Twentieth Year of Publication 
THE 
JOURNAL OF SCIENCE 
AND ANNALS OF 
Astronomn, JSiologir, (Seologji, Industrial Arts, 
Jltamtfartnm, and ffisrijnalogn. 
MONTHLY, FORMERLY “ THE QUARTERLY JOURNAL OF SCIENCE.' 
PRICE, ONE SHILLING AND SIXPENCE. 
This Journal is an established medium of communication 
between the Scientific Investigator and the Reading Public, as 
well as between Students in the various branches of Science. It 
also constitutes a Review of the Progress of Science in all parts 
of the world. Its past and present Contributors include the 
following names : — 
F. A. Abel, C.B., F.R.S. 
Prof. Ansted, F.R.S. 
W. E. A. Axon 
Prof. W. E. Ayrton 
Rev. S. Barber 
Prof. W. F. Barrett 
Dr. Lionel S.Beale, F.R.S. 
Dr. G. M. Beard 
Thomas Belt 
A. W. Bennett 
Professor Bentley 
E. W. Binney, F.R.S. 
Dr. H. Carrington Bolton 
F. W. Brearey 
Sir Charles Bright 
H. W. Bristow, F.R.S. 
Capt. Richard F. Burt 
Dr.W. B. Carpenter, C.B. 
F.R.S. 
1vol. A. H. Church 
Professor Coughtrie 
James Croll, F.R.S. 
William Crookes, F.R.S. 
F. C. Danvers 
W.Boyd Dawkins, F.R.S. 
Dr. Henry Draper 
Colonel Drayson, R.A. 
Sir William Fairbairn, 
Bart., F.R.S. 
Frederick Field, F.R.S. 
Rev. O. Fisher 
•Camille Flammarion 
Sir Charles Fox 
Prof. Frankland, F.R.S 
Dr. Gladstone, F.R.S. 
James Glashier, F.R.S. 
George Gore, F.R.S. 
A. Vernon Harcourt, 
F.R.S. 
Edward T. Hardman 
Prof. Harkness, F.R.S. 
Prof. W. Noel Hartley 
Rev. S. Haughton, F.R.S. 
Prof. F. V. Hayden 
Sir John Herschel, F.R.S. 
Rev. H. H. Higgins 
J. R. Hind, F.R.S. 
Prof. Hofmann, F.R.S. 
William Huggins, F.R.S. 
Prof. Hull, F.R.S. 
Robert Hunt, F.R.S. 
H. M. Jenkins 
Prof. W. Stanley Jevons, 
F.R.S. 
G. H. Kinahan 
Prof. W. King 
Sir Frantis Knowles, 
Bart., F.R.S. 
: Dr. Lankester, F.R.S. 
Prof. A. R. Leeds 
J. Norman Lockyer, 
F.R.S. 
Robert Mallet, F.R.S. 
Dr. R. J. Mann 
Prof. N. S. Maskelyne, 
F.R.S. 
Prof.Thompson B. Maury 
Prof. Henry Mnrton 
J. Chalmers Morton 
Prof. M. M. Pattison 
Muir 
J. Munro 
Edmund Neison 
Prof. Simon Newcomb, 
F R S 
Prof. Od’ling, F.R.S. 
Capt. Oliver, R.A. 
Dr. J. Bell Pettigrew, 
F.R.S. 
Dr. Paul 
William Pengelly, F.R.S. 
Prof. Phillips, F.R.S. 
J. A. Phillips 
Raoul Pidtet 
Mungo Ponton 
S. Tolver Preston 
T. Symes Prideaux 
H. Baden Pritchard 
R. A. Prodtor 
C. W. Quin 
Prof.A.C. Ramsay, F.R.S. 
G. F. Rodwell 
Dr. Rolleston, F.R.S. 
G. J. Romanes, F.R.S. 
James Samuelson 
Dr. A. E. Sansom 
Dr. P. L. Sclater, F.R.S 
R. H. Scott, F.R.S. 
Prof. H.G. Seeley, F.R.S. 
J. W. Slater 
Dr. R. Angus Smith 
F.R.S. 
Piazzi Smyth 
H. C. Sorby, F.R.S. 
Prof. Balfour Stewart 
F.R.S. 
W. T. Suffolk 
Prof. Silvanus Thompson 
William Topley 
Prof. Tyndall, F.R.S. 
: Dr. Voelcker, F.R.S. 
Alfred Russel Wallace 
Dr. Wallich 
Dr. W. M. Watts 
Rev. J. Clifton Ward 
Dr. F. C. Webb 
W. Mattieu Williams 
Henry Woodward, F.R.S 
Horace B. Woodward 
Prof. Zollner 
LONDON : 3 . HORSE-SHOE COURT, LUDGATE HILL, 
And All Booksellefs. 
