLOTH FROM
MOUNDS, COPPER AXES WITH CLOTH ADHERING TO THE SAME,
AND POTTERY WITH IMPRESSIONS OF CLOTH ON THE SURFACE.

By J. G. Henderson, of Winchester, Ill.

ENGRAVED TABLET FROM A MOUND IN OHIO. By W. J. Knowlton, of Boston, Mass.

THE VOGULS. By A. Kocsis, of Tullahoma, Tenn.

THE INDIAN QUESTION. By D. A. Lyle, of Springfield, Mass. SCHEME OF THE TENTH CENSUS FOR OBTAINING STATISTICS Of unTAXED INDIANS. By Garrick Mallery, of Washington, D. C.

A COMPARISON BETWEEN THE SHELLS OF KJÖKKENMÖDDINGS, AND PRESENT FORMS OF THE SAME SPECIES. By E. S. Morse, of Salem, Mass.

JAPANESE CAVES. By E. S. Morse, of Salem, Mass.

PERSISTENCE OF KOREAN ORNAMENTATIOn in Japanese pottery. By E. S. Morse, of Salem, Mass.

PREHISTORIC AND EARLY TYPES OF JAPANESE POTTERY.

Morse, of Salem, Mass.

By E. S.

THE MILITARY SYSTEM OF THE EMBLEMATIC MOUND-BUILDERS. By S. D. Peet, of Clinton, Wis.

THE TOPOGRAPHICAL SURVEY OF THE WORKS AT AZTALAN, WIS. By S. D. Peet, of Clinton, Wis.

RELATION OF THE ARCHEOLOGY OF VERMONT TO THAT OF THE
ADJACENT STATES. By George H. Perkins, of Burlington, Vt.
ON THE RANK OF INDIAN LANGUAGES. By J. W. Powell, of Wash-
ington, D. C.

THE CLASSIFICATION OF KINDRED BY THE N. A. INDIANS.
J. W. Powell, of Washington, D. C. '

By

CONVENTIONALISM IN ORNAMENTATION OF ANCIENT AMERICAN POTTERY. By F. W. Putnam, of Cambridge, Mass.

ON THE OCCURRENCE IN NEW ENGLAND OF CARVINGS BY THE INDIANS OF THE NORTHWEST COAST OF AMERICA. By F. W. Putnam, of Cambridge, Mass.

MYTHS AND FOLK-LORE OF THE IROQUOIS. By Erminnie A. Smith, of Jersey City, N. J.

ON THE IROQUOIS LANGUAGE. By Erminnie A. Smith, of Jersey. City, N. J.

EXHIBITION OF SOME GAMBLING GAMES OF THE IROquois. By Erminnie A. Smith, of Jersey City, N. J.

FEELING AND FUNCTION AS FACTORS IN HUMAN DEVELOPMENT. By Lester F. Ward, of Washington, D. C.

PARTURITION IN A KNEELING POSTURE, AS PRACTISED BY THE WOMEN OF THE MOUND-BUILDER AND STONE-GRAVE RACE. By C. Foster Williams, of Ashwood, Tenn.

EXECUTIVE PROCEEDINGS.

REPORT OF THE GENERAL SECRETARY.

Wednesday, August 25, 1880.—At 10.45 A. M. the Association was called to order in Huntington Hall, Massachusetts Institute of Technology, Boston, by the retiring President, Professor GEORGE F. BARKER, of Philadelphia, who presented the President elect, the Hon. LEWIS H. MORGAN, of Rochester, who expressed his thanks for the honor and his desire to discharge his duties with promptness and impartiality.

At the request of the President, the Rev. GEORGE E. ELLIS, D.D., Boston, offered prayer.

of

WILLIAM B. ROGERS, LL.D., President of the Massachusetts Institute of Technology, and Chairman of the Local Committee, then addressed the Association as follows:

Ladies and Gentlemen:- Speaking as the representative of the local committee of the hospitable city of Boston, and speaking as one of the old representatives of the American Association for the Advancement of Science, I have a double duty to perform, to speak for the guest and for the entertainer. The American Association for the Advancement of Science has never yet held a meeting in this the city of Franklin, of Bowditch, and of the long line of other scientific worthies, prominent among whom have been Wyman and our great instructor, our adopted citizen, Louis Agassiz. It seems a fitting place for such an association to convene. Its spirit, its institutions, its history, its habits and sympathies, all favor such a reunion between its citizens and the lovers and promoters of science. It was my good fortune, if it is a good fortune to be able to date back one's life for a long period of years, to have been familiar with this institution from its cradle, when it first presented itself as the Association of American Naturalists and Geologists. This, however, was not the earliest congress of science assembled in the world. The origin of this thought of an annual parliament of scientific men seems properly to belong to the great German philosopher Oken, who as early as 1822 organized the German Association for the Advancement of Science. For eight or nine years this example was not followed, but in 1831 Brewster, aided by Brougham, established the British Association for the Advancement of Science, which we are to regard as the parent institution from which we have sprung.

This British Association, meeting first in the ancient city of York in 1831, has held its annual meetings, for a series of years, in all the great capitals and some of the secondary cities of the kingdom, faithfully ad(737)

A. A. A. S., VOL. XXIX.

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