APPENDIX II.

Page 23; note at line 3. Prof. Osborne Reynolds made the interesting remark (_Collected Papers_, Vol. ii., p. 154), "That if solid matter had certain kinds of internal motions, such as the box has, pears differing, say, from apples, the laws of motion would not have been discovered; if discovered for pears they would not have applied to apples."

Page 38; note at line 8. The motion of a rifle bullet is therefore one of precession about the tangent to the path. The mathematical solution is difficult, but Prof. Greenhill has satisfied himself mathematically that air friction damps the precession, and causes the axis of the shot to get nearer the tangential direction, so that fig. 10 ill.u.s.trates what would occur in a vacuum, but not in air. It is probable that this statement applies only to certain proportions of length to diameter.

Page 129; note at line 5. Many men wonder how the ether can have the enormous rigidity necessary for light transmission, and yet behave like a frictionless fluid. One way of seeing how this may occur is to imagine that when ordinary matter moves in the ether it only tends to produce motion of translation of the ether particles, and therefore no resistance. But anything such as light, which must operate in turning axes of rotating parts, may encounter enormous elastic resistance.

_Richard Clay & Sons, Limited, London and Bungay._

PUBLICATIONS

OF THE

SOCIETY FOR PROMOTING CHRISTIAN KNOWLEDGE.

THE ROMANCE OF SCIENCE.

Small post 8vo, cloth boards.

COAL, AND WHAT WE GET FROM IT. By Professor R. MELDOLA, F.R.S., F.I.C.

With several Ill.u.s.trations. 2s. 6d.

COLOUR MEASUREMENT AND MIXTURE. By Sir W. DE W. ABNEY, K.C.B., R.E., F.R.S. Numerous Ill.u.s.trations. 2s. 6d.

DISEASES OF PLANTS. By Professor MARSHALL WARD. Numerous Ill.u.s.trations.

2s. 6d.

OUR SECRET FRIENDS AND FOES. By PERCY FARADAY FRANKLAND, Ph.D., B.Sc.

(Lond.), F.R.S. Ill.u.s.trated. 3s.

SOAP-BUBBLES, AND THE FORCES WHICH MOULD THEM. By C. V. BOYS, A.R.S.M., F.R.S. Ill.u.s.trated. 2s. 6d.

SOUNDING THE OCEAN OF AIR. By A. LAWRENCE ROTCH, S.B., A.M. Numerous Ill.u.s.trations. 2s. 6d.

SPINNING TOPS. By Professor J. PERRY, M.E. With several Ill.u.s.trations.

2s. 6d.

THE MAKING OF FLOWERS. By the Rev. Professor GEORGE HENSLOW, M.A., F.L.S., F.G.S. With Ill.u.s.trations. 2s. 6d.

THE STORY OF A TINDER-BOX. By the late CHARLES MEYMOTT TIDY, M.B., M.S., F.C.S. Numerous Ill.u.s.trations. 2s.

TIME AND TIDE. A Romance of the Moon. By Sir ROBERT S. BALL, LL.D. With Ill.u.s.trations. 2s. 6d.

THE BIRTH AND GROWTH OF WORLDS. By the late Professor GREEN, F.R.S.

With Ill.u.s.trations. 1s.

THE SPLASH OF A DROP. By Professor A. M. WORTHINGTON, F.R.S. Numerous Ill.u.s.trations. 1s. 6d.

THE MACHINERY OF THE UNIVERSE. By Professor A. E. DOLBEAR, A.B., A.M., M.E., Ph.D. Ill.u.s.trated. 2s.

THE NEW STATE OF MATTER. An Address by Professor H. PELLAT. Translated by EDMUND MCCLURE, M.A. 1s.

TURBINES. By Engineer-Commander A. E. TOMPKINS, R.N. Ill.u.s.trated. 3s.

6d.

WORKS BY MRS. RUNDLE CHARLES, AUTHOR OF "The Chronicles of the Schonberg-Cotta Family."

THE BEAt.i.tUDES. Thoughts for All Saints' Day. Post 8vo. _Cloth boards.

1s._

"BY THE MYSTERY OF THY HOLY INCARNATION." Post 8vo. _Cloth boards. 1s._

"BY THY CROSS AND Pa.s.sION." Thoughts on the words spoken around and on the Cross. Post 8vo. _Cloth boards. 1s._

"BY THY GLORIOUS RESURRECTION AND ASCENSION." Easter Thoughts. Post 8vo. _Cloth boards. 1s._

"BY THE COMING OF THE HOLY GHOST." Thoughts for Whitsuntide. Post 8vo.

_Cloth boards. 1s._

THE TRUE VINE. Post 8vo. _Cloth boards. 1s._

THE GREAT PRAYER OF CHRISTENDOM. Thoughts on the Lord's Prayer. Post 8vo. _Cloth boards. 1s._

AN OLD STORY OF BETHLEHEM. One link in the great Pedigree. Fcap. 4to, with six plates, beautifully printed in colours. _Cloth boards. 2s._

JOAN THE MAID, Deliverer of England and France. Demy 8vo. _Cloth boards. 2s. 6d._

SONGS, OLD AND NEW. Demy 16mo. _Cloth boards. 2s. 6d._

ECCE ANCILLA DOMINI. Mary the Mother of our Lord. Studies in the Ideal of Womanhood. Post 8vo. _Cloth boards. 1s. 6d._

ECCE h.o.m.o, ECCE REX. Pages from the Story of the Moral Conquests of Christianity. Crown 8vo. _Cloth boards. 2s. 6d._

THREE MARTYRS OF THE NINETEENTH CENTURY. Studies from the Lives of Gordon, Livingstone, and Patteson. Crown 8vo. _Cloth boards. 2s. 6d._

MARTYRS AND SAINTS OF THE FIRST TWELVE CENTURIES. Studies from the Lives of the Black-letter Saints of the English Calendar. Crown 8vo.

_Cloth boards. 2s. 6d._

AGAINST THE STREAM. The Story of an Heroic Age in England. With eight page woodcuts. Crown 8vo. _Cloth boards. 2s. 6d._

CONQUERING AND TO CONQUER. A Story of Rome in the days of St. Jerome.

Ill.u.s.trated. Crown 8vo. _Cloth boards. 2s._