A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE 
“To the solid ground 
Of Nature trusts the mind which builds for aye.” —WoRDSWORTH 
No. 7] 
THURSDAY, DECEMBER 16, 1869 
Registered for Transmission Abroad] 
(All Rights are Reserved 
ROYAL INSTITUTION OF GREAT 
BRITAIN, Albemarle Street, W.—PROFESSOR TYNDALL, LL.D., 
F.R-S., will commence a Course of Six Lecrures (adapted to a Juvenile 
Auditory), “On LIGHT,” on TUESDAY, December 28th, at Three 
o'clock. Payment for this Course, One Guinea. (Children under 16, Half- 
a-Guinea) ; for all the Courses in the Season, Two Guineas. 
December, 1869. H. BENCE JONES, Hox. See. 
ROYAL INSTITUTION OF GREAT 
BRITAIN, Albemarle Street. W.—PROFESSOR TYNDALL, LL.D., 
F.R.S., will deliver, during the Christmas Vacation, a Course of Six 
Lectures (adapted to a Juvenile Auditory). ‘On LIGHT.” They will 
commence on TUESDAY, December 28th, at Three o'clock. Payment for 
this Course One Guinea. Children under 16 years of age, Half-a-Guinea ; 
for all the Courses of Lectures in the Season, Two Guineas. 
December, 1869. H. BENCE JONES, Hon. Sec. 
LADIES’ EDUCATIONAL ASSOCIATION, 
LONDON. 
A Course of Twenty-four Lectures on the Elements of Geometry will be 
given by Professor Hirst, at St. George’s Hall, Langham Place, on Mondays 
and Fridays at 11 A.M. (beginning on Jan. 17). The lectures will be of an 
elementary character requiring no previous knowledge of the subject: the 
extent to which it will ultimately be carried being dependent upon the 
progress of the class as studied by written exercises. 
Fee for the course of Geometry or any other Course in connection with the 
Association (except that of Chemistry) 41 11s. 6a. Governesses £1 1s. 
Chemistry Course 42 4s. Ladies over 17 years of age may join the classes 
after Christmas on the above terms. 
Applications for tickets to be made to the Hon. Sec., J. E. MYLNE, Esq., 
27, Oxford Square, W. 
THE UNIVERSE; or, the Infinitely Great 
and the Infinitely Little. By F. A. POUCHET, M.D. Illustrated by 343 
Engravings on Wood, of which 73 are full-page size, and 4 Coloured Plates. 
Handsomely bound, gilt top, 315. 6d. 
BLACKIE & SON, 44, Paternoster Row. 
In Crown 8yo. price r2s. 
SYMBOLISM; or, MIND, MATTER, 
LANGUAGE, as the Elements of Thinking and Reasoning, and as the 
Necessary Factors of Human Knowledge. By JAMES HAIG, M.A. 
WILLIAM BLACKWOOD & SONS, Edinburgh and London. 
BYRON’S POETICAL WORKS. 
Now ready, Post 8vo. price Half-a-Crown. 
THE PEARL BYRON; Being a New 
and Copyright Edition of the Complete POETICAL WORKS of LORD 
BYRON, collated and revised from the Author's MSS. 
The Pall Mall Gazette. 
“This PEARL EDITION of LORD BYRON’S WORKS is certainly 
the most remarkable reprint. For HALF-a-CROWN may now be hada 
complete and faithful collection of the poet’s works. 
“The BEST EDITION of BYRON ?s now brought within the means of 
the poorest student of the English classics.” 
JOHN MURRAY, Albemarle Street. 
WOL,, Le 
| 
CLERGY MUTUAL ASSURANCE 
SOCIETY. 
ESTABLISHED IN 1829. 
OFFICE—No. 2, BROAD SANCTUARY, WESTMINSTER. 
TRUSTEES, 
The ArcupisHop of CANTERBURY. The BisHop of WINCHESTER. 
The Arcueisuop of Dustin. The ARCHDEACON of MarpsToNe. 
CHAIRMAN. 
The Venerable the ARCHDEACON of Lonpon. 
DEPUTY-CHAIRMAN. 
The Honourable Enwarp W. Dovuctas. 
ACTUARY. 
Stewart HeEtper, Esq. 
SECRETARY. 
The Rev. Joun Hopcson, M.A. 
ner Existing Assurances. . . 
Total Annual Income. bb oO 6 Dido 173) 
| ‘DotaliinvestediCapitalame ep halen on ote merce 2 z 
_For the year ending 31st May, 1869, 315 proposals, assuring £274,540, and 
yielding in annual premiums £9,383 16s. 6¢., were completed ; and £88,482 
13s. 1d. was (notwithstanding the large reduction made by Bonus in every 
fifth year from 1831 to 1866, both inclusive) added to the Fund accumulating 
for the purpose of meeting future claims. 
Prospectuses, Accounts of Bonus, &c. &c., to be had at the Office, on 
application personally, or by letter ; also a Pamphlet by the Rev. J. Hodgson, 
called ‘‘ Notes on Life Assurance,” containing explanations on various inte- 
resting points. 
Clergymen and their Wives, and the relations of Clergymen and of their 
Wives, are invited to make Life Assurances in this Society. 
44,473,023 0 6 
OBSERVATIONS IN REFERENCE TO DURATION OF LIFE 
AMONGST CLERGYMEN. 
| _ Established upon investigations made in the case of five thousand Incunt- 
| bents of livings, from the middle of the last century to the middle of the 
present. 
| BY THE REV. JOHN HODGSON, M.A. 
Of Trinity College, Cambridge, Secretary of the Clergy Mutual Assurance 
| Society, and formerly Vicar of St. Peter's, in the Isle of Thanet, and Rural 
Dean of Westbere. To which is added a Supplement, by Samuel Brown, 
| Esq., President of the Institute of Actuaries. Copies may be had of Messrs. 
C. and E. Layton, Fleet-street. Price 2s. 6d. each. 
| NEW ELECTRIC LAMP.—Browning’s 
New Large Automatic Electric Lamp. In this lamp both carbons are moved 
by the eleetricity of the battery employed (without the aid of clockwork) : 
the light remains uniform in height, and more steady in action than any of 
the expensive regulators previously introduced. Price £8 8s. Illustrated 
circular for stamped envelope. 
JOHN BROWNING, Optical and Physical Instrument Maker to the Royal 
Observatory, &c. &c., t1t, Minories, E., London. Established 100 years. 
SPECTRUM APPARATUS. —John 
BROWNING has great pleasure in introducing, to the notice of Lecturersand 
others, an economical set of apparatus for projecting the spectra of metals, 
or the absorption bands of liquids, on a screen. [Illustrated catalogue of 
Spectroscopes sent for thirteen stamps. 
JOHN BROWNING, Optical and Physical Instrument Maker to the 
Royal Observatory, &c., &c., rrz, Minories. Prize Medal, 1862. 
Established 100 years, 
ce) 
