448 SEC. 12. APPLIED MECHANICS.
1928h. Model of Wheel (probably for grinding). With
sliding axle.
19281. Fragment of Model (probably a pump bucket).
1928k. Models on a Stand, of four trussed beams, probably
used experimentally for testing the strength of different methods of
trussing.
19281. Fragment of a Model of a Frame for a Ma-
chine.
1928m. Fragment of a Frame.
1928n. Model of a Horse Mill, with roller and trough,
apparently designed for crushing material.
1928o. Model of a Train of Wheels.
1928p, Model of Beam and two connecting Bods with
universal motion at their upper ends, and connected to transverse
hinged links at their lower ends.
1928q. Model of Beam Pumping Engine, single acting
and condensing, worked by tappet valve motion.
1928r. Model of double acting Beam Condensing En-
gine, conical valves worked by eccentric.
1928r. Model of inverted Cylinder direct-acting
Pumping Engine, with tappet valve motion.
1928s. Sectional Model of Beam Engine, worked by
eccentric and hollow valve.
19 2 St. Sectional Model of Engine, with shifting eccentric
for altering valve.
1928u. Model of a Pair of Tilt Hammers, alongside each
other. Two beams and connecting rods, with cranked pins at an
angle to each other, and one of the wheels provided with a
balance weight.
(NOTE. Part of the above model missing.)
1928v. Fragment of a Model with part of Sun and planet
motion.
1928w. Fragment of a Model with Sun and planet motion
and weighted disc.
1928x. Fragment, an arch head.
1928y. Model of a Water Wheel.
III. PRIME MOVERS. 449
1928z. Measuring Apparatus, with Micrometer Screw,
for taking end measures.
1928aa. Model of Garnet's Patent Friction Hollers.
192 8bb. Model used for Testing Pressure due to
Vacuum.
1928cc. Model of Valve with Universal Joint.
1928dd. Brass Model in two Pieces.
1928ee. Model used in experiments on Governor.
1928ff. Experimental Model.
1928gg. Experimental Model.
1928hh. Experimental Model.
1928ii. Original Model of Cylinder with separate
Condenser.
1828jj. Model of Surface Condenser.
III. PRIME MOVERS.
a. STATIONARY ENGINES.
2019d. Papin's Steam Cylinder.
Royal Museum, Cassel (Director, Dr. Pinder).
This cast-iron cylinder was to have formed part of a large pumping
engine, which, however, was never completed. The object was to supply a
canal at the level of Hofgeismar with water, whereby the Landgraf Charles
hoped to draw the traffic of the Weser to Cassel. An explosion which took
place in Papin's laboratory when the Landgraf was contemplating a visit, led
to the bold investigator withdrawing from the influence of his enemies. He
came to England (1707), but did not succeed with his plans, and died in
poverty. Papin's sketch of his contemplated pumping engine is exhibited
with the cylinder. It was a peculiar combination of the Savery engine and
the piston engine recommended by Papin for other purposes. In the closed
boiler A (with safety-valve of Papin's design) , steam was generated, which (on
opening the cock C) could pass through pipe B to cylinder D. Here it
pressed down the close fitting piston or float E which rested on water that
had been supplied through the funnel I from a reservoir. The water was
thus forced into the chamber F ; its return was prevented by a valve at H ;
and the steam-cock C being now shut and the condensed steam allowed to
escape from the upper part of D, water from the reservoir was admitted
anew, and the process repeated. The water raised into F could be further
directed through the tube G. Papin proposed to add to the effect by
introducing red hot irons through the opening in the cover of the cylinder D.
Of the two cylinders it is probably D that is exhibited.
40075. F f
LIBRARV
OF TIM
UNIVERSITY OF CALIFORNIA
OIF-T OR
Received CL
Accession No. 3~? / ^ f . Class No.
^y
...
gtiente antr &rt
of tye Committee of (ffounril on (Strurattom
I s===s==s====
CATALOGUE
OF THE
SPECIAL LOAN COLLECTION OF
SCIENTIFIC APPARATUS
AT THE
SOUTH KENSINGTON MUSEUM.
V
MDCCCLXXVI.
THIRD EDITION.
TJKIVEESIf?
LONDON:
PRINTED BY GEORGE E. EYRE AND WILLIAM SPOTTISWOODE,
PRINTERS TO THE QUEEN'S MOST EXCELLENT MAJESTY.
FOU HER MAJESTY'S STATIONERY OFFICE.
1877.
SCIENCE AND ART DEPARTMENT
OF THE COMMITTEE OF COUNCIL ON EDUCATION.
SOUTH KENSINGTON.
ESTABLISHED in connexion with the Board of Trade in March 1853 as a develop-
ment of the Department of Practical Art, which in 1852 had been created for the
re-organisation of Schools of Design. Placed under the direction of the Committee of
Council on Education in 1856.
Lists of Presidents and Vice-Presidents.
Board of Trade.
1852. Rt. Hon. H. Labouehere, M.P., President.
Rt. Hon. J. W. Henley, M.P.. President.
1853. Rt.Hon.Edward Cm-dwell, M.P., President.
1855. Rt. Hon. Lord Stanley of Alderley, Pros.
Committee of Council on Education.
185G. Rt. Hon. Earl Granville, K.G., Lord Presi-
dent.
Rt.Hon.W. E.Cowpcr,M.P.,Vioe-President.
1858. Most Hon. Marquess of Salisbury, K.G.
Rt. Hon. Sir C. B. Adderley, K.C.M.G.,
M.P., Vice- President.
1859. Rt. Hon. Earl Granville, K.G.
Rt. Hon. Robert Lowe, M.P., Vice-Pros.
1864. Rt. Hon. H. A. Bruce, M.P., Vice-Pres.
1866. His Grace the Duke of Buckingham and
Chandos.
Rt. Hon. H. T. Lowry Corry, M.P., Vice-
President.
1867. His Grace the Duke of Marlborough, K.G.
Rt. Hon. Lord Robert Montagu, M.P., V.-P.
1868. Most Hon. the Marquess of Ripon, K.G.
Rt. Hon. W. E. Forster, M.P., Vice-Pres.
1873. Rt. Hon. Lord Aberdare.
Rt. Hon. W. E. Forster, M.P., Vice-Pres.
1874. His Grace the Duke of Richmond and
Gordon, K.G., Lord President.
The Right Hon. the Viscount Sandon,
M.P., Vice President.
OFFICE HOURS, TEN TO FOUR.
GENERAL ADMINISTRATION.
Secret anj Sir Francis R. Sandford, C.B.
Assistant Secretary. Xorinnn MacLeod.
Chief Clerk. G. Francis Duncombe.
First-class Clerks. \. J. R. Trendell ; Alan S.
Cole ; F. R. Fowke ; A. S. Bury.
Second-class Clerks. J. B. Rundell ; H. W.
Williams ; E. Belshaw ; G. G. Millard ; A. F.
E. Torrens ; O. J. Dullea.
Postal Clerk Vi. Burtt.
Clerk nf Accou >ifx.V;\.cant.
Jiook-keeper.T. A. Bovrler.
Assistant Book-kecper.~E. Harris.
GENERAL STORES.
Storekeeper. W. G. Groser. Deputy. H.Lloyd.
Clerks J. Smith ; F. Walters.
SCIENCE DIVISION.
Director. Major Donnelly, R.E.
Occasional Inspectors. F. J. Sidney, LL.D. ;
('apt. Harris, E.I.C. (Navigation).
Official Examiner G. G. T. Bartlcy.
Assistant Professional Examiner. T. Healey.
Professional Examiners for Science.
Subjects.
L Practical, plane, and solid Geometry.
II. Machine Construction and Drawing.
W. C. Unwin, B.Sc.
III. Building Construction. Major Seddon,
R.E.
IV. Naval Architecture. W. B. Baskcomb.
V Pure Mathematics. C. W. Merrifield,
F.R.S. ; T. Savage, M.A.
VI. Theoretical Mechanics. Rev. John F.
Twisden, M.A.
VII.-Applied Mechanics. T.M.Goodeve.M.A.
VIII Acoustics, Light, and Heat. J. Tyn-
dall, LL.D., F.R.S. ; F. Guthrie,
F.R.S.
TX. Magnetism and Electricity. J. Tyn-
dall, LL.D., F.R.S.; H. Debus, F.R.S.
X. Inorganic Chemistry. E. Frankland,
D.C.L.. Ph.D., F.R.S.
40075.
Subjects.
XL Organic Chemistry. E. Frankland,
D.C.L., Ph.D., F.R.S.
XII. Geology. A. C. Ramsay, LL.D., F.R.S.
XIII Mineralogy W. W. Smyth, MA.,
F.R.S.
XIV. Animal Physiology. T. H. Huxley,
LL.D..F.R.S.
XV. Elementary Botany. W. T. T. Dyer,
M.A., B.Sc., F.L.S.
XVI. } General Biolosry. T. H. Huxley,
XVII. J LL.D., F.R.S. f W. T. T. Dyer, M.A.,
B.Sc., F.L.S.
XVIII. Mining. W. W. Smyth, M.A., F.R.S.
XIX. Metallurgy J. Percy, M.D., F.R.S.
XX. Navigation J. Woolley, LL.D.
XXL Nautical Astronomy. J. Woolley,
LL.D.
XXII Steam T. M. Goodeve, M.A.
(Physical Geography. D. T. Ansted,
XXI II J M.A..F.R.S.
C Physiography .
XXIV. Principles of Agriculture. H. Tanner,
F.C.S.
ART DIVISION.
Director. E. J. Poynter, R.A.
Assistant Director. H. A. Bowler.
Occasional Inspectors. S. A. Hart, R.A. ; F. B.
Barwell ; W. B. Scott.
Official Examiner. 1. Chesman, B.A., LL.B.
Professional Examiners. F. R. Pickersgill,
R.A.; W. F. Yeames, A.R.A. ; J. E. Boehm;
Val. Prinsep ; W. Morris ; G. Atchison ; J.
Marshall,F.R.S.,F.R.C.S. ; E. J. Poynter, R.A.,
and H. A. Bowler.
Assistant Professional Examiner. J. A. D.
Campbell.
Occasional Examiners. G. M. Atkinson; G.
R. Redgrave.
Inspectors of Local Schools of Science and Art.
R. G. Wylde ; J. F. Iselin, M.A. ; E. P.
Bartlett; Captain W. de W. Abney, R.E.,
F.R.S.
Organising Master of Science and Art Classes.
J. C. Buckmaster, F.C.S.
a 2
iv
NATIONAL ART TRAINING SCHOOL.
Principal. TO,, J. Poynter, R.A.
Head Master. J. Sparkes.
Registrar. R. W. Herman.
Mechanical and Architectural Draiving.
H. B. Hagre^n.
Geometry and Perspective. E. S. Bnrchett.
Painting, Freehand Drawing of Ornament, &c.,
the Figure and Anatomy, and Ornamental
Design. 3. Sparkes; C. P. Slocombe ; T.
Clack, and F. M. Miller.
Modelling . M. Miller.
Lady Superintendent of Female Classes.
Miss Trulock.
Instructors. Mrs. S. E. Casabianca : Miss
Channon.
Occasional Lecturers. E. Bellamy, F.R.C.S.,
Eng., Anatomy; Dr. Zerffi, Historic Orna-
ment; R. W. Herman, Principles of Orna-
mental Construction; F.W.Moody, TheFigure.
Teacher of Etching Class. A. Legros.
Teacher of Wood Engraving Class. C. Roberts.
SOUTH KENSIXG-TOX MUSEUM.
Director. -P. Cunliffe Owen, C.B. (temp, absent) .
Acting Director. E,. A. Thompson.
Assistant Directors Major E. R. Fcsting, R.E. ;
Col. Sir H. B. Sandford.
Director ofNeio Buildings. Major-Gen. Scott,
C.B., F.R.S.
Decorative Artist. R,. Townroe.
Instructor in Decorative Art and Decorative
Artist F. W. Moody.
Museum Keeper (Art Collections}. -G. Wallis.
Museum Keeper (National Art Library). R.
H. Soden Smith, M.A., Trinity College, Dub-
lin, F.S.A.
Museum Keeper (Educational Library and
Collections). A. C. King, F.S.A.
Assistant Museum Keepers. W. Matchwick,
F.L.S.; H. Sandham; K.Laskey; C. B. Wor-
snop ; R. F. Sketchier, B.A., Exeter College,
Oxford; H. E. Acton; J. W. Appcll, Ph.D.;
J. Barrett, B.A. ; C. H. Derby, B.A.
Museum Clerks.- -M. Webb ; H. M. Cundall ;
L. Finding.
Technical and Special Assistants. R. Vernon ;
A. Masson ; W. E. Streatfeild ; A. Reid ; F.
Coles ; W. G. Johnson ; G. H. Wallis ; S. Cow-
per ; O. Scott.
Superintendent for Examples and Publica-
tions. J. Cundall.
BETHNAL GREEN BRANCH OF THE
SOUTH KENSINGTON MUSEUM.
(Opened on June 24, 1872.)
GEOLOGICAL SURVEY.
Director-General. A.C. Ramsay, LL.D., F.R.S.
Director for England and Wales. H. W.
Bristow, F.R.S.
Director for Ireland. E. Hull, M.A., F.R.S.
Director for Scotland. A. Geikie, F.R.S.
Naturalist T. H. Huxley, LL.D., F.R.S.
Paleontologist R. Etheridge, F.R.S.
ROYAL SCHOOL OF MINES AND MU-
SEUM OF PRACTICAL GEOLOGY.
Director of Museum of Practical Geology
A. C. Ramsay, LL.D., F.R.S. =
Keeper^ of Mining Records. Robert Hunt,
F.R.S.
Assistants. Richard Meade ; James B. Jordan *
Registrar, Curator, and Librarian. T. Reeks.
Assistant Librarian -T. Newton.
Assistant Curator. A Pringle.
PBOFESSOES.
Chemistrff.~-%faa.rd. Frankland, D.C.L., Ph.D.,
F.R.S.
\ahiral History T. H. Huxley, LL.D., F.R.S.
Physics F. Guthric, B.A., PhJ)., F.R.S.
Applied Mechanics T. M. Goodeve, M.A.
Metallurgy J. Percy, M.D., F.R.S.
Geology. S. W. Judd.
Mining and Mineralogy* W. W. Smyth, M.A.,
F.R.S.
Mechanical Drawing Ttev. J. II. Edgar, M.A.
Museum open every week-day but Friday, and
on Saturdays and Mondays till 10 p.m., except
from the 10th of August to the 10th of Sep-
tember.
EDINBURGH MUSEUM OF SCIENCE AND
ART.
Director. 'Prof. T. C. Archer, F.R.S.E.
Keeper of Natural History Collections. Prof.
R. H. Traquair, M.D.
Curator. Alexander Galletly.
Assistant in Natural History Museum. J.
Gibson.
Assistant in Industrial Museum. W. Clark.
Clerks. C. N. B. Muston ; T. Stock.
ROYAL COLLEGE OF SCIENCE, DUBLIN.
Dean of Faculty. J. P. O'Reilly, C.E.,M.R.I.A.
Secretary F. J. Sidney, LL.D.
Curator of Museum. A.. Gages.
Clerk G. C. Penny.
PEOFESSOES.
Physics W. F. Barrett, F.C.S.
Chemistry. B* Galloway. F.C.S.
Geology E. Hull, M.A., F.R.S.
Applied Mathematics. II. Hennessy, F.R.S.
Botany. W. R. McNab, M.D.
Zoology.^. Leith Adams, M.B., F.R.S.
Descriptive Geometry and Drawing. Thomas
F. Pigot, C.E.
Mining and Mineralogy J. P. O'Reilly, C.E.,
M.R.I.A.
Demonstrator in Paleontology. W. H. Baily,
F.L.S.
Assistant Chemist. W. Plunkett.
Assistant Physicist. A. E. Porte.
ROYAL DUBLIN SOCIETY.
President His Grace the Duke of Leinster.
Secretaries G. J. Stone, A.M., F.R.S. ; C. Kelly,
J.P., Q.C.
Registrar and Assistant Secretary. W. E.
Steele, M.D.
Treasurer, cfcc.-H. C. White.
Director of Natural History Museum. A..
Carte, M.A., M.D.
Keeper of Minerals R. J. Moss, F.C.S.
Librarian -W '. Archer, F.R.S.
Temporary Assistant. H. W. D. Dunlop,
A.B., C.E.
Director of Botanic Gardens, Glasnevm.D.
Moore, Ph.D.
ZOOLOGICAL GARDENS, DUBLIN.
Sesretary. 'B&v. S. Haughton, M.D., D.C.L.,
F.T.C.D., F.R.S.
SOUTH KENS1
1.0 AN COLLECTION OF 9
PLAN OF GALLERIES LENT BY H . IV
Royal
REFERENT!
G R O U
A E D U CAT 10 N A L
B.C. APPLIED M E c
D NAVAL ARCHIT
E Lie HT-H o u s
F MAGNETISM
C ARITHMETIC AN
.K. MEASUREMENT .
L . ASTRONOMY AI
(M) GEOGRAPHY, CE
(N) BIOUOCY,
O) CONFERENCE
(P) CHEM ISTRY .
LIGHT, HEAT, Soui
JTON MUSEUM.
ENTIFIC APPARATUS
OMIV1ISSIONERS OP THE EXHIBITION or 1851
or tic ultural
FLOOR
GY, AND MINING.
(ND MOLECULAR PHYSICS
CONTENTS.
PAOK
PREFACE TO THIRD EDITION - - vii
INTRODUCTION, LISTS OF COMMITTEES, &c. - ix
LIST OF CONTRIBUTORS, WITH ADDRESSES - xxix
SECTION 1. ARITHMETIC - ... 1
2. GEOMETRY - - - - 15
3. MEASUREMENT - - 42
4. KINEMATICS, STATICS, AND DYNAMICS - 131
5. MOLECULAR PHYSICS - - 155
6. SOUND- - - - 178
7. LIGHT - - - 203
8. HEAT - - - 252
9. MAGNETISM - - - - - . 279
10. ELECTRICITY - - 298
11. ASTRONOMY - - 391
12. APPLIED MECHANICS - 444
13. CHEMISTRY - - 563
14. METEOROLOGY .... 573
15. GEOGRAPHY ... 725
16. GEOLOGY AND MINING * 815
17. MINERALOGY, CRYSTALLOGRAPHY, &c. - 884
18. BIOLOGY - - 900
19. EDUCATIONAL APPLIANCES - - 1004
20. MISCELLANEOUS - - - 1064
PREFACE TO THE THIRD EDITION.
THE receipt of a large number of objects since the com-
pilation of the Second Edition has rendered necessary the
publication of a Third Edition, to afford a complete record
of the collection for future reference. Every endeavour
has been made to ensure its correctness. Slips from the
former edition have been sent, wherever practicable, to the
several contributors for their corrections, in order that all
errors might, as far as possible, be eliminated.
Although a considerable amount of re-arrangement has
been found necessary, it has been thought advisable to
retain the numbers given to the objects in the former
edition, as those numbers have already been quoted in the
Handbook and other publications.
This edition has been revised and passed through the
press by Mr. A. T. Atchison, to whom the thanks of my
Lords are due for the great care and trouble he has bestowed
upon it.
South Kensington Museum,
May 1877.
INTRODUCTION.
By Minute dated 22nd January 1875, the Lords of the
Committee of Council on Education approved of a proposal
to form a Loan Collection of Scientific Apparatus, which
was to include not only apparatus for teaching and for
investigation, but also such as possessed historic interest
on account of the persons by whom, or the researches in
which, it had been employed. Their Lordships then in-
vited some of the leading men of science of the country
the Presidents of the learned Societies and others to act
on a Committee to consider the matter, and aid them with
their advice. This Committee, to whose exertions the
formation of the collection is so largely due, consisted of
The Right Hon. the Lord Chancellor.
Professor F. A. Abel, F.R.S., Presi-
dent of the Chemical Society.
The Right Hon. Lord Aberdare,
President of the Horticultural
Society.
Capt. W. de W. Abney, R.E., F.R.S.
Professor H. W. Acland, M.D.,
E.R.S., President of the Medical
Council of the United Kingdom.
Professor J. C. Adams, M.A., F.R.S.
Professor W. G. Adams, ALA.,
F.R.S.
Sir G. B. Airy, K.C.B., D.C.L.,
F.R.S., the Astronomer Royal.
Dr. G. J. Allman, F.R.S., President
of the Linnaan Society.
Mr. J. Anderson, LL.D., C.E.
Mr. D. T. Ansted, M.A., F.R.S.
Professor E. Atkinson, Ph.D.
Professor R. Stawell Ball, LL.D.,
F.R.S.
Professor W. F. Barrett,
Rev. A. Barry, D.D.
Mr. W. B. Baskcomb.
Mr. H. Bauerman.
Mr. G. Benthain, F.R.S.
Mr. Hugh Birley, M.P.
Professor Bloxam.
Major Bolton.
Professor F. A. Bradley.
Mr. F. J. Bramwell, F.R.S.
Mr. T. Brassey, M.P.
Mr. H. W. Bristow, F.R.S.
Mr. C. Brooke, M.A., F.R.S.
Mr. G. Busk, F.R.S.
Major -General Cameron, C.B., F.R.S.
Dr. W. B. Carpenter, C.B., F.R.S.
Mr. C. O. F. Cator.
Mr. W. Chappell.
Mr. H. W. Chisholm, Warden of the
Standards.
Lord Alfred Churchill, Chairman of
Council of Society of Arts.
Mr. G. T. Clark.
Mr. Latimer Clark.
Professor R, Bellamy Clifton, M.A.,
F.R.S.
Sir Henry Cole, K.C.B.
Vice-Admiral Sir R. Collinson,
K.C.B., Deputy Master of the
Trinity House.
Dr. Debus, F.R.S.
Mr. Warren De La Rue, D.C.L.,
F.R.S.
Mr. G. Dixon, M.P.
Professor P. M. Duncan, M.B.,
F.R.S., President of the Geological
Society.
Professor W. T. Thiselton Dyer,
M.A., B.Sc.
Major-General F. Eardley-Wilmot,
R.A., F.R.S.
INTRODUCTION.
Mr. H. S. Eaton, President of the
Meteorological Society.
Sir P. De M. G. Egerton, Bart.,
M.P., F.R.S.
Mr. K. Etheridge, F.R.S.
Capt. Evans, R.N., C.B., F.R.S.,
Hydrographer of the Navy.
Mr. J. Evans, F.R.S.
Professor W. H. Flower, F.R.S.
Mr. D. Forbes, F.R.S.
Professor G. Carey Foster, B.A.,
F.R.S., President of the Physical
Society.
Professor Michael Foster, M.D.,
F.R.S.
Colonel Lane Fox, F.R.S., President
of the Anthropological Institute.
Professor Frankland, Ph.D., D.C.L.,
F.R.S.
Mr. A. H. Garrod, M.A., F.R.S.
Dr. Gilbert. F.R.S.
Dr. J. H. Gladstone, F.R.S.
Mr. D. Glasgow.
Professor Goodeve, M.A.
Mr. A. C. L. G. Giinther, M.A.,
M.D., F.R.S.
Professor Guthrie, Ph.D., F.R.S.
Mr. J. Baillie- Hamilton.
The Right Hon. Lord Hampton,
G.C.B., F.R.S., President of the
Institute of Naval Architects.
Mr. T. E. Harrison.
Sir J. Hawkshaw, F.R.S.
Mr. T. Hawksley, President of the
Institute of Mechanical Engineers.
The Hon. Alan Herbert.
Mr. J. Hick, M.P.
Dr. J. D. Hooker, C.B., President of
the Royal Society.
Mr. J. Hopkinson, B.A., D.Sc.
Mr. W- Huggins, D.C.L., F.R.S.,
President of the Royal Astrono-
mical Society.
Professor W. Hughes.
Professor T. H. Huxley, LL.D., Sec.
R.S.
Lieut.-General Sir H. James, R.E.,
F.R.S.
Rev. J. H. Jellett, B.D.
Professor E. Ray Lankester, M.A.,
F.R.S.
Lord Lindsay, M.P., F.R.S.
Mr. J. Norman Lockyer, F.R.S.
Rev. R. Main, M.A., F.R.S.
Dr. R. J. Mann.
Mr. N. Story-Mr.Pkeljne,M.A.,F.:R.S.
Professor J. Clerk Maxwell, M.A.
F.R.S.
Mr. C. W. Merrifield, F.R.S.
Professor Miller, M.A., LL.D.,
F.R.S.
Professor Morris.
Mr. A. J. Mundella, M.P.
Professor Odling, M.A., F.R.S.
Mr. W. K. Parker, F.R.S.
Dr. Percy, F.R.S.
Mr. J. A. Phillips.
The Right Hon. Lyon Playfair, C.B,,
M.P., F.R.S.
Dr. Pole, F.R.S.
Professor Prestwich, F.R.S.
Professor A. C. Ramsay, LL.D.,
F.R.S.
Major-General Sir H. C. Rawlinson,
K.C.B., F.R.S., President of the
Royal Geographical Society.
The "Right Hon. Lord Rayleigh,
F.R.S.
Professor A. W. Reinold, M.A.
Professor Roscoe, Ph.D., F.R.S.
The Right Hon. the Earl of Rosse,
D.C.L., F.R.S.
Mr. G. W. Royston-Pigott, M.A.,
M.D., F.R.S.
Mr. J. Scott Russell, F.R.S.
Dr. W. J. Russell, F.R.S.
Professor W. Rutherford, M.D.,
F.R.S.
Mr. B. Samuelson, M.P.
Professor J. S. Burdon Sanderson,
M.D., F.R.S.
Mr. T. Savage, M.A.
Mr. R. H. Scott, M.A., F.R.S.
Major Seddon, R.E.
Professor Shelley.
Sir J. P. Kay-Shuttleworth, Bart.
Mr. C. W. Siemens, D.C.L., F.R.S.
Professor H. J. S. Smith, M.A.,
F.R.S.
Mr. W. Warington Smyth, M.A.,
F.R.S.
Mr. H. C. Sorby, F.R.S., President
of the Royal Microscopical Society.
Mr. W. Spottiswoode, M.A., LL.D.,
Treasurer of the Royal Society.
Mr. G. R. Stephenson, President of
the Institution of Civil Engineers.
Professor Balfour Stewart, LL.D.,
F.R.S.
Dr. W. H. Stone.
Major -General Strachey, C.S.T.,
F.R.S.
'INTRODUCTION.
XI
Lieut.-Col. Strange, F.R.S. (since
deceased).
Professor P. G. Tait, M.A.
Mr. J. Torr, M.P.
Rev. J. F. Twisden, M.A.
Professor Tyndall, LL.D., F.R.S.
Professor W. C. Unwin, B.Sc.
Mr. C. V. Walker, F.R.S., Presi-
dent of Society of Telegraphic
Engineers.
Mr. F. H. Wcnham.
Sir C. Wheatstone, F.R.S. (since de-
ceased).
Sir J. Whitworth, Bart., F.R.S.
Professor A. W. Williamson, Ph.D.,
F.R.S.
Mr. Bennet Woodcroft, F.R.S.
Dr. J. Woolley, F.R.S.
Colonel H. Stuart Wortley.
The first meeting of this Committee was held on the 13th
February 1875 ; the number of those who were present
showing the interest already felt in the subject. The Lord
President of the Council, the Duke of Richmond, and the
Vice-President, Viscount Sandon, in explaining the objects
of the Collection, took occasion to refer to the recommen-
dations of the Royal Commission on Scientific Instruction,
with regard to the creation of a Science Museum.
Their Lordships stated their conviction that the develop-
ment of the Educational, and certain other, Departments of
the South Kensington Museum, and their enlargement into
a Museum somewhat of the nature of the Conservatoire
des Arts et Metiers in Paris, and other similar institutions
on the Continent, would tend to the advancement of
science, and be of great service to the industrial progress
of this country. While expressing their hope that the
Loan Collection might forward this desirable object, their
Lordships guarded themselves against committing Her Ma-
jesty's Government, which had not yet fully considered
the subject, to any definite scheme.
On the motion of the President of the Royal Society,
Dr. Hooker, it was unanimously resolved by the meeting
that an exhibition such as that proposed would be most
instructive and valuable.
The question of the limits of the collection were dis-
cussed, and Sub-Committees were appointed to consider the
limitations it might be desirable to place on the term
" scientific apparatus " in the respective sections, while
bearing in mind the space disposable for the exhibition in
the Museum. As a provisional arrangement five Sub-Com-
mittees of sections were appointed, to whom it was left to
suggest such modifications in classification as might be found
advisable.
Xll INTRODUCTION.
The sections were
1. Mechanics (including pure and applied mathe-
matics).
2. Physics.
3. Chemistry (including metallurgy).
4. Geology, Mineralogy, and Geography.
5. Biology.
The Committees for the several sections are given at
page xxv.
The question of classification, having been carefully con-
sidered at numerous meetings of these Sub-Committees, was
brought before the General Committee on the 1 2th May, and
the several schemes were referred to a special Sub-Com-
mittee, formed of three members from each sectional Sub-
Committee. It was also decided to postpone the Exhibition,
which it was originally intended to open in June 1875, to
March 1876. The large number of objects sent from abroad,
and the late period of their arrival, have necessitated a
further postponement of the opening to May 1876.
The Sub-Committee appointed to revise and report on
the classification of the Collection after three meetings,
under the chairmanship of the President of the Royal
Society, submitted a scheme of classification to the General
Committee on June 22nd. After having been carefully
considered, it was, with some slight alterations, approved,
and is given at page xix. This programme was imme-
diately issued, and the classification into sections is that
adopted for the catalogue and exhibition, though the nature
of the Galleries has necessitated some alteration in the order
of the sections.
It had been the intention from the first to give the Loan
Collection an international character, so as to afford men of
science and those interested in education an opportunity of
seeing what was being done by other countries than their
own in the production of apparatus, both for research and
for instruction an opportunity which it was hoped would
be of advantage also to the makers of instruments. As soon,
therefore, as the programme had been definitely settled, steps
were taken to interest foreign countries in the Exhibition ;
and it was determined to obtain the co-operation of men of
science on the Continent, who, while acting as members of
INTRODUCTION. Xlil
the General Committee, should form special Sub-Committees
charged with the due representation of the science of their
respective countries.
It was necessary to take special precautions to prevent
misunderstanding as to the character of the Collection.
The mention of internationality at once suggested the idea
of an International Exhibition similar in its character and
arrangements to the numerous Industrial Exhibitions which
have been held in various countries. A wrong impression
of this kind would have entailed serious inconvenience.
In International Exhibitions a certain amount of space is
allotted to each country. These spaces are then divided by
the Commissioners of each country among its exhibitors,
who display their objects subject to certain general rules
of classification as they consider most advantageous, retain-
ing the custody of their own property. The expenses of
transport, arrangement, &c., are borne by the countries who
exhibit. And the Exhibitions appeal naturally, more or
less exclusively, to the industrial or trade-producing interests
of those countries.
This was not the idea of the proposed Loan Collection at
South Kensington. For that Collection it was desired to
obtain not only apparatus and objects from manufacturers,
but also objects of historic interest from museums and
private cabinets, where they are treasured as sacred relics,
as well as apparatus in present use in the laboratories of
professors. The transport of all objects was undertaken
by the English Government, and they were to be handed
over absolutely to the custody of the Science and Art
Department for exhibition ; the arrangement being not by
countries but strictly according to the general classification.
So soon as the object and scope of the Collection were
thoroughly understood, the Committee of Council on Edu-
cation met with the most gratifying responses to their
invitations, which were communicated officially through
the Foreign Office. Her Majesty's Ministers at Paris, Berlin,
St. Petersburgh, Vienna, Florence, Brussels, the Hague,
Stockholm, Madrid, Berne, and Washington, have personally
interested themselves in the matter. And the Foreign
Governments have afforded every facility and encourage-
ment in forwarding this strictly international undertaking.
XIV
INTRODUCTION.
The subjoined list of the foreign members of the General
Committee speaks for itself by the eminence and European
reputation of its members.
BELGIUM.
M. Stas, Membre de 1'Academie
Royale (President).
M. le General Brialmont, President
de 1'Academie Royale et Inspecteur
General du Genie.
M. Dewalque, Membre de 1' Academic
Royale, Professeur de Geologic et
de Mineral ogie it 1'Universite de
Liege.
M. Maus, Membre de 1'Academie,
Inspecteur General des Ponts et
Chaussees.
M. Plateau, Membre de 1' Academic
Royale, F.R.S.
M. Schwann, Membre de 1'Academie
Royale, Professeur a. 1' Universite de
Liege.
M. Van Beneden, Membre de 1'Aca-
demie et Professeur a 1'Universite
de Louvain, F.R.S.
M. le General Liagre, Secretaire per-
petuel de 1'Academie Royale, et
Commandant et Directeur des
Etudes de l'E"cole Militaire (Secre-
tary).
FRANCE.
M. le General Arthur Jules Morin,
Membre de 1'Academie des Sciences,
Directeur du Conservatoire des
Arts et Metiers (President).
M. Alexre. Edmond Becquerel,
Membre de 1'Academie des
Sciences, Professeur au Conserva-
toire des Arts et Metiers, F.R.S.
M. Henri Marie Bouley, Membre de
1'Academie des Sciences, Inspec-
teur General des ficoles Veteri-
naires.
M. Gabriel Auguste Daubree, Mem-
bre de 1'Academie des Sciences,
Directeur de 1'^cole des Mines.
M. Jean Louis Armand de Quatre-
fages de Breau, Membre de 1'Aca-
demie des Sciences, Professeur au
Museum d'Histoire Naturelle.
M. Jean Baptiste Dumas, Secretaire
perpetuel de 1'Academie des
Sciences, F.R.S.
M. Herve Auguste Etienne Albans
Faye, Membre de 1'Academie des
Sciences, President du Bureau des
Longitudes.
M. Edmond Fremy, Membre de
1'Academie des Sciences, Profes-
seur au Museum d'Histoire Natu-
relle.
M. Jules Celestin Jamin, Membre de
1'Academie des Sciences, Profes-
feur a 1'ficole Polyetcbnique.
M. Leuglet,Consul General de France
& Londres.
M. Urbain Jean Joseph Le Verrier,
Membre de 1'Academie des
Sciences, Directeur de 1'Observa-
toire, F.R.S.
M. Eugene Melchior Peligot, Mem-
bre de 1'Academie des Sciences,
Directeur des Essaish, la Monuuiu.
M. Henri Edouard Tresca, Membre
de 1'Academie des Sciences, Sous-
Directeur du Conservatoire des
Arts et Metiers (Secretary).
GERMANY.
I. BERLIN COMMITTEE.
Dr. A. W. Hofmann, Professor of
Chemistry, F.R.S. (President).
Dr. Beyrich, Professor of Geology.
Dr. du Bois-Reymond, Professor of
Physiology.
Dr. Dove, Professor of Physics,
F.R.S.
Dr. Forster, Director of the Obser-
vatory.
Dr. Hagen, President of the Board of
Works.
T. G. Halske, Telegraphic Engi-
neer.
INTRODUCTION.
XV
Dr. Hauchecorne, Director of the
School of Mines.
Dr. Ilelmholtz, Professor of Physics,
F.fc.S.
Dr. Kiepert, Professor of Geo-
graphy.
Dr. G. Kirchhoff, Professor of Phy-
sics, F.R.S.
Dr. Kronecker, Professor of Mathe-
matics.
Dr. C. D. Martius, Chemist.
Von Morozowicz, General.
Dr. Neumayer, Hydrogvapher of the
Imperial Admiralty.
Dr. Reuleaux, Director of the Poly-
technic Academy.
Dr. Schellbach, Professor of Mathe-
matics.
Dr. Werner Siemens, Telegraphic
Engineer.
Dr. Virchow, Professor of Patho-
lo gj-
Dr. C. H. Vogel, Astronomer.
Dr. Websky, Professor of Minera-
logy.
II. COMMITTEE REPRESENTING OTHER CITIES AND TOWNS OF
GEKMANV.
Dr. Von Babo, Professor of Che-
mistry, Freiburg.
Dr. Beetz, Professor of Physics,
Munich.
Dr. Buff, Professor of Physics, Gies-
sen.
Dr. Clausius, Professor of Physics,
Bonn, F.R.S.
His Excellency Dr. Von Dechen,
Director of the Mining Depart-
ment, Bonn.
Dr. Von Fehling, Professor of Che-
mistry, Stuttgart.
Dr. Vou Feilitzsch, Professor of
Physics, Greifswald.
Dr. Graebe, Professor of Chemistry,
Konigsberg.
Dr. Von Groddeck, Director of the
School of Mines, Klausthal.
Dr. Ileeren, Professor of Chemistry,
Hanover.
Dr. Hittorf, Professor of Chemistry,
Miiuster.
Dr. Karsten, Professor of Physics,
Kiel.
Dr. Karsten, Professor of Physics,
Rostock.
Dr. Knapp, Professor of Chemistry,
Braunschweig.
Dr. Knoblauch, Professor of Physics,
Halle.
Dr. Kolliker, Professor of Physiology,
"\Viirzburg, F.R.S.
Dr. Kundt, Professor of Physics,
Strasburg.
Dr. Launhardt, Director of the Poly-
technic School, Hanover.
Dr. Mohl, Cassel.
Dr. Poleck, Professor of Chemistry,
Breslau.
Dr. Preyer, Professor of Physiology,
Jena.
Dr. Vou Quintus-Tcilius, Professor
of Physics, Hanover.
Dr. Reusch, Professor of Physics,
Tubingen.
Dr. Romberg, Professor in the Nau-
tical School, Bremen.
Dr. Rosenthal, Professor of Physio-
logy, Erlangen.
Dr. Riimker, Director of the Obser-
vatory, Hamburg.
Dr. Serlo, Director of the Mining
Department, Brcslau.
Dr. C. Von Siemens, Professor in
the Agricultural Academy, Hohen-
heim.
His Excellency Dr. Von Steinbeis,
President, Stuttgart.
Dr. W. Weber, Professor of Physics,
Gottingen, F.R.S.
Dr. Wiedemunn, Professor of Phy-
sical Chemistry, Leipzig.
Dr. Winkler, Professor cf Metal-
lurgy, Freiberg.
Dr. Wohler, Professor of Chemistry,
Gottingeu, F.R.S.
Dr. Wulluer, Professor of Physics,
Aachen.
Dr. Zeuner, Director of the Poly-
technic School, Dresden.
Dr. Zetzsche, Director of the Poly-
technic School, Chemnitz.
XVI
INTRODUCTION.
ITALY.
II Com. Blaserna, Professor of Phy-
sics and Kector of the Royal Uni-
versity of Rome.
II Com. Cantoni, Professor of Phy-
sics at the Royal University of
Pavia.
II Cav. Respighi, Professor of Astrc
nomy in the Royal University c
Rome, and Director of the Obsei
vatory of the Campidoglio.
THE NETHERLANDS.
Professor Dr. P. L. Rijke, Conseiller
d'etat (President).
Professor Dr. H. G. de Sande Bak-
huyzen.
Professor Dr. C. II. D. Buys Ballot
Professor Dr. J. Bosscha.
Professor Dr. F. C. Donders, F.R.S.,
President of the Royal Academy of
Science, Amsterdam.
Professor Dr. J. W. Gunning.
Professor Dr. R. A. Mees.
Professor Dr. V. S. M. Van de
Willigen.
Dr. D. de Loos, Director of the Se
condary Town-School of Leyde
(Secretary).
NORWAY.
Professor Esmark.
Herr Mohn, Director of the Meteoro-
logical Institute of Norway.
Professor Waage.
RUSSIA.
M. Struve, Conseiller Prive, Directeur
de 1'Observatoire Central Nicolas
(President).
M. Ovsiannikow, Membre de 1'Aca-
demie.
M. Gadolin, Membre de 1' Academic.
M. Gruber, Professeur de 1'Academie
de Medecine et de Chirurgerie.
M. Stubendorf, Colonel d'^tat-Major.
M. Wyschnegradsky, Professeur d
1'Institut technologique.
M. Beilstein, Professeur de FInstitu
technologique.
M. Barbot de Marny, Professeur d<
1'Institut des Mines.
M. Koulibine, Professeur de FInstitu
des Mines.
SWITZERLAND.
Professor E. Wartmann (President).
Professor J. Amsler Laffon.
Professor D. Colladon-Ador.
Professor Dr. F. A. Forel.
Professor Dr. E. Hagenbach-Bischoff.
Professor Ad. Hirsch.
Professor Albert Mousson.
M. E. Sarasin-Diodati.
Professor L. Soret.
Colonel Gautier (Secretary).
AUSTRIA AND HUNGARY.
The Minister of Public Instruction has appointed Sectionschef Fidler tc
organise the contributions from these countries.
SPAIN.
No committee has been formed, but the Government has promised to contri-
bute, and Senor Riano has been specially appointed to make the necessary
arrangements.
INTRODUCTION.
UNITED STATES.
The Government has, through Mr. Fish, replied that it is in communication
with the various departments and scientific institutions with the object of
forwarding the Exhibition.
When men of this position in all branches of science have
given their adhesion to the programme of such an Exhi-
bition, its success might well be considered as secured. But
these gentlemen did not rest satisfied with merely giving
their names in recognition of its value : they have spared
no time and labour in making the undertaking a real
success. And the Lords of the Committee of Council on
Education feel assured that, in offering them their thanks
for their invaluable services, they convey not only their
own sentiments but the grateful recognition of their labours
by the country at large.
It will be readily understood from what has been said
of the nature, scope, and method of the Exhibition that
a large staff was required, in addition to the permanent
staff of the Museum, to organise and arrange the collec-
tion in the limited time which could be afforded for that
purpose. Special arrangements had, therefore, to be made ;
and their Lordships have great satisfaction in recording
the names of those gentlemen who have rendered very
valuable services many of them as volunteers greatly
aiding the staff of the Museum in their laborious duties.
These were Captain Abney, RE. ; Dr. Atkinson ; Mr. Bart-
lett ; Dr. Brunton ; Dr. Biedermann ; Professor Crum-
Brown; Captain Fellowes, RE.; Professor Carey Foster;
Dr. Michael Foster ; Herr Kirchner ; Professor Goodeve ;
Dr. Guthrie ; Commander T. A. Hull, RN. ; Mr. Iselin ;
Mr. Judd ; Mr. Norman Lockyer ; Dr. R. J. Mann ; Mr. Cle-
ments Markham ; Professor H. MacLeod ; Professor Roscoe ;
Professor Shelley ; Dr. Burdon Sanderson ; Dr. Schuster ;
Dr. Voit ; and Mr. R Wylde.
To those men of science, who, in this matter and in the
work of the General Committee and Sub-Committees, have
given much valuable time, and have afforded them the
benefit of their great knowledge and experience, the Lords
of the Committee of Council on Education feel their best
thanks are due, and they trust that the immediate success
and future results of the Exhibition, which owes so much to
40075. b
XVlil INTRODUCTION.
them, will reward them for the labours which they have
ungrudgingly devoted to it.
In order to make the Collection as useful and interesting
as possible, a Handbook containing introductory notices to
the several sections has been prepared. For writing these
notices the Lords of the Committee of Council on Education
have been fortunate in securing the services of gentlemen
the mention of whose names will be a sufficient indication
of the character of the work. These gentlemen are
Capt. W. de W. Abuey, R.E. ; Mr. N. Story Maskelync, M.A.,
Professor W. Kingdon Clifford, M. A., I F.R.S.
F.R.S. i Professor J. Clerk Maxwell, M.A.,
Capt. J. E. Davis. F.R.S.
Professor G. Carey Foster, B.A., Mr. R. H. Scott, M.A., F.R.S.
F.R.S. J Professor H. J. S. Smith, M.A.,
Professor Geikie, F.R.S.
Professor Goodeve, M.A.
Professor Guthrie, F.R.S.
Professor T. H. Huxley, LL.D.,
F.R.S.
Mr. W. Warington Smyth, M.A.,
F.R.S.
Mr. H. C. Sorby, F.R.S.
Secretary of the Royal Society^ | Mr. W. Spottiswoode, M.A., LL.D.,
Mr. J. Norman Lockyer, F.R.S. F.R.S.
Professor MacLeod. j Dr. W. H. Stone.
Mr. Clements Markham, C.B., j Professor P. G. Tait, M.A.
F.R.S. |
It had been originally proposed to exhibit the Collection
of Scientific Apparatus in the South Kensington Museum ;
but various circumstances, which could not be foreseen,
having rendered it necessary to abandon this intention,
Her Majesty's Commissioners for the Exhibition of 1851,
most liberally placed the galleries on the western side of the
Horticultural Gardens at the disposal of the Science and
Art Department. Though, unfortunately, these galleries
are disconnected from the Kensington Museum, they are
admirably adapted to the present purpose, and afford an
accommodation which could not otherwise have been ob-
tained.
By order,
F. R. SANDFORD,
Secretary, Committee of Council
on Education.
INTRODUCTION. XIX
CLASSIFICATION OF THE COLLECTION.
Arithmetic.
Apparatus for teaching arithmetic. Calculating machines.
Instruments for solving equations. Slide rules. Numbering and
enumerating apparatus, &c.
Geometry.
Instruments used in geometrical drawing. Methods of copying
Pantigraph, micrograph. Peaucellier's cell and parallel motion
Machines for description of curves and specimens of the curves
they describe, including geometric turning. Instruments for giving
graphic representations of phenomena. Models to illustrate de-
scriptive geometry. Specimens to illustrate the process of making
models according to a design. Models to illustrate solid geometry,
perspective, crystallography, &c. Stereoscopic illustrations of
solid geometry.
Measurement.
Of length. Standard yard, metre, &c. Comparator for stand-
ards of length (sight and touch). Gauges, measuring wheels,
steel tapes, &c. Micrometers and verniers. Cathetometers.
Of area. Planimeters, &c.
Of volume. Standard gallon, litre, &c. Pipettes, burettes.
Meters for gas, water, &c.
Of angles. Divided circles, theodolites, clinometers, gonio-
meters, &c.
Of mass. Standard pound, kilogramme, &c. Vacuum and
other balances.
Of density. Specific gravity bottles, areometers, &c.
Of time. Clocks and pendulums, chronometers, watches, and
balance wheels. Tuning forks for measuring small intervals of
time. Chronographs.
Of velocity. Such as Morin's machine. Strophometers, cur-
rent meters, ships' logs, &c.
Of momentum. Ballistic apparatus.
Of force. Spring balances, pressure gauges, torsion balances,
&c.
Of work. Indicators, dynamometers, &c.
Kinematics, Statics, and Dynamics.
Elementary illustrations. Position and displacement of a point,
a rigid body, or a material system. Composition and resolution of
displacements. Velocity and acceleration, their composition and
2
XX INTRODUCTION.
resolution. Displacements of a connected system. Principles of
mechanism. Rolling contact, sliding contact, belting, link con-
nexions, shafting, universal joints, &c. Transmission of work.
Relation between the displacement of two pieces of a machine and
the forces which they transmit. The mechanical powers. Instru-
ments for illustrating the laws of motion, such as pendulums,
gyroscopes, dynamical tops.
Laws of fluid pressure ; stability of floating bodies.
Discharge of fluids through orifices, and their motion in
channels.
Hydraulic and pneumatic transmission of power.
Molecular Physics.
Instruments and apparatus employed in teaching, and in the
investigations and observations connected with :
Pressure on Matter. Tension, Compression (piezometer) Tor-
sion, Flexion ; Relation of volume to pressure ; Elasticity of
liquids and gases. Hardness (of solids and liquids), Toughness,
Brittleness, Malleability, &c.
Communication of Pressure through Fltiids. Pressure of air, its
consequences and applications. Barometers, Air-pumps, Siphons,
Suclion-pumps, Spirators, &c. ; Pressure of water, its consequences
and applications, Levels, Side pressure, &c.
Density. Methods of measuring densities of Gases, Vapours,
Liquids, Solids.
Adhesion and Cohesion. Condensation of gases in solids, Solu-
tion of gases in liquids, Mixing of gases with gases (Diffusion,
Transpiration, &c.), Absorption of liquids by solids (Capillarity,
&c), Absorption of liquids by gases (Evaporation, &c.), Mixing of
liquids with liquids (Osmose, Diffusion Dialysis). Evaporation of
solids, Solution of solids, Mixture of solids with solids (Cementa-
tion, &c.).
Sound.
Instruments and apparatus employed in teaching, and in the
investigations and observations connected with :
Geometrical, Mechanical, and Optical methods of Illustrating
the Laws of Wave .Motion. Progressive waves, Composition of
Vibrations, Interference, Stationary waves.
Generation of Sound. Fog-horn, &c.
Conduction of Sound. Through solids, liquids, and gases,
Stethoscopes.
Velocity of Sound.
Detection of Sound. Sensitive flame, &c.
Reflexion and Refraction. Ear trumpets, Acoustic lenses, vie.
Dispersion and Absorption.
INTRODUCTION. XXI
Musical Sounds. Pitch, Standards of Pitch, Standard Tuning
Forks. &c. ; Methods of measuring and comparing rates of vibra-
tion ; Toothed wheels, Syrens, &c. ; Vibration Microscopes, &c. ;
Methods of illustrating the nature of musical intervals; Mano-
ni( trie flames, Mirrored Tuning Forks, &c.
Musical Quality. Illustrations of the different quality of the
sounds of various instruments, Harmonics, and overtones. Resul-
tant rones, Instruments for studying quality, Resonators, Phonau-
tographs, &c.
Musical Instruments Illustrating the above. Methods o ex-
hibiting the mode of vibration of various instruments and the
quality of the sounds yielded by them.
Light.
Instruments and apparatus employed in teaching, and in the
investigations and observations connected with:
Production. Combustion, Electric discharge, &c.
Measurement of Intensity, Velocity.
Action of Matter on Light. Reflection, Refraction, Dispersion,
Achromatism, Direct vision prisms, Polarization, Absorption
(colour), Fluorescence, &c.
Action of Light on Light. Interference, Diffraction, Measure-
ment of wave length (optical banks), &c.
Action of Light on Matter. Photography, Radiometry, Phos-
phorescence, &c.
Technical Applications of Optical Principles. Lighthouse
illumination, &c.
Heat.
Instruments and apparatus employed in teaching, and in the
investigations and observations connected with :
Sources of Heat. Chemical, Electrical, Dynamical, Solar,
Calorescence, &c.
Effects of Heat on Matter. Changes of Temperature, Expan-
sion and change of Elasticity, Liquefaction, Vaporization, &c.
Measurement of Temperature. Thermometers, Pyrometers,
&c.
Propagation of Heat. Radiant Heat, Radiometer, Re-
flexion, Refraction, Radiation, Absorption, Polarization ; Conduc-
tion, Solids, Liquids, Gases ; Convection, Ventilation, &c.
Effect of change of Molecular State on Temperature. Freez-
ing mixtures, Ice machines, &c.
Effect of change of Pressure and Volume.
Heat Quantity. Unit of Heat, Calorimeters, Specific Heat, &c.
Licthods of determining Latent Heat.
Mechanical Equivalent of Heat. Methods of determining.
Illustrations of Thermodynamics.
INTRODUCTION.
Electrical Equivalent of Heat. Methods of determining.
Analysis of Solar Radiation.
Magnetism.
Instruments and apparatus employed in teaching, and in the
investigations and observations connected with :
Natural Magnets.
Permanent Artificial Magnets.
Electro- Mag nets.
Methods of Magnetization. Effects of Magnetization. Con-
ditions affecting intensity of Magnetization : Temperature (che-
mical), Composition, Strains, &c.
Magnetic Induction of all Substances. Diamagnetism.
Measurement of Intensity of Magnetization, Magnetic moment.
Terrestrial Magnetism. Instruments for observation and auto*
matic registration of the magnetic elements.
Electricity.
Instruments and apparatus employed in teaching, and in the
investigations and observations connected with :
Production and Maintenance of Difference of Potential.
Electrical machines acting by friction, induction (doubters, re-
plenishers, &c., Holz's and Toppler's machines, &c.) ; Galvanic
batteries ; Thermo-electric piles ; Magneto-electric machines.
Other sources, such as Pyro-electricity, Pressure electricity, Cleav-
age, Capillarity, Osmose, &c.
Detection and Measurement of Difference of Potential. Elec-
troscopes, Electrometers, Standards of electro-motive force, Me-
thods of comparison.
Accumulation of Electricity. Insulators, Condensers, Accumu-
lators, Effects due to accumulated electricity, Distribution on con-
ductors, Polarization of dielectrics, &c.
Measurement of Electric Quantity. Torsion balances, Stand-
ard accumulators, Methods of comparing electric capacities and
dielectric coefficients.
Detection and Measurement of Electric Currents. Galvano-
scopes, Galvanometers, Voltameters, Electro- dynamometers, &c.
Resistance. Standards of resistance, Methods of comparing
resistances, Methods of establishing absolute standards (British
Association unit appar.).
Effects of Electric Currents. Production of light, heat,
Electrolysis, Electro-diffusion. Action on magnets, soft iron
(electro-magnets), Action of currents on currents.
Technical Application of Electricity. Electric telegraph, &e.
INTRODUCTION. XX Hi
Astronomy.
Star maps, catalogues, globes, orreries, &c.
Meridian instruments.
Arrangements for communicating true time.
Altazimuths, zenith-sectors, sextants, &c.
Equatoreal Telescopes
Micrometers.
Driving clocks.
Special arrangements for
Celestial photography.
Spectroscopic observations.
Thermo-electric observations.
Siderostats.
Applied Mechanics.
As the Exhibition must be regarded as chiefly referring to edu-
cation, research, and other scientific purposes, it must in this
division consist principally of models, diagrams, mechanical draw-
ings, and small machines, illustrative of the principles and progress
of mechanical science, and of the application of mechanics to the
arts.
Properties of Materials.
Structures at Rest and in Motion.
Prime Movers.
Reservoirs of Energy.
Regulators.
The Application of the Principles of Mechanics to Machinery
as used in the Arts.
Shipping, Naval Architecture, and Marine Engineering.
Chemistry.
Scientific instruments, apparatus, and materials employed in the
investigation and teaching of Chemical Science, and in the appli-
cation of its principles to scientific purposes.
Diagrams and models.
Illustrations of analytical results.
Specimens of chemicals, (a) organic, (b) mineral.
Apparatus and fittings for laboratory and lectures.
Apparatus for gravimetric and volumetric operations.
Apparatus for distillation and filtration.
Apparatus for operations by the dry or hot method, such as
furnace, blowpipe, &c.
Refrigeratory apparatus.
Apparatus for spectrum analysis.
XXIV INTRODUCTION.
iSoTE. Operations of the following nature may be illustrated,
viz. :
Organic analysis.
Mineral analysis.
Electrolysis.
Water analysis.
Gas analysis.
Spectrum analysis.
Methods of investigation connected with vegetation and re-
spiration.
Meteorology.
Thermometers and barometers, of special construction.
Anemometers, rain gauges, hydrometers, &c.
Self-recording meteorological apparatus.
Illustrations of various systems of storm signals.
Weather maps.
Instruments illustrating the phenomena of atmospheric elec-
tricity.
Instrument stands.
Geography.
Instruments used in surveying.
Instruments used in Geodesy and Hydrography, including
hypsometrical instruments, tide gauges, &c.
Projections, maps, charts, models, and globes.
Deep-sea sounding apparatus. Seismographical instruments.
Geology and Mining.
Instruments for field and underground surveying.
Typical collections of rock specimens, including vein stones.
Typical fossils arranged stratigraphically.
Maps in different stages, and finished maps.
Geological models, horizontal and vertical sections.
Diagrams and plates of fossils, and general geological diagrams
used in lecture rooms.
Microscopic sections of rocks and minerals, and apparatus for
cutting such sections.
Anemometers, water gauges, mining barometers, and thermo-
meters.
Mining plans, sections, and models of workings.
Mineralogy, Crystallography, &c.
Goniometers.
Apparatus for studying and exhibiting the optical characters of
crystals.
INTRODUCTION.
XXV
Sections for optical examination.
Blowpipe and other portable apparatus for determining mi-
nerals.
Collections of crystals, models of crystals, plates of crystals, and
apparatus for drawing them.
Educational collections of minerals, &c.
Diagrams and models for lecture rooms.
with
Biology.
accessory apparatus
for biological re-
1. Microscopes
search, &c.
2. Physiological apparatus for investigating
a. The growth and mechanical movements of living organ-
isms and their parts.
b. The chemical phenomena of living organisms.
c. The electrical phenomena of living organisms.
d. The functions of the nervous and other systems.
3. Apparatus for anatomical research.
4. Apparatus for collecting and preserving object of natural
history.
5. Appliances for teaching biology.
A limited number of examples illustrating the performances of
the apparatus will be admissible.
Sub-Committees of Sections.
SECTION I. MECHANICS, INCLUDING PURE AND APPLIED MATHEMATICS
AND MECHANICAL DRAWING.
Professor J. C. Adams, M.A.,
F.R.S.
Mr. J. Anderson, LL.D., C.E.
Professor R. Stawell Ball, LL.D.,
F.R.S.
Rev. A. Barry, D.D.
Mr. W. B. Baskcomb.
Mr. Hugh Birley, M.P.
Major Bolton.
Professor F. A. Bradley.
Mr. F. J. Bramwell, F.R.S.
Mr. T. Brassey, M.P.
Mr. H. W. Chisholm, Warden of the
Standards.
Mr. G. T. Clark.
Mr. Latimer Clark.
Professor R. B. Clifton, M.A.,
F.R.S.
Sir Henry Cole, K.C.B.
Mr. G. Dixon, M.P.
Major-General F. Eardley-Wilmot,
R.A., F.R.S.
Mr. D. Glasgow.
Professor T. M. Goodeve, M.A.
The Right Hon. Lord Hampton.
G.C.B., F.R.S., President of the
Institute of Naval Architects.
Mr. T. E. Harrison. .
Sir J. Hawkshaw, F.R.S.
Mr. T. Hawksley, President of the
Institute of Mechanical Engineers.
Mi-. J, Hick, M.P.
Professor J. C. Maxwell, M.A.,
F.R.S.
Mr. C. W. Merrifield, F.R.S.
Mr. A. J. Mundella, M.P.
Dr. Pole, F.R.S.
The Right Hon. Lord Rayleigh,
F.R.S.
Mr. J. Scott Russell, F.R.S.
Major Seddon, R.E.
Professor Shelley.
Mr. C. W. Siemens, D.C.L., F.R.S.
Professor H. J. S. Smith, M.A.,
F.R.S.
XXVI
INTRODUCTION.
Mr. G. li. Stephenson, President of
the Institute of Civil Engineers.
Professor P. G. Tait, M.A.
Mr. J. Torr, M.P.
Eev. J. F. Twisden, M.A.
Professor W. C. Unwin, B.Sc.
Sir C. Wheatstonc, F.R.S. (since
deceased).
Sir J. Whitworth, Bart., F.R.S.
Mr. Bennet Woodcroft, F.R.S.
Dr. J. Woolley, F.R.S.
Colonel H. Stuart Wortley.
SECTION II. PHYSICS.
Capt. W. de W. Abney, R.E.
Professor W. G. Adams, M.A., F.R.S.
Sir G. B. Airy, K.C.B., D.C.L.,
F.R.S., Astronomer Royal.
Professor E. Atkinson, Ph.D.
Professor R. Stawell Ball, LL.D.,
F.R.S.
Professor W. F. Barrett.
Mr. C. Brooke, M.A., F.R.S.
Mr. C. O. F. Cator.
Mr. W. Chappell.
Professor R, B. Clifton, M.A., F.R.S.
Vice- Admiral SirR. Collinsou,K.C.B.,
Deputy Master of the Trinity
House.
Dr. Debus, F.R.S.
Mr. Warren De La Rue, D.C.L.,
F.R.S.
'Mr. H. S. Eaton, President of the
Meteorological Society.
Professor G. Carey Foster, B.A.,
F.R.S., President of the Physical
Society.
Dr. J. H. Gladstone, F.R.S.
Professor Guthrie, Ph.D., F.R.S.
Mr. J. Baillie-Hamilton.
Mr. J. Hopkinson, B.A., D.Sc.
Mr. W. Huggins, D.C.L., F.R.S.,
President of the Royal Astrono-
mical Society.
Lord Lindsay, M.P.
Mr. J. Norman Lockyer, F.R.S.
Reverend R. Main, M.A., F.R.S.
Dr. R. J. Mann.
Mr. C. W. Merrifield, F.R.S.
Dr. Pole, F.R.S.
The Right Hon. Lord Ray leigh, F.R.S.
Professor A. W. Remold, M.A.
Earl of Rosse, D.C.L., F.R.S.
Mr. R. II. Scott, M.A., F.R.S.
Mr. W. Spottiswoode, M.A., LL.D.,
F.R.S.
Dr. W. H. Stone.
Lieut.- Colonel Strange, F.R.S. (since
deceased).
Professor P. G. Tait, M.A.
Professor Tyudall, LL.D., F.R.S.
Mr. C. V. Walker, F.R.S., President
of Society of Telegraphic Engineers.
Sir C. Wheatstone, F.R.S. (since de-
ceased).
Dr. Woolley.
SECTION III. CHEMISTRY.
Professor F. A. Abel, F.R.S., Chemist
to the War Department.
Professor Bloxam.
Sir Henry Cole, K.C.B.
Mr. Warren De La Rue, D.C.L.,
F.R.S.
Professor Frankland, Ph.D., D.C.L.,
F.R.S.
Dr. Gilbert, F.R.S.
Dr. J. H. Gladstone, F.R.S.
i Professor Odling, M.A., F.R.S., Pre-
sident of the Chemical Society.
Dr. Percy, F.R.S.
Mr. J. A. Phillips.
The Right Hon. Lyon Play fair, Ph.D.,
C.B., M.P., F.R.S.
Professor Roscoe, Ph.D., F.R.S.
Dr. W. J. Russell, F.R.S.
Professor Williamson, Ph.D., F.R.S.
SECTION IV. PHYSICAL GEOGRAPHY, GEOLOGY, AND MINERALOGY.
Mr. D. T. Ansted, M.A., F.R.S.
Mr. H. Bauerman.
Professor F. A. Bradley.
Mr. H. W. Bristow, F.R.S.
Major-General Cameron, C.B., F.R.S.
Mr. C. 0. F. Cator.
Vice-Admiral Sir R. Collinson,
K.C.B., Deputy Master of the
Trinity House.
Professor P. M. Duncan, M.B.,
F.R.S., President of the Geological
Society.
INTRODUCTION.
XXV11
Mr. H. S. Eaton, President of the
Meteorological Society.
Sir P. De M. G. Egcrton, Bart.,
M.P., F.R.S.
Mr. K. Etheridge, F.R.S.
Captain Evans, R.N., C.B., F.R.S.,
Hydrographer of the Navy.
Mr. J. Evans, F.R.S.
Mr. D. Forbes, F.R.S.
Professor Hughes.
Lieut.-General Sir H. James, R.E.,
F.R.S.
Dr. R. J. Mann.
Mr. N. Story-Maskelyne, M.A.,
F.R.S.
Mr. C. W. Merrifield, F.R.S.
Professor Miller, M.A., LL.D.,
F.R.S.
Professor Morris.
Professor Prestwich, F.R.S.
Professor A. C. Ramsay, LL.D.,
F.R.S.
Major-General Sir H. C. Rawlinsou,
K.C.B., F.R.S., President of the
Royal Geographical Society.
Mr. R. H. Scott, M.A., F.R.S.
Mr. W. Warington Smyth, M.A.,
F.R.S.
Mr. H. C. Sorby, F.R.S., President
of the Royal Microscopical
Society.
Major-General R. Strachey, C.S.I.,
F.R.S.
SECTION V. BIOLOGY.
The Right Hon. Lord Aberdare, Pre-
sident of the Royal Horticultural
Society.
Professor H. W. Acland, M.D.,
F.R.S., President of the Medical
Council of the United Kingdom.
Dr. G. J. Allmau, F.R.S., President
of the Linuaeau Society.
Mr. G. Bentham, F.R.S.
Mr. C. Brooke, M.A., F.R.S.
Mr. G. Busk, F.R.S.
Dr. W. B. Carpenter, C.B., F.R.S.
Professor W. T. Thiselton Dyer,
M.A., B.Sc.
Professor Flower, F.R.S.
Professor Michael Foster, M.D.,
F.R.S.
Colonel Lane Fox, F.R.S., President
of the Anthropological Institute.
Mr. A. H. Garrod, M.A., F.R.S.
Mr. A. C. L. G. Guiithcr, M. A., M.D.,
F.R.S.
The Hon. Alan Herbert.
Dr. J. D. Hooker, C.B., President of
the Royal Society.
Professor T. H. Huxley, LL.D,,
F.R.S.
Professor E. Ray Lankester, M.A.,
F.R.S.
Mr. W. K. Parker, F.R.S.
Mr. G. W. Royston-Pigott, M.A.,
M.D., F.R.S.
Professor W. Rutherford, M.D., F.R. S.
Professor J. S. Burdon Sanderson,
M.D., F.R.S.
Mr. H. C. Sorby, F.R.S., President
of the Royal Microscopical Society.
Mr. F. H. Wenham.
XXIX
LIST OF CONTRIBUTORS, WITH
ADDRESSES.
%* The numbers refer to the Pages of the Catalogue.
UNITED KINGDOM.
AUKL, F. A., F.R.S., Royal Arsenal,
Woolwich-, 377-8.
AP.KUCROMBY, HON. R., 21, Chapel
Street, Mai/fair, London ; 684.
ABNEY, CAPT. W. DE W., R.E., Chat-
ham ; 234, 424, 707.
ABRAHAM, C., University of Edin-
burgh ; 595.
ACLANI), DR., F.R.S. on behalf of the
Iladcliffe Trustees, Oxford; 851,
861.
ADAMS, PROF. A. L., M.A., F.R.S. ,
Royal College of Science, Dublin ;
994.
A;>AMS, J. C., Cambridge University ;
400.
ADIK, P., 15, Pall Mall, London-,
55, 444, 677, 751, 756, 872.
ADMIRALTY (Hydrographic Depart-
ment), Whitehall, London; 95, 287-
9, 731-8, 774-6, 795-8.
AERONAUTICAL SOCIETY OF GREAT
BRITAIN (F. W. Brearey, Hon.
Sec.), Maiden stone Hill, Green-
wich ; 108.
AGRICULTURAL SOCIETY OF ENG-
LAND, ROYAL, 12, Hanover Square,
London ; 474.
AIIKBECKER, H. C., 117, Stamford
Street, London; 74, 531.
ALLKN, H., Homewood, South Orange,
Neio Jersey, U.S.A. ; 429.
ALLPOUT, S. B., 50, Whittall Street,
Birmingham ; 59.
AMIIURST-TYSSEN, W. A., Didd-
lington Hall, Norfolk ; 471.
ANATOMICAL DEPARTMENT, Oxford
University Museum ; 983-4.
ANDREWS, DR., F.R.S., Queen's Col-
lege, Belfast; 162, 168, 169, 268,
325, 570, 575, 671.
ANDREWS, W., Indo-European Te-
legraph Company, Old Broad
Street; 368.
Arrs, A., 433, Strand, London ; 216,
311, 760.
ARCHBUTT, J. AND W. E., 201,
Westminster Bridge Road, London:
76.
ASTON AND MANDER, 25, Old Comp-
ton Street, Soho, London ; 1, 2, 20.
ASTRONOMER ROYAL, THE (Sir G.
B. Airy, K.C.B., F.R.S.), Green-
wich, London; 413, 421-2.
ASTRONOMICAL SOCIETY, ROYAL,
Burlington House, Piccadilly, Lon-
don ; 413.
AUSTEN, MAJOR G., 17, Bessborough
Gardens, S. W. ; 803.
AUSTIN AND HUNTER, Sunderland ;
513, 528.
AUTOTYPE COMPANY, 36, Rathbone
Place, London ; 243-4, 433.
AVELING AND PORTER, 72, Cannon
Street, London ; and Rochester ; 459.
BABBAGE, MAJOR-GENERAL, Dainlon
House, Bromley, Kent ; 5, 6, 532-
3.
BADEN-POWELL, MRS., 1, Hyde Park
Gate South, London ; 230.
BAGOT, A. C., Pembroke College,
Cambridge; 10.
BAILEY, WALTER, 176, Haversloch
Hill, London; 217.
BAILEY, W. H., & Co., Albion Works,
Salford, Manchester ; 98, 267, 445,
456, 548.
BAKER, W. CLINTON, Bayfordbury,
Herts. ; 420.
BALDWIN, A. C., 37, Chester Square,
S.W.;391, 419.
XXX
LIST OF CONTK1BUTOES.
BALL, R. S., LL.D., F.R.S., Royal
Astronomer of Ireland, The Obser-
vatory, Dunskin, co. Dublin ; 35.
BARKER, R.E., Clifton, Bristol; 762.
BARLOW, W. H., F.R.S., High
Combe, Old Charlton, S.E. ; 189,
552.
BARRETT, PROF. W. F., F.C.S., Royal
College of Science, Dublin ; 166
-8, 177, 180-2, 184, 190-1, 246,
259, 285-6, 298, 304, 306, 339, 464,
535, 813, 1072.
BASHFORTH, REV. F., Minting Vi-
carage, Horncastle, Lincolnshire ;
101.
BASSETT, H., 44, St. Paul's Road,
Camden Toivn, London ; 196.
BAXTER, BROTHERS, Dundee ; 530.
BECK,J.,31, Cornhill, London ; 905-6.
BECK, R. AND J., 31, Cornhill, Lon-
don ; 905-6, 916-7, 920.
BEL, A., & Co., 34, Maiden Lane,
Strand, London-, 13, 196-7, 202,
667, 1004-6.
BELCHER, ADMIRAL SIR E., K.C.B.,
13, Dorset Street ; 523.
BELL, J., Rushpool, Saltburn-by-
Sea ; 830.
BEST, E., 23, Jermyn Street, S. W. ;
828.
BIDDER, S. P., 24, Great George
Street, Westminster 878-9.
BIRD, P. H., F.R.C.S., I, Norfolk
Square, London ; and Lytham, Lan-
cashire ; 258.
BISCHOFF, G., 4, Hart Street,
Bloomsbury, W.C. ; 672.
BLACKMORE, T., 2, Apsley Road,
Wandsworth, S. W. ; 550.
BLAGDIN, J. A., Petworth, Sussex-,
419-20.
BLAKE, H. WOLLASTON, F.R.S., 8,
Devonshire Place, Portland Place,
London ; 400.
BOARD OF TRADE, Standards De-
partment of, London ; 42-7.
BOARD OF WORKS, London 6, 1002.
BONOMI, J., 13, Lincoln's Inn Fields,
London; 939.
BOSANQUET, R. H. M., St. John's
College, Oxford ; 191,223.
BOUCK & Co., LIMITED, Miles Plat-
ting, Manchester ; 661.
BOWLING IRON COMPANY, Bowling,
Bradford, Yorkshire; 669.
BRACEY, J., Yarmouth, Norfolk ; 449.
BRADY, REV. NICHOLAS, M.A., Rain-
ham Hall, Romford, Essex ; 216,
222, 670, 885, 895-7.
BRAMWELL, F. J., C.E., F.R.S., Par-
liament Street, Westminster ; 546-
7.
BRIGHTON FREE LIBRARY AND MU-
SEUM, Brighton ; 843.
BRION, H. F., 231, Albany Road,
London ; 810, 839.
BRISTOL MUSEUM AND LIBRARY,
Bristol ; 829.
BRISTOW, H. W., F.R.S., Director,
Geological Survey for England and
Wales, Jermyn Street, London ;
757, 803, 861.
BRITISH HOROLOGICAL INSTITUTE,
35, Northampton Square, London ;
123-5.
BRITISH TELEGRAPH MANUFACTORY,
374, Eustnn Road, London ; 118-9,
150, 184, 333, 365-7, 375-6, 379.
BRODIE, SIR B. C., BART., Brockham
Warren, Reigate ; 570-5.
BRODRICK, THE HON. Miss, 18,
Queen Square, Bath ; 413.
BROOKE;, C., F.R.S., 16, Fitzroy
Square, London ; 151, 295-6, 712,
885.
BROOKE, MRS. CROFT, Tunbridqe
Wells-, 545.
BROOKE, SIMPSON, AND SPILLER, 50,
Old Broad Street, London; 654.
BROTHERHOOD AND HARDINGHAM,
52 and 56, Compton Street, Gos-
wellRoad-, 525.
BROUN, COLIN, Andersonian Uni-
versity, Glasgow; 193.
BROWN, J. A., F.R.S., 3, Newcastle
Place, Clerkenwett ; 106.
BROWN, PROF. A. CRUM, University
of Edinburgh ; 593-4, 630, 897,
936-7.
BROWNING, JOHN, 63, Strand, Lon-
don; 206, 209-10, 226, 311,395,
398, 400, 403, 412, 756, 908.
BRUNTON, T. L., F.R.S., 23, Somer-
set Street, Port man Square ; 952-3.
BUDDEN, E. R., Elm Villa, Horn
Lane, Acton ; 902.
BURGH OF STIRLING, THE, Stirling,
Scotland; 55.
BURT, T., Society for- Promoting
Christian Knowledge, 77, Great
Queen Street, London; 829.
LIST OF CONTRIBUTORS.
XXXI
Bu,SK,G., 32, Hm ley Street, London ;
938.
BUTLER, P. J., 55, De Beauvolr
Road, London ; 128.
CALVERT, F. C., & Co., Tower
Chemical Works, Bradford, near
Manchester ; 654.
CAMBRIDGE OBSERVATORY, Cam- \
bridge ; 400.
CAMPBELL, JOHXSTOM: & Co., 6,
Founders Court, Lothbury, E.C.
520.
CAMPBELL, LIEUT.-COL. A. C. (of
Blythswood}, 2, Seamore Place,
Mayfair, London ; 420.
CAMPBELL'S SHIPBUILDING AND
FLOATING DOCK COMPANY, Silver
Town, North Woolwich; 521.
CANN-LIPPINCOTT, E. C., JUN., Over- I
court, Bristol ; 715-6.
CAPRON, Jonx RAND, Guildford ;
217.
CASARTELLI, J., 43, Market Street,
Manchester-, 99,267, 741, 751-2,
872-3.
CASELLA, L. P., 147, Holborn Bars,
London ; 85, 95, 394, 683, 685, 687,
689, 691, 694, 702-3, 741, 759, j
762, 770, 781, 872.
CASSELL, PETTER, & GALPIN, Belle
Sauvage Yard, Ludgate Hill,
E.G.-, 1069.
CATOR, C. O. F., M.A., The Hall,
Beckenham, Kent ; 707.
CAULFIELD, R., LL.D., F.S.A.,
Queen's College and Royal Institu-
tion, Cork ; 740.
CAVENDISH LABORATORY, Cam-
bridge; 109, 383.
CAYLBY, PROF., F.R.S., Garden
House, Cambridge ; 34.
CETTI, E., & Co., 11 and 31, Brooke
Street, Holborn, London ; 163, 166,
264, 305, 322, 626, 629, 639, 659, i
661, 672, 683, 698, 700, 872, 944-5,
1003.
CHANCE BROTHERS & Co., Bir-
mingham ; 412.
CHAPMAN AND HALL, 193, Picca-
dilly; 1011.
CHAPPE DE LEONVAL,T. F., 29, Stan-
ley Gardens, Notting Hill Gate,
London ; 20.
CHAPPELL, W., F.S.A., 49, Strafford
Lodge, Oatlands Park, Surrey ;
194-6.
CHATHAM, School of Military En-
gineering ; 237.
CHAUMONT, SURGEON-MAJOR F. DE,
Netley, Southampton ; 700.
CHESNBY, COL. G., Royal Indian
Engineering College, Cooper's Hill,
Staincs; 461.
CHISHOLM, H. W., Warden of the
Standards, 7, Old Palace Yard,
London ; 82, 87.
CHISHOLM, MRS., Church Lane
House, Haslemere, Surrey"; 50.
CHRISTY, T., & Co., 155, Fenchurch
Street, London ; 171.
CHURCH, PROF. A. H., Agricultural
College, Cirencester ; 86.
CLARE, T. D., Heathfield Place,
Handsworth, Birmingham ; 368.
CLARK, LATIMER, 5, Westminster
Chambers; 346-7.
CLIFTON, R. B., F.R.S., Clarendon
Laboratory, University Museum,
Oxford; 189,427.
COHEN, J. & Co., Charterhouse Street,
London ; 95.
COLE, A. C., AND SON, 62, St. Do-
mingo Vale, Evert on, Liverpool ;
983.
COLLEGE OF SURGEONS, ROYAL,
Lincoln's Inn Fields, London; 976.
COMMISSIONERS OF NORTHERN
LIGHTS, Edinburgh; 536-8, 545-6.
COMMISSIONERS OF PATENTS, Patent
Office Museum, South Kensington,
London; 4, 65, 116, 283, 451-2,
457, 460, 462, 465, 467, 469-72,
477, 480, 491, 498, 529.
COODE, SIR J., 2, Westminster Cham-
bers, London ; 545.
COOKB, C. W., C.E., M. Soc., T. E.,
57, Landor Place, Clapham Rise,,
S. W. ; 246 , 324.
COOKE, J., Lang fey Hall, Langley
Moor, Durham ; 870.
COOKE, T. AND SONS., Buckingham
Works, York; 128.
CORK, THE EARL OF, K. P., Marston,
Frome; 428.
COWPER, E. A., 6, Great George
Street, Westminster; 173, 254,
265, 479, 548.
COWPER, MRS. C., 3, The Residences,
South Kensington Museum; 383.
CRAIG, JOHN., Washington Street,
Glasgow; 630-3.
CRAMPTON, T. R., 4, Victoria Street,
Westminster ; 348, 458, 668.
TXXU
LIST OF CONTRIBUTORS.
CRIPPS, W. H., F.R.C.S., 53a, Pall
Mall, London- 691-2.
CRISP, F., 134, Adelaide Road, Lon-
don ; 911-2.
CROSSLEY BROTHERS, Great Marl-
borough Street, Manchester ; 455.
CROSSLEY, E., F.R.A.S., Bermerside,
Halifax; 53.
CROSSLEY, L. J., Moorside, Halifax,
Yorkshire; 369.
CROUCH, H., 66, Barbican. London ;
907, 916.
CULLEY, R. S., General Post Office,
London ; 347.
CURTIS, PROF. A. H.,LL.D., Queen's
College, Galway ; 227.
CURWEN, J., Plaistow, Essex; 192.
CUTTELL, F. G., 52, New Compton
Street, Soho, London ; 850.
DAGLISH, R., & Co., St. Helen's,
Lancashire ; 453.
DAINTREE, R., Tralee Lodge, Bourne-
mouth ; 928.
DALE, R, S., B.A., Owen's College,
Manchester; 592.
DALLAS, D. C., 362, Gray's Inn
Road, London ; 233.
DALLINGER, REV. W. H., F.R.M.S.,
4, Fair holme Road, Great Crosby,
Liverpool ; 916-7.
DALLMEYER, JOHN H., 19, Blooms-
bury Street, London ; 240-3.
DAMON, R., Wey mouth ; 860, 975-6.
DARLING, W. H., Owen's College,
Manchester; 591.
DARTON, F., & Co., 72, St. John
Street, West Smithfield, London;
693, 699.
DARWIN, G. H., Trinity College,
Cambridge; 809-10.
DAVEY, H., Sun Foundry, Leeds ;
464.
DAVIDSON, J., University of Edin-
burgh ; 596-7.
DAVIS, CAPT. J. E., R.N., F.R.G.S.,
Douglas House, Maze Hill, Green-
wich; 402, 755-6.
DAVIS, J., AND SON, All Saints
Works, Derby; 99, 100, 870-1,
874.
DAVIS, REAR - ADMIRAL, C. H.,
United States Naval Observatory,
Washington ; 434-5.
DEACON, H., Widnes, Lancashire ; 99,
100. 647.
DENT, E.,& Co., 61, Strand, London ;
117, 122, 123, 127, 128, 414-5.
DE LA RUE, W.,F.R,S, 73, Portland
Place, London; 236, 303, 424,
426.
DE MICHKLE, V., Higham Hall,
Rochester ; 445.
DENTON, S.G., 128, Gray's Inn Road,
Holborn, London ; 260, 689-90.
DENTON, W., Sunderland ; 513.
DE RANCE, C. E., F.G.S., Geological
Survey, Jermyn Street, London;
829.
DE RATTI, A., Bradford Grammar
School, Bradford, Yorkshire ; 303.
DEWAR, PROF., Cambridge; 310.
DEWRANCE, J. & Co., 176, Great
Dover Street, Borough ; 551.
DICKINSON, J., Engineer, Sunder-
land ; 525.
DIXON, A., St. Anne's, Howard Road,
Penge, Surrey ; 419.
DONKIN, A. E., M.A., Rugby ; 21.
DONKIN, BRYAN, Engineer Works,
Bermondserj ; 65.
Dow, T., Exeter; 451.
DOWNING, T. J., 38, Whiskin Street,
London ; 867, 884, 888, 1042.
DOXFORD, W., AND SONS, Sunder-
land; 515,527.
DRING AND FAGE, 19 & 20, Tooley
Street, London ; 2, 3, 5, 8, 56, 169
-72, 260-1, 687, 690.
DRYSDALE, J. J., M.D., 4, Fairholme
Road, Great Crosby, Liverpool ;
917.
DUDGEON, R. E., M.D., 53, Mon-
tague Square, London,' W. ; 531.
DUER, S., B.Sc., 6, Westminster
Chambers, Victoria St., London ;
472.
DUNCAN. R., & Co., Ship-builders,
Port Glasgow 527-8.
DUNN, E. J. ; 828.
DUNSCOMHE, M. W., 10, St. Augus-
tine's Parade, Bristol; 1024-6.
DUPRAT, LE YICOMTE, Consul-
General of Portugal, St. Mary
Axe, E.C. ; 102, 428.
EAMES, M., 40, Sclater Street, Shore-
ditch, London ; 17.
EDINBURGH MUSEUM OF SCIENCE
AND ART, Edinburgh ; 220, 257,
285, 347, 563-4.
EDINBURGH UKi\EnsiTY,Edi?iburgh ;
276, 295,316, 398, 451, 721.
LIST OF CONTRIBUTORS.
XXX111
EDWARDS, B. J., Co., G, Lincoln
Terrace, Kit burn, London ; 232.
ELDER, J., & Co., Govan, near Glas-
gow ; 498.
ELKINGTON & Co. ,22, Regent Street,
London ; 379.
ELLIOTT BROTHERS, 449, Strand,
London; 2, 3, 51,57, 74, 75,77,
95-6, 99, 103, 109, 147, 152,
181-3, 229, 250, 259, 261, 279,
281, 290, 298, 300, 305, 308, 316
-8, 327, 333-4, 339-45, 370, 375,
419, 4(i5, 475-6, 681, 689, 693,
699, 708, 722, 747, 751, 780, 870.
ENOCH, F., 30, Russell Road, Hollo-
way ; 924, 978.
ERARD, MESSRS., 18, Great Marl-
borough Street, London ; 192.
ESSEX AND ClIELMSFOliD MUSEUM,
Chelmsford ; 903-4.
ETLER, C., 1st Battalion Grenadier
Guards, Chelsea Barracks, S. W. ;
302.
EVANS, L., Hemcl Hempsted; 8, 17.
FAIJA, H., 4, Great Queen Street,
Westminster; 103.
FARADAY, MRS., Barnsbury Villa,
320, Liverpool Road, London ;
382-3.
FARWIG, J. F., 36, Queen Street,
Cheaps ide, London ; 252.
FAULKNER, J., 13, Great Dude
Street, Strangeways, Manchester ;
281-2, 319.
FELLOWES, I. H., 46, South Quay,
Great Yarmouth; 515.
FLANNERY, J. F., G, Broadway Cham-
bers, Westminster; 103,524-5.
FLETCHER, A. E., 21, Overtoil Street,
Liverpool ; 97-8, 657.
FLETCHER, T., F.C.S., Museum
Street, Warrinyton; 252-3.
FORSTER, P., Sunderland ; 515.
FOSTER, ROBERT. Sunderland ; 74.
FOWLER, J., C.E., 2, Queen Square
Place, Westminster; 548.
FRANCIS, G., C.E., Chester ; 745.
FRANKLAND, PROF., Ph.D., D.C.L.,
F.R.S., Royal School of Mines,
Jermyn Street, London ; 580-6,
623-4, 672.
FRODSHAM, C., & Co., 84, Strand,
London ; 118.
FROUDE, W., F.R.S., Chelston Cross,
Torquay; 487-9.
FULLER, G., Belfast; 381.
40075.
| FULTON, J., University of Edinburgh ;
592-3.
GAIRDNER, 45, South Bridge, Edin-
burgh; 923.
GALLETLY, A., Museum of Science
and Art, Edinburgh ; 159, 160.
I GALLOWAY, PROF. R., Royal College
of Science, Dublin ; 658.
1 GALTON, F., F.R.S., 42, Rutland
Gate, London; 13, 14, 21, 178,
767, 769, 802.
| GARDNER, J. STARKIE, Park House,
St. John's Wood Park, London ;
88, 437-8, 549, 552, 866-7.
I GARDNER, J., AND SONS, 453, Strand,
London; 250.
GARNER, R., F.R.C.S., Stoke-upon-
Trent ; 257, 904.
GARNHAM & Co., Sash Court, Wilson
Street, Finsbury, London ; 376.
j GASKELL, DEACON, & Co., Widnes,
Lancashire; 644-5.
j GEIKIE,PROF., Di RECTOR, Geological
Survey of Scotland, Edinburgh ;
827.
GEOGRAPHICAL SOCIETY OF LON-
DON, ROYAL, 1, Savile Row, Bur-
lington Gardens, London ; 798, 801.
GEOLOGICAL MUSEUM, Jermyn Street;
668.
GEOLOGICAL SECTION, UNIVERSITY
MUSEUM, Oxford ; 844.
GEOLOGICAL SOCIETY OF LONDON,
Burlington House, Piccadilly,
London; 815-21.
GEOLOGICAL SURVEY OF ENGLAND
AND WALES, Jermyn Street, Lon-
don-, 821-3.
GEOLOGICAL SURVEY OF SCOTLAND
(Prof. Geikie, F.R.S., Director),
Edinburgh-, 827.
GEOLOGICAL SURVEY OF THE
UNITED KINGDOM (A. C. Ram-
say, LL.D., F.R.S., Director-Ge-
neral), Jermyn Street, London ;
823-8.
GEORGE, CAPT. C., Royal Geographi-
cal Society, 1, Savile Row, London ;
754-8, 769.
GLADSTONE, J. H.. Ph.D., F.R.S.,
17, Pembridge Square, London ;
579-80.
GLASGOW MECHANICS' INSTITU-
TION ; 451,460,497.
GOODMAN, G. H., 55, Penrose Street,
Newinyton, S.E. ; 472.
XXXIV
LIST OF CONTRIBUTORS.
GORDON, J. E. H., B.A., Gonville
and Caius College, Cambridge ;
705.
GORE, G., F.R.S., 50, Islington Row,
Edgbaston, Birmingham { 163, 256,
285-7, 308-9, 316-7, 323, 325-7,
335, 340, 576-7, 1069-70.
GOSSAGE, W., AND SONS, Widiies,
Lancashire ; 652-3.
GRANTHAM, MRS. J., Kirkby Cottage,
Cray don, Surrey ; 549.
GRAY, J. W., AND SON, Mary Street,
Rhodcswell Road, Limeliouse, Lon-
don; 318.
GREEN, R. AND H., Blackwall,
London; 505-6.
GREENHILL, A. G., Royal Artillery,
Woolwich; 21.
GREGORY, J. R., 88, Charlotte Street,
Fitzroy Square, London; 861, 884,
888, 893, 1042.
GRIESBACH, MRS., Holland Street,
Kensington, London ; 197.
GRIFFIN, J. J., AND SONS, 22, Gar-
rick Street, Covent Garden, Lon-
don; 1026-34.
GROVE, THE HON. SIR VV. R.,
115, Harley Street, London; 304.
GROVES, W., 89, Bolsover Street,
London ; 181, 426.
GRTTBB, H., F.R.A.S., Dublin ; 400-
1, 432.
GUEST ANDCHRiMES,J?oAer/JGfm; 80.
GURNEY, S., 20, Hanover Terrace,
N.W.; 814.
GTJTHRIE, PROF. F., Ph.D., F.R.S.,
Royal School of Mines, Jermyn
Street, London; 104, 151, 163,
178, 182-3, 190, 275, 280, 282,
298-9, 311, 320, 323, 327, 337,
591, 885, 1006-9.
HAMILTON, J., 2, Granby Terrace,
Glasgow; 491.
HAMILTON, J. BAILLIE, Greenwich
Park; 200-1.
HANKEY, T., 71, Chester Square,
S.W.; 129.
HARDING, A. B., F.P.S., 1, Albion
Villas, Forest Hill, London ; 323.
HARDING, T. R., AND SON, Tower
Works, Leeds ; 102-3.
HARGREAVES, J., Widnes, Lanca-
shire; 273.
HARGREAVES AND ROBINSON, Wid-
nes, Lancashire ; 643.
HARRISON, W. J., F.G.S., Curator,
Town Museum, Leicester ; 839.
HARVEY, REYNOLDS, & Co., 14,
Commercial Street, Leeds; 239,
257, 263, 280, 301, 309, 315, 334,
641, 913, 926, 942-3.
HASWELL, J., Sunderland ; 514.
HATHORN & Co., Sun Foundry,
Leeds; 464.
HAWKINS, S. J., 27, Lichfield Grove,
Finchley ; 16, 75.
HAWKSLEY, T., 300, Oxford Street,
London; 53, 179, 462, 915,922,
926-7, 931, 933-6, 939, 944, 948-
50, 952, 954, 995, 1001.
HAY, R. H., Sunderland ; 514.
HAYDEN, W., Little London, Chiches-
ter; 477.
HEAD, J., M.I.C.E., Middlesborough ;
453, 469, 479, 548-9, 667.
HECTOR, J., C.M.G., M.D., F.R.S.,
7, Westminster Chambers, London ;
830.
HEDGES, K. W., & Co., 36, King
William Street, London, E.C.;
462.
HENDERSON, D. AND W., & Co.,
Meadowside Works, Glasgow ;
509-12.
HENDERSON, R., Timsbury, Bath;
762,873.
HENNESSV, PROF. H., F.R.S., Royal
College of Science, Dublin ; 7, 35,
51, 87, 109, 724.
HENRICI, PROF. O., F.R.S., Univer-
sity College, London ; 34, 35.
HERMANN, I., 21, Northampton
Square, E.G.; 125.
HERSCHEL, PROF. A. S., College of
Physical Science, Newcasile-on-
Tyne; 207, 234, 247, 412.
HICKS, J., 8, 'Hatton Garden, E.G. ;
171, 680, 689-90, 698, 714.
HIGHAM, A. J., 13, Blackheath Ter-
race, London, S.E. ; 118.
HILGER, A., 192, Tottenham Court
Road, London ; 59, 88, 204, 213,
227, 230, 402-3, 405, 438, 763.
HILL, CAPT. H., 53, Marine Parade,
Brighton ; 346.
HIRSCH,H., 25, Craven Street, Strand,
W.C.; 525-6.
HIRST, I3ROOKE, AND HIRST, Leeds ;
661.
HODGKIN, NEUHAUS, & Co., 61,
63, Queen Victoria Street, E.G. ;
463.
LIST OF CONTRIBUTORS.
XXXY
HOGGAN, G. & E. E., M. D., 13,
(rrenrille Place, Portnutn Square ;
977.
HOLMAN, D. S., Philadelphia, U.S.A.-,
928.
HOLMK.S, J . M., Town Hall Chambers,
ttirminyham ; 549.
HOLMES, N. J., 8, Gt. Winchester
Street Buildings, E.C. ; 534-5.
HOLT, H. P., C!E., Royal Insurance
Buildings, Leeds ; 75, 453, 456,
469, 474, 498.
HOOKER, J. D., M.D., P.R.S., Royal
Gardens, Kew, Surrey ; 112, 904.
HOPKINS & WILLIAMS, 16, Cross
Street, Hatton Garden, E.C. ;
620.
HORNER, C., Fern Villa, Mortlake,
Surrey, 231.
HOROLOGICAL INSTITUTE, BRITISH,
35, Northampton Square, London ;
123-5.
How, J., & Co., 5, St. Bride Street,
Fleet Street, late 2, Foster Lane,
London ; 166, 214, 280, 290, 305,
313, 339, 380-1, G29, 839, 884,
907,916,979.
HOWE, \V., Clay Cross, Chesterfield ;
146.
HULL, E., DIRECTOR, (Geological
Society of London) -, 815-21.
HULL, PROP. E., M.A., F.R.S.,
Royal College of Science, Dublin ;
813.
HUNT, R., Craven Hotel, Strand ;
550.
HUXTER ENGLISH, Bow ; 525.
HUSBANDS, H., Bristol 743, 753.
HUTCHINSON, J., & Co., Windes,
Lancashire ; 645-7.
HUXLEY, PROF., F.R.S., Royal School
of Mines, Jerniyn Street, London ;
993-4.
HYDRAULIC ENGINEERING Co.,
Chester ; 455.
INDIA, SECRETARY or STATE FOR,
India Office, Whitehall, London;
729-30, 787-9.
IRELAND, GENERAL VALUATION OF,
Dublin; 803.
IRELAND, ROYAL COLLEGE OF
SCIENCE FOR, Stephen's Green,
Dublin. (See ROYAL COLLEGE
OF SCIENCE.)
JACKSON, REV. J. C., 67, Amherst
Road, Hackney, London ; 116, 391.
JACKSON, M., 65, Barbican, Lon-
don ; 1009-10.
JEBB, G. R., Chester ; 553.
JELLETT, REV. J. H., B.D., Trinity
College, Dublin; 21 7.
JOHNSON, MATTHEY, & Co., Hatton
Garden, London ; 53, 88, 641,
669.
JOHNSTON, W. & A. K., 18, Pater-
noster Mow, E.C. ; 1034-5.
JORDAN, J. B., Museum of Practical
Geology, Jennyn Street, London ;
681, 815, 851.
JOULE, J. P., D.C.L., F.R.S.,
Broughton, Manchester; 163, 281,
287, 290.
KEMPE, A. B., B.A., 7, Crown Office
Row, Inner Temple, London ; 1 45
-6.
I^ESSELMEYER, CH. A., Manchester ;
439. >:->'.'
KEW COMMITTEE OF THE ROYAL
SOCIETY, Kew Observatory, Sur-
rey ; 212, 261, 291, 293-6, 299,
332-3, 398, 421, 424, 694, 697,
701, 711, 738-9, 768.
KEW MUSEUM, Royal Gardens, Kew,
Surrey, 982.
KING'S COLLEGE, LONDON, COUNCIL
OP, Somerset House, Strand,
London ; 13, 147, 150, 162-3,
166,202,204, 223, 237, 258,283,
301-2, 311, 321, 324, 342, 368-9,
382, 426, ' 450, 464-5, 479, 529;
547, 553, 702, 1046.
KINGSTON, G. T., Meteorological
Office of the Dominion of Canada ;
Toronto, Canada ; 695-6.
KNOBEL, E. B., F.R.A.S., F.G.S.
20, Avenue Road, Regent's Park,
London ; 406, 438.
KULLBERG, V., 135, Liverpool Road,
N. ; 127.
LADD, W., & Co., 11 and 12, Beak
Street, Regent Street, London ; 223,
224,313, 909.
LAIDLER, W. H., 9, Edward Street ;
Bow Common, London ; 60.
LAING, J., Deptford Yard, Sunder-
land; 517.
LAIRD BROTHERS, Birkenhead Iron
Works, Birkenhead; 500-5, 531.
LASLETT, T. N., 97, Mary on Road t
Charlton, S.E. ; 748.
LATHBURY, R., JUN., Park House,
Chiswick, Middlesex ; 499.
c 2
XXXVI
LIST OF CONTRIBUTORS.
LAW, C., Champion Park, Camber-
well, S.E.; 567.
LA WES, J. B., F.R.S., Rothamsted, St.
Albans ; 661, 662, 994-5.
LAWRENCE AND PORTER, 36, Parlia-
ment Street, London ; 464.
L AWT ON, W., 49, High Street, Hull ;
412.
LEARD, A., M.D., 12, Old Burling-
ton Street, W. ; 948.
LECKEY, K. J. , F.R.A.S., Scientific
Club, 7, Saville Row; 391, 398,
750.
LETTS, DR. E. A., University of
Edinburgh ; 262, 592-7.
LETTSOM, W. G., 2, Thurlow Place,
Lower Norwood ; 249.
LEY, H.-W., 16, Bear Street, Leices-
ter Square, London ; 11921.
LIDSTONE,T., Dartmouth, Devon ;450.
LIGGINS, H.,3, Ladbrohe Square, W. ;
510.
LIGHTS, NORTHERN, COMMISSION-
ERS or, Edinburgh ; 536-8, 545-6.
LINN LAN SOCIETY, Burlington House,
London; 980-2.
LIPPINCOTT. See CANN-LIPPINCOTT.
LITERARY AND PHILOSOPHICAL SO-
CIETY OP MANCHESTER ; 564-7.
LLOYD, KEY. H., D.D., F.R.S.,
Trinity College, Dublin ; 168, 182,
217, 223, 228, 229, 274, 290, 339-
40, 386.
LLOYD'S REGISTER OF BRITISH AND
FOREIGN SHIPPING, Cornhill, Lon-
don ; 508.
LOCKYER, J. NORMAN, F.R.S., 5,
Alexandra Road, London ; 404,
420, 424-6, 432-34, 717, 814,
1064.
LOCKYER, MRS. NORMAN, 5, Alex-
andra Road, London ; 433.
LONDON, GEOLOGICAL SOCIETY OP,
Burlington House, Piccadilly,
London ; 815-21.
LONDON INSTITUTION, Finsbury
Circus, London ; 304.
LONDON MATHEMATICAL SOCIETY,
22, Albemarle Street, London ;
30-4.
LONDON ORDNANCE Co., Vavasseur
Street. Southwark ; 55 1-2.
LONDON, ZOOLOGICAL SOCIETY or,
11, Hanover Square, London ;
995-7.
LONGMANS, MESSRS., Paternoster
Row, London ; 1068-9.
LOVELL, T. M., INST. C. E. per
GARNHAM AND Co., Wilson Street,
Finsbury, London ; 548.
LOWNE, 11. M., Leicester House,
East End, Finchley, London ; 98-9,
945.
LUVINI, PROF., per METEOROLOGICAL
OFFICE, 116, Victoria Street, S.W.;
717.
MACLAUCHLAN, J. (Chief Librarian),
Dundee Free Library and Mu-
seum ; 203, 476, 479.
McLEOD, PROF. H., Cooper's Hill
College, Staines ; 163, 172, 620,
625.
MACMILLAN & Co., Bedford Street,
Strand; 1065-8.
McNAB, PROF. W. R., M.D., Royal
College of Science, Dublin ; 926,
994.
MADDOX, DR. (See How AND Co.,
5, St. Bride Street, Fleet Street,
E.G., London.}
MAIN, REV. R., F.R.S., Director of
the Radcliffe Observatory, Oxford ;
411, 717.
MAJOR, DR. H., West Riding
Asijlum, Wakefield ; 664.
MAKINS, G. H., Danesfield, Walton-
on-Thames ; 478.
MALLET, R., C.E., F.R.S., The
Grove, Clapham Road, S. ; 773.
MANCHESTER, COUNCIL OF THE
LITERARY AND PHILOSOPHICAL
SOCIETY OF ; 564.
MANN, R. J., M.D., 5, Kingsdown
Villas, Wandsworth Common, Lon-
don. ; 323, 337, 425, 805, 839, 1064.
MARRATT, J. S., 63, King William
Street, London ; 428.
MARSDEN, 11. S., University of Edin-
burgh ; 595.
MARSHALL, A., Perseverance Iron
Works, Hencage Street, White-
chapel, E. ; 457-8.
MARSHALL, J., SONS AND Co., Leeds,
661.
MARTIN, J., 58, Arundel Square,
London; 234.
MASKELYNE, PROF. N. S., F.R.S.,
112, Gloucester Terrace, Hyde
Park, London 227, 887, 895.
MASSEY ; E., Openshaw Works, Man-
chester; 95, 770.
MASTER OF THE MINT, THE, Lon-
don; 665-6.
LIST OP CONTRIBUTORS.
XXXVll
MATHEMATICAL SOCIETY, LONDON,
22, Albemarle Street, London;
.30-4.
MATHIESON, N., & Co., Widnes,
Lancashire ; 647-8.
MAFDSLAY, SONS, AND FIELD, Lam-
beth, London; 455, 483-5, 491-2,
518-20.
MAXWKLL, PUOF. CLERK, 11,
Xrroope Terrace, Cambridge ; 40,
276, 341-2.
MAYLAND, W.. 236, Regent Street,
London-, 237.
MECHANICS' INSTITUTION, Glasgow ;
451, 460, 497.
MENZIES AND BLAGUUKX, King Street,
Newcastle-upon- Tyne ; 477.
MERRIFIELD, C. \V., F.R.S., Edu-
cation Department, Whitehall,
London ; 813.
METEOROLOGICAL COMMITTEE OP
THE ROYAL SOCIETY, LONDON ;
243, G73-6, 698, 705, 711, 721.
METEOROLOGICAL OFFICE, 116, Vic-
toria Street, S.W. ; 676, 717-8.
METEOROLOGICAL SOCIETY, 30, Great
George Street, Westminster; 673-
4,676.
METEOROLOGICAL SOCIETY, SCOT-
TISH, General Post Office JBuild-
ings, Edinburgh ; 225, 674, 680,
686, 689, 692, 697, 713, 716, 718-
20, 7ti3.
MILLAR, W. J., C.E., 100, Wellington
Street, Glasgoio ; 446.
MILLER, W. H., M.A., F.R.S., Pro-
fessor of Mineralogy, Cambridge ;
126, 767, 886.
MILTON, J. L., Sion House, King's
Road, London ; 252.
MINES, ROYAL SCHOOL OF, Jcrmyn
Street, London ; 59, 553-62.
MINING AND MECHANICAL ENGI-
NEERS, NORTH OF ENGLAND
INSTITUTE OF, Newcastle-upon-
Tyne; 876-8.
MITCHELL, C., & Co.. Newcastle-on-
Tyne ; 508-9.
MITCHELL, W. S., LL.B. ; 823.
MOLINEUX, T., 8, Park Village East,
Regent's Park ; 193.
MOODY, W., 2, Nightingale Vale,
Woolwich, Kent ; 500.
MOON, G. W., 164, Regent Street,
W.; 685.
MOORE, B. T. ; Spring Grove,
Meworth ; 95, 97.
MORISON, D. P., 21, Collinywood
Street, Newcastle-upon-Tyne ; 869-
70.
MORRIS PATENTS ENGINEERING
WORKS, 50, High Street, Bir-
mingham ; 75-6.
MORRISON, R. M., University of
Edinburgh; 597.
MOTTERSHEAD & Co., Manchester ;
321, 102fi.
MoY,T. ; Institution of Naval Archi-
tects, John St., Adelphi, London ;
524.
MULLER, HUGO W., F.R.S. ; 303.
MULLER, J. A., C.E., 30, Craven
Street, Strand, London ; 96.
MURBY, T., 32, Bouverie Street, E.C. ;
431, 1046.
MURRAY, CAI-T. (per F. BUCKLAND) ;
781.
MURRAY & Co., Chester-le-Street,
Durham ; 550.
MURRAY, R. C., 69, Jermyn Street,
London ; 229.
MUSEUM OF SCIENCE AND ART,
Edinburgh ; 220, 257, 285, 347,
563-4.
MUSPRATT, J., & SONS, Widnes,
Lancashire ; 651-2.
MYLNE, R. W., C.E., F.R.S., F.G.S.,
21, Whitehall Place, London;
828-9.
NAPIER AND ETTKICK, LORD, 40,
Queen Anne's Gate'; 7.
NAPIER, R., West Shandon, Dumbar-
tonshire, Scotland ; 491, 509.
NASMYTH, J., Hammerfield, Pens-
hurst, Kent ; 473.
NAVAL ARCHITECTS, INSTITUTE OF,
20, John Street, Adelphi; 516, 529.
NAVAL MUSKUM, ROYAL, Greenwich,
117,391,499, 781.
NESBITT, A., F.S.A., Oldlands, Uck-
field; 74.
NEGRETTI AND ZAMBRA, Hatton
Garden, London ; 675, 677-9, 684,
687-9, 691, 700.
NELSON DOCK Co., LIMITED, 16,
London Street, Rotherhithe, Lon-
don ; 515.
NE\VALL AND Co. ; 130, Strand, Lon-
don; 530.
NEWTON, E. T., Museum of Practical
Geology, Jermyn Street, London ;
978.
XXXV1J1
LIST OF CONTRIBUTORS.
NICHOLAS, J., 90, Brunswick Street, \
Manchester 67, 467.
NICKOLL AND CREWS ; 36, St. Mary j
Axe, London ; 522-3.
NICOL, W. J., University of Edin- |
burgh ; 595-6.
NORRIS, TV. J., AND BROTHER,
Colder Chemical Works, Sowerby
Bridge, Halifax ; 654.
NORTH OF ENGLAND INSTITUTE OP ,
MINING AND MECHANICAL ENGI-
NEERS, Newcastle - upon - Tyne ; ;
876-8.
NORTHERN LIGHTS, COMMISSIONERS <
OF, Edinburgh ; 536-8, 545-6.
OERTLING, L., Turnmill Street,
London-, 15, 81, 88, 171.
OLRICK, L., 37, Leadenhall Street,
E.G.; 446.
OMMANEY, ADMIRAL, 6, Talbot \
Square, Sussex Gardens, W.; 741. j
ORDNANCE SURVEY (Maj.-Gen. Ca- j
meron, R.E., F.R.S., Director Gene- j
ral), Southampton ; 725-8, 783-5.
ORDNANCE SURVEY OF PALESTINE,
9, Pall Mall East, London ; 786.
O'REILLY, PROF. J. P., Royal College
of Science, Dublin ; 214,679,849-
50, 879, 885, 888, 894.
ORTON, REV. W. PREVITK, M.A.,
Ornesby , Rugby ; 221.
OXFORD, UNIVERSITY OF ; 885-6.
OXFORD UNIVERSITY MUSEUM, Ox- \
ford ; 840, 844, 983-4.
PALESTINE, ORDNANCE SURVEY OF, \
9, Pall Mall East, London; 786.
PARKES, MRS., 17, Wimpole Street,
W.; 208.
PARKINSON AND ERODSHAM,4, Change
Alley, E.C. ; 126, 636.
PASTORELLI, E., 208, Piccadilly, Lon-
don ; 96, 99, 675, 682, 685-6, 689-
90, 694-5, 698, 708, 742, 752, 871
-2, 942.
PATENTS, COMMISSIONERS OF, Patent \
Office Museum, South Kensington,
London-, 4, 65, 116, 283, 451-2,
457, 460, 462, 465, 467, 469-72,
477, 480, 491, 498, 529.
PEARSON, A. A., 44 and 46, Queen's ,
Place, Leeds ; 438.
PENDRED, V., Streatham Hill, Surrey ;
508.
PERIGAL, H., E.R.A.S., 9, North
Crescent, Bedford Square, Lon- \
don-, 21, 147-8.
PERKIN, W. H., F.R.S., The Chest-
nuts, Sudbury, Harrow 586-90.
PHORSON, P., Sunderland 518.
PICHLER, S. F., 162, Great Portland
Street, London-, 17S, 196, 250,
475, 530, 916.
PIGOT, PROF. T. F., C.E., M.K.I. A..
Royal College of Science, Dublin ;
39,' 55, 476, 551.
PILLISCHER, M., 88, New Bond
Street, London ; 679,684, 703, 907,
916.
POOLE, J., & Co., 33, Spencer Street,
Clerkenwell, London ; 117.
PORTER, H., 181, Strand, London ;
17, 680, 685, 741, 752, 756, 768.
POSTMASTER -GENERAL, II. M., St.
Martin We- Grand, London ; 349-
61, 550.
PREECE, W. H., General Post Office,
London; 336.
PRESTWICH, PROF. J., E.R.S., Ox-
ford; 844.
PRICE, W., 181, Burrage Road,
Plumstead; 656.
PRITCHARD, URBAN, M.D., 41, Guil-
ford Street, Russell Square, Lon-
don ; 920.
PROSSER, W. H., 108, South Hi/I
Park, Hampstead; 5, 477.
PURVES, W. L., 7, Hanover Street,
Hanover Square, W.; 929-30,
933.
RANSOMES, SIMS, & HEAD, Orwell
Works, Ipswich ; 454.
RATTI, AUREL DE, Bradford Gram-
mar School ; 303.
RAYLEIGH, LORD, E.R.S., 4, Carlton
Gardens, London ; 165, 191.
RAYNOR, W., Radcliffe, Manchester;
315.
READ, MRS., 27, Sussex Place, South
Kensington, London ; 194.
REID, J., & Co., Port Glasgow ;
490, 497.
REID, BROTHERS, 1 2, Wharf Road,
City Road, London; 347-9. '
RENNIE, J. & G., Holland Street,
BLickfriars, S.E. ; 520-2.
REYNOLDS, PROF. O., Owen's Col-
lege, Manchester ; 39, 108.
RIANO, SENO-R E., 23a, Connaught
Square, W. ; 374.
RICHARDSON, DUCK, & Co., Stockton-
on-Tees; 508.
RICHARDSON, T. & SONS, Hartlepool ;
522.
LIST OF CONTRIBUTORS.
XXXIX
RITCHIE, J., & SON, 25, Leith Street,
Edinburgh; 415-9.
ROBERTS, W. H., Snodland, Kent ;
781.
ROBERTS, W. CHANDLER, F.R.S.,
Royal Mint, London ; 208, 568-70.
ROBERTS, DALE, & Co., Manchester
and Warriju/ton ; 653.
ROSCOB, PROF., F.R.S., Owen's Col-
lege, Manchester; 217,' 563, 567,
577-9, 644, 670, 705-7.
Ross AND Co., 7, Wigmore Street,
Cavcndisk Square, London ; 239,
905.
Ross, MAJOR W. A., 3, Mayland
Row, Shepherd's Bush ; 638.
Ros8E,EARL OF,F.R.S., Birr Castle,
Parsonstown, Ireland; 401, 406,
412,432, 438.
ROUND, J., 196, Camberwcll Road,
London ; 376.
ROWLEY, W., C.E.,F.G.S., 74, Albion
Street, Leeds ; 874, 879-80.
ROYAL AGRICULTURAL SOCIETY OF
ENGLAND, 12, Hanover Square,
London ; 474.
ROYAL ASTRONOMICAL SOCIETY,
Burlington House, Piccadilly,
London ; 41 1, 413.
ROYAL COLLEGE OF SCIENCE FOR
IRELAND, Stephen's Green, Dub-
lin ; 8. See also PROFESSORS
ADAMS, BARRETT, GALLOWAY,
HENNESSY, HULL, McNAB,
O'REILLY, and PIGOT.
ROYAL COLLEGE OF SURGEONS OF
ENGLAND, Lincoln's Inn Fields,
London ; 976.
ROYAJL COMMISSIONERS FOR THE
INTERNATIONAL EXHIBITION, 1851 ;
724, 814.
ROYAL GEOGRAPHICAL SOCIETY OF
LONDON, 1, Savile Row, Burlington
Gardens, London ; 740, 798-801.
ROYAL INDIAN ENGINEERING COL-
LEGE, Cooper's Hill ; 461.
ROYAL INSTITUTION OF GREAT BRI-
TAIN, 2 1 , Albemarle Street, London ;
257, 286, 302, 381-2, 477, 563,
567-8, 878.
ROYAL MICROSCOPICAL SOCIETY,
King's College, London ; 475, 902-3.
ROYAL MUSEUM, SALFORD, Peel
Park, Salford; 1, 8, 119, 250, 281,
476-7, 487, 550, 681, 901-2.
ROYAL NAVAL MUSEUM, Greenwich ;
117, 391, 781.
ROYAL OBSERVATORY, Greenwich ;
129.
ROYAL POLYTECHNIC INSTITUTION,
Regent Street, W.; 312.
ROYAL SCHOOL OF MINES, Jermyn
Street, London ; 59, 553-62.
ROYAL SOCIETY, Burlington House,
Piccadilly, London; 57, 89, 111,
117,159,171,291,298,399,410-11,
413,421,431, 690, 699, 738, 741,
750, 875.
ROYAL UNITED SERVICE INSTITU-
TION, Whitehall Yard, London ;
115-6,392.
ROYDEN, T., (Shipbuilder} Liver-
pool; 507.
ROYSTON-PlGOTT, G. W., M.D.,
F.R.S., Hartley Court, Reading,
57, 908, 919.
RUBIE, G. P. ; 527.
RUCKJSB, PROF. A. W., M.A., York-
shire College of Science, Leeds; 63.
RUHMKORFF, 11, Beak Street, Regent
Street; 311, 314.
RUSSIAN EMBASSY, THE, Chesham
Place, S.W.; 516.
RUTHERFORD, PROF., Edinburgh ;
944.
RUTLEY, F., Geological Survey Office,
Jermyn Street, London ; 826-7.
RUTTER, H. L., 1, St. Barnabas
Villas, Lansdowne Circus, South
Lambeth, S.W.; 281,316.
RUTTER, J. O. N., F.R.A.S., Black
Rock, Brighton; 313.
SABINE, R., 2o, Cumberland Terrace,
Regent's Park, Lo.ndon ; 181, 203,
208, 233-4, 244, 348.
SALFORD ROYAL MUSEUM, Peel Park,
Salford; 7,8,119,250,281,476-7,
487, 550, 681, 901-2.
SAMUDA, BROTHERS, Poplar ; 522.
SAMUELSON, B., M.P., Middles-
borough ; 668.
SANDERSON, DR. B., F.R.S., 49
Queen Anne Street, W. ; 948.
SANDERSON AND PHOCTOR, Shore
Works, Huddersfield, and 19 and
21, Queen Victoria Street, London ;
277, 318.
SCHERZER, DR. K. von, Austrian
Consulate General, 29, St. Sivithin's
Lane, London ; 748.
SCHOOL OF MILITARY ENGINEERING,
Chatham; 237.
SCHORLEMMER, C., F.R.S., Owen's
College, Manchester; 591-2.
LIST OF CONTIUBUTORS.
SCHUNK, DR., Owen's College, Man-
chester; 663.
SCIENCE SCHOOLS, South Kensington
Museum ; 1063.
SCOTLAND, GEOLOGICAL SURVEY OF,
Edinburgh-, 827.
SCOTT-MONCRIEFF, W. D., 9, Great
Queen Street, Westminster', 468,
489-90.
SCOTT, R. H., F.R.S., Director, Me-
teorological Office, 116, Victoria
Street, Westminster-, 689.
SCOTTISH METEOROLOGICAL SO-
CIETY-, General Post Office Build-
ings, Edinburgh-, 225, 674, 680,
686, 689, 692, 697, 713, 716, 718-
20, 723.
SECRETARY OF STATE FOR INDIA,
India Office, Whitehall, London ;
729-30, 787-9.
SHAND, MASON, & Co., 75, Upper
Ground Street, London ; 463.
SHARMAN, G., St. Leonard's Villa,
West End Lane, Kilburn, Lon-
don-, 861.
SHORT, BROTHERS, Sunderland; 528-
9.
SIEBE AND GORMAN, Mason Street,
Westminster Bridge Road ; 531.
SIEMENS, DR. C. W., London 250,
265-7, 468.
SIMEY, A., & Co., Sunderland ; 518.
SINCLAIR, J., 104, Leadenhall Street,
London ; 487.
SKERTCHLY, SYDNEY B. J., F.G.S.,
Geological Survey, Jermyn Street,
London; 712.
SKINNER, (Shipbuilder} Sunderland ;
518.
SMITH, DEW, 7a, Eaton Square,
S.W.; 950.
SMITH, EDWIN, Bath ; 411.
SMITH'S INSTITUTE, Sttriinc/ ; 79.
SMITH, LIEUT.- GEN. M. ' W., 58,
Gloucester Crescent, Hyde Park,
W.; 19.
SMITH, T. AND W., Neivcastlc-on-
Tyne ; 530.
SMITH, W., V.^Newcastlc-on-Tyne;
523-4.
SMITH, W. G., 15, Mildmay Grove,
N.-, 985.
SMYTH, J., JUN., M.I.C.E.I., Milltown,
Banbridge, Ireland 714-5.
SMYTH, PROF. PIAZZI, Royal Obser-
vatory, Edinburgh-, 50, 51, 111,
239, 258.
[ SOCIETY FOR PROMOTING CHRISTIAN
KNOWLEDGE, Lincoln** Inn Fields,
W.C.; 829.
SOMERVILLE, J., 20, Wcstlatid Row,
Dublin; 472.
SORBY, II. C., F.R.S., Broomfield,
Sheffield-, 845-6, 905.
SOUTH KENSINGTON MUSEUM, Lon-
don; 22-30, 129, 193-4,203, 205,
227, 379, 395, 447-9, 454-5, 458,
464, 465-7, 470, 480-3, 492-7, 532,
546, 782.'
I SPEECHLY, H., 43, King's Road, St.
Pancr as, London; 194.
SPEKE, W., jun., Jordans, llminster,
Somersetshire; 741.
I SPENCE, P., Pendleton Alum Works,
Manchester ; 65 1 .
j SPILLER, J., F.C.S.,2, St. Mary's Rd.,
Canonbury, London ; 205,207, 905.
SPOTTISWOODE, W., F.H.S., 50, Gros-
venor Place, London ; 220, 222.
SPOTTISWOODE, MRS. W., 50, Gros-
renor Place, London ; '222.
SPRAGUE, J. T., 315, Green Lane,
Birmingham ; 337.
SPKENGEL, H., 44, Charlwood Street,
Pimlico, London ; 165.
STANDARDS DEPARTMENT, BOARD OF
TRADE (H. W. Chusholm, War-
den), 7, Old Palace Yard, Lon-
don ; 42-7.
STANFORD, E., Charing Cross, Lon-
don; 824, 827-8.
STANLEY, A. AND F. New Britain,
35, Chambers St., New York ; 53.
STANLEY, W. F., 3, Great Turnstile,
Holborn, London; 17.
STEELE, R. & Co., Greeiiock ; 517-8.
STEPHENSON, G. 1&.,Albemarlc Lodge,
Wimbledon Park ; 457.
STEPHENSON, J. W., Equitable As-
surance Office, Mansion House
Street, London ; 906.
STEVENSON, D. AND T., Northern
Lighthouse Office, Edinburgh ; 546.
STEWART, PROF. BALFOUR, F.R.S.,
Owen's College, Manchester ; 243,
276, 692.
STIFF AND SONS, London Pottery,
Lambeth ; 655.
STIRLING, THE BURGH OF, Stirling ;
55.
STONE, DR. W. II., Dean's Yard,
Westminster; 153, 166, 181, 183,
193, 196, 207, 246,281,287,298,
300, 426.
LIST OF CONTRIBUTORS.
xli
STRAWSON, G. W., 9, Pancras Lane,
London-, 17, 112, 747, 75u, 752,
873.
STRUTHERS, PROF., Aberdeen Uni-
versity, 937, 979.
SUB-WEALDEN EXPLORATION COM-
MITTEE (W. Topley, F.G.S., and
H. Willett, F.G.S.) ; 837-9.
SUGG, W., Vincent Works, Vincent
Street, Westminster ; 22. r >, 249.
SULLIVAN & Co., British Alkali
Works, Widnes, Lancashire ; 642-
3.
SUNDERLAND, CORPORATION OF ;
518.
SWIFT, J., 43, University Street,
Tottenliam Court Road, London ;
907-8,917,927.
SYMONS, G. J., 62, Camden Square,
London ; 289, 682, 686-7, 698,
700, 702, 717, 720-1, 743.
TAIT, PROF. P. G., M.A., University
of Edinburgh ; 275, 310, 321, 324.
TALBOT, H. 'Fox, F.R.S., Lacock
Abbey, Chippenham ; 237.
TANGYK BROTHERS, AND HOLMAN,
10, Laurence Pountney Lane, Lon-
don ; 454.
TAYLOK, MAJOR M. L., R.A., Royal
Artillery Institution, Woolwich ;
104, 117,741.
TEASDALE, W., Headingley, Leeds ;
908.
TENNANT, PROF., Piccadilly, Lon-
don ; 829.
THAMES IRON WORKS AND SHIP-
BUILDING Co., Orchard Yard,
Blackwall ; 506, 507.
THERMO-ELECTRIC GENERATOR Co.,
27, New Street, Cloth Fair, Lon-
don; 310.
THOMAS, J. W., The Laboratory,
Cardiff, Wales ; 473, 640.
THOMSON, PROF., JAS. University,
Glasyuw ; 460-1.
THOMSON, PROF. SIR W., F.R.S.,
The University, Glasgow; 11, 12,
49, 50, 152, 321, 329-31, 335-6,
342, 349, 371, 373, 445, 451, 770,
776-9.
THOMPSON, J. L., AND SONS, Sunder-
hind; 518.
THOMPSON, R., Junr., Sunderland;
514.
THORPE, PROF., Yorkshire College
of Science, Leeds-, 217, 653.
TIIWAITES AND CARBUTT, Bradford
Yorkshire ; 473, 643-4.
TISLEY AND SPILLER, 172, Brompton
Road, London; 149, 302-3, 318,
716.
TOPLEY, W r ., F.G.S., Geological
Surveij, Jermyn Street, London ;
815-6.
TRIBE, A., 17, Pembridge Square,
London ; 579.
TRINITY COLLEGE, DUBLIN, Dublin.
(See JELLETT AND LLOYD.)
TRINITY HOUSE, LONDON, CORPO-
RATION OF, Trinity Square, Tourer
Hill, London ; 532-6.
TROUGHTON AND SIMMS, 138, Fleet
Street, London ; 1 12, 394, 741.
TURNBULL, R., 823.
TURNER, B. B., 31, Haymarkct,
S.W.; 239.
TYLER, HAYWARD & Co., 84, Upper
Whitecross Street, London ; 455, 463.
TYLOR, J., AND SONS, 2, Newgate
Street, E.C.; 80.
TYNDALL, PROF., F.R.S., 21, Albc-
marle Street, London; 190, 274
287.
UNITED SERVICE INSTITUTION,ROYA L,
Whitehall Yard, London; 115-6,
392.
UNIVERSITY of EDINBURGH, Edin-
burgh; 276, 295, 316, 398, 451,
721.
UNIVERSITY OF OXFORD, 885-6.
UNIVERSITY OF OXFORD MUSEUM,
Oxford ; 840, 844, 983-4.
UN WIN, PROF. W. C., Cooper's Hill
College, Staines ; 96, 461.
VARLEY, S. A., Hatfield, Herts ; 314,
373.
VICTORIA, THE AGENT-GENERAL OF,
Victoria Chambers, S. W. ; 803.
WALLACE, J. (TANGYE BROTHERS &
RAKE), 3, St. Nicholas Buildings,
Newcastle-upon-Tyne ; 633-5.
WALTER, J., M.P., 40, Upper Grcs-
venor Street, London ; 479.
WAR OFFICE, Pall Mall, London ;
56, 379.
WARD, J. CLIFTON, Greta Bank
Cottage, Keswick ; 823-6.
WARD, W. S., Denison Hall, Leeds ;
167, 335, 370, 563, 754, 904.
WARDEN, MUIRHEAD, AND CLARK,
29, Regent Street, Westminster,
London ; 304, 336-7, 344-6, 368-
73, 377.
xlii
LIST OF CONTRIBUTORS.
WARWICK, J. A., Derby ; 348.
WATERHOUSE, A., 20, New Caven-
dish Street, London ; 1070-2.
WATKIN, LIEUT. H., R.A., 1, Ux-
bridge Villa, Page} Road, Shooters
Hill, London ; 100.
WATSON AND Sox, 313, High Hoi-
born, London ; 394, 397, 750, 757.
WAUGH, J., 29, Tyrrell St., Brad-
ford; 915,918.
WEAR, COMMISSIONERS OF THE
KIVER, Sunderland ; 471.
WEBB, F. W., Locomotive Depart-
ment, L. and N. W. Railway,
Crewe ; 458-9, 547-8.
WEDEKIND, II., 4, Great Tower
Street, London ; 254, 655.
WEST WOOD, PROF., Oxford,-, 986.
WHEATSTONE COLLECTION OF PHY-
SICAL APPARATUS, King's College,
London. (See KING'S COLLEGE,
London.')
WHEATSTONE, the late SIR C. ; 346.
WHEELER, E., 48, Tollington Road,
Holloway, London ; 909, 918.
WHITE, J., 241, Sauchiehall Street,
Glasgow ; 329,498.
WHITE, J., Cowes, Isle of Wight ;
498.
WHIT WELL, T., Stockton -on-Tees ;
668.
WHITWORTH, SIR JOSEPH, F.R.S.,
& Co., 44, Chorlton Street, Man-
chester ; 48-49, 444, 669.
WIDNES METAL Co., West Bank,
Widnes, Lancashire ; 648-50.
WILLIAMS, J., F.C.S., 16, Cross
Street, Hatton Garden, London ;
263.
WILLIAMS, THOMAS, AND DOWER,
Star Chemical Works, Hrentford,
Middlesex ; 655.
WILLIS, W-, 49, Palace Grove,
Bromley, Kent ; 232, 525, 553.
WILTSHIRE, EEV. T., M.A., Secre-
tary, Geological Society, Burlington
House, Piccadilly, London ; 852.
WINCHESTER, CORPORATION OF, Win-
chester; 478.
WOLLASTON COLLECTION, Cavendish
Laboratory, Cambridge ; 57, 205.
WOLLASTON, G. H., 117, Pembroke
Road, Clifton, Bristol; 183, 205,
567, 885.
WOOD, G. S., 20, Lord Street, Liver-
pool; 908.
WOOD, J., Ivy Cottage, Burnley
Lane; 456.
WOODBURY PERMANENT PHOTOGRA-
PHIC PRINTING Co., 157, Great
Portland Street, London ; 232,
240, 470-2, 474, 481, 487, 490,
492.
WOODBURY, W. B., Manor House,
South Norwood; 233, 245, 700.
WOODCROFT, BENNET, F.R.S., Great
Seal Patent Office, London ; 8, 17,
83,97, 279, 451-3, 457-8,470-2,
474, 480, 487, 490, 492.
WOODWARD, C. J., Birmingham and
Midland Institute, Birmingham ;
150,205.
WORKS, H.M. OFFICE OF, London
6, 1002.
WORNUM AND SONS, 16, Store Street,
London ; 193.
WORTLEY, COL. STUART, Patent
Museum, South Kensington, Lon-
don ; 233.
WRIGHTS ON, T., Sunderland; 513.
YE ATE s AND SON, 2, Grajton Street,
Dublin; 181, 189, 214, 265, 311,
339, 400, 694, 698.
YEO, PROF. GERALD, King's College,
W.C.; 950.
YOUNG, J., West Docks, South
Shields ; 512-3.
YORKSHIRE COLLEGE OF SCIENCE,
COUNCIL OF, Leeds; 5, 75, 153,
176, 653.
YORKSHIRE PHILOSOPHICAL SO-
CIETY. COUNCIL OF, York ; 399. .
ZANM, G., 31, Compton Road, High-
bury, and 1 , James Street, Old
Street, City Road, London ; 370,
373, 376-7.
ZOOLOGICAL SOCIETY or LONDON,
11, Hanover Square, London ;
995-7.
ATJSTRO-HUNGARIAN EMPIRE.
ARZBERGEK, PROF. F., Imp. Sf Royal
Technical High School, Brilnn ;
639, 770.
BAUER, PROF. DR. A., Polytechnic
Institute, 20, Kamtnerstrasse,
Vienna ; 253, 671.
BORRICKY, DR. E., Prof, of Mineral-
ogy, University of Prague ; 894.
LIST OP CONTRIBUTORS.
xliii
ETTINGSHAUSEN, BARON C. von, Prof,
of Botany, University of Gratz ;
852-60.
EXNER, DR. W. F., Professor of
Engineering, High School of Agri-
culture and Forestry, Vienna ; 475.
FORESTS, IMP. AND KOYAL INSTITU-
TION FOR CARRYING OUT EXPERI-
MENTS RELATING TO (Dr. W.
Velten, Physiologist to the Institu-
tion), Vienna ; 993.
FRIG, V., Prague ; 989.
GONDA, HERR BELA, Magyar, Ovar,
Hungary ; 663.
GROHMANN, ED., Vienna ; 7.
HANTKEN, PROF. M., University of
Buda-Pest; 867.
IIOPFGARTNEK, LlKI'T. Y. (Imp. and
Royal Navy}, Vienna ; 769-70.
IMP. AND KOYAL CENTRAL INSTITUTE
OF METEOROLOGY AND MAGNETISM,
Vienna ; 119, 705, 712, 717.
IMP. AND ROYAL MARITIME GOVERN-
MENT, Trieste ; 534.
INSTITUTE OF PATHOLOGY, Univer-
sity of Vienna (Prof. S. Strieker,
Director) ; 944.
JENNY, C., Professor, Imperial and
Royal Polytechnic Institute, Vienna;
445.
KLEBS, DR. E. B., (Pathological In-
stitute}, Prague ; 927-8, 999, 1000.
LANG, PROF. V. von, University of
Vienna ; 1 54.
MILLER, F., Innsbruck ; 751, 759.
MOSER, PROF. I., Director of the
Imp. and Royal Chemical Institu-
tion for Agricultural Researches,
Vienna ; 939, 978-9.
OSNAGHI, PROF. F., Imp. and Royal
Central Institute of Meteorology,
Hohe Warte, Vienna; 119, 705,
712, 717.
PATHOLOGY, INSTITUTE OF, Univer-
sity of Vienna (Prof. S. Strieker,
Director) ; 944.
PAUGGER, DR. F., Director of the
Imp. and Royal Commercial and
Nautical Academy, Trieste ; 703-
4,780.
PFAUNDLER, DR. L., Prof, of
Physics, University of Innsbruck ;
150, 152-3, 261, 273.
PHYSIOLOGICAL INSTITUTE, Prague
936, 939, 947-8.
PRAGUE, PATHOLOGICAL INSTITUTE
OF THE UNIVERSITY OF (Dr.
E. Klebs, Djrector) ; 927-8, 999-
1000.
RICHTER, C. W., Oedenburg, Hun-
gary, 251.
ROESLER, PROF. DR. L., Director
of the Imp. and Royal Experi-
mental Station for the Cultivation
of the Vine and Fruits, Kloster-
neuburg ; 664, 919.
SCHLBSINGER, PROF. J., High School
of Agriculture, Vienna; 747, 759.
SCHOEN, PROF. J. G., Polytechnic
Institute, Briinn ; 705.
SCHOPFLKI TIIXKR, DR. F., 9, Wallen-
stein Strasse, Vienna ; 529-30, 870.
STREINTZ, PROF. DR. H., University
of Gratz; 60.
STRICKER, PROF. S., University of
Vienna (Institute of Pathology);
944.
SZABO, PROF. DR. J., University of
Buda-Pest ; 867.
TILLE, J., PROF., Bohemian Poly-
technic Institute, Prague ; 473.
TINTER, PROF. DR. W., Polytechnic
Institute, Vienna ; 683, 764-6.
TLLSER, PROF. F., Bohemian Poly-
technic Institute, Prague ; 35-4J6.
TRIESTE, IMPERIAL AND ROYAL
MARITIME GOVERNMENT AT ; 534.
UNIVERSITY OF GRATZ ; 60.
UNIVERSITY OF VIENNA, INSTITUTE
OF PATHOLOGY ; 944.
VELTEN, DR. W., Imp. and Royal
Institution for carrying out experi-
ments relating to Forests, Vienna ;
993.
VIENNA, IMP. AND ROYAL CENTRAL
INSTITUTE OF METEOROLOGY AND
MAGNETISM ; 119, 705, 712, 717.
VIENNA UNIVERSITY, INSTITUTE OF
PATHOLOGY; 944.
WALTENHOFEN, DR. A. von, Prof,
of Physics, German Polytechnic
Institution, Prague ; 283.
ZENGER, C. W., Prof, of Physics,
Bohemian Polytechnic Institution,
Prague; 89, 209, 225, 318, 403,
423/427, 929.
xliv
LIST OP CONTRIBUTORS.
ZMURKO, DR. L., Prof, of Mathe-
matics, University, and Polytechnic
Institute, Lembery ; 18,20,21.
ZULKOWSKY, PROF. C., Imp. and
Royal Technical High School,
Brilnn ; 639.
BELGIUM.
ARENS, ANTOINE MARIANUS, Rue de
Bruxelles, Namur ; 1012.
BRUVLANTS, G., Laboratory of
General Chemistry, University of
Louvain ; 592.
COUGNET, J., Ixelles, Brussels; 165.
GERARD, A. J., 5, Place St. Lambert,
Liege ; 100, 107-8, 128.
GOCHET, PROF. A. M., Normal
School, Carlsbourq, Luxembourg ;
813, 1026.
HENRY, L., Professor of Chemistry,
University of Louvain ; 592.
LE BOULENGE, MAJOR, 23, Thier de
la Fojitaine, Liege-, 56, 100.
LEURS, LIEDT.-GENERAL, 9, Hue de
la Longue-haie, Brussels; 100.
MALAISE, PROF. C., MEMBER OF THE
ROYAL ACADEMY OF BELGIUM,
State Agricultural Institute, Gem-
bloux, Province of Namur ; 836.
MARTINOT, A., Nismes, Mariem-
bourg; 1011.
NAVEZ, LIEUT. COL., Schaerbeeth,
Brussels.
PIRON, FRERE M., Director of the
Normal School, Carlsbourg ; 13, 39.
REXARD, A., 11, Rue des Recollets,
Louvain ; 845.
SACRE, E., 30, Rue Cantersteen,
Brussels ; 83.
SCHWANN, PROF. T., 11, Quai de
V Universite, Liege ; 954-5, 1002.
SIMONAN AND TOOVEY, Chausse de
Lille, Tournai; 236.
VAN RYSSELBERGHE, F., Paymaster,
Royal Navy, Antwerp, late Pro-
fessor at the School of Navigation,
Ostend ; 74, 709.
VAN SCIIERPENZEEL TlIINI, J.,
Director of Mines, 34, Rue Nysten,
Liege ; 878, 880.
FRANCE.
ALVERGNIAT FRERE s, 10, Rue de la
Sorbonne, Paris ; 250, 322, 641.
Auzoux, DR., 96, Rue de Vaugirard,
Paris; 982-3.
BAUDIN, 276, Rue St. Jacques, Paris ;
171, 723.
BECQUEREL, M. E., 47, Rue Cuvier,
Paris ; 237, 425.
BERTHELOT, M., 97, Boulevard St.
Michel, Paris ; 1035.
BIARD, M., 10, Rue Mont Theibord,
Paris ; 813.
BONIS, MADAME, 18, Rue Mont-
martrc, Paris; 317.
BONTKAIPS, Telegraph Inspector,
Paris; 377.
BOURDON, C., 74, Rue du Faubovrg
du Temple, Paris; 128, 146, 166,
456, 470.
BOURGOGNE, E., 34, Rue Cardinal
Lemoine, Paris ; 977.
BREGUET, 81, Boulevard Mont Par-
nasse, Paris; 173, 280-1, 306-7,
316, 328, 426, 669, 711, 781, 878.
CACHELEUX, 6, Rue des Vieilles
Haudriettes, Paris ; 549.
CARRE, E., 24, Rue d'Assas, Paris ;
166, 299, 328.
CHAMEROY, 162, Faubourg St. Martin,
Paris; 83.
CLETJET, 196, Rue d'Allemagne,
Paris; 469.
COLLEGE OF FRANCE, PARIS ; 147,
182, 222, 255, 258, 268, 312, 327.
COLLIN & Co., 6, Rue de VEcole de
Medecine, Paris ; 945.
COLLOT, BROTHERS, Boulevard de
Montr ouge, Paris ; 79, 83, 87.
CONSERVATOIRE DES ARTS ET
METIERS, Paris ; 3, 12, 21, 128,
162-9, 182, 196, 234, 255, 261, 268,
274, 295, 305, 307, 324, 338, 381,
414, 420, 427, 430, 460, 487, 638,
683, 696, 743, 887.
CRETES, M., 66, Rue de Rennes,
Paris ; 204, 227, 930, 933.
DAUBREE, M., Membre de 1'Institut,
Director of the School of Mines,
Paris; 847.
LIST OF CONTRIBUTORS.
xlv
D'ABBORDRE, A., 120, Rue du Bac,
Paris; 746-7.
DELAGRAVE, M., 58, Rue des Ecoles,
Paris; 813.
DELES SE, M., Chiej Engineer of
Mines, Paris; 811-2, 844.
DELEUIL, 42, Rue des Fourneaux,
Paris ; 85, 87.
DEPARTMENT OF LIGHTHOUSES,
France; 538-45.
DEPOT OF MARINE CHARTS AND
PLANS, Part's; 813.
DEPREZ, M., 16, Rue Cassine, Paris ;
370, 467.
DESAINS, MEMBRE DE L'INSTITUT,
78, Rue d' Arras, Paris ; 274.
DESCIIIENS, )23, Boulevard St.
Michel, Paris ; 372.
DIGKON, 13, Rue de Marseille, \
Paris ; 153, 446, 476.
DOLFUS, E., 9, Rue St. Fiacre, Paris ;
470.
DUBOSCQ, J., 21, Rue de VOdeon, j
Paris; 183, 190,205-6, 215,218,
240, 250, 328, 337, 420.
DUMOULIN-FROMENT, 85, Rue Notre
Dame des Champs, Paris ; 21, 60,
75, 101, 374, 781.
DUMAS, J., 69, Rue St. Dominique,
St. Germain, Paris ; 568.
EASTERN RAILWAY OF FRANCE,
Pan's ; 1 1 1 .
COLE DE PHARMACIE, Rue de I'Ar-
baletc, Paris ; 223.
ECOLE POLYTECUNIQUE, Paris; 63,
169,182, 191, 203, 255,268,281,
343, 383.
ENFER FILS, 10, Rue de Rambouillet,
Paris; 669.
ERHARD, 12, Rue Duguay Trouin,
Paris; 236, 381.
EVRARD, 30, Rue des Blancs Man-
teaux, Paris ; 413.
FACULTY OF SCIENCES, Par is ; 168,
275.
FEIL, 56, Rue Lebrun, Paris; 215.
FIZEAU, M., MEMBRE DE L'INSTITUT,
3, Rue de la Vieille Estrapade,
Paris ; 234, 237.
FONTOURE, H., 92, Rue St. Georges,
Paris ; 314.
FORTIN HERMAMN, MM., 122, Boule-
vard Mont Parnasse, Paris ; 56,
66, 458.
FRENCH COMMISSION FOR OBSERVING
THE TRANSIT OF VENUS IN 1874;
413,423.
GAVARD, A., 70, Quai des Orfevres,
Paris; 16,21.
GILLOT, Madame, 179, Rue du Fau-
bourg, St. Martin, Paris ; 234.
GIRARD, A., Prof., Conservatoire
des Arts et Metiers, 292, Rue St.
Martin, Paris ; 918.
GOLAZ, 24, Rue des Fosses, St.
Jacques, Par is; 169, 268-72, 620-
3, 625-6.
GONDOLO & Co. (misprinted TON-
DOLA), 9, Boulevard du Palais,
Paris ; 129.
GOUPIL & Co., 9, Rue Chaptal,
Paris; 234.
GROS, 94, Rue de Montreuil, Paris ;
467.
GUEROULT, G., 2, Rue de Vienne,
Paris; 192.
GUYOT D'ARLINCOURT, 102, Rue
Neuve des Mathurins, Paris; 373-4.
HANICQUE DE ST. SENOCH, 19, Rue
Denwurs, Paris ; 810.
HAYAUX DU TILLY, 15, Rue de Lis-
bonne, Paris ; 803, 813.
HIRN, G. A., 3, Logelbach, Colmar ;
110.
HONZEAU, M., Rouen ; 663.
ISOARD FILS, 78, Rue St. Maur,
Paris-, 59.
JAMIN, 24, Rue Soufflot, Paris ; 280.
JANNETTAZ, 9, Rue Linne, Paris;
275-6.
JANSSEN, M., Membre de 1'Institut,
33, Rue Labat, Paris ; 423.
KASTNER, F., 43, Rue de Clichy,
Paris; 179.
LABORATOIRE DU COLLEGE DE
FRANCE, Place Cambrai, Paris ;
590.
LANCELOT, 11, Rue des Poitevins,
Paris; 196.
LARREY, BARON, 91, Rue de Lille,
Paris ; 927.
LA UNA Y, PROF., Lycte, Caen ; 802.
LAURENT, LEON, 21, Rue de VOdeon,
Paris ; 214, 218, 221, 223, 226, 248,
255, 277, 391,412, 914-5.
LAUSSEDAT, COL., PROF., Conserva-
toire des Arts et Metiers, Paris ;
768.
LEMAIRE DOUGHY, 64, Rue Taiibout,
Paris; 879.
xlvi
LIST OF CONTRIBUTORS.
LETELLIER ; 90, Rue Chateau Lan-
don ; 1043.
LOISEAU FILS, 29, Rue Richelieu,
Paris; 166,282-3,311.
LUIZARD, 43, Rue St. Andri des
Arts, Paris ; 166, 250, 337.
LUTZ, M., Paris; 117, 122, 204-5,
215, 218, 219, 221, 223, 226-30,
250, 438, 886, 916.
MALLIGAND FILS, 1, Boulevard St.
Michel, Paris ; 663.
MANNHEIM, PROF., Ecole Polytech-
nique, Paris ; 3.
MARIAIS, 260, Rue St. Honore,
Paris-, 376.
MARET, PROF. (College of France*),
13, Rue Dug ay Trouin, Paris ;
970-5.
MASCART, PROF. ( College of France) ,
Paris; 230.
MATHIEU, M. L., 16, Carrefour de
VOdeon, Paris ; 955-6.
MERCADIER, M., Ecole Poly technique,
Paris; 189.
MOLTENI, J. AND A., 44, Rue du
Chateau d*Eau, Paris ; 39, 226,
430, 438, 750.
MOTTRET, 8, Cour des Petites Ecu-
ries (Redier), Paris ; 428.
NACHET, A., 17, Rue St. Severin.
Paris ; 205, 911, 930, 934, 936, 945.
ORSAT, M., 29, Rue de la Victoire,
Paris; 657.
PARIS OBSERVATORY ; 215, 247, 398,
420.
PARIS, VICE-ADMIRAL, President de
VAcademie des Sciences, Paris ;
498.
PHARES DE FRANCE, SERVICE DES,
Place du Trocadero, Paris ; 538-
45.
Pi CART, A., 20, Rue Mayet, Paris ;
909, 914.
POLYTECHNIC SCHOOL, Paris ; 63,
169. 182, 191, 203, 230, 255, 268,
281, 343,383.
REDIER, Rue des Petites Ecuries,
Paris ; 128, 328, 682, 712.
KENAUD-TACIIET, AIM., 17, Rue
Richelieu, Paris ; 4, 15, 17, 21.
EICHARD, M., Paris ; 683.
ROULOT, 3, Rue des Vielles Hau-
driettes, Paris ; 929-31, 934.
RUHMKORFF, 15, Rue Champollion ,
Paris; 261, 300, 950.
SAUTTER, LEMONNIER, ET CIE.,
26, Avenue de Souffren, Paris ; 538.
SCHLOESING, M., 27, Quai d'Orsay,
Paris; 638.
SCHOOL OF PHARMACY, Paris ; 223.
SCIENCES, FACULTE DES, Paris ; ] 68,
275.
SEGUIER, M. LE, 3, Rue du Regard,
Paris ; 86, 457, 492, 499, 550.
SERVICE DES PHARES DE FRANCE
(Lighthouse Service of France),
Place du Trocadero, Paris ; 538-
45.
SOCIETE DE L' ALLIANCE, LA, 25, Rue
Dufrenoy, Paris ; 313-4.
SOCIETE FRANAISE DE PHOTO-
GRAPHIE, 20, Rue Louis le Grand,
Paris ; 234, 237.
TAVERNIER GRAVET, 39, Rue de
Babylonc, Paris ; 3, 56, 752.
TELEGRAPH DEPARTMENT, Paris ;
375.
THIEL, AINE, 75 & 77, Rue Lacon-
damine, Paris ; 235-6.
TRAMOND, 9, Rue de I 'Ecole de Mede-
cine, Paris; 997-8.
TROUVE, G., 6, Rue Therese, Paris ;
147, 283, 377, 380, 951-2.
VIDAL, L., 13, Quai Voltaire, Paris ;
233, 237.
VILLARCEAU, Y., Membre de I'ln-
stitut, 18, Avenue de I'Observa-
toire, Paris ; 128.
WENTZEL, MADAME, 6, Rue Breton-
viller, Paris ; 39.
WERLEIN, 38, Rue d'Ulm, Paris;
887-8, 936.
WIESNEGG, 64, Rue Gay Lussac,
Paris ; 636.
WINNEREL, M., 35, Galerie Mont-
pensier (Gabriel), Paris ; 104, 127.
GERMANY.
ACADEMY OF MINES, KOYAL (Prof.
Hauchecorne, Director), Berlin ;
452-3, 485-6, 835.
ACADEMY OF MINES, ROYAL (Prof.
Richter, Director), Freiberg,
Saxony; 172, 472, 657,849,870,
874, 884-5, 894, 897.
ADMIRALTY, IMPERIAL, HYDRO-
GRAPHIC DEPARTMENT AND NAU-
TICAL OBSERVATORY, Berlin and
LIST OF CONTRIBUTORS.
xlvii
Hamburg; 259,293,681,712, 721-
2, SU2.
VLHERT, J. W., 34, Nette Mainzer,
stnisse, Frankfort-on-Maine ; 188,
20G.218, 245.
ALBKECIIT, Tubingen; 180,189,896.
ALTIIAUS, E., Superintendent of
Mines, Breslau; 277.
ANATOMICAL INSTITUTE (Prof. Dr.
B. Gerlach), Erlangen ; 991-2.
APEL, W., Gottingen ; 219, 713,897.
APPUUN, G., AND SONS, Hanau ;
198-9.
ASSOCIATION FOR THE MANUFAC-
TURE OF ANILINE, Rnmmelsburg,
near Berlin ; 598.
Ai:<;i:.-iT, 1-hi. F., Humboldt-Gt/mna-
sium, Berlin ; 436-7.
BABO, Piior. von (Chemical Labora-
tory), Freiburg, /irdsgau; 182.
BACH, DR. O., Leipzig; 637.
BAEYER, LIETT.-GENERAL (Presi-
dent of the Geodetic Institute),
Berlin; 67.
BALL, JULIUS, Freiburg, Rrcisgau ;
639.
BAMBERG, C., 158, Linienstrassc,
Berlin; 63, 290, 401-2, 721, 740,
780.
BAU-DEPUTATION, Hamburg ; 746,
763, 806-9.
BAUERNFEIND, PROF. DR. von
(Geodetic Institute, Royal Poly-
technic School), Munich ; 22, 744,
761.
BAUR, GUSTAV, Stuttgart; 314, 338.
BECKER, AUG. (DR. MEYERSTEIN'S
Workshops), Gottingen; 211, 212,
928.
BEETZ, PROF. DR. (Polytechnic
School), Munich; 102, 262, 306,
333, 341, 343, 986.
BERGGEWERKSCHAFTSKASSE (Dr.
Heintzmann), Bochum; 80,419,
549, 629, 657, 880, 1036.
BERLIN, PHYSICAL INSTITUTION OF
THE UNIVERSITY (Dr. Helmholtz);
282.
BERNSTEIN, A., AND Co., 50, Mark-
grafen Strasse, Berlin ; 85.
BERNSTEIN, PROF. (Director), Phy-
siological Institute, University of
Halle; 78.
BEZOLD, PROF. W. von (Poly-
technic School), Munich ; 248, 324.
BIEDERMANN, DR. B., Berlin ; 598.
BLATTNKR, C. (Polytechnic School),
Munich; 245.
BLATZBECKER, Dr. A. A., Cologne ;
599.
BOCK AND HANDRIK, 2, Falken-
strasse, Dresden ; 17,20, 55, 469 ;
478-9, 552.
BOHN, PROF. DR., Aschaffenburg ;
169, 680.
BONSACK, A., 27, Prinzenstr, Ber-
lin; 80, 744, 753, 771.
BORCHARDT, PROF., Berlin ; 38.
BORCHARDT, E., 37, Heinrichstrasse,
Hanover ; 302, 320.
BORNEMANN, F., Verden; 599.
BRAUN, DR. O., Berlin ; 487.
BREITIIAIMT, F. W., AND SON,
Cassel ; 53, 78, 403, 433, 744-5,
749, 753, 874-5, 886, 1069.
BRENDEL, E., Kurfiirstendamm,
Berlin; 988.
BRESLAU COMMITTEE FOR THE
SCIENTIFIC APPARATUS EXHIBI-
TION, LONDON, Breslau ; 16, 130,
203, 257, 324, 393, 398, 419, 430,
667, 670, 701, 900.
I BRILL, PROF. DR. A. (Polytechnic
School), Munich ; 36.
i BROCKING, W., Hamburg ; 129.
BRUHNS, PROF. DR., Leipzig ; 396.
BiiciiLER, J. H., Breslau; 657, 659.
BUFF, PROF. DR., Giessen ; 84, 154,
225, 245, 340.
BUNGE, P., Hamburg ; 94.
CARL AND HOMANN, Nuremberg;
804.
CECH, Dr. C. V., Berlin ; 600.
CHEMICAL INSTITUTE, STRASBURQ
UNIVERSITY ; 620, 1036.
CHEMICAL LABORATORY OF THE
UNIVERSITY, Freiburg, Breisgau
(Prof, von Babo) ; 182.
CHEMICAL LABORATORY, POLY-
TECHNIC INSTITUTION, Carlsrulie;
599, 600.
CHEMICAL LABORATORY OF THE UNI-
VERSITY (Prof. A. W. Hofmann),
Berlin; 165.
CHEMICAL SOCIETY, GERMAN ; Ber-
lin, 597-610.
CHEMICAL WORKS COMPANY
(UNITED), Leopoldshall, Stassfurt;
604.
GLAUS, PROF. DR. A. (Institute of
Physics), Freiburg University ;
1063.
xlviii
LIST OF CONTRIBUTORS.
COAL MINING Co., UNITED (Director
Hilt), Kohlscheid,Aix-la-ChapeUe ;
880.
COIIN, PROF. DR. F., Breslau ; 904,
924, 987, 999, 1000.
COHN, PROF. DR. H., Breslau ; 932-3,
936.
" COLLEGIUM CAROLINUM " (Prof-
Weber), Brunswick', 158.
CONSERVATORIUM OF THE MATHE-
MATICAL AND PHYSICAL COLLEC-
TIONS OF BAVARIA (Prof. Seidel),
Munich ; 397.
DE DIETRICH & Co., Niederbponn ; 67.
DENCKER, C., Hamburg ; 129-30.
DENNERT AND PAPE, Altona; 743,
745.
DEPARTMENT FOR PUBLIC WORKS
(" Ban-Deputation "), Hamburg ;
746, 763, 806-9.
DESAGA, C., Heidelberg ; 635-6.
DEUTSCHBEIN, R., Hamburg ; 684-5.
DICKERT, TH., Pnppelsdorf, Bonn ;
839.
DOLL, DR. M. (Polytechnic School),
Carlsruhe ; 37.
DORFFEL, P., 46, Unter den Linden,
Berlin; 309-10.
DOVE, PROF. DR., Berlin-, 55, 64,
286, 307, 374, 935.
DRE VERM ANN, DR., Hoerde, West-
phalia; 627.
DREYER, ROSENKRANZ, AND DROOP,
Hanover ; 80.
DURRE, PROF. DR., Aix-la-Chapelle ;
669-70.
EBERMAYER, PROF. DR. (Director,
Academy of Forestry), Aschaffen-
burg; 686, 713.
EDELMANN, M. T. (Polytechnic
School), Munich; 100, 102, 128,
206, 291-2, 319, 324, 332, 338-40,
343, 403, 426.
ELBE, M., Ellwanycn ; 430.
ENGEL, F., 21, Graskeller, Ham-
burg ; 485-6.
ENGLER, PROF. DR., Halle ; 600.
ERIIARDT AND METZGER, 47, Elisa-
bethcn Strasse, Darmstadt ; 663.
ERNECKE, F., 6, Wilhelmstrasse,
Berlin; 144, 145, 154, 165, 179.
FEILITZSCH, PROF. Baron von, Greifs-
wald; 54, 64, 112, 164, 886.
FEIN, C. AND E., Stuttgart ; 67, 375.
FENNEL, O., Cassel ; 18, 742, 875.
FISCHER, H., Hanover ; 640.
FISCHER, PROF. L. H., Freiburg,
Breisgau ; 898.
FISCHER, PROF. DR. R., Breslau ;
306, 1002.
FISCHER, T., Cassel; 805, 814.
FRIEDERICHSEN, L., & Co., Ham-
burg ; 40, 41, 805.
FRIEDLANDER, DR. C., Strasburg ;
946.
FRITSCH, PROF. DR., Berlin ; 925.
FUESS, R., 108, Jacobstrasse, Ber-
lin; 60, 423, 847-8, 851, 886-7,
912.
FURTENBACH ANO OEHIAFEN, Rei-
chelsdorf, Number g ; 600.
GABLER, C. D., Hamburg; 173, 174.
GASSER, DR., Marburg ; 923.
GASWORKS, MUNICIPAL, Berlin ; 600.
GEHREN, F. W. von (STAUDINGER
& Co.), Giessen ; 60, 64, 84, 164.
GEISSLER, C. F., & SON, Berlin ;
172,259, 263, 627, 641,702,925,
943, 1001, 1035.
GEISSLER, DR. H., Bonn; 164,172,
225, 263, 322, 627-8,641, 700.
GEISSLER, P. C., Nuremberg ; 894.
GEODETIC INSTITUTE, Berlin ; 63.
GEODETIC INSTITUTE, Munich; 22,
744, 761.
GEOLOGICAL SURVEY OF BAVARIA
(Dr. Giimbel), Munich ; 835-6.
GERLACII, PROF. DR., Erlangen;
991-2.
GERLAND, DR. E. (Polytechnic
School), Cassel ; 64,293,887.
GERSTKyHdmR,M., Freiberg, Saxony;
100.
GIESSEN, UNIVERSITY OF, (Dr. Buff,
Prof.) ; 84, 154, 225, 245, 319, 340.
GIZYCKI, PROF, von (Polytechnic
School) , Aix-la- Chapelle ; 456, 470.
GODEFFROY, J. C., Museum
Godeffroy, Hamburg ; 814.
GOLDSCHMIDT, T., Berlin ; 600.
GOPPERT, PROF. DR., Royal Bota-
nical Garden and Museum of the
University of Breslau ; 988-9, 995.
GOTTINGEN, INSTITUTE OF VEGE-
TABLE PHYSIOLOGY OF (Prof. Dr.
Grisebach, Director) ; 1000.
GOTTINGEN OBSERVATORY ; 414, 767.
GOTTINGEN, UNIVERSITY OF; 219,
293, 348, 601, 1040.
GREIFSWALD, UNIVERSITY OF ; 164.
GREINER, PAUL, Hamburg ; 738.
GRUNEBERG, Cologne ; 738.
LIST OF CONTRIBUTORS.
xlix
GUMBKL, DR. (Geological Survey of
Bavaria) ; 835-6, 848.
HAAK, W., Neuhaus, Thilringen ; 172,
255, 262, 691, 702, 759, 944.
HAEDICKE, G., Uemmin; 103, 109,
111, 169, 177, 763.
HAIIN, A. & R,, Cassel; 89-94,
741-2, 873.
HALLE, INDUSTRIAL SCHOOL (Dr.
Kohlmanii) ; 54, 80, 85, 147, 455.
HALLE, TOWN SCHOOL (Meyer) ; 54.
HALLE, UNIVERSITY OP (Physical
Institute), Prof. Knoblauch; 85-
7, 148.
HALLE, UNIVERSITY OF (Physiologi-
cal Institute) ; 78.
HAAEMANN,Dll.W.,.ffo/.2Wen ; 607.
HAHTNACK,DR. E., Potsdam; 912-3.
IlAuciiECORNE, PROF. (Director,
Royal Geological Institute and
Mining Academy), Berlin; 452-3,
485-6, 835.
HEINTZ, PROF. DR., Halle-, 601.
HKINZERLING, PROF. DR. (Poly-
technic School), Aix-la-CJiapeUe ;
552.
HEIS, PROF. DR. E., Miinster; 38,
296, 436.
HELLER, F., Nuremberg; 1002.
HELMERT, PROF. DR. (Polytechnic
School), Aix-la-C handle ; 746,
761.
HELMHOLTZ, PROF. DR., Berlin ;
282.
HENNEBERG, PROF. DR., Gottingen ;
1000.
HENSEN, PROF. DR., Kiel ; 925.
HERBST, A., 26A, Krautstrasse,
Berlin; 207,369,428, 627.
HERMANN, PROF. G. (Polytechnic
School), Aix-la-Chapelle; 9.
HEUSTREU, H., Kid ; 404.
HIMLY, PROF. DR., Kiel ; 263.
HIRSCHBERG, F., 9, Weidenstmsse,
Breslau; 192.
HITTORF, PROF. DR., Miinster ; 322-
3, 326, 341,601.
HOFMANN, PROF. DR. A. W.,
Berlin ; 165, 602, 603.
HONIGMANN, M., Aix-la-Chapelle ;
603.
HORNUNG, F., Langenbeutingen ; 428.
HUBNER, PROF. DR., Gottinqen ; 601,
1040.
HTTGERSHOFF, F., Leipzig ; 640, 657,
663, 1035.
HULWA, PROF. DR., Breslau ; 603.
40075.
HUTSTEIN, J., Breslau ; 603.
IMPERIAL GERMAN NAVY ; 745,753.
INDUSTRY, ROYAL HIGH SCHOOL OF,
(Dr. Wiecke, Director), Cassel;
15, 38, 39, 64, 293, 887.
INDUSTRIAL SCHOOL (Dr. Kohlmann,
Director), Halle ; 54, 80, 85, 147,
455.
INSTITUTE OF PHYSICS (Prof. Dr.
A. Glaus), University of Freiburg,
Baden ; 1063.
INSTITUTE OF PHYSICS (Prof. Kars-
ten, Director), University of Kiel ;
60.
INTZE, PROF. O. (Polytechnic
School), Aix-la-Chapelle ; 96.
JACOBSEN, PROF. DR., Rostock ; 626.
JESSEN, PROF. DR., Eldena, Pome-
rania ; 923, 941, 987.
JOBST, F., Stuttgart.; 603.
JOLLY, PROF. DR. von, Munich ; 54,
164,263,275, 629.
JUNG, R., Heidelberg ; 248, 325, 333,
925, 936.
KAHLBAUM, 0. A. F., Berlin ; 603.
KARSTEN, PROF. DR., Kiel; 60.
KARSTEN, PROF. DR., Rostock; 219,
| 754.
KAUFMANN, K. J., Konigsberg,
Prussia ; 604.
KEISER & SCHMIDT, 14, Johannis
Strasse, Berlin ; 249, 305, 311-2,
338.
KLEEMANN, Halle ; 54, 85, 88.
KLINKERFUES, PROF.DR., Gottingen ;
56,701.
KNOBLAUCH, PROF. DR., Halle ; 85-
7, 148, 187.
KNOBLICH, T., 24, Amiralitdt Strasse,
Hamburg; 129.
KNY, PROF. DR., Berlin ; 986.
KOBELL, PROF. DR. F. von,
Munich ; 220.
KOHLMANN, DR., Director, Indus-
trial School, Halle ; 54, 80, 85,
147, 455.
KRAMER, C., Freiburg, Breisgau ;
639,641.
KRAUSE, PROF. DR., GQttingen ; 924.
KREBS, PROF. DR. G., Frankforl-on-
Maine ; 143.
KRONECKER, PROF. DR. (Physiolo-
gical Institute), Leipzig; 954.
KRUSS, A., Hamburg ; 206.
KUHNEMANN, DR. G., Dresden ; 604.
KUHTZ & Co., Brandenburg -on-
Havel; 939.
d
1
LIST OP CONTRIBUTORS.
KUMMER, PROF. DR. E. E., Berlin ;
153.
KUNDT, PROF. DR., Strasburg; 211,
291.
LANDOIS, PROF. DR., Miinster ; 990.
LANDOLT, PROF. DR. (Polytechnic
School), Aix-la-Chapelle; 224,
620, 1041-2.
LANDSBERG & WOLPERS, Hanover ;
8, 59, 368, 1010.
LAQUETJR, PROF., Strasburg ; 934-5.
LASAULX, PROF, von, Breslau ; 604,
772-3, 849, 869.
LASPEYRES, PROF. (Polytechnic
School), Aix-la-Chapelle -, 96.
LEITZ, E., Wetzlar; 910-11.
LENTZ, E. A., 36 & 37, Spandauer
Strasse, Berlin; 638, 1036.
LEPSIUS, PROF. DR., Royal Library,
Berlin-, 158,159.
LEYBOLD, E. (Successors to), Co-
logne; 1047-54.
LEYSER, G. MORITZ, Leipsic Uni-
versity; 926.
LIEBERMAN, PROF. C., Berlin ; 604.
LINGKE, A., & Co. (M. Hildebrand
and E. Schramm), Freiberg,
Saxony; 396-7, 745, 753, 873, 875,
884.
LIST, DR. K., Hagen ; 173.
LISTING, PROF. DR., Gottingen ; 219.
LOCHMANN, P., Zeitz; 456, 459,
LOCKERMANN, DR., Hamburg ; 430.
LOHDE, L.,33, Haide Strasse, Berlin ;
37.
LOHMANN, K., 3, Briickenstrasse,
Berlin; 84.
LOHSE, DR., C. (Astronomer of the
Royal Astro-Physical Observa-
tory'), Potsdam; 425-6.
LOMMEL, PROF. DR., Erlangen ; 247-
8.
LUCAE, PROF. A., Berlin ; 1 83.
MAGNUS, DR., Breslau ; 934.
MAJER, E., Strasburg ; 923.
MARBURG, MATH. AND PHYSICAL
INSTITUTE (Prof. Melde) ; 53.
MATTHIESSEN, PROF. DR., Rostock;
714.
MEIDINGER, PROF. DR. H., Carlsruhe,
278, 367.
MEISSNER, A.(Muller andReinecke),
Berlin ; 60, 746, 749, 751.
MELDE, PROF. DR., Mathematical
and Physical Institute, Marbura
53.
! MERCK, E., Darmstadt ; 605.
1 MEYER, L., Berlin 263.
MEYER, PROF. L., Carlsruhe ; 599.
MEYER, DR. O. E. (The University),
Breslau; 176.
MEYER (Town Sclwol), Halle ; 54.
MICHAELIS, PROF. A., Carlsruhe ;
600.
MINISTERIAL COMMISSION FOR THE
SCIENTIFIC EXPLORATION OF THE
GERMAN SEAS, Kiel ; 771.
MITSCHERLICH, PROF. A., Mimden,
Hanover-, 164, 213, 262, 570, 629,
641, 886, 889, 894, 1036.
MlTTELSTRASS BROTHERS, Magde-
burg; 319.
MOBIUS, PROF. DR., Kiel ; 925.
MOHL, DR. H. (Royal High School of
Industry), Cass'el ; 839, 848, 883.
MOLLER, L., Giessen ; 888.
MULLER, DR. E., Osnabrilck ; 704.
MUNICH, UNIVERSITY OF ; 54, 84,
86, 106, 263, 275, 629.
NARTEN, DR. W. (Royal High School
of Industry), Cosset-, 15, 748, 754,
875.
NAUTICAL OBSERVATORY-"DEUTSCHE
SEEWARTE " (Dr. Neumayer,
Director), Hamburg ; 259, 293,
681, 712, 721-2, 802.
NORDLINGER, PROF. DR., Hohenheim ,
Wurtemberg ; 89, 445-6, 1001.
OPPEL, PROF., J. J., Frankfort-on-
Maine; 36,179, 188,245-6,427,
429, 431.
OPPEL, DR. K. Frankfurt ; 429.
OPPENHEIM, PROF. A., Berlin ; ^05.
ORTH, PROF. DR., Berlin ; 835.
OSTERLAND, C., Freiberg, Saxony ;
638, 667, 873, 875.
OTT & COR ADI, Kemptcn, Bavaria ;
15, 77, 750, 753.
PANSCH, DR., Kiel ; 989.
PERNET, DR. (Assistant, Cabinet of
Physics), Breslau ; 262-3.
PETTENKOFER, PHOF. DR. MAX,
Munich ; 950.
PFAFF, PROF. DR., Erlangen ; 255,
887,897.
PHARMACEUTICAL INSTITUTE OF THE
UNIVERSITY, Breslau ; 599.
PHYSICAL INSTITUTE, Freiburg ; 255.
PHYSIOLOGICAL INSTITUTE, Prague ;
954.
PIEL, H., Bonn ; 897.
LIST OF CONTRIBUTORS.
H
PJNDEK, DR. (Director of the Royal
Museum), Cosset-, 56, 160-1,393,
398, 410, 449-50, 900-1, 976.
PINNER, DR. A., Berlin ; 605.
PINZGER, C. G., Breslau ; 164.
POLECK, DR., Breslau; 599, 701,
900.
POLYTECHNIC SCHOOL (Dr. E. Ger-
land), Cassel; 64.
POLYTECHNIC SCHOOL (M. T. Edel-
inami), Munich ; 100, 102, 128, 206.
PRESTEL, PROF., Emden; 9, 431,
436, 693, 701, 714, 722, 898.
PROELL, Dit. R., Civil Engineer,
Gorlitz; 469.
PRUGGER, B utter melc her Strasse,
Munich; 1011.
RAMME AND SODTMANN, Hamburg;
990.
RAPHAEL, M., Breslau ; 17, 221, 320,
629, 641,781, 889,926.
RATH, PROF. DR. G. vom, Bonn ;
897.
RECKE, H., Freiburg, Saxony ; 693.
RECKLINGHAUSEN, PROF. DR., Stras-
burg; 912.
RECKNAGEL, DR. (Royal School of
Industry), Kaiserslautern ; 174,
693.
REIMER, D. (Reimer and Hoefer),
Berlin; 431, 805, 810-1.
REPSOLD & SONS, Hamburg ; 395-6,
400-1, 423, 739, 749.
REULEAUX, PROF. (Director of the
Royal Polytechnic Academy), Ber-
lin ; 9, 103, 132, 143, 429.
RHENANIA COMPANY, Stolberg, Aix-
la-Chape/le; 657.
RICHTER, E. O., & Co., Chemnitz,
Saxony; 18, 19.
RIECKE, PROF. DR., University of
Gottingcn ; 293, 348.
RODIG, C., Hamburg; 993.
ROHRBECK, LUHME, & Co., Berlin ;
148, 152, 154, 658, 1055-63.
ROSENTHAL. PROF. DR., Erlangen ;
943, 953-4.
ROYAL LIBRARY (Prof. Dr. Lepsius,
Chief Librarian), Berlin ; 158-9.
ROYAL MUSING DIRECTORY, Saar-
brilck; 881-2.
ROYAL MT:SEUM (Dr. Pinder, Di-
rector), Cassel; 56, 160, 161, 393,
398, 410, 449-50, 900-1, 976.
40075.
ROYAL POLYTECHNIC (GEWERKE)
ACADEMY (Prof. F. Reuleaux,
Director), Berlin; 9, 103, 132-
43,429.
ROYAL POLYTECHNIC SCHOOL, Aix-
/a-Chapelle; 96.
ROYAL PRUSSIAN GENERAL STAFF,
ORDNANCE SURVEY (Lieut.-Gene-
ral von Morozowitsch), Berlin ;
728-9, 746, 786-7.
ROYAL PRUSSIAN UPPER MINING
COURT, Breslau; 873, 882-3,
1010, 1043-5.
ROYAL RHENISH WESTPIIALIAN
POLYTECHNIC SCHOOL, Aix-la-
C/iapelle; 146.
ROYAL SURGICAL CLINICAL SOCIETY
(Prof. Dr. R. Fischer), Breslau;
306, 1002.
RCMANN, C., Gottitigen ; 924-5.
SAAME & Co., Ludwigshafen-am-
Rhein; 606.
SARTORIUS, F., Gottingen ; 82, 83,
169, 639.
SCHAFFER, H., Darmstadt; 76.
SCHEIBLER, DR. C., Berlin ; 659-61.
SCHEBING, PROF. DR., Gottingen ;
292-3, 414, 767.
SCIIERING, E., Berlin, Fentistr ; 606.
SCIIICKERT, H., Dresden ; 83, 84, 87.
SCHMIDT AND HAENSCII, 2, Neue
Schonhauser Stras&e, Berlin ; 211,
212, 218, 220, 221, 225, 230, 407,
640, 760, 910, 935, 998.
SCHOBER, J., 35, Adalbert Slrasse,
Berlin ; 576, 626-7, 629, 633, 638,
1035-6.
SCHOTTE, E., Potsdamer Strasse,
Berlin; 428,811.
SCHREIBER, DR., Chemnitz ; 709-11.
SCHRODER, H., Hamburg ; 402-4.
SCHUBRING, G., Erfurt; 191, 202,
439.
SCIIUCHARDT, DR. T., Gorlitz; 231,
607, 899.
SCHUR, DR. (Assistant, Observatory),
Strasburg; 424.
SCHUTTE, O., Cologne ; 265.
SCHWERD, L. E., Carlsruhe ; 367-8.
SEIBERT ANDKRAFFT, Wetzlar ; 910,
915.
SEIDEL, PROF. ( Conservator! um of
the Mathematical and Physical
Collections of Bavaria), Munich ;
397.
Hi
LIST OF CONTRIBUTORS.
SIEMENS, DR. W., Berlin ; 101-2,
104-5, 338, 716.
SIEMENS BROS. & Co., Cliarlotten-
burg, Berlin; 175,363-5,468,474.
SIEMENS AND HALSKE, Markyrafen
Strasse, Berlin ; 67, 79, 102, 225,
309, 315-6,328, 338, 343,345-6,
372.
SIEVERS, F., Wehlheiden, Cassel ;
839-40.
SITTE, K., JBreslau ; 931.
SOHNCKE, PROF., Carlsruhe ; 899.
SOMMERBRODT, DR., Bresluu ; 946.
SOMMERING, C., Fran kf or t-on- Maine,
346.
SPRENGER, E., 75, Ritterstrassc,
Berlin ; 55, 745, 753-4.
STAUDINGER & Co. (F. W. von
Gehren), Giessen ; 60, 64, 84, 164.
STEEG, W., Hamburg vor der Hake ;
277, 887, 889, 893-4.
STEGER, A., Kiel ; 255.
STEGEU, ~L.,Kiel; 54, 771.
STEGER & HONIKEL, Leipzig ; 986.
STEIN, DR. S. T., Frankfort-on-
Maine ; 945, 986, 998.
STEINHEIL, C. A. AND SONS, Munich ;
402.
STERN, H., Obn-siein ; 54, 84, 88.
STOHRER, E., Leipzig-, 282,302, 331,
338, 929, 932, 935, 1000, 1046.
STOLLNREUTHER, AND SONS, Mu-
nich; 949.
STURTZ, B., Bonn ; 868, 888-9.
STRASBURG, CHEMICAL INSTITUTE
OF THE UNIVERSITY OF ; 620,
1036.
Suss, F., Marburg; 184-7, 218,
922-3.
TALBOT, R., 68, Auguststrasse,
Berlin ; 240, 244.
TORNOW, R. von, Berlin ; 250.
TASCIIE, DR., Giessen ; 306, 319.
TELEGRAPH DEPARTMENT, IM-
PERIAL GERMAN, Berlin ; 361-3.
TELLER, JUL., Munich ; 302, 306, 318.
TESCHNER, W. (Successor to J.
Annul), 180, Friedrichstrasse, Ber-
lin; 914-5.
TOLLENS, PROF. B., Gottingen ; 607.
TIEFTRUNK, DR., Municipal Gas-
works, Berlin ; 600.
TIEMANN, DR. F., Berlin ; 607.
TONINETTI, P. (Pathological Institu-
tion, Prof. Dr. Virchow, Director),
Berlin; 992-3.
TROMMSDORFF, DR. II., Erfurt ;
607-9.
TRUNK, C., Eisenach; 430.
UHLENHTJTH, J. t Anclam, Pomerania ;
21, 810.
URACH, H. H. THE DUCHESS OF,
Stuttgart; 8.
VAAST AND LITTMANN, Halle ; 275.
VETTER C. (formerly L. Hester-
mann), Hamburg ; 1055.
VIERORDT, PROF. DR. \ou, Tubin-
gen; 945.
VOCJEL, DR. H. C. (Astronomer of
the Royal Astro-Physical Observa-
tory), Potsdam ; 425-6.
VOGEL, PROF. DR. H. W., Berlin ;
423-5, 677.
VOIGT, G. (Voigt & Hochgesang)
Gottingen ; 66, 849, 881, 924.
VOIGTLANDER AND SON (Chevalier
von Voigtlander), Brunswick ;
203, 204,240.
VORSTER AND GfiUNEBERG, Kalk,
Cologne ; 609-10.
Voss, T. R., Berlin, 19, Pallisa-
denstr; 282, 301, 324,331.
WAIBLER, L., Darmstadt ; 345.
WANNSCHAFF, J., 63, Gros&beercn
Strasse, Berlin ; 743-4, 749.
WARMBRDNN, QUILITZ, & Co., 40
Roscnthaler Strasse, Berlin; 165,
230, 249, 259, 274-5, 286-7, 298,
302, 320-1, 325, 343, 691, 701,
1001, 1036-41.
WASSERLEIN, R., 34, Bernburyer
Strasse, Berlin ; 910, 922.
WEBER, DR. A., Darmstadt; 929,
931-2, 934-5.
WEBER, PROF. DR. H. (" Collegium
Carolinum"), Brunswick ; 158, 159.
WEBER, PROF. R. (Academy of
Forestry), Aschaffenburg ; 8, 620.
WEBER, A., Wiirzburg; 166,946.
WEBER, Cii., Eisenach ; 851.
WEINIIOLD, PROF., Chemnitz; 225.
WEINZIERL, J., Glogau, Silesia ; 16.
WELCKER, PROF. DR., Halle ; 926,
993.
WALDENBURG, PROF. DR., Berlin ;
946-7.
WESSELHOFT, Halle ; 263.
WESTPHAL, G., Celle, Hanover ; 84,
87.
WICHELHAUS, PROF., Berlin; 610.
WICHMANN, A., n,Johannis Strasse,
Hamburg; 813,938,1001.
LIST OF CONTRIBUTORS.
liii
WIECKE,DR., Cosset-, 38, 39.
WIKNKK, PROF. DR. C., Carlsruhe ;
37.
WIXKEL, R., Gottingen ; 912.
WINKLER, PROF., Freiberg ; 610.
WJNNECKE, PKOF. DR., Strasburg ;
404, 432, 740.
WINTER, E., Hambwy, Einisbiittel ;
207.
WUILER, PROF. DR., Gotlingen ;
601.
WOHLERS (Successor to Campbell),
Hamburg ; 930, 936.
WOLFF & SONS, Heilbronn and
Vienna ; 639, 641,672, 1036.
WULLNER, PROF. DR. (Polytechnic
School), Aix-la-Cliapelle ; 331,
460.
ZEISS, C., Jena-, 211, 215, 230,
909-10.
ZIEGLER, DR. A., Freiburg, Baden ;
898, 984.
ZIM.MER BROTHERS, Stuttgart; 89,
744, 759.
ZORN, W., Berlin, 17, Schoneberger
Sir.; 174.
HOLLAND.
ASSEN SECONDARY GOVERNMENT
SCHOOL; 118, 258, 278.
BAKHUYZEX, H. G. VAN DE SANDE,
Director, Observatory, Ley den ;
392-4, 398-9, 428-9, 438.
BECKERS SONS, West Zeedyk, Rot-
terdam ; 82.
BLEEKRODE, DR. L., The Hague ;
299, 1041-2.
BOCGAARD, PROF.DR. J. A., Director
of the Museum of Anatomy, Aca-
demy of Ley den ; 900.
BOSSCIIA, PROF. J., Royal Polytech-
nic School, Delft ; 255, 342, 345,
579,885, 888, 921.
BRONDGEEST, DR., Physiological La-
boratory and Ophthalnwlogical
School, Utrecht; 958.
BUYS-BALLOT, PROF., Utrecht ; 53,
127, 184,264,391, 413, 700, 766,
904, 934.
DE Loos, DR. D., Director of the
Secondary Town School, Lcyden ;
259,671.
DONDERS, PROF., Physiological La-
boratory and Ophthalmoloyical
School, Utrecht; 178, 318, 957-
60, 962-70.
ENGELMANN, PROF., Physiological
Laboratory and Ophthalmological
School, Utrecht; 167, 317, 957,
959-60.
FERHAAR, A. T., Utrecht; 977-8.
GRONEMAN, DR. F. G., Director of
the Secondary Government School,
Groningen-, 149.
; GUNNING, DR. J. W., Professor of
Chemistry. " Athen&um Illustre"
Amsterdam, and Scientific Adviser
to the Treasury Department, Hol-
land, Amsterdam ; 156-7, 259.
HARTING, PROF. DR. P., University
of Utrecht; 938.
HOOGEWKIUTF, S.,Pii. D., Rotterdam*,
176, 255.
JIui/iNGA, PROF., Director of the
Physiological Laboratory, Univer-
sity of Groningen ; 940, 976.
MEES, PROF. R. A., Director of the
Physical Laboratory, University of
Groningen; 162, 189, 190, 335,
475.
MULDER, DR. M. E., Groningen ; 920.
OTTMANS, H., 141, Amstel Hooge
Sluis, Amsterdam ; 901.
OUDEMANS, PROF. A. C., Hoyal
Polytechnic School, Delft ; 591.
ROYAL POLYTECHNIC SCHOOL (Prof.
J. Bosscha), Delft ; 255, 342, 345,
579, 885, 888, 921.
RUKE, PROF. DR. P. L., Director of
the Cabinet of Physics, University
of Leydcn; 81, 131, 178, 246, 255,
321, 410, 413, 427, 462, 900.
SCHOOL, SECONDARY GOVERNMENT,
Assen; 118,258, 278.
SCIENTIFIC SOCIETY OF ZEELAND
(G. N. de Stoppelaar, Sec.), Mid-
delburgh; 900.
SNELLEN, DR., Physiological Labora-
tory and Ophthalnwlogical School,
Utrecht ; 748, 961-2, 964-5, 967.
SNYDERS, J. A., Lecturer, Royal
Polytechnic School, Delft; 176,
936.
liv
LIST OF CONTRIBUTORS.
SURINGAR, W. F. R., Professor of
Botany, University of Leyden, and
Director of the Royal Botanic
Gardens and Royal Herbarium ;
918.
TEYLEU FOUNDATION, THE, Haarlem ;
209, 229, 279-80, 285, 319-20,
322, 328, 410, 1064.
VAN ANKUM, PROF. U. J., Zoological
Laboratory, University of Groniu-
gen-, 1002.
VAN DE SANDE BAKHUYZEN, II. (T.,
Director of the Observatory, Ley-
den ; 392-4, 398-9, 428-9, 438.
VAN RUN, H. B. J., Venlo ; 651.
ZEELAKD, SCIENTIFIC SOCIETY OF
(G. N. de Stoppelaar, Secretary),
Middelburgh ; 900.
ITALY.
ACCADEMIA DEL CiMENTO, Florence ;
155-6, 256, 257, 279, 699, 941-2.
ALBINI, PROF. G., Director of the
Physiological Institute, Royal Uni-
versity of Naples ; 949,
BLASERNA, PROF., Director of the
Institute of Physical Science, Royal
University of Rome; 1073-4.
CACCIATORE, PROF. G., Director of
the Royal University, Palermo ;
1083.
CANTONI, PROF. G., Director of the
Institute of Physical Science, Uni-
versity ofPavia ; 1082-3.
CECCHI, PRO*. F., (Z. Pelli Sf Co.),
]2, Viale Militare, Florence ; 299,
389-90.
COLLEGIO ROMANO (OBSERVATORY),
Rome ; 405, 709.
FELICI, R., Director of the Univer-
sity of Pisa; 1084.
FLORENCE, ROYAL INSTITUTE "DI
STUDII SUPERIORI " (Sig. Peruzzi,
President); 16,77, 113-5,256,276,
279, 307, 312, 334, 393, 397, 403,
407-10, 431, 437, 439, 703, 780,
900-1.
GAMBARA, PROF. G., Liceo Volta,
Conio; 381.
GIORDANO, PROF. G., Director of
the Cabinet of Physical Science,
University of Naples ; 1083.
LEGNAZZI, PROF., Royal University,
Padua ; 1074-8.
LICEO VOLTA, COMO, CABINET OF
PHYSIC AND CHEMISTRY (Prof.
G. Gambara) ; 381.
Mossi, DR. A., Director of the Uni-
versity, Turin ; 949.
NAPLES, ROYAL UNIVERSITY OF ; 20.
NAPLES, VESUVIAN AND METEORO-
LOGICAL OBSERVATORY ; 1084.
OBSERVATORY OF THE ROYAL UNI-
VERSITY (Prof. D. Ragoua, Di-
rector), Modena ; 1083.
OBSERVATORY, ROYAL, Palermo ;
1083.
OBSERVATORY, COLLEGIO ROMANO,
(Padre Secclii, Director), Rome ;
405, 709.
PADUA, ROYAL UNIVERSITY OF:
1074-8.
PALMIERI, PROF., Director of the
Vesuvian and Meteorological Ob-
servatory, Naples ; 1084.
PAVIA, UNIVERSITY OF ; 1082-3.
PELLI, L., 12, Viale Militare, Flo-
rence ; 749.
PERUZZI, SIG., President of the Royal
Institute " di Studii Sitperiori,"
Florence; 16, 113, 115, 256,276,
279, 307, 312, 334, 393, 397, 403,
407-10, 431, 439, 703, 780, 900
-1.
PISA, UNIVERSITY OF, Pisa ; 1084
PIZZORNO, F., Bologna ; 264, 300.
RAGONA, PROF. D., Director of the
Observatory, Royal University of
Modena; 1083.
RESPIGHI, PROF. L., Director of the
Royal Observatory oj the Campi-
doglio, Rome ; 394, 405.
RIGHI, PROF. A., Royal Technical
Institute, Bologna ; 204, 300, 332.
ROME, COLLEGIO ROMANO (OBSER-
VATORY) ; 405, 709.
ROME, ROYAL UNIVERSITY, INSTI-
TUTE OF PHYSICAL SCIENCE (Prof.
Blaserna, Director) ; 1073-4.
ROSSETTI, PROF., Director of the
Cabinet of Physical Science, Royal
University, Padua ; 1078-82.
LIST OF CONTRIBUTORS.
IV
ROYAL INSTITUTE " di Studii Superi-
or!," Florence (Sig. Peruzzi, Presi-
dent). (See FLORENCE, ROYAL
INSTITUTE.)
ROYAL LOMBARDIAN INSTITUTION OP
SCIENCE AND LETTERS ; 386.
ROYAL UNIVERSITY, MODENA (OB-
SERVATORY) ; 1083.
ROYAL UNIVERSITY OF NAPLES,
CABINET OF PHYSICAL SCIENCE
(Prof. G. Giordano, Director) ;
1083.
ROYAL UNIVERSITY OF NAPLES,
PHYSIOLOGICAL INSTITUTE (Prof.
G. Albini, Director) ; 949.
ROYAL UNIVERSITY OF PADUA,
CABINET OF GEODESY AND HY-
DROMETRY (Prof. Legnazzi, Di-
rector) ; 1074-8.
ROYAL UNIVERSITY OF PADUA,
CABINET OF PHYSICAL SCIENCE
(Prof. Rossetti, Director) ; 1078-
82.
ROYAL OBSERVATORY OF PALERMO
(Prof. G. Cacciatore, Director) 5
1083.
ROYAL OBSERVATORY OF THE CAM-
PIDOQLIO (Prof. L. Respighi,
Director), Rome ; 394, 405.
ROYAL UNIVERSITY OF ROME, IN-
STITUTE OF PHYSICAL SCIENCE
(Prof. Blaserna, Director) ; 1073-4.
SECCHI, PADRE, Director of the Ob-
servatory of the Collegia Romano,
Rome ; 405, 709.
TABANELLX, T., Prof, of Physical and
Natural Science, Technical School,
Udine; 832.
TURIN, UNIVERSITY OF (Director,
Dr. A. Mossi) ; 949.
UDINE, TECHNICAL SCHOOL ; 832.
VESUVIAN AND METEOROLOGICAL
OBSERVATORY (Prof. L. Palmieri,
Director), Naples ; 1084.
NORWAY.
DIETRICIISON, J. L. W., Christiania ;
771-2.
ESMARK, L., Prof, of Zoology, Uni-
versity of Christiania ; 1002.
HOLLER, DR. F., Selbo, Drontheim ;
112.
HOLST, ELLING, B., The University,
Christiania ; 35.
MOHN, PROF. H., Director of the
Meteorological Institute of Norway ,
Christiania-, 697,717, 723.
OLSEN, C. H. G., Christiania, Nor-
way ; 374.
SURVEY OFFICE, Christiania ; 762.
WAAGE, PROF. P., University of
Christiania, Norway ; 627, 639, 723,
WELLESEN, Christiania ; 278.
RUSSIA.
ACADEMY OF SCIENCES, THE IM-
PERIAL, St. Petersburg; 63, 342,
347, 373,410.
ARSENAL, THE, St. Petersburg-, 57.
BAIHD, G., St. Petersburg ; 491,499.
BtNG, E., Riga ; 14.
BRAUKU, G., Wasili-Ostrof, 22,
No. 5, St. Petersburg-, 58, 781.
CHEMICAL LABORATORY (Agricul-
tural Institute), St. Petersburg-,
611.
CHEMICAL LABORATORY (Imperial
Berg-Institute}, St. Petersburg-,
612.
CHEMICAL LABORATORY (Michailow
Artillery Academy) ; 613.
CHEMICAL LABORATORY (Imperial
Academy of Sciences), St. Peters-
burg; 613.
CHEMICAL LABORATORY ( Technologi-
cal Institute}, St. Petersburg;
613-7.
CHEMICAL LABORATORY, University
of St. Petersburg ; 611.
CHEMICAL SOCIETY or RUSSIA, Uni-
versity of St. Petersburg ; 610.
COMMITTEE OF THE PEDAGOGICAL
MUSEUM, St. Petersburg ; 1012,
1065.
CZECHOVICZ, C., Gymnasium of
Belostok; 231,1010-11.
Ivi
LIST OF CONTRIBUTORS.
DADIANE, P. NICHOLAS, 80, Grand
Sadorai (log No. 13), St. Peters-
bury ; 7, 13.
DEGEN, COLONEL, Bobruisk ; 781.
ERMOLIN (Pedagogical Museum), St.
Petersburg-, 1017.
ESERSKY, THEOD., St. Petersburg ; 7.
FOENULT (Pedagogical Museum); St.
Petersburg ; 1017, 1019.
GADOLIN, M., St. Petersburg ; 58.
GIVOTOVSKY (Pedagogical Museum},
St. Petersburg ; 1023.
GLOUKHOFF, W. (Warden of Stan-
dards, Ministry of Finance), St.
Petersburg; 175, 260, 278, 679,
1045.
HERBST, M. W., Observatory, Pul-
kowa ; 758.
ILYIN (Pedagogical Museuni), St.
Petersburg; io 18-19.
IMPERIAL ESTABLISHMENT FOR THE
PREPARATION OF OFFICIAL PA-
PERS, St. Petersburg ; 238.
IMPERIAL Moscow UNIVERSITY,
Moscow ; 619, 638.
IMPERIAL OBSERVATORY, Pulkowa ;
406, 432, 720, 749.
IMPERIAL TECHNICAL SOCIETY, St.
Petersburg ; 444.
IMPERIAL UNIVERSITY, St. Peters-
burg ; 284, 295, 308, 317, 334, 1073.
KOVALSKY (Pedagogical Museum),
St. Petersburg; 1019.
KRESTEN (Pedagogical Museuni), St.
Petersburg; 1012.
KRUEGER, PROF. DR. A., Helsingfors ;
126, 681.
LEMSTROM, PROF. S., Helsingfors,
Finland; 386-9.
LERMONTOFF (Pedagogical Museum),
St. Petersburg ; 1012,1014.
MARKOVNIKOFF, Professor of Che-
mistry, Moscow University; 613,
638.
MECHANICAL LABORATORY, TECH-
NOLOGICAL INSTITUTE, St. Peters-
burg; 446.
MENDELEEFF, PROF., St. Peters-
burg ; 63.
MICHAILOFF (Pedagogical Museum),
St. Petersburg; 1020.
MINING INSTITUTE, St. Petersburg,
830-2.
MINING SCHOOL, St. Petersburg; 861-
6, 868-9, 889-93.
Moscow JUVENILE AND PEDAGOGI-
CAL LIBRARY (Pedagogical Mu-
seum), St. Petersburg ; 1017-8.
NIPPE, R., St. Petersburg; 172,464.
OBSERVATORY, THE IMPERIAL, Pul-
kowa ; 406, 432, 720, 749.
OBSERVATORY, Wilna ; 425.
OETTINGEN, PROFESSOR DR. A. von,
Imperial University, Dorpat ; 693,
708.
OUSSOFF, DR. M., Zoological Museum
of the University, St. Petersburg ;
976.
OVSIANNIKOW, PH., M. ACAD. Sc.,
Professor of Physiology, University
St. Petersburg; 984-5, 991.
PASCHKIEWITCH, CAPTAIN W., Cen-
tral Administration of Artillery,
St. Petersburg ; 108.
PEDAGOGICAL MUSEUM, St. Peters-
burg; 1012.
PENKIN (Pedagogical Museum), St.
Petersburg ; 1019.
PETROFF, Kalouga ; 13.
PHYSICAL SCIENCE CABINET (//-
perial Academy of Sciences), St.
Petersburg ; 63, 342, 347, 373,410.
ST. PETERSBURG WORKSHOP OF
SCHOOL APPARATUS (Pedagogical
Museum), St. Petersburg; 1013,
1016-7, 1020, 1023.
SCHILDKNECHT (Pedagogical Mu-
seum), St. Petersburg ; 1017.
SCHINDHELM (Pedagogical Museum),
St. Petersburg; 1021.
SHULGIN (Pedagogical Museum), St.
Petersburg; 1018.
SKIBINEVSKY (Pedagogical Museum),
St. Petersburg ; 1023.
SOKOLOFF, N. W., Imperial Medica I
Academy of St. Petersburg ; 617.
STATISTICAL COMMITTEE (Pedago-
gical Museum), St. Petersburg;
1018.
STREMBITSKY (Pedagogical Museum),
St. Petersburg; 1020-3.
STROOKOFF (Pedagogical Museum),
St. Petersburg; 1013, 1017, 1023.
TCHEBICHEFF, PROF. P., The Univer-
sity, St. Petersburg ; 22, 146.
TECHNICAL SOCIETY, THE IMPERIAL,
St. Petersburg ; 444.
TECHNOLOGICAL INSTITUTE, St. Pe-
tersburg; 59, 111, 446, 458.
LIST OF CONTRIBUTORS.
Ivii
TECHNOLOGICAL INSTITUTE, The
Physical Laboratory of, St. Peters-
burg ; 171, 341.
TELEGRAPHS, GENERAL DIRECTION
OF; 363.
TOPOGRAPHICAL DEPARTMENT OF
THE IMPERIAL RUSSIAN GENE UAL
STAFF, St. Petersburg-, 237-8,
760, 803.
TOPOGRAPHICAL DEPARTMENT OF
THE IMPERIAL RUSSIAN GENERAL
STAFF, Tiflis ; 804.
WILD, DR. H., Central Physical
Observatory, St. Petersburg ; 680.
ZINGER, COLONEL, Pulkowa ; 395.
SPAIN.
ACADEMIA DE ClENCIAS NATURALES
Y AKTES DE BARCELONA, Spain ;
1064.
ACADEMY OF SCIENCES, Madrid;
442.
ARCHAEOLOGICAL MUSEUM, Madrid ;
7, 78, 87, 392-3, 397, 419, 443,492,
814.
ASTRONOMICAL OBSERVATORY, Ma-
drid-, 411.
BOTELLA Y DE HORNOS, B. FliDE-
RICO DE, 34, Calle de San Andres,
Madrid; 833-4.
CALDERON, S., Plaza de Santa Bar-
bara, Madrid ; 849.
COMISION DEL MAP A GEOLOGICO DE
ESFAXA, 23, Calle de Isabel la
Catolica, Madrid ; 832-4.
DIRECCION GENERAL DE CORREOS
Y TELKGRAFOS, Madrid ; 1064.
GEOGRAPHICAL ATD STATISTICAL
INSTITUTE OF SPAIN, Madrid ;
789-95.
GONZALEZ, MANUEL, Madrid ; 671.
MINISTRY OF MARINE, Madrid; 116,
393, 754, 782.
QuiROGA, F., 8, Union, Madrid;
840-3.
ROYAL SCHOOL OF MINES, Madrid ;
6, 146, 451, 868, 873, 881, 1065.
SAAVEDRA, E., 14, Calle de SanJua-
quin, Madrid ; 1065.
SWITZERLAND.
BAUMGARTNER, H., 14, Heumatt-
strasse, Basle ; 52, 79, 88, 126.
BERNOULLIANUM, THE, Basle ; 257,
280, 289.
BROCUER, L., 45, Boulevard des
Tranchees, Geneva ; 758.
CAUDERAY, J., 15, Rue St. Pierre,
Lausanne ; 369.
COLLADON, PROF. D., 1, Boulevard
du Phi, Geneva; 109, 145, 182,
231,327, 335, 460, 476.
DE LA RIVE, L., Geneva; 10, 273,
386.
DE LA RIVE COLLECTION, Geneva ;
172, 224, 383-6.
DE SAUSSURE, H., Geneva ; 328, 679,
701, 717.
EKEGREN, H. R., Geneva; 117.
FAVRE, E., 6, Eue des Granger,
Geneva ; 803, 805.
FOREL, PROF. DR. F. A., Morals ;
709.
GENEVA ASSOCIATION FOR THE CON-
STRUCTION OF SCIENTIFIC INSTRU-
MENTS, Geneva; 17, 52, 57, 59,
63, 147, 162, 176-7, 208, 210, 249,
253, 274, 307, 319, 326, 335, 340,
405, 679, 701-2, 743,913-4,920-2,
932, 945.
GOLDSCHMID, J., Zurich ; 684.
IlAGENBACH-BlSCHOFF, PROF. DR. E.,
Institution for Physical Science at
the Bernoullianum, Basle; 257,
280, 289.
HERMANN, PROF. T)R.L.,Physiolo</ic<il
Laboratory, University of Zurich;
209, 934, 944, 950.
LINDER, G., 29, Gerbergasse, Bas^e ;
319,321.
MONNIER, D., Geneva ; 626.
Iviii
LIST OP CONTRIBUTORS.
Morssox, PROF. A., Zurich; 167,
226.
PICTET (RAOUL) & Co., Geneva ; 274.
RAMBOZ AND SCHUCHARDT, Geneva ;
717.
RKCORDON, PROF. E., 53, Terrassiere,
Geneva ; 428, 430, 474, 813.
RENEVIER, PROF. E., Lausanne,
Switzerland:, 829.
SARASIN, G., Tour de Balessart,
Geneva ; 18, 442, 766.
SCHMID, A., Engineer, Zurich ; 79.
SORET, J. L., Geneva ; 219, 229, 274,
570.
SORET, PERROT, AND SARASIN (De
la Rive Collection), Geneva ; 172,
224, 383-6.
STAPFF, DR. F. M., Geological and
Mining Engineer, St. Got hard
Railway; 2.
STUDKR, PROF. B., Commission of
Switzerland, Geological Survey,
Berne; 829.
WARTMANN, E., Professor of Natural
Philosophy, University of Geneva ;
273, 327-8, 370-1.
WOLF, PROF. R., Director of the
Observatory, Zurich; 722.
CATALOGUE,
SECTION 1. ARITHMETIC.
WEST GALLERY, GROUND FLOOR, ROOM G.
L SLIDE RULES.
1. Slide Rule, of box wood, arranged by Mr. Dixon, Lowmoor
Ironworks. Aston fy Mander.
In addition to the lines of the ordinary slide rule this instrument contains :
Lines of common and hyperbolic logs and numbers.
Lines of sines, cosines, and numbers.
Lines of cubes and roots, direct.
A copy of Dixon's " Slide Rule Practice " is issued with each rule.
2. Slide Rule, of ivory, showing the actual and racing tonnage
of yachts. Aston $ Mander.
The length and breadth of beam being " set together," as directed in the in-
structions, the racing tonnage of yachts of any size is shown as marked.
3. Slide Rule, of boxwood, adapted to brickwork measurement
in all its branches, cubing stone, &c. Aston 3? Mander.
In this adaptation of the rule to brickwork measurements, all the results
are obtained by one setting, viz., " length to height :) ; while, immediately oppo-
site, any thickness will be found ; the superficial area in square feet ; the con-
tents in rods of reduced work 1^ bricks, in cubic feet, in cubic yards, and
the number of bricks required.
4. Slide Rule, of boxwood, adapted to timber measurement
in all its branches, giving the superficial or cubic contents of
round and unequal sided timber, St. Petersburg standard, price,
c. Aston fy Mander.
5. Slide Rule, of boxwood, with reversible slides, movable
inverted lines, &c. Arranged by Chas. Hoare. Aston $ Mander.
Uses explained in Hoare's " A. B. C. of Slide Rule Practice."
6. Slide Rule, of ivory, with reversible slides, movable inverted
lines, &c. Arranged by Chas. Hoare. Aston 8? Mander*
Uses explained in Hoare's " A. B. C. of Slide Rule Practice."
40075. Wt. 7183. A
2 SEC. 1. ARITHMETIC.
7. Slide Rule, of ivory, adapted for use in iron and steel plate
and sheet rolling mills. Designed by Okas. Hoare.
Aston Sf Mander.
This rule will show directly the precise net and waste weight of iron and
steel plates, and sheets, of any size, shape, and thickness. It may be applied
to all ordinary metals, and to find areas, cubic contents, liquid capacity, &c.
8. Slide Rule, of boxAvood, adapted for sheet iron and steel
manufacturers. The dimensions, thicknesses, and weights are
given both in English and metrical standards. Designed by
Chas. Hoare. Aston fy Mander.
The length of the sheet or plate (on the slide) being first set to the width,
then immediately below any thickness (on the top lines) will be found (on
the slide) the actual weight of the sheet either in pounds (avoirdupois) or
kilogrammes, metrical Or English measures being used without previous
conversion.
9. Slide Rule, of ivory, adapted for use in iron and steel-bar
rolling mills, showing instantly the precise net and waste weights
for bars of any length, size, and form. Designed by Chas. Hoare.
Aston $ Mander.
24. Scales, of boxwood, to show cubes, squares, and roots,
areas, diameters, circumferences, and decimal equivalents. De-
signed by Chas. Hoare. Aston $ Mander.
The bevel edged set square is used to read the divisions, and dispenses with
the need of voluminous printed tables.
9a. Three Slide Rules. Elliott Brothers.
10. Estimator. A slide rule, by which the volume of
prismoidal bodies (embankments, ditches, cuttings, &c., occurring
in the construction of railroads, canals, fortifications, c.,) is cal-
culated mechanically.
Dr. F. M. Stapff, Geological and Mining Engineer at the
St. Gotthard Railway. ^
This instrument, invented by the exhibitor, is patented in Sweden and the
United States of America.
lla. Timber Rule, for finding the content of timber of
any form, regular or irregular. The rule has eight gauge points
or divisors for reducing dimensions in inches to contents in square
feet. Dring and Page.
lib. " Verie " or Excise Officer's Rule.
Dring and Page.
Verie is probably a corruption of " Vero," a revenue officer who made an
alteration in the method of laying down some of the lines on the rule ;
previously to which they were called Everard's rules.
I. SLIDE KULES. 3
The lines on the rule are the A, B, C, D, MD, (or malt depth) 6x or variety
lines, viz., 1st, 2nd, 3rd, 4th, Dr. Button's and Dr. Young's, and two ullage
lines (segment standing and segment lying).
The A, B, C, and D lines are commonly called Gunter's lines (from Gunter,
the celebrated mathematician, who was the first to apply a logarithmic line
to the instrument for the solution of arithmetical problems) of which the A,
B, and C, are merely repetitions of each, and laid down to single radius, and
the D to double radius.
The MD line is similar to the A, B, and C, but is a broken line of two radii,
with the figures and divisions in an inverted order (reading from right to left),
commencing at 2218 192 in the right-hand radius, and ending at the same
point in the left-hand radius, 2218- 192 being the number of inches in a
bushel. By the method in which this line is arranged and used in conjunction
with the A, B, and C lines the contents in bushels of rectangular and similar
figures may be found at one operation.
The X or variety lines or lines of special gauge points (invented by Mr.
Woolgar) for finding the mean diameter of a cask whatever its form ; these
lines commence at 18 789, the circular gauge point, and are extended accord-
ing to each variety to which they may be applied.
The ullage lines are rules for finding the contents of a cask by comparison
with a standard cask holding 100 gallons, a form nearest those frequently
occurring in practice.
It cannot be ascertained by whom these lines were invented.
The fixed gauge points on the rule are those for the imperial gallon and
bushel, both square and round.
These rules are principally used by excise officers and maltsters. So ad-
mirable is the arrangement, that nearly every problem to which the principle
of the slide rule is applicable can be solved on one of these rules.
lie. Slide Rule, invented by Mr. Coulson, of Redan, used
for setting out railway curves, finding the weights of materials
from their specific gravities, breaking strains, &c.
Dring and Page.
The applications of this rule are so varied that the author's description of
them exceeds 400 octavo pages of closely printed matter.
12. Slide Rule, by M. Mabire.
Conservatoire des Arts et Metiers, Paris.
12a. Cylindrical Beckoning Rule. (The property of the
Conservatoire des Arts et Metiers.)
M. Mannheim, Professor at the Polytechnic School, Paris.
13. Calculating Rules, 1 of 50 cm., 1 of 36 cm., 1 of 26
cm., as arranged by M. Mannheim.
M. Tavernier Gravet, Paris.
13a. Small Cylindrical Calculating Machine. Arranged
by M. Mannheim. Conservatoire des Arts et Metiers, Paris.
14. Pocket Calculator, arranged by Major-General A. De
Lisle, R.E., for the use of engineers. ' Elliott Brothers.
A 2
4 SEC. 1. - ARITHMETIC.
This slide rule is useful for finding the weight of various materials, with the
help of the small tables on the back, for checking bills of quantities, and for
all approximate calculations required in engineering practice. The slides
are:
On Face.
On Stock A. The ordinary logarithmic line.
I. The same inverted.
On Slides Upper I. Inverted line.
D. Line of squares.
Lower B. Ordinary logarithmic lines.
an (^ Trigonometric lines.
Special Marks
M. Modulus of logs, to find prop, parts of logs.
A. Reciprocal of M. to find hyperbolic logs.
S" To find length of arcs, &c.
R' Radius for minutes.
R" Radius for seconds.
On Bach.
On Stock D. Line of squares.
On Slide E. Line of cubes read with D on line of % powers read with A.
* F. Line of f powers read with D, or of ^ powers read with A.
Tables and useful Numbers.
Line E with A gives variation in depth of water running over weir due to
alteration of length of weir. Neville's Hydraulics, page 22, 3rd edition.
A l4B=d __
E 220=1 ~" " " 60^7
Line F with D assists in finding the dimensions of a pipe or channel, with
a given hydraulic inclination to discharge a given quantity from the calculated
discharge of a pipe or channel of known dimensions and the same incli-
nation. Thus, if a pipe 4" diameter discharge 15 cubic feet per minute, what
diameter will discharge 33 cubic feet ? Neville's Hydraulics, page 245.
D _____
F _ ~l5 = D 33 =D'
D 4 = d 5.48 = d'
The two slides on the face working together solve the following equations :
al> ale abed
X ~; X = - X -
cde de e
15. Slide Rule, of boxwood, with double slide.
Renaud- Tachet, Paris.
16. Routledge's Original Engineers' Slide Rule and
manuscript book of instructions for using it.
PI. M. Commissioners of Patents.
II. CALCULATING MACHINES. 5
17. Kentish's Compound Slide Rule.
Thing and Page.
This is a new and ingenious arrangement of Gunter's lines, by means of
which problems in trigonometry and navigation can be solved, in addition to
those ordinarily done on the slide rule.
17a. Dr. Roget's Slide Rule of Involution.
W. H. Prosser.
This rule exhibits at one view all the powers and roots of any given number.
It is a measure of the powers of numbers, in the same way as Gunter's scale
is a measure of their ratios. Described in Phil. Trans. 1815, Part 1.
17b. Slide Rules (3), with double sliders, being suggested*
improvements on the ordinary slide rule, giving greater clearness
in reading off, and avoiding complication in the lines.
W. PL Prosser.
17c. Glass Slide Rule, invented by Leon Lalanne.
W. ff. Prosser.
This rule is made of two slips of card, upon which the scales are printed.
The slider, nlso made of card, has scales, constants, and gauge points printed
on both sides, and moves between the two slips. The whole is enclosed
between two pieces of glass.
17d. Slide Rule, with only one slider, adapted for the pocket-
book. Arranged by J. W. Woollgar. W. H. Prosser.
18. Sailer en's Slide Rule for reduction of volumes of gases
to standard temperature and pressure.
The Council of the Yorkshire College of Science.
19. Salleron's Slide Rule for reducing barometric heights
to standard temperature.
The Council of the Yorkshire College of Science.
II. CALCULATING MACHINES.
20. Calculating Machine, adapted to trigonometrical
computations, invented by Sir Samuel Morland (1625-1695), and
constructed by Henry Sutton and Samuel Knibbs of London, in
1664. Formerly belonging to Mr. C. Babbage, F.R.S.
Major- General Babbage.
On the lid of this machine is the following inscription :
" Machina Cyclologica Trigonometrice Qu& Tribus datis, reliqua oninia iu
Triangulis Planis Quaesita faciliter atque unico intuitu expediuntur a Samuele
Morlando inventa Anno Salutis MDCLXIII.
6 SEC. 1. ARITHMETIC.
21. Calculating Machine, designed by Viscount Mahon,
afterwards third Earl Stanhope (1753-1816), and constructed by
James Bullock in 1775. Formerly belonging to Mr. C. Babbage,
F.E.S. Major- General Babbage.
22. Calculating Machine, designed by Viscount Mahon,
afterwards third Earl Stanhope (1753-1816), and constructed by
James Bullock in 1777. Formerly belonging to Mr. C. Babbage,
F.R.S. Major- General Babbage.
23. Babbage's Calculating Machine ; or Difference
Engine. H.M. Board of Works.
This machine was invented by the late Mr. Charles Babbage, F.R.S., who
was born on the 26th December 1791, and died on the 18th October 1871.
Its construction was commenced in 1823 by authority, and at the cost of
the Government, and was carried on for several years under Mr. Babbage' s
gratuitous supervision. The work was suspended in 1833, and after many
delays, Mr. Babbage was informed in November 1842 that the Government
regretted the necessity of abandoning the machine, alleging the expense of
its completion as the ground for their decision.
At the time of its suspension about 17,000/. had been expended by Govern-
ment upon its construction, and a large part of the machinery had been
made. The small portion now exhibited was put ogether in 1833, prior to
the suspension of the work, in order to show the action of the machinery.
The whole engine, when completed, was intended to have had 20 places of
figures and 6 orders of differences.
This machine was expressly designed for the purpose of calculating and
printing tables, and not to perform single arithmetical sums.
If a single article is wanted, it is not, generally speaking, worth while to
construct a machine to make it ; but, when large numbers are required, their
production comes within the true province of machinery, and in this sense the
Difference Engine is emphatically a machine for manufacturing tables.
The mode in which the Difference Engine calculates tables is, by the con-
tinual repetition of the simultaneous addition of several columns of figures to
other columns, in the manner more particularly described below, and printing
the result.
In the small portion put together, and now exhibited, the figure opposite
the index on the .lowest wheel visible, in all cases, represents units ; the
figure on the next wheel above, tens ; that on the one above it, hundreds ;
the next thousands, and so on.
The right hand column of wheels shows the result of the calculation or the
tabular number ; for instance, series of squares, cubes, or logarithms, &c.
appear upon it, according to the nature of the calculation the machine is
making.
The next or central column represents the First Difference, and the left
hand column the Second Difference. At the bottom of the central column is
a figure wheel, covered, which can be used as a third difference, so as to
enable this portion of the machine to calculate tables of which the Third
Difference does not exceed 9. This will be better understood if this last
wheel is supposed to represent the lowest wheel of a fourth column of figures
standing beyond the left hand side of the machine, as it would be if it formed
part of the complete machine.
This arrangement is effected by a movable platform, with axles, and gearino-
wheels upon them, which are used for adding from the third difference wheel
II. CALCULATING MACHINES. 7
at the bottom of the central column to the second difference which is shown
on the left hand column. The effects capable of being produced by this
mechanism, when the gearing is altered, and the loose wheels belonging to it
are put into gear with certain figure wheels, is explained in Cabbage's Ninth
Bridgewater Treatise, together with the new views which it opened up to him
upon the subject of natural laws.
The three upper wheels of the left hand column are separated from the rest
of the machine, and are employed in counting the natural numbers. In other
words, they register the number of calculations made by the machine, and give
the natural numbers corresponding with the respective terms of the table.
Four half turns of the handle, two backwards and two forwards, are
required for each calculation, and the words " calculation complete " come
round upon a wheel at the top of the central column to show when this is
done. This wheel also shows, by the word "adjust," in what position of the
handle the figure wheels may be freely moved by hand, in order to introduce
different numbers or a different table.
24b. Cabinet, containing tablets for making mathematical
calculations. Archceological Museum, Madrid.
Rose wood cabinet, inlaid with ivory. In three divisions are thirty small
drawers, containing ivory plates with numbers and divisions for making mathe-
matical calculations. In the inside are the arms of the monastery of the
Escorial. Milanese work of the 16th century.
25. Fanometer, or Calculating Machine.
Edward Grohmann, Vienna.
By this extremely simple apparatus, various arithmetical computations can
be performed with great readiness.
25a. Calculating Machine for Multiplication.
P. Nicholas Dadiane, St. Petersburg.
26. Calculating Machine, for performing complex arith-
metical operations ; invented by M. Thomas of Colmar.
Professor Henncssy, F.R.S.
2 6 a. Calculating Machine for Adding, Subtracting,
Multiplying, and Dividing.
Theodore Esersky, St. Petersburg.
26b. Small Calculating Machine, encased in a pocket-
book. Theodore Esersky, St. Petersburg.
26c. Ten Copies of Multiplication and Division Tables.
Theodore Esersky, St. Petersburg.
27. Wertheimber's Calculating Machine, applicable to
wheel work. Patent, No. 96161843.
The Committee, Royal Museum^ Peel Park, Salford.
28b. Original Calculating Machine, known as " Napier's
Bones." Lord Napier and Ettrick.
One of the earliest attempts to construct a calculating machine, made by
John Napier, the inventor of logarithms. His method of calculating by rods
was published in a volume (which is exhibited with the machine) at Edin-
burgh in 1617. The apparatus was commonly known as " Napier's Bones."
8 SEC. 1. ARITHMETIC.
28. "Napier's Bones" or Bods. Made about 1700.
Dring and Fage.
Invented by Baron Napier, the originator of logarithms, used for per-
forming division and multiplication.
28a. Set of " Napier's Bones." 16th century.
Lewis Evans.
29. Calculating Disc, size about 18 centimeters, with double
divided circle ; constructed on the system of Prof. Soune.
Landsberg and Wolpcrs, Hanover.
30. Calculating Disc, with index of logarithms.
Landsberg and Wolpers, Hanover.
31. Calculating Disc, pocket apparatus.
Landsberg and Wolpers, Hanover.
32. Calculating Circle, O'OS meter in diameter, with single
scale of brass. Rudolf Weber, Ascliaffenburg.
33. Calculating Circle, O'lo meter in diameter, with single
square and cubic scale. Rudolf Weber, Ascliaffenburg.
The circles are on account of their continuous scale more convenient and
more accurate than straight slide rules. They are, therefore, peculiarly
adapted as pocket instruments for practical purposes, and can be relied on to be
as accurate as logarithms to four places.
34. Cubing Circle, 08 meter in diameter, for ascertaining
the cubical contents of trees in forests.
Rudolf Weber, Ascliaffenburg.
The cubing circle is to be noted as giving the index numbers for obtaining
the cubical contents of standing (not felled) timber ; these have been ob-
tained from practical experiments carried out by the Government Department
of Forests in Bavaria 011 more than 40,000 trunks of different kinds of trees.
The circle may be relied on for great accuracy in forest valuation.
35. Calculating Instrument, invented by Sir S. Morlaud.
Sennet Woodcraft, F.R.S.
35a. Calculating Planisphere.
Royal College of Science for Ireland, Dublin.
35b. McFarlane's Calculating Planisphere.
The Committee, Royal Museum, Peel Park, Salford.
36. Calculating Machine, designed by the Vicar Hahn
of Echterdingen, in 1770-1776; constructed by his son, Court
Mechanician in Stuttgart, in 1809 ; fourth specimen.
Her Highness the Duchess of Urach.
The machine which is exhibited is on exactly the same principle as that of
the one now in general use which was invented by Thomas, the only differ-
ence being that in Thomas's machine the numbers are placed in straight lines,
and in that of Hahn in a circle. It must have served as a model for
the machine of Thomas. The machine is to the present day in perfect order,
and works calculations up to numbers of 1 2 digits.
II. - CALCULATING MACHINES. 9
37. Logarithmic Calculation Apparatus, with one folding
scale, equivalent to five meters in length.
Prof. Gustav Hermann, Aix-la-Chapelle.
Calculation by means of this instrument is effected with the use of only one
scale. The two revolving arms are used like a compass. When the logarithm
a
of a quotient has been fixed between the arms, the plate must be
turned until the one arm is brought to a factor c, the product , c will then be
read on the other arm. This arrangement admits of the scale being made as
long as may be necessary by breaking it into lengths, without rendering the
instrument inconvenient. In the exhibited instrument ten circles are used,
by which means the scale attains a length of five meters, and is accurate up
to 16 06 . In using the instrument care must be taken to mark the number
of each scale circle, which can be fixed by small sliding buttons. The
number of the circle on which the result is to be read is found by the same
rules as the characteristic of a logarithm, on the supposition that the ten scale-
circles form a graphic table of logarithms of all the natural numbers, the base
of the system being ^
38. Arithmetical Disc, a very simple calculating machine,
with accompanying description. Prof. Prestel, Emden.
39. Calculating Machine, of the last century.
The Royal Gcwcrbe Academy, Berlin (Director, Prof.
Rculcaux).
This calculating machine formed part of the legacy of Hofrath Beireis,
the well-known ph} r sicist and chemist in the 18th century, and is very
similar to the calculating machine, No. 36. The following description
which accompanies this calculating machine is especially interesting, as it
was probably drawn up and written by the maker.
On the Use of the Calculating Machine.
There are on the small number-discs [Zahlen-Scheiblein] in the smallest
[circles], as well as on the large, in the great circles, the numbers 1,
10, 100, 1,000, and so on ; these indicate that the numerals on the first disc,.
where the (1) is marked, are units, on the second disc, where the numeral (10)
is marked, the tenfold of the numbers, and on the third, the hundredfold,
and so on ; and this applies also to those arcs on the largest circles. And if
on its first six discs respectively the following numerals were placed, 357,862,
they would indicate multiples of the numbers 1, 10, 100, which are on the
respective discs. On the sixth disc, where the numeral (3) is placed, is to
be found the number 100,000 ; thus indicating three times a hundred thousand.
On the fifth disc the numeral 5 represents 50,000, similarly the numeral 7,
7,000, and so on ; this would, in the first place, be " ciphering.'"
Now follows, iu the second place, addition. In calculating use is made of
the same numbers that are placed in the openings on the number disc, the
black numbers on the large discs are used for addition and multiplication,
and at the commencement noughts must be placed in all the apertures. As
q , an example, the following numbers will now be added together.
These numbers must be placed on those arcs which are found con-
r* secutively in the outer circle. The handle must then be turned,
when the numerals 352 will have come in the place of the noughts,
~7~~ on the three first large discs under the opening. Then the second
_'__ an( i Aird row are placed on the discs and by turning the handle
added to the preceding.
10 SEC. 1. ARITHMETIC.
Iu the third place comes subtraction, and it must first of all be understood
that the red numbers are to be used on the larger discs ; for the rest the
method is very easy.
The following is an example:
The numbers 5,786, as the larger numbers are placed in red figures
5,786 in the openings of the large discs ; (6) in the units, (8) in the tens,
3,524 and so on. The smaller number, which is to be subtracted, must
be placed on the arcs, in the same order as was shown for addition.
2,262 And in the same manner likewise must the handle be turned round
=: once, and then all is done, and the remainder appears in the
openings in which the larger amount was previously to be seen.
For multiplication (as for addition) the black numbers must be used on the
large discs, and before anything else, plain noughts must be placed in the
openings. And because in this method of reckoning small discs are also
used, noughts must at first be placed on them. Let the numbers
365 365, as in the case of addition, be placed on the arcs. One of the
24 hands, working from the centre, points to the units on the small
discs, and shows that multiplication will be effected with the units
1,460 as long as the hand is unaltered. Now if the handle be turned
7,300 round once, the numbers 365 will appear on the larger discs, instead
of the noughts which were there previously. But on the smaller
8,760 discs where the hand points, the number (1), and this proves, that
= the numbers 365 have been carried once under the aperture of the
large disc. The handle is again turned, and there will be seen on
the large disc the numbers 730 and on the smaller one the number (2). But
it must in the units' place be multiplied by (4), and so the handle has to be
turned four times round, and there will then appear on the large disc the
number 1,4CC, and on the smaller the number (4), and therefore, in this
problem, enough has been done with the units. Since 365 had to be multi-
plied by 24, the operation is repeated twice in the tenfold numbers, and the
desired result obtained ; this is effected in the following way :
The hand acting from the centre must be placed on the second disc, which
corresponds to tens. Near to the spot where the handle has its resting-
point, there is at the circumference of the machine a steel catch pressed down
in a notch;' this must be lifted up, and so turned round at the circumference of
the machine that the hand working from the centre comes to point on the
tens disc, and as in this case the catch will be pressed into the newly found
notch, the handle being turned round twice, the product 8,760 will be found
in the openings of the large discs.
For division the red figures must be used, as in the case of subtraction.
As an example take the number 8,760, which was obtained by the first
multiplication, and divide it by 365. The number 8,760 must be placed on
the large discs, in red figures, under the openings. The divisor 365 must be
placed on the arcs ; the first digit of the divisor (3) must be turned round
under the first digit of the dividend, viz., under the number (8) ; on the
small discs noughts must everywhere be placed. The catch must be left in
the notch. Now 3 can be taken from 8, the handle is turned once round,
and the numbers 5,110 appear, which is the remainder after 3,650 has
been taken from 8,760. 3 can again be taken from 5 ; the handle is again
turned round once more, and the remainder 1,460 appears. Since 3 cannot
be taken from 1, the catch is lifted, and 3, the first digit of the divisor,
brought under the 4 in the dividend. The handle is then turned 4 times,
and the remainders, 1,095, 730, 365, and 0, appear in succession, being those
due to the successive subtractions of 365 from 1,460. The value of the
quotient is seen to be as follows, 3,650 or 365 x 10 is subtracted twice, giving
20 as the first part of the quotient, then 365 is subtracted 4 times, giving 4
as the second part, with no remainder ; thus the quotient sought is 24.
II. CALCULATING MACHINES. 11
40. Tide Calculating Machine.
Sir William Thomson, F.R.S.
The object is to predict the tides for any port for which the tidal con-
stituents have heen found by the harmonic analysis from tide gauge obser-
vations : not merely to predict the times and heights of high water, but the
depth of water at any and every instant, showing it by a continuous curve,
for a year, or for any number of years in advance.
This object requires the summation of the simple harmonic functions repre-
senting the several tidal constituents to be taken into account, which is per-
formed by the machine in the following manner : For each tidal constituent
to be taken into account the machine has a shaft with an overhanging crank,
which carries a pulley pivoted on a parallel axis adjustable to a greater or
less distance from the shaft's axis, according to the greater or less range of
the particular tidal constituent for the different ports for which the machine
is to be used. The several shafts, with their axes all parallel, are geared
together so that their periods are to a sufficient degree of approximation pro-
portional to the periods of the tidal constituents. The crank on each shaft
can be turned round on the shaft and clamped in any position : thus it is set
to the proper position for the epoch of the particular tide which it is to pro-
duce. The axes of the several shafts are horizontal, and their vertical planes
are at successive distances one from another, each equal to the diameter of one
of the pulleys (the diameters of these being equal). The shafts are in two
rows, an upper and a lower, and the grooves of the pulleys are all in one
plane perpendicular to their axes. Suppose, now, the axes of the pulleys to
be set each at zero distance from the axis of its shaft, and let a fine wire or
chain, with one end hanging down and carrying a weight, pass alternately
over and under the pulleys in order, and vertically upwards or downwards
(according as the number of pulleys is even or odd) from the last pulley to a
fixed point. The weight is to be properly guided for vertical motion by a
geometrical slide. Turn the machine now, and the wire will remain undis-
turbed, with all its free parts vertical and the hanging weight unmoved. But
uow set the axis of any one of the pulleys to a distance T from its shaft's
axis, and turn the machine. If the distance of this pulley from the two on
each side of it in the other row is a considerable multiple of T, the hanging
weight will now (if the machine is turned uniformly) move up and down with
a simple harmonic motion of amplitude (or semi-range) equal to T in the
period of its shaft. If, next, a second pulley is displaced to a distance T', a
third to a distance T", and so on, the hanging weight will now perform a
complex harmonic motion equal to the sum of the several harmonic motions,
each in its proper period, which would be produced separately by the displace-
ments T, T', T". Thus, if the machine was made on a large scale, with T,
T'... equal respectively to the actual semi-ranges of the several constituent
tides, and if it is turned round slowly (by clockwork, for example), so that
each shaft goes once round in the actual period of the tide which it represents,
the hanging weight would rise and fall exactly with the water level as affected
by the whole tidal action. This, of course, could be of no use, and is only
suggested by way of illustration. The actual machine is made of such mag-
nitude that it can be set to give a motion to the hanging weight equal to the
actual motion of the water level reduced to any convenient scale : and pro-
vided the whole range does not exceed about 30 centimetres, the geometrical
error due to the deviation from perfect parallelism in the successive free parts
of the wire is not so great as to be practically objectionable. The proper
order for the shafts is the order of magnitude of the constituent tides which
they produce, the greatest next the hanging weight, and the least next the
fixed end of the wire : this so that the greatest constituent may have only one
pulley to move, the second in magnitude only two pulleys, and so on. In the
12 SEC. 1. ARITHMETIC.
actual machine there are 10 shafts, which, taken in order from the hanging
weight, give respectively the following tidal constituents :
1. The mean lunar semi-diurnal.
2. The mean solar semi-diurnal.
3. The larger elliptic semi-diurnal.
4. The luni-solar diurnal declinational.
5. The lunar diurnal declinational.
6. The luni-solar semi-diurnal declinational.
7. The smaller elliptic semi-diurnal.
8. The solar diurnal declinational.
9. The lunar quarter-diurnal, or first shallow-water overtide of mean lunar
semi-diurnal.
10. The luni-solar quarter diurnal, shallow-water tide.
The hanging weight consists of an ink bottle with a glass tubular pen
which marks the tide level in a continuous curve on a long band of paper moved
horizontally across the line of motion of the pen, by a vertical cylinder geared
to the revolving shafts of the machine. One of the five sliding points of the
geometrical slide is the point of the pen sliding on the paper stretched on the
cylinder, and the couple formed by the normal pressure on this point, and on
another of the five, which is about 4 centimetres above its level and ] centi-
metres from the paper, balances the couple due to gravity of the ink bottle
and the vertical component of the pull of the bearing wire, which is in a line
about a millimetre or two farther from the paper than that in which the centre
of gravity moves. Thus is ensured, notwithstanding small inequalities of the
paper, a pressure of the pen on the paper very approximately constant, and as
small as is desired.
Hour marks are made on the curve by a small horizontal movement of the
ink bottle's lateral guides, made once an hour ; a somewhat greater move-
ment, giving a deeper notch, to mark the noon of every day.
The machine may be turned so rapidly as to run off a year's tides for any
port in about four hours.
It is intended that each crank shall carry an adjustable counterpoise, to be
adjusted so that when the crank is not vertical the pulls of the approximately
vertical portions of wire acting on it through the pulley which it carries shall,
as exactly as may be, balance on the axis of the shaft, and that the motion of
the shaft shall be resisted by a slight weight hanging on a thread wrapped
once round it and attached at its other end to a fixed point. This part of the
design, planned to secure against " lost time " or " back-lash " in the gearings
of the shafts, and to preserve uniformity of pressures between teeth and teeth,
teeth and screws, and ends of axles and " end-plates," was not carried out,
but can easily be applied to the machine now exhibited.
The general plan of the screw gearing for the motions of the different
shafts is due to Mr. Lege, the maker of the machine. The construction has
been superintended throughout by Mr. Roberts, and to him is due the whole
arithmetical design of the gearing to give with sufficient approximation the
proper periods to the several shafts.
4Oa. Sir William Thomson's Instrument for Harmonic
Analysis of Tidal Observations, and for other uses.
It includes a disc-ball and cylinder integrator of Professor James
Thomson. For explanations, reference may be made to proceed-
ings of the Royal Society for February 3, 1 876.
Sir William Thomson.
41. Pascal's Calculating Machine (1642).
Conservatoire des Arts et Metiers, Paris.
III. MISCELLANEOUS. 13
42. Fetroff's Arithmetical Apparatus.
M. Petroff, Kalouga.
43. Arithmometer, with measuring apparatus, and the full
size skeleton of the square metre and cubic metre, folding up by
means of a hinge. frere Memoire Piron.
43a. Counting Machine.
P. N. Dadiane, St. Petersburg.
43b. Calculating Machine.
P. N. Dadiane, St, Petersburg.
45. Model of Gas Meter Counting Machine.
Council of King's College, London.
46. Cavendish's Original Counting Machine.
Council of King's College, London.
III. MISCELLANEOUS.
48. Apparatus for the Statistical Treatment of large
numbers of Seeds, &c., to sort them rapidly into classes
differing by regular gradations of magnitude, with the view of
testing how far the relative numbers in the several classes accord
with the results of the Law of Error or Dispersion.
Francis Gqlton, F.R.S.
It consists of a square box, having parallel bars fixed across its top at
equal distances apart. An equal number of similarly arranged bars are con-
nected by means of rods running along 1 tbeir ends, like the bars of a gridiron,
thus forming a framework that is laid on the top of the box. Hence there
are two systems of parallel bars in the same plane, one of which is fixed and
the other movable. When the frame is pulled forwards as far as it can go,
each of its bars presses along its whole length against one of the fixed bars,
and when it is pushed gently back the framework bars separate simultaneously
and equally from the fixed bars, and any objects that may have been laid
between their edges, and are small enough, will drop through. The bars are
bevelled along their opposite faces, in order to receive these objects. The
framework is moved by a screw turned by a ratchet wheel, which is itself
moved by the to-and-fro action of a handle between stops, one of which is
adjustable at pleasure. Hence, every time the handle is worked, the space
between the bars is widened by a definite space, and all the seeds, &c., whose
diameter is greater than the original and less than the final space, will drop
through. A tray, divided into compartments, slides beneath the box ; it is
pushed forward through the space of one compartment before giving a fresh
movement to the handle, and thus the seeds become sorted into the different
compartments. (This instrument was used to illustrate a lecture before the
Royal Institution on Friday evening, February 27, 1874.)
14 SEC. 1. ARITHMETIC.
49. Apparatus affording Physical Illustration of the
action of the Law of Error or of Dispersion.
Francis Galton, F.R.S.
Shot are caused to run through a narrow opening among pins fixed in the
face of an inclined plane, like teeth in a harrow, so that each time a shot passes
between any two pins it is compelled to roll against another pin in the row
immediately below, to one side or other of which it must pass, and, as the
arrangement is strictly symmetrical, there is an equal chance of either event.
The effect of subjecting each shot to this succession of alternative courses is,
to disperse the stream of shot during its downward course under conditions
identical with those supposed by the hypothesis on which the binomial law
of error is founded. Consequently, when the shot have reached the bottom of
the tray, where long narrow compartments are arranged to receive them, the
general outline of the mass of shot there collected is always found to assimi-
late to the well-known bell-shaped curve, by which the law of error or of
dispersion is mathematically expressed. (This arrangement was devised, by
the exhibitor, to illustrate a lecture before the Royal Institution on Friday
evening, February 27, 1874.) When using the machine, tilt it backwards
and all the shot will be returned to the receptacle at the top ; then set it in
its proper position, and the shot will run to the opening whence they distribute
themselves. It is now necessary to press to and fro a button at the top of
the frame, which sets a small rake in action, which prevents the shot from
getting jammed at the mouth of the opening.
50. Practical Approximation to the value of the circum-
ference in terms of the diameter, by means of a right angled
triangle having one acute angle =27 35' 49-636".
Edward Bing, Riga.
For the purpose of effecting this object, as well as for answering
kindred questions, use is made of a triangle, specimens of which are
here exhibited, and of which one angle is a right angle and another
is defined by an equation.
SECTION 2. GEOMETRY.
WEST GALLERY, GROUND FLOOR, ROOM G.
. i&
L INSTRUMENTS USED IN GEOMETRICAL
DRAWING.
52. Pantograph, by Breithaupt and Son.
Royal High School of Industry, Cassel. (JV. Narten.)
This pantograph was made for the geodetic collection of the school, in the
year 1866, by Messrs. Breithaupt nnd Son, Cassel. It is used for enlarging
and reducing maps and plans. The peculiarity of its construction is the
movement of all the arms between pairs of points, by which means friction
is as far as possible avoided. The employment of tubes instead of the usual
rectangular bars is also to be recommended, by which means bending, which
creates errors in the use of the instrument, is avoided ; besides which, the
weight of the whole is considerably decreased, thus also lessening friction in
the movement of the points.
The peculiar construction of this pantograph was invented and carried out
by Messrs. Breithaupt and Sou, and the instrument possesses great accu-
racy and facility of use.
53. Pantograph. Menaud Tachet, Paris.
54. Pantograph, with free hanging arms of new construction.
Ott and Coradi Kempten, Baviera.
By means of this instrument figures on a reduced or an enlarged scale can
be transferred either to paper, stone, or metal.
These pantographs differ in their construction from other similar instru-
ments by not resting on friction-rollers, but are freely suspended by means
of metal wires from cast-iron curved standards ; thus only a small portion of
the weight of the instrument rests on the table. The advantages of this con-
struction are these : easy and secure management of the instrument ; any
ordinary table may be used of a size sufficient to afford room for the stands,
the original, and copy ; the accuracy of the graphic representation is greater
at less cost.
The guidance of the instrument is so easy and so accurate that with a
little practice every outline can be reproduced. Drawings, likewise, can be
transferred to substances measuring a certain height, such as lithographic
stones, it being only necessary to place frame and original correspondingly
higher. In producing enlarged copies the guiding peg and the drawing pencil
must be exchanged, and the releasing cord fastened accordingly. The guidance,
in making enlarged copies, is also performed with the handle of the tracing
pencil with the same accuracy as when making reduced copies.
54a. Horizontal Pantograph, traversing a surface of 36
inches in length by 20 inches in width. Reduction from \ to T ^.
L. Oertlina.
16 SEC. 2. GEOMETRY.
54b. Pantograph, large model, with double scale and reverse
action, belonging to the Indian service. Four of these large in-
struments are now in use. M. Adrian Gavard, Paris.
54c. Frame, containing the Drawings of Pantographs
and Fantopoly graphs made by the exhibitor.
M. Adrian Gavard, Paris.
54d. Pantograph by Adrian Gavard, Paris.
S. J. Hawkins.
Size 56 centimeters.
A method of raising and lowering the tracer A by a rack and pinion
movement, for use when the reduction of a drawing has to be made on tracing
paper, enables the tracer to pass over any irregularity of surface, and thus
prevents injury to the paper.
There is also a method of ascertaining when the tracer A, the pencil or cen-
tral point B, and the fulcrum C, are in a straight line, for use with maps or
drawings of irregular scales, and for which there are not any corresponding
divisions on the Pantograph. The points A, b, C, D, e are removed when the
instrument is adjusted, and the two small screws f, f screwed into the head of
the tracer and fulcrum.
The instrument is adjusted for the reduction of Ordnance maps 25 '34
inches to the mile to 5 chains to the inch or 16 inches to the mile.
54e. Pantograph made at Madrid by Kostriaga, and which
has been used at the mines of Almadin since the end of the last
century. Royal School of Mines, Madrid.
Compass of Proportion, called also military compass,
invented by Galileo in 1596.
Royal Institute of " Studii Superiorly Florence.
On one side are engraved the arithmetical lines, the geometrical lines, the
stereometrical lines, and the metallic lines ; on the opposite side are the polygra-
fical lines, the tetragonical lines, and the joined lines for the squaring of figures
comprised by right angles and curves together. By means of it 40 important
operations can be carried on, and it has in addition a quadrant with a squadron
of bombardiers, and transversal lines to take the inclination of the scarp of
any wall.
Galileo presented compasses of a similar kind, in the year 1598, to the
Prince of Holstein, Sagredo, and Bentivoglio, who was afterwards made
Cardinal, to Ottone Brahe, to the Count of Luxemburg, and many other
gentlemen, both Italians and foreigners, who had gone to Padua to follow the
lectures of so eminent a philosopher. He also presented one made of silver
to the Archduke Ferdinand of Austria, and to the Landgrave of Hesse.
55. Large Collection of Mathematical Instruments
for Geometrical and Fortification Drawing, as well as for
Artillery purposes. The property of His Highness the Prince
Pless, Fiirstenstein. The Breslau Committee.
This ancient collection, dating from the commencement of the last century,
is remarkable for the excellent workmanship and good state of preservation
of the instruments.
I. GEOMETRICAL DRAWING. 17
It contains 19 compasses and 11 accessory parts, 28 rules and scales, two of
the same with two keys for fortification drawing, eight triangles and set
squares, 10 protractors, two pantographs, and 52 other instruments. In all,
134 pieces.
56. Case of Mathematical Instruments.
Renaud Tachet, Paris.
57. Proportional Compasses. Renaud Tachet, Paris.
58. T-squares, Set Squares, and Curves.
Renaud Tachct, Paris.
59. Diagonal Scale.
Geneva Association for the Construction of Scientific In-
struments.
60. Scales made of Mica, for use in geometrical drawing.
Max. Raphael, Breslau.
275. Meter-measures, constructed of mica.
Max. Raphael, Breslau.
These measures have the advantage of being transparent, and may serve
for copying geometrical drawings. Owing to their remaining unaffected by
the ordinary changes of temperature they may also be used as standard
measures.
61. Perspective Apparatus invented by James Watt.
Bennet Woodcroft, F.R.S.
62. Set of Mathematical Instruments, with all the
modern improvements : as used by professional draughtsmen, &c. ;
illustrated by diagrams of work performed. Win. Ford Stanley.
62a. Magazine Case of Drawing Instruments.
Henry Porter.
64. Case of Mathematical Instruments, probably Dutch,
made at the beginning of the 18th century. Lewis Evans.
65. Two Magazine Cases of Drawing Instruments.
Mark Eames.
65a. Large Magazine Case of Instruments.
G. W. Strawson.
65b. Magazine Cases of Instruments (2).
G. W. Strawson.
65c. Morocco Case of Instruments. G. W. Strawson.
65d. Napier's Compasses (Electrum). G. W. Strawson.
66. Beam Compass, T-squares, Set Squares, and
Curves. Bock and Handrick, Dresden.
40075. B
18 SEC. 2. GEOMETRY.
67. Models of Mathematical Instruments. The ortho-
compass and the addition compass. Prof. L. Zmurko, Lemberg.
The first of these instruments is constructed so that the points of the compass
are always parallel to each other, and perpendicular to the surface of the
paper. The second is a compass which can be used also as a protractor, as it
contains an apparatus which indicates the amount of opening between the
arms.
69a. Photographs of Mathematical Instruments.
Otto Fennel, Cassel.
69d. Revoil Tele-iconograph, altered for perspective draw-
ings enlarged to 20 times on a horizontal plane-table.
M. Georges Sarasin, Geneva.
The instrument consists of a telescope, adapted to a Wollaston camera lucida,
and fixed on a stand arranged so as to make it a mathematical or scientific
instrument ; while on a separate stand is placed a plane table for drawing. In
order to facilitate the exact grouping of the partial perspectives in accordance
with a general cylindrical perspective, and capable of being developed, and in
order to permit of drawing while the telescope is inclined at great angles,
the following additions have been made to the Revoil model: 1st. A
tightening ring with an adjusting screw, which fixes the prism to any point
on the thread of the screw by which it is fixed to the eye piece. 2d. A web
of six threads crossed at right angles in the focus of the object glass for
the purpose of setting the partial images in a straight line and in a direction
in accordance with the horizontal or vertical. 3d. A spirit level on the
telescope stand to ensure the verticality of the axis of rotation. 4th. A
socket and rack joint, permitting the height of the prism above the drawing
to be determined whatever be the angle of the telescope and, consequently,
the scale of the drawing. 5th. A graduated scale with vernier, giving a
reading to five minutes on the horizontal limb. 6th. A method of attaching
the instrument to its stand, so as to be at the same time firm and easy to
work.
69e. Patent Dotting Pen.
E. O. Richter and Co., Chemnitz, Saxony.
The arrangement is as follows :
A small toothed wheel adapted to the kind of dotted lines to be drawn is
attached to a plate, which, rolling on the paper, lifts a lever, which is again
dropped by means of a spring. Attached to this arm is a drawing-pen, easily
adjustable, by means of a hinge, to the correct position suited to the wheel.
The wheel itself is held in position by a small, somewhat elastic plate, which
can be displaced a little for fitting the different reserve wheels on which
the kind of lines to be drawn depends.
69f. Patent Compasses with stationary centre point.
E. O. Richter and Co., Chemnitz, Saxony.
These compasses differ from others, chiefly by the centre-point being
stationary on the paper, so that the tracing-pen, resting on the paper by its own
gravity, moves about the centre-point as axis, whilst the movable pen can be
displaced, without removing the compasses from the paper. By these advan-
tages speedy and neat tracing will be achieved, even when the smallest circles
are to be drawn.
I. GEOMETRICAL DRAWING. 19
69g. Patent Compasses, with drawing pen and leaden tube.
E. O. Richter and Co., Chemnitz, Saxony.
69h. Patent Diamond Compasses, for lithography.
E. 0. Richter and Co., Chemnitz, Saxony.
69i. Patent Diamond Compasses with drawing pen, for
lithography. E. O. Richter and Co., Chemnitz, Saxony.
69j. Patent Hatching Ruler (for shading by cross-lines in
drawing and engraving).
E. 0. Richter and Co., Chemnitz, Saxony.
A ruler is attached to a cylinder which, rolling on a plate, draws the
former after it. By means of an endless screw, working in a wheel, the
cylinder is moved forward. A cogwheel is attached to the endless screw,
in which a bar catches, and by the depression of which the mechanism is
put in motion. The depression can be regulated by a screw, by which means
the various distances of the lines are obtained. One finger is sufficient for
working the ruler by simply pressing on the screw, and holding it until
the line is drawn.
69k. Six Setter Diamonds, for lithography.
691. Five Machine Diamonds, for lithography.
69m. Six Scratching Diamonds, for lithography.
E. O. Richter and Co., Chemnitz, Saxony.
69n. Perspectograph. Lieut. -General M. W. Smith.
This instrument is employed to determine the perspective position of a
point on the surface of a picture corresponding to any point in nature, the
actual position of which is ascertained by means of ground plans, elevations,
sections, actual measurement, or otherwise, or else assumed in the composi-
tion of a picture. A horizontal line is drawn across the picture and a point
assumed upon it to represent the point or centre of view, the perspective point
(the two ordinates, of which one parallel and the other perpendicular to
the horizontal line are determined by the instrument) is then laid down from
the point of view by scale and offset. The manipulation of the instrument is
very simple and easily acquired ; and as the perspective representation of any
number of points, constituting lines, planes, solids, &c., can be rapidly
transferred to the picture, the most complicated problems of perspective,
whether rectangular or oblique, can be performed without lines of geometrical
construction, or the transferrence of the subject from a plan previously pre-
pared to the picture. A detailed description of the working of these instru-
ments, as well as of the system upon which their construction depends, will be
found in " Engineering," 1876.
69o. Pointfinder. Lieut.- General M. W. Smith.
This instrument is used in sketching from nature and is employed to
determine a point on the surface of the picture corresponding to any point in
nature to which the sights of the instrument may be directed, as follows :
Having drawn a line horizontally across the paper to represent the horizontal
line, and assumed a point upon it as the point of view, the instrument is set to
zero both on the horizontal, and side vertical graduated arcs ; and levelled by
means of the small plumb bob, the sights being at the same time upon any
B 2
20 SEC. 2.- -GEOMETRY.
point in nature which may be chosen as the point of view. The sights of the
instrument are then directed to any point in nature which it may be desirable
to introduce into the picture. This may be done by the lateral and vertical
movements of the horizontal disc and plate to which the sights are attached ;
the divisions and subdivisions indicated by the zero mark on the horizontal
disc, and index on the side arc, are then read off and transferred to the picture
by means of the graduated scale and offset, the zero of the scale being placed
to the point of view and the bevelled edge to the horizontal line, the offset is
then moved along the edge of the scale till the bevelled edge corresponds with
the division or subdivision read off from the circular disc, when a slight dot
with the point of a pencil at the division or subdivision on the offset corre-
sponding to the reading on the side vertical arc will indicate the point which is
the perspective representation of the point in nature. The scale can be in-
creased, if desired, by multiplying the number of divisions or subdivisions read
off on the graduated arcs by 2, 3, 4, or any other common multiplier. The
offset also may be dispensed with by placing the edge of the scale first to the
horizontal line, for the first reading making a slight mark on the line with a
pencil at the number indicated, and then perpendicular to it for the second
reading, this maybe the most convenient mode of laying down the points
when the sketching book is held in the hand. The stand of the instrument
folds up, and the apparatus when packed is very light and portable, consisting
of camp stool, drawing book, instrument and stand.
443a. Plate Glass Sector, designed for the purpose of
plotting angles on plans or charts where it is necessary to see the
work under the sector, and the divisions being . on the side next
the paper no variation in pricking off can take place,
Thos. F. Chappe, M. Inst. C.E.
Boxwood Beam Compasses.
Bock and Handrick, Dresden.
244. Scales, of boxwood, showing the equivalents of English
and Foreign measures of length. Aston fy Mander.
The bevel edged set square slide is used to show the divisions coinciding ;
and the equivalent values of English and Foreign measures of length may thus
be readily obtained.
245. Plotting Scales. Ivory. Two specimens, to show fine
and accurate dividing. Aston fy Mander.
No. 1 shows two chains to the inch, represented by 200 divisions to the
inch.
No. 2 shows one chain to the inch, represented by 100 divisions to the
inch.
II. INSTRUMENTS FOR TRACING SPECIAL CURVES.
7O. Conograph. An instrument by which the various conic
sections may be drawn. .
a. Ellipso-Pnrabolograph.
b. Hyperbolograph.
Dr. Lawrence Zmurko, Lemberg.
II. CURVE TRACING. 21
This instrument consists of two movements independent of, and perpendicu-
lar to, each other; the first of these is set in action by turning a disc, the
second by moans of a spring. These movements are so contrived that the
extent of the second motion shall be such a function of that of the first as to
cause a conic section to be described.
71. Cycloidograph. An instrument for tracing cycloids.
Dr. Lawrence Zmurko, Lemberg.
7 la. Instrument for tracing with accuracy ellipses and spirals
up to 25 centimetres. M. Adrian Gavard, Paris.
72. Instrument for drawing Conic Sections.
Edward Uhlcnhuth, Anc/am, Pommerania.
This instrument, which was invented by the exhibitor, shows in the first
place the formation of the parabola. By altering the arrangement, the con-
struction of the ellipse and hyperbola easily follows.
73. Elliptic Compass. Renaud- Tachet, Paris.
74. Colonel Feaucellier's Compound Compass.
Conservatoire dcs Arts et Metiers, Paris.
75. Compound Geometric Chuck, producing the kine-
matic retrogressive parabola, by continuous motion ; either on a
moving plane by a fixed point, or on a fixed plane by a moving
point. Henry Perigal.
76. Machine for Compounding two Simple Har-
monic Curves. Invented and constructed by the exhibitor.
A. E. Donkin.
A strip of paper is wound round the cylinder ; the little glass pen moving
backwards and forwards on it draws one curve, a similar motion of the
cylinder the other. Since both move at once the curves are combined, and
the result rendered visible to the eye by the revolution of the cylinder.
A. Eccentric for giving simple harmonic motion to pen.
B. cylinder C.
D. 1 wheels for determining relative numbers of vibrations of pen and
E. J cylinder.
F. Wheel for transmitting slow motion to pinion G which turns the
cylinder.
H. Idle wheel.
I. Change wheels to supply different ratios of vibration of pen and
cylinder.
76c. Bow and Scale for Exhibiting Elliptic Func-
tions. A. G. Greenhill.
76e. Spherical Rules and Squares for Spherical
Drawing. Dumoulin Froment, Paris.
76a. Bough Model of the Trace-Computer, designed by
the Exhibitor, for the use of the Meteorological Office.
Francis Galton, F.R.S.
Given two ordinates having the same abscissa, the instrument, of which this
is a working model, pricks out a third ordinate that shall be some desired
22 SEC. 2. GEOMETRY.
function of the other two. The original instrument was contrived for the use
of the Meteorological Office, where it is employed to derive the trace for
humidity from the traces of the dry and wet bulb thermometers. It consists
of a horizontal slab, whose upper surface has been shaped, as hereafter de-
scribed, in accordance with the numerical tables that have been calculated
from the desired function, the height of its surface at each point being the
tabular value corresponding to the two entries severally represented by the
distance of that point from the front and from one side of the slab. The
plate that carries the two traces is placed horizontally on a frame that travels
in front of the slab. Two slides move at right angles to this plate, and have
microscopes attached to them, that traverse the paper along ordinates having
the same abscissa. One of these slides is rigidly connected with a frame on
which the slab is able to move from front to back ; when this slide is pushed,
the frame and the slab together are pushed with it. When the other slide
is pushed, it also gives a sidelong movement to the slab on the frame by means
of a toothed wheel acting on a rack. Thus the particular point of the slab that
corresponds to the values of the two ordinates is brought vertically below a
descending rod, and this is caused to drop gently on the surface of the slab
by touching a treadle. The vertical space through which the rod descends
is consequently the function required. The rod carries a horizontal pricker,
with which it makes a dot on a plate held vertically in the same stage that
carries the plate on which the two traces are drawn. The slabs can readily
be fashioned Toy instrument-makers, who possess the necessary apparatus,
according to any required tables. They are drilled to the requisite depth at
various points, and are afterwards smoothed down. In the machine in use at
the Meteorological Office, there are many additional appliances not shown in
this rough model.
76b. Rule; with joint, which serves to curve an elastic plate
into an arc of the circle, of any radius.
Professor Tchebichejf, University of St. Petersburg.
3O99. Intersecting Compasses (Arcograph).
Geodetic Institute of the Royal Polytechnic School at
Munich, Prof. Dr. von Bauernfeind.
The Arcograph serves to describe upon a given chord a circle the arc
of which contains a given angle. The exhibitor, by this invention, has
supplied the wants of the practical geometrician in solving, graphically, and
without construction Pothenot's problem and all the problems which are
described in geometry as " Kuckwartseinschneiden ". See Bauernfeind's
"Elemente der Vermessungskunde," 5th edition, Vol. II., pp. 167-173.
III. MODELS OF FIGURES IN SPACE.
COLLECTION OP MODELS OF RULED SURFACES, CONSTRUCTED
BY M. FABRE DE LAGRANGE, IN 1872, FOR THE SOUTH
KENSINGTON MUSEUM.
This collection illustrates the principal types of the class of surfaces which
can be traced out m space by the motion of a straight line.
These surfaces, on account of the facility with which they can be con-
structed and represented, and of the ease with which their intersections can
termmed, are of more consequence than any others in the geometry of
III. MODELS. 23
the Industrial Arts. It is only in small work, -which can be put into the
lathe, that the class of surfaces of revolution approaches them, in respect of
general utility. The most important surfaces of all, the plane, the right
cylinder, the right cone, and the common screw, belong to both classes.
The representation of the surfaces by means of silk threads is of course
only approximate ; an approximation of the same character as the representa-
tion of a curve by a dotted or chain line, Fig. I, or by a series of right lines
touching the actual curve, Fig. 2.
The models are constructed with especial reference to the possibility of
changing their shape, by moving some of the supports of the strings, by altering
the lengths or positions of certain parts, or by converting upright forms into
oblique. This possibility of deformation, as the process is technically called,
greatly enhances the value of the models, by allowing them to represent a
much greater variety of surfaces than if they were fixed. They are, how-
ever, too delicate to be much pulled about, and, unless they are very cautiously
handled, the strings are apt to become entangled or break. They should never
be used except by a person who understands them, and they should not be
shifted without some good reason.
FIG. 1. FIG. 2.
Fig. 1 is an example of the first, and Fig. 2 of the second. In both cases,
the curve, although not actually drawn, is indicated with sufficient approxi-
mation for most practical purposes. Models Nos. 10 and 30 also afford illus-
trations of the principle exhibited in Fig. 2.
Geometrical drawings of most of the surfaces represented by these models
are contained in BRADLEY'S Practical Geometry (2 vols., oblong folio, pub-
lished by Chapman and Hall). Many of them will also be found in the
French treatises on practical and descriptive geometry, such as LEROY,
ADHEMAR, LEFEBURE DE FOURCY, DE LA GOURNERIE, and in their treatises
on Stereotomy and Stone-cutting (coupe des pierres). Many of them are also
given in SONNET'S Dictionnaire des Math^matiques Appliqu6es. A catalogue
of this collection of models, with an appendix containing an account of the
application of analysis to their investigation and classification, was prepared
for the South Kensington Museum in 1872, by Mr. C. W. Merrifield, F.B.S.
The following descriptions are extracted from this catalogue :
77. Hyperbolic Paraboloid generated by a single system
of right lines.
Two bars, each pierced with holes, equally spaced. One bar is fixed,
the other swings round an axis, which, moreover, can be inclined at different
angles to the fixed bar.
When the bars are parallel the strings indicate a plane. When they are
clined to one another, but still in the same plane, the strings still indicate a
24 SEC. -2. GEOMETRY.
plane ; but Avhen the bars are not in the same plane, the surface is the hyper-
bolic paraboloid.
The surface is sometimes called the twisted plane. But it must not be
supposed that it can be made by bending a plane. On the contrary, when
the surface is twisted, no two of the strings lie in the same plane, and, there-
fore, no part of the surface is plane. It can neither be flattened nor made
from a plane, without stretching or contraction.
The hyperbolic paraboloid is the natural surface proper for a ploughshare.
78. Hyperbolic Paraboloid.
Two bars, pierced -with holes at equal distances, the holes being connected
by two different systems of strings. The surface, as well as the arrangement,
is very nearly the same as in No. 77, only that there are two paraboloids in-
stead of one. As the movable bar swings round, one paraboloid opens out
while the other closes up. If the -bars are swung so as to be in the same
plane, one system of strings describes a plane by parallel lines, and the other
by lines radiating from a point. If one bar is now turned so as to be end for
end, we still get a plane, the set of parallel lines now passing through a point,
while the set Avhich previously passed through a point has now become
parallel.
The pair of paraboloids intersect in three right lines. There is also a
fourth intersection on the " line at infinity."
79. Hyperbolic Paraboloid.
Two bars equally spaced ; each turns on an arm perpendicular to itself,
and one arm swings on a pillar. These arms can be ranged in one plane, and
also turned end for end.
80. Hyperbolic Paraboloid generated by two systems of
right lines.
A skew quadrilateral with four equal sides, each pierced with the same
number of holes, equally spaced. The model exhibits the double generation
of the surface. The plane containing two of the sides turns about hinges
connecting it with the plane of the other two sides. By closing or opening
this hinge the paraboloid opens out or closes. When completely open, it
forms a plane divided into diamonds. When completely closed it again forms
a plane, but the division is no longer uniform. The strings then become
tangents to a plane parabola.
81. Hyperbolic Paraboloid.
A skew quadrilateral turning upon four hinges with parallel axes or pins.
The difference between this and the last is not in the kind of surface or
mode of generation, but in the manner of deforming the surface. In No. 80
the lengths of the strings alter ; while in this model they remain unaltered.
Moreover, although the surface flattens in two ways, yet in both ways the
strings become tangents to a plane parabola instead of parallel.
This model is well adapted for showing the leading sections of the solid
All sections parallel to the pins of the hinges are plane parabolas, which de-
generate into right lines when taken also parallel to the brass bars. Any
other sections, whether perpendicular to the hinges or inclined to them, give
hyperbolas, which degenerate into a pair of right lines when the plane of
section is a tangent to the surface.
It may b? worth while to remark that there is nothing absurd in the
tangent plane to a surface cutting that surface, as a student unaccustomed to
those subjects might at first think. On the contrary, when a surface is bent
one way in one direction, and the other way in the opposite direction, the
III. MODELS. 25
tangent plane must cut it. In this case, the plane passing through any two
intersecting strings is a tangent plane, and evidently cuts the surface along
each string.
If we imagine two planes parallel to the hinge pins, and each bisecting a
pair of opposite bars, we obtain the asymptotic planes of the paraboloid, each
of which is the assemblage of the asymptotic lines of the hyperbolas parallel
to the principal hyperbolic section. Their being asymptotic has reference to
these hyperbolas, and not to the parabolic character of the surface.
82. Hyperbolic Paraboloid.
A skew quadrilateral, with its opposite sides equal in length, and pierced
with holes at equal distances.
Nearly similar to No. 81, but differently mounted, and with the sides of
different lengths, the alternate sides only being equal. It is virtually a slightly
different aspect of the same surface as No. 81.
83. Hyperbolic Paraboloid.
A skew quadrilateral, with all its sides equal, and pierced holes at equal
distances.
As far as the curved surface is concerned, the same as No. 81. But the
hinges are altered in direction, and the model shows plans and elevations of
the right line generators of the surface. The rings also show parabolic sections
of the surface.
In consequence of the alteration in the direction of the hinges, the spacing
of the inclined bars, although equidistant, is at a different pitch from that of
the horizontal bars.
84. Hyperbolic Paraboloid.
A skew quadrilateral, with all its sides equal, and pierced with holes at equal
distances. It shows the plans and elevations of the right line generators.
The rings show the parabolas of the principal sections.
No. 83 represents one quarter of what is here shown. The upper corners
ofNos. 83 and 84 correspond; but the lower corner of the former corre-
sponds with the middle ring of the latter.
85. Hyperbolic Paraboloid.
A skew quadrilateral, with all its sides unequal. The surface is the same as
Nos. 83 and 84, but the proportions and the portion of the surface chosen for
representation are different. The quadrilateral base being irregular, the
strings alter in length as the surface is deformed by closing the hinges.
86. Hyperbolic Paraboloid.
Skew quadrilateral, pivoting on a single hinge. Intended to show the con-
struction of the parabola connecting two roads which meet obliquely. This
construction is used by engineers in laying out roads.
87. Hyperboloid of one Sheet.
Two rings or circles, in parallel planes, are pierced with equally spaced
holes. In a certain position the threads give, 1st, a cylinder; and 2ndly, a
cone.
The upper ring turns round a pin at its centre. In turning it, the cy Under
closes in and the cone opens out, each altering into a hyperboloid of one
sheet. We can go on turning the ring until these coincide in one hyperbo-
loid, of which we thus get both systems of generating lines.
if the rings are set on a slope the hyperboloid is elliptic. If the rings are
horizontal the hyperboloid is one of revolution.
26 SEQ. 2. GEOMETRY.
Sloping one ring, so as not to be parallel with the other, gives rise to some
curious ruled surfaces, but these are not in general hyperboloids.
88. Hyperboloid of one Sheet.
Two rings of different radius, in parallel planes, are divided into the same
number of equal parts. The smaller and upper ring turns round a pin at its
centre. In a particular position of the rings, the threads give two cones.
Turning the ring transforms each of the cones into a hyperboloid, and
when the two hyperboloids coincide, we get the two systems of right line
generators.
The same stand also has a model of a hyperboloid with only one set of
strings. By turning the upper ring either way it deforms into a cone ; in the
one case with its vertex between the rings, and in the other with its vertex a
a considerable height above the rings.
Both these can have their upper rings moved along the top bar so as
to incline the surfaces. We still get cones and hyperboloids, but it is only
when the rings are horizontal, and centre to centre, that we get surfaces of
revolution.
89. Hyperboloid of one Sheet, with its asymptotic cone.
90. Hyperboloid of one Sheet, with its asymptotic cone.
The tangent plane to the cone is also drawn. It meets the hyperboloid in
two parallel right lines.
One of these right lines is the line of contact of a hyperbolic paraboloid
with the hyperboloid, and the tangent plane is one of the director planes of
the paraboloid, both systems of generating lines of which are exhibited.
91. Hyperboloid of one Sheet.
A slight variation from No. 90. The paraboloid only shows one system of
right line generators, and the tangent plane is made by parallel instead of
radiating lines.
92. Hyperboloid of one Sheet, and its tangent para-
boloid.
This shows the transformation of a cylinder and its tangent plane into a
hyperboloid and its tangent paraboloid.
93. Conoid, with its director plane. The director curve is a
plane curve.
By shifting the position of the brasses the conoids deform into different
conoids or other allied surfaces.
94. Conoid, with a director cone. The director curve is of
double curvature.
By shifting the position of the brasses the conoids deform into different
conoids or other allied surfaces.
i
95. Conoid, showing both sheets of the surface.
By shifting the position of the brasses the conoids deform into different
conoids or other allied surfaces.
96. Conoids. Model showing the transformation of a cylinder
into a conoid and back again. Also model showing the trans-
formation of a cone into a conoid and back again. It is to
m. MODELS. 27
be noticed that the head lines of the two conoids, that is to say,
the right line in which the two sheets of each conoid meet, are
perpendicular to one another.
The transformation is effected by making the upper semicircle turn through
two right angles.
97. Conoids.
Intersection of two equal conoids having a common director plane. The
horizontal intersection is a plane ellipse.
98. Conoid, in contact with a hyperbolic paraboloid.
99. Conoids. Two equal circles in parallel planes, divided
equidistantly, are connected by threads, so as to form four surfaces.
A cylinder. A conoid.
A cone. A second conoid.
The director planes, as well as the head lines, of these conoids
are at right angles to one another.
100. Conoids.
Two equal circles in parallel planes are connected by threads so
as to form four surfaces.
A cylinder.
A cone.
A conoid.
A second conoid, with its director plane and line at right
angles to those of the former.
Same arrangement as No. 99, except that the lower ring is replaced by a
plane of section a little higher up. The section gives,
For the cone, a circle smaller than the upper ring.
For the cylinder, a circle of the same size as the upper ring.
For the conoids, two ellipses turned crosswise.
101. Model exhibiting the simultaneous transformation of a
conoid into a cylinder, a cylinder into a conoid, the paraboloid
touching the conoid into the tangent plane of a cylinder, and
the tangent plane of a cylinder into the tangent paraboloid of a
conoid, and reciprocally.
The changes may be arranged as follows :
From.
Conoid.
Tangent paraboloid.
Cylinder.
Tangent plane.
Into.
Cylinder.
Tangent plane.
Conoid.
Tangent paraboloid.
These changes are all effected simultaneously by one movement, which can
be reversed.
102. Model exhibiting the transformation, first, of a conoid
into a cylinder ; second, of the tangent paraboloid of the conoid
into the tangent plane of the cylinder.
28 SEC. 2. GEOMETRY.
1O3. Trench Skew Arch (biais passe).
The inner drum, of yellow thread, represents this surface. It
is a skew surface, with a right line director ; and its faces, the
planes of the two semicircles, are usually parallel, although the
model permits them to be placed obliquely to one another. The
horizontal line joining the centres of the two large semicircles is
the right line director.
The construction for any one of the generating lines is as follows : Draw
a plane through the right line director at any selected obliquity. It will, of
course, give the radii of the outside circles, and the line joining the points
at which it cuts the inside semicircles will be a generator of the surface.
This line will evidently pass through the director line, because it is in the
same plane with it.
In stone or brickwork, the sides of the voussoirs, will be given by the
auxiliary plane in question. When the openings are parallel the voussoir
joints are therefore plane, and the simplicity thus gained is the chief reason
for adopting this form of skew arch. It is usual to take the right line
direct or perpendicular to the openings, and symmetrical to them, that is to
say, passing through the middle point of the parallelogram of the springing
plane.
When the openings are not parallel the voussoir joints shown by the model
are deformed into hyberbolic paraboloids. This deformation is, however,
very slight, and in practical work would be avoided altogether by adhering to
tbe principle of drawing a plane througb the director line.
The opening of the voussoirs is usually determined by dividing the outer
semicircle into equal parts.
This form of arch is inconvenient when the obliquity and the length of
the barrel are excessive, for the generators are not generating lines of the
cylinder containing the opening semicircles, but chords of it, and, therefore,
at the middle, falling considerably inside it. The arch, therefore, droops in
the middle, and this would be ugly and inconvenient if the proportions were
excessive.
104. Staircase Vault for a square wall (vis St. Gilles carree).
105. Staircase Vault. Model for exhibiting some properties
of this ruled surface, by showing how it is obtained from the
deformation of a cylinder (douelle de la vis St. Gilles carree).
106. Cylinder with Helix and developable Helixoid.
The helix is simply a screw thread. The developable helixoid, shown by
the purple threads, is the surface swept out by the right line tangents of the
helix. If we consider that each gore can be turned a very little bit about
the thread which separates it from the next gore, we see that the surface can
be flattened out or developed into a plane, without any crumpling. This
happens because every two consecutive generating lines meet one another on
the helix. That is why its surface is called developable. Its section by a
horizontal plane is the involute of the circle.
The model allows the pitch of the helix to be shortened by lowering the
upper plate, and the cylinder can also be inclined. When oblique, however,
the curve which replaces the helix is not such a screw thread as can be turned
in the lathe.
III. MODELS. 29
107. Skew Helixoid.
This surface is described by a right line, which always passes through the
axis of a cylinder, and makes a constant angle with that axis. It also passes
through a helix or screw thread traced on the cylinder. The model only
shows the surface, not the cylinder. The section by a horizontal plane is the
spiral of Archimedes. It is the surface of what is known as the screw with
a triangular thread.
This is not the commonest form of the skew helixoid ; that is best seen on
the underside of a screw staircase, or on the driving face of a common screw-
propeller. In these, two generating lines are at right angles to the axis.
The surface may also be considered as generated by a line which makes a
constant angle with a given fixed line, and moves up that line, and at the
same time turns round it, at uniform rates.
108. Skew Surface with its tangent paraboloid, capable of
transformation into another skew surface while the paraboloid
deforms into a plane.
This is (for a certain position of the lower semicircle) a skew surface with
a director plane, the plane being vertical. The director carves are: one. of
them a circle divided equidistautly, the other a semicircle divided so as to
keep the strings parallel to the director plane.
109. Intersection of Two Cones having double contact
with one another, that is to say, having a pair of tangent planes
in common.
The consequence of their having double contact is that their curve of inter-
section breaks up into two plane ellipses.
The vertices of the cones slide along a rule which turns on a universal
joint. See also model No. 114.
110. Common Groin. Intersection of two cylinders having
a pair of common tangents. The model may be set square or
oblique.
111. Intersection of Two Cylinders, one piercing the
other so as to give two separate loops of intersection.
112. Intersection of Two Cylinders, having a common
tangent, so as to give a curve having a double point at the point
of contact.
113. Intersection of Two Cylinders, neither completely
piercing the other, so as to give only one loop of intersection.
114. Intersection of Two Cones, having double contact,
along a pair of plane ellipses.
115. Groin. Oblique intersection of two splayed vaults of the
same spring.
116. Pair of Intersecting Planes, which, by pulling the
brass ball so as to give simultaneous rotation to the two upper
rods, deform into paraboloids first, and then into planes described
by radiating strings.
30 SEC. 2. GEOMETRY.
117. Intersecting Cylinder and Plane. By pulling the
brass ball the head brasses rotate together, and the cylinder de-
forms into, first, a hyperboloid, and then a cone, while the plane
deforms into, first, a paraboloid, and then again into a plane with
radiating lines.
118. Fair of Intersecting Cylinders on circular bases.
By Dulling the brass ball the head brasses rotate together, and
the cylinders deform, first, into hyperboloids, and then into cones.
119. Pair of Intersecting Cylinders on irregular bases.
By pulling the brass ball the head brasses rotate together, and
the cylinders deform, becoming at last cones.
120. Groin.
Model showing the deformation of a common groin, both ob-
liquely, and by splaying the vaults. The model shows not only the
intersection, but the plans of the intersection and of the generating
lines.
121. Helix or Screw-thread.
Model showing the transformation of the right line genera-
tors of a right cylinder into screw threads of various pitch or
obliquity.
The pitch of a screw is the distance between two successive
turns, measured in a direction parallel to the axis. When this
distance is small, the screw is said to have a fine pitch ; when
great, a coarse or high pitch.
COLLECTION OF MODELS CONTRIBUTED BY THE LONDON
MATHEMATICAL SOCIETY.
123. Pliicker's Models (14) of certain quartic surfaces,
representing the equatorial form of complex surfaces.
London Mathematical Society.
At the meeting of the British Association at Nottingham, in 1866, Prof.
Pliicker read a paper on " Complexes of the Second Order." On this occasion
he showed a series of models constructed by Epkens, of Bonn, of which the
above are copies made for Dr. Hirst, and presented to the London Mathe-
matical Society.
The following is Prof. Cayley's description of the models, extracted from
Nos. 37 and 38 of the Mathematical Society's Proceedings, vol. iii., pp. 281-
285, supplemented by a description of models A, B, C, D, E, F, drawn up
by Prof. Henrici.
The Society possesses a series of 14 wooden models of surfaces, constructed
under the direction of the late Prof. Pliicker, in illustration of the theory
developed in his posthumous work " Neue Geometric des Raumes gegrvindet
" auf die Betrachtung der geraden Linie als Kaum-elemente," Leipzig, 1869.
III. MODELS. 31
These, all of them, represent, I believe, equatorial surfaces, viz., eight repre-
sent cases of the 78 forms of equatorial surfaces, " deren Breiten-Curven
" eine feste Axenrichtuug besitzen," vol. ii. pp. 352-363 ; the remaining
models, A, B, C, D, E, F, I have not completely identified. I propose to go
into the theory only so far as is required for the explanation of the models.
In a " complex," or triply infinite system of lines, there is, in any plane
whatever, a singly infinite system of lines enveloping a curve ; and if we
attend only to the curves the planes of which pass through a given fixed line,
the locus of these curves is a " complex surface." Similarly, there is through
any point whatever a single infinite series of lines generating a cone ; and if
we attend only to the cones which have their vertices in the given fixed line,
then the envelope of these cones is the same complex surface. In the case
considered of a complex of the second degree, the curves and cones are, each
of them, of the second order ; the fixed line is a double line on the surface,
so that (attending to the first mode of generation) the complete section by
any plane through the fixed line is made up of this line twice, and of a conic.
The surface is thus of the order 4 ; it is also of the class 4 ; the surface has,
in fact, the nodal line, and also 8 nodes (conical points), and we have thus
a reduction = 32 in the class of the surface.
In the particular case where the nodal line is at infinity, the complex
surface becomes an equatorial surface ; viz. (attending to the first mode of
generation), we have here a series of parallel planes each containing a conic,
and the locus of these conies is the equatorial surface.
It is convenient to remark that, taking a, b, //., to be homogeneous functions
of (r, w>) of the order 2 ; f, <jr, of the order 1 ; and c of the order (a constant) ;
then the equation of a complex surface is
y z 1 1=0;
y a h g
z k b f
1 9 f
and that, writing w?= 1, or considering a, h, b; f, y c, as functions of x of
the orders 2, 1, respectively, we have an equatorial surface.
A particular form of equatorial surface is thus, bcy~ + caz" + ab = Q, or
taking c= 1, this is fy/ 2 + a* 2 + a6 = 0, where a, b, are quadric functions of x.
The surface is still, in general, of the fourth order ; it may, however,
degenerate into a cubic surface, or even into a quadric surface ; the last case
is, however, excluded from the enumeration. The section by any plane
parallel to that of yz is a conic ; the section by the plane y = Q is made up of
the pair of lines a=0, and of the conic z 2 + &=0 ; that by the plane z=0 is
made up of the pair of lines 6 = 0, and of the conic ?/ 2 + a = ; the last-men-
tioned planes may be called the principal planes, and the conies contained in
them principal conies. The surface is thus the locus of a variable conic, the
plane of which is parallel to that of yz, and which has for its vertices the
intersections of its plane with the two pi'incipal conies respectively. And we
have thus the particular equatorial surfaces considered by Pliieker, vol. ii.
pp. 346-363 (as already mentioned), under the form
Ex- + 2U.r + C + For 2 2RrTl3 + l ''
and of which he enumerates 78 kinds, viz.: these are
1 to 17. Principal conies, each proper.
18 to 29. One of them a line-pair.
30 to 32. Each a line-pair.
33 to 39. Principal conies, each proper, but having a common point.
40 to 43. One of them a line-pair, its centre on the other principal conic.
44 to 61. One principal conic, a parabola.
32 SEC. 2. GEOMETKY.
62 to 73. One principal conic, a pair of parallel lines.
74 to 76. Principal conies, each a parabola.
77 and 78. Principal conies, one of them a parabola, the other a pair of
parallel lines.
Model 2. The form of the equation is here,
viz., the principal conies are one of them a hyperbola, the other imaginary ;
hence the generating conic has always two, and only two, real vertices, viz.,
it is always a hyperbola. There are no real lines.
Model 3. The form of the equation is
/ 2 [(;t- a) 2 + /8 2 ] 7 //2[(#_ a ')2 + 0/2-| ~
viz., the principal conies are each of them a hyperbola ; the generating conic
has four real vertices, viz., it is always an ellipse. There are no real lines.
Model 4. The form of the equation is
+ 1 = 0.
The principal conies are one of them an ellipse, the other imaginary ; for
values of x between y and 8, the variable conic has two real vertices, or it is
a hyperbola ; for any other values it is imaginary, so that the surface lies
wholly between the planes ^ = 7, a; = 5. The surface contains the real lines
y r=o, x = y, and y = Q, x = 5.
Model 9. The form of the equation is
/(*- 7 )(*-) + /' 2 (* /)<>- 80 +
where, say the values 7, 5, lie between the values y, 8', the principal conies
are each of them an ellipse, the vertices (on the axis or line ,y = 0, 2 = 0) of
the one ellipse lying between those of the other ellipse. The variable conic
for values of x between 7 and 5 has four real vertices, or it is an ellipse ; for
values beyond these limits, but within the limits 7', 8' say, from 7 to 7' and
from 8 to 8' there are two real vertices, or the conic is a hyperbola ; and
for values beyond the limits y, 8', the variable conic is imaginary.
There are four real lines (y = 0,z = y), (?/ = 0, x = 8), (z = Q, x = y r ), (2 = 0,
or = 8'). The surface consists of a central pillow-like portion, joined on by
two conical points to an upper portion, and by two conical points to an under
portion, the whole being included between the planes x = y, x = 8'.
Model 13. The form of the equation is
the values y, 8', lying between y, 8 ; the principal conies are one of them a
hyperbola, the other an ellipse, the vertices (on the axis or line z/ = 0, z = 0)
of the hyperbola lying between those of the ellipse. The variable conic, for
values of x between y f , 8', has two real vertices, or it is a hyperbola ; for
the values, say, from y to y, and 8' to 8, there are four real vertices, or
the conic is an ellipse ; for values beyond the limits y^ 8, there are two
real vertices, and the conic is a hyperbola. There are the four real lines
(# = 0, x=y\ (# = 0, x=8~), and (z=0, #=7'), (*=0, # = 8'). The surface
consists of eight portions joined to each other by eight conical points, but the
form can scarcely be explained by a description.
Model 32. The form of the equation is
r2
= 1
III. - MODELS. 33
riz.,the principal conies are each of them a line-pair, the variable conic is
always an ellipse.
There are the two real nodal lines (z/ = 0, #=7) and (2=0, #=/), each of
these being in the neighbourhood of the axis crunodal, and beyond certain
limits acnodal ; the surface is a scroll, being, in fact, the well-known surface
which is the boundary of a small circular pencil of rays obliquely reflected,
and consequently passing through two focal lines.
Model 34. The equation is
where x= Sis not intermediate between the values x=y and x=y ; say the
order is 8, 7, 7'. The surface is thus a cubic surface ; the principal conies
are ellipses, having on the axis a common vertex, at the point x=S, and the
remaining two vertices on the same side of the last-mentioned one. The
variable conic for values between 5 and 7 has four real vertices, or it is an
ellipse ; for values between 7 and 7' two real vertices, or it is a hyperbola ;
and for values beyond the limits 5, 7', it is imaginary. There are on the
surface the two real lines 0/ = 0, ^ = 7) and (z = 0, x = 7')- The surface
consists of a finite portion joined on by two conical points to the remaining
portion.
Model 40. The form of equation is
y 2 z 2
zV-7X*-5) + r*&=vy* +
The surface is thus a cubic surface ; the principal conies are, one of them
an ellipse, the other a pair of imaginary lines intersecting on the ellipse ; for
values of x between 7 and 5, the variable conic has thus two real vertices, and
it is a hyperbola ; for values beyond these limits it is imaginary, and the
whole surface is thus included between the planes #=7 and x=8. There are
the two real lines (y = 0, x = 7) and (2=0, x=5).
Taking / 2 =/ /2 = i } the surface is
y 2 2 2
Gr-7)(*-5) + (*=W 2 + l = (
which is a particular case of the parabolic cy elide.
The equatorial surfaces, not included in the preceding 78 cases, Pliicker
distinguishes (vol. ii. p. 363) as " gedrehte " or " tordirte," say, as twisted
equatorial surfaces, the equation of such a surface is
by 2 + 2hyz + az 2 + ab - A 2 =
where b = Fx 2 - 2R.r + B
A=K:r 2 Oar G (or in particular = O-r G).
Model A. is such a surface, being a twisted form of Model 9.
Model B. belongs to the case a = ; viz., the form of the equation is
The variable conic is a hyperbola, the direction of one of the asymptotes
being constant (vol. ii. p. 368).
There are, moreover, (p. 372) equatorial surfaces in which the variable conic
is always a parabola, and where there are on the surface four real or imaginary
singular lines.
In Model C the singular lines are all four real, but two of them coincide with
the nodal line at infinity. Consequently, the variable parabola has its axis in
a fixed direction. Its vertex moves along a hyperbola which has one asymp-
40075.
34 SEC. 2. GEOMETRY.
tote in that fixed direction. The other two singular lines are on opposite sides
of this asymptote and parallel to it. When the plane of the variable parabola
passes through one of these lines, the parameter vanishes and changes sign.
When it passes through the above-mentioned asymptote, the parabola, reduces
to the line at infinity and the plane becomes asymptotic to the surface. The
latter consists of four parts, two on opposite sides of the asymptotic plane
between this and one of the singular lines respectively, the other two extending
from the singular lines to infinity.
The remaining three models, D, E, F, represent twisted surfaces. Of the
four singular lines two are in each case imaginary. The remaining two are
real on the first, coincident on the second, and imaginary on the third.
Model D consists, therefore, of three, Model E of two, and Model F of one part.
The models are copies from some constructed by Epkens of Bonn. They
were presented to the London Mathematical Society by Dr. Hirst, F.ll.S.
They have been remounted under the direction of Prof. Henrici, by M. Nolet,
u student of University College, London.
Some account of complexes and complex surfaces will be found in Dr.
Salmon's Geometry of Three Dimensions (3rd edition, pp. 405, 493, 566, 570).
123a. Hough Model of Steiner's Surface.
Prof. Cayley.
Steiner's surface is the quartic surface represented by the equation
Vx+ \'y + Vz + \/w*=Q ; where the co-ordinates x, y, z, w, of a point are
proportional to arbitrary multiples of the perpendicular distances from four
given planes ; in the model, x, y, z, w are proportional to the perpendicular
distances from the faces of a regular tetrahedron, the co-ordinates being
positive for a point inside the tetrahedron.
The surface may be regarded as inscribed in the tetrahedron, touching each
face along the circle inscribed in the face. The general form is that of the
tetrahedron with its summits rounded off, and with the portions within the
inscribed circles scooped away down to the centre of the tetrahedron, in such
wise that the surface intersects itself along the lines drawn from the centre to
the mid-points of the sides (or, what is the same thing, the lines joining the
mid-points of opposite sides). The lines in question produced both ways to
infinity are nodal lines of the surface, but as regards the portions outside the
tetrahedron, they are acnodal lines, without any real sheet through them ; and
these portions of the lines are not represented in the model.
The sections by a plane parallel to a face of the tetrahedron are trinodal
quartics, which (as the position of the plane is varied) pass successively
through the forms :
1. Four acnodes.
2. Trigonoid, with three acnodes.
3. Tricuspidal.
4. Trifoliate, with three crunodes, cis-centric.
5. Do. with triple point at centre.
6. Do. with three crunodes, trans-centric.
7. Twice-repeated circle.
The three nodes are in each case the intersections of the plane by the nodal
lines, and the twice-repeated circle is the circle inscribed in the face of the
tetrahedron.
123b. Model of a Cubic Surface.
Prof. O. Henrici, F.R.S.
III. - MODELS. 35
The equation to this surface is xyz = k* (x + y + 2 I) 3 . There are 3 bi-
planar nodes as shown on the model. The 27 straight lines on the surface
are all real, but coincide 9 to each with the 3 black lines^ drawn on the model.
123c. Sylvester's Amphigenous Surface, a surface of
the ninth order. Prof. O. Henrici, F.R.S.
This surface is connected with the reality of the roots of equations of the
ninth degree.
123d. Model representing the Right Lines on a
Surface of the Third Class, having a tangent-plane touching
along a conic (the singularity dualistically corresponding to a
double-point of the second order).
Elling B. Hoist, Stipendiary of the University of
Christiania.
The model is composed of twenty-one wires, six of which, painted light
red, lie in the same plane and touch the conic in points painted dark red.
Through the fifteen points of intersection of these six lines the others,
painted white, pass, again intersecting three and three, and are the lines in
which the surface cuts itself. All points on these lines have therefore two
tangent-planes ; where the latter are imaginary the lines are black. The
black is in part laid on schematically, especially where the black part contains
the point at infinity. The parabolic curve consists of the conic aforesaid
and two species of cuspidal curves, viz. :
1. One curve passing the dark red points and having cusps in those six
limiting-points between black and white which are nearest to the conic, the
curve therefore having a zig-zag course.
2. Four closed branches having cusps in the other twelve limiting-points.
All these parabolic curves together separate ten distinct ellipsoidally
curved parts from the surface everywhere else hyperboloidally curved.
124. Models. A series illustrative of Pliicker's Researches
in Geometry of Three Dimensions. See explanation No. 123.
Prof. Hennessy, Dublin.
126. Model of the ruled cubic surface called the Cylindroid.
Dr. Robert S. Ball, LL.D., F.R.S.
This surface was discussed by Pliicker in connexion with the theory of
the linear-complex. The kinematical and physical significance of the sur-
face will be found in the "Theory of Screws." The equation of the surface
is z (x* + ?/ 2 ) '2mxy = O.
125. Diagrams (48) showing the Fundamental Principles
of the exhibitor's " Organic Geometry of Form."
Prof. Franz Tilser, Prague.
The above work demonstrates the necessity for a reform in geometry, and
furnishes the necessary basis for establishing a new system adapted to satisfy
the requirements of an exact science. To the above are added 7 " Paragram "
Tablets, representing in natural organic connexion a synopsis of the principal
elements to be observed in every graphical representation.
127. Models (6) illustrating the relative bases of Descriptive
Geometry and the Organic Geometry of Form.
Prof. Franz Tilser, Prague.
C 2
36 SEC. 2. GEOMETRY.
128. Drawings. A collection, executed by the Students of
the Bohemian Polytechnic Institute, illustrative of the instruction
received in the subject of Organic Geometry of Form.
Prof. Franz Tilscr, Prague.
129. Two specimens of Wire Stereometrical Models,
with letters on cork.
Prof. J. Joseph Oppcl, Frankfort-on- Maine.
ISO. Two specimens of Wire Trigonometrical Models,
with letters. Prof. J. Joseph Oppel, Frankfort-on- Maine.
131. Two specimens of Wooden Stereometrical Mo-
dels, with letters.
Prof. J. Joseph Oppel, Frankfort-on- Maine.
The auxiliary lines, diagonals, &c. are distinguished by wires of different
colours or thicknesses. They are in many cases movable, so that the perfect
figure can be constructed before the eyes of the pupil.
Auxiliary planes are also distinguished by their colour. The angular
points are provided with metal pins, to which letters on cork discs can be
attached, so as to be turned upright towards the observer.
These models have proved highly serviceable for instruction during the
past 20 years.
132. Large Model of an Ellipsoid, of white cardboard,
on a turned stand. Prof. Dr. A. Brill, Munich.
133. Cardboard Models of Surfaces of the second
order, on frames. Made up of circular sections. The sections
are attached to each other. Prof' Dr. A. Brill, Munich.
This collection of models consists of :
1. Ellipsoid having 20 circular sections.
2. Ellipsoid having 30 circular sections.
3. Hyperboloid of one sheet.
4. Hyperboloid of two sheets.
5. Elliptic Paraboloid.
6. Cone in two sheets.
7. Hyperbolic Paraboloid.
141. Series of Cardboard Models of Surfaces, of the
second order, in a cardboard box. The sections are not
attached to each other. Prof. Dr. A. Brill, Munich.
These models, Nos. 132, 133, 141, are distinguished from those in common
use by their mobility, by means of which each one represents not only a single
ellipsoid or hyperboloid, but a series of surfaces of one or the other kind.
For when the angle of inclination of the circular sections is altered, in a direc-
tion easily recognised by pressing or drawing out the model, there will be
obtained a simple but infinite system, the individual forms of which can be
converted from a flat figure through gradually-changing solid bodies to just
such another figure with a different relation of axes, without, however, losing
its properties.
III. MODELS. 37
The equations representing these systems of surfaces are in rectangular
co-ordinates :
For central surfaces :
^ . v 2 /I 1\ . * 2
a 2 cos-V \a hi ksm^
For the elliptic paraboloid :
For the hyperbolic paraboloid :
a 2 cos 2 ^ ~ a^in 2 ^ ~ It =
WTiere 2^ is the inclination of the circular sections, and a and k are real con-
stants. From the first equation it appears that among the series of ellipsoids
there will always be a sphere.
142. Model of a Surface of the third order, made in
plaster of Paris, with 27 real right lines.
Prof. Dr. Christian Wiener, Carlsruhe.
The construction of the model is described on a placard fixed to the model.
143. Model of the same surface of the third order,
in discs of card-board, with 27 real right lines.
Prof. Dr. Christian Wiener, Carlsruhe.
144. Poinsot's Star Polyhedra. Dr. M. Doll, Carlsruhe.
These models show the star dodecahedron with 20 points, the star dode-
cahedron with 12 points, the icosahedron, and dodecahedron.
148. Curvilinear central surface of the Ellipsoid, in
four separate pieces. Proportions of the axes of the ellipsoid,
3:4:5. Ludwig Lohde, Berlin.
149. Dupin's Cyclide, according to the calculation of Pro-
fessor Kummer, at Berlin. Model 0*094 m. diameter.
(Sec Monatsbericht der Akademie der Wissenschaf ten zu Berlin,
1863, pp. 328 and 336.) Ludwig Lohde, Berlin.
150. Hummer's Cyclide. Ludwig Lohde, Berlin.
151. Minimum-surface in a recurring number of tetra-
hedral surfaces.
(Submitted to the Berlin Academy of Sciences by Professor
Kummer, on the 6th April 1865.) Ludwig Lohde, Berlin.
152. Maximum of Attraction of the Earth's Surface.
Ludwig Lohde, Berlin.
153. Geometric Body, executed in plaster of Paris, called
"Podoid"; a transcendental curved surface, which Js deter-
mined by the variable parallel co-ordinates p., <j>, and K, whose
equation represents the elliptic function
f* ^
38 SEC. 2. GEOMETRY.
The construction in plaster of Paris embraces the limits
K= -f 1 to K= 1 and <p0 to <=7r.
Prof. Dr. Edward Heis, Munster, Westphalia.
154. The same Fodoid 9 executed on a smaller scale, embracing
the limits K= + ! to K= l, 0>=0 to <p=2v.
Prof. Dr. Edward ffeis, Miinster, Westphalia.
155. Hight double circular Cone, of white wood.
Prof. Borchardt, Berlin.
On the one sheet of the double cone 'are shown, by sections, the circle,
the ellipse, and the hyperbola ; on the other, the circle, the parabola, and
the corresponding hyperbola. The model takes to pieces at the sections.
156. Elliptic Cone, of white and brown wood.
Prof. Borchardt, Berlin.
On the oblique cone are shown the two circular sections, and the elliptic,
hyperbolic, and parabolic sections. At the sections of the ellipse and parabola
the model takes to pieces ; the other sections are shown by the lines defined
by the dark and light wood.
157. Huled Surface of the fourth degree.
Prof. Borcha.rdt, Berlin.
This model represents a surface of the fourth order determined by the
equation
3* 2 8g =1
(2-0)2 ( + o) 2
The surface has two double right lines, between which lies a finite sheet
of the surface as shown on the model, whilst beyond each double right line
there extends a. second and third infinite sheet of the surface. Every hori-
zontal section of the surface is an ellipse. Of these are shown the circular
section corresponding to zQ, and the two ellipses corresponding to z = a
The model can be taken to pieces at each of these sections.
158. Bectangular Parallelepiped, intersected by a skew
surface. Prof. Borchardf, Berlin.
159. Bight Circular Cylinder, with spiral surface inter-
secting it. Prof Borchardf, Berlin.
These five models, Nos. 155-159, were executed by the late Ferd. Engel,
known from the drawings, which he has furnished to Pro/. Schellbach's
" Darstellende Optik."
160. String Model, representing a hyperboloid of one sheet.
On it are shown the principal ellipse, the asymptotic cone, and a
tangential surface, in threads of different colours.
Dr. Wiccke, Casscl.
This model represents by means of strings (kept tight by springs) of
different colours the hyperboloid of one sheet and its principal auxiliary-
surfaces. The two sides of the surface are shown by the green and red strings
respectively ; the principal ellipse is given by the points at which the strings
pass through the network stretched on the frame ; the asymptotic cone is
shown by yellow, and a tangent plane by white strings.
IV. DRAWINGS. 39
161. Model iii plaster of Vans, representing the eighth part
of the former (No. 160) with a developable normal surface, lines of
curvature, and edge of regression. Dr. Wiccke, Cassel.
This plaster model represents the eighth part of the surface of an hyper-
bolokl of one sheet ; it is constructed on the principal ellipse, and shows
the principal axes. It is also attempted to demonstrate on this hyperboloid
the lines of curvature of the first and second kind, first investigated byMonge.
On this account the hyperboloid is bounded on the side opposite to the
principal ellipse by a normal surface of which the directrix is one of the
lines of curvature of the first kind. The normals are drawn in this normal
surface, and produced to meet in the edge of regression,' which with two of the
normals will then become the boundaries of the normal surface.
161a. Collection of 45 geometrical solids in cut crystal, for
purposes of demonstration. Madame Wentzel.
162. Intuitive Method of Projection, by movable planes.
Cardboard models (19), practically illustrating problems of space.
Frerc Memoir e Piron.
162a. Open Frames containing Photographs for teaching
by projection. J. and A. Molteni, Paris.
162b. Projection Apparatus, polyorama for superposed
images. J. and A. Molteni, Paris.
IV. REPRESENTATION OF FIGURES IN SPACE BY
MEANS OF DRAWINGS ON A PLANE.
163. Diagrams and Models, illustrative of Descriptive
Geometry, executed by the Freres de la Doctrine Chretienne, of
Paris. Prof. Piaot, Dublin.
164. Drawings, executed in the college by the students,
showing the nature of the courses of Descriptive Geometry
and engineering. Prof. Pigot, Dublin.
165. Specimens of a series of simple folding models for
illustrating the various propositions in Descriptive Geometry.
Prof. Osborne Reynolds.
These are specimens of a series of models designed for illustrating the
various propositions in descriptive geometry. They are especially designed
for lecturing purposes, for which their simple construction, and the capability
which they possess of folding into small compass, well adapts them.
These models contain a complete drawing for each proposition. The hori-
zontal and vertical planes are hinged together, so that they can be folded
40 SEC. 2. GEOMETRY.
flat, and the Hues, planes, and surfaces are represented by coloured strings,
which assume their positions when the planes are at right angles.
1. Illustrating the relation between the projections, traces, directions, and
lengths of straight lines.
2. Illustrating the relation between the traces of planes, their inclinations,
and intersections.
3. Illustrating the relation between the projections of a line and the traces
of a plane ; also the normal to a plane.
4. Illustrating the relation between the projections of lines and the angles
between them.
5. Illustrating the relation between the traces of a cone and the traces of
its tangent plane, and hence the method of drawing a plane having a
given inclination.
6. Model, capable of opening out flat, so as to show how the horizontal and
vertical planes may be represented on a drawing^
166. Stereoscopic Figures, for demonstration and use in
the study of stereometry and spherical irigonometry. Edited
by Julius Schlotke. L. Friederichsen and Co., Hamburg.
166a. Stereograms of the Lines of Curvature of
Surfaces. Drawn by the exhibitor. Prof. J. Clerk Maxwell.
Lines of curvature of the cy elide of Dupiu (4).
Curves on a sphere (4) :
a Two systems of orthogonal circles.
/J Concyclic spherical ellipses. (This represents a spherical har-
monic of the second degree.)
7 Confocal spherical ellipses.
5 The projections of a spherical ellipse on the three principal
planes.
Quadric surfaces (4) :
Elliptic paraboloid, hyperbolic paraboloid, ellipsoid, and the surface
of centres of ellipsoid.
FresnePs wave surface (3):
The lines are in the direction of the vibrations of the two polarized
rays.
Steiner's surface (2).
Twisted cubics (2) :
tx a sin 26 (vertical).
Curves y = b sin 30 (horizontal).
[ z = c cos 50 (perpendicular to paper).
f x a sin 29.
\ y b sii
Curve < y = b sin 30.
[2 = c sin 70.
Icosahedrou in octahedron.
22 in all.
166b. Heal Image Stereoscope for showing the above.
Prof. "Clerk Maxwell.
The observer places his eyes about two feet from the large lens, and sees
the united real images of the figures at or near the surface of the lens.
IV. DRAWINGS. 41
167. The principal Problems of Descriptive Geo-
metry, represented by stereoscopic figures, by Julius Schlotke.
L. Friederichscn and Co., Hamburg.
168. Stereoscopic representation of a number of the most
important crystals, their combinations, &c., by Julius Schlotke.
L. Friederichsen and Co., Hamburg.
f? The stereoscopic figures of Schlotke are as yet the only ones of their kind
in use for illustrating instruction in descriptive geometry and crystallography,
in polytechnic and other higher educational institutions, where they are much
appreciated.
More particularly the division of crystallography is recommended, as it
renders unnecessary the usual expensive models, and, better than those
models, demonstrates the combinations and growth of crystals.
A stereoscopic apparatus is placed near the objects.
42
SECTION 3. MEASUREMENT.
WEST GALLERY, GROUND FLOOR, ROOMS H. K.
ISPECIAL COLLECTIONS.
COLLECTION OF STANDARD MEASURING APPARATUS CONTRIBUTED
BY THE STANDARDS DEPARTMENT OF THE BOARD OF TRADE.
A. Comparing Apparatus, Sf-c.for Standard Weights and
Measures.
169. Comparing Apparatus for End-Standards of length.
Used by Mr. Sheepshanks in the work of the Commission for
Restoration of the Imperial Standards, 1844-1850. Constructed by
Troughton and Simms.
The standard, and compared end-bars are placed successively on the V
supports, with one defining end in contact with the left hand stud and the
other defining end with the suspended gravity-piece interposed between it
and the screw on the right hand. The micrometer screw is to be gently
pressed forward until it just holds up the gravity piece in position, thus
ensuring constant pressure for each observation. The readings of the micro-
meter being taken, the difference of the two readings shows the difference in
length of the two end bars to less than O'OOOl inch, which is the value of
one division of the micrometer.
To obtain results with scientific precision the temperature of the measuring
axis of each bar during the comparison should be known, as well as its rate of
expansion. The temperature and length of the bar connecting the stud and
gravity piece and of the metal of the apparatus should also be constant.
170. Two Lever Frames, with rollers for supporting stand-
ard bars. Such lever frames are used for supporting all the Im-
perial Standard yards made by the Commission for restoring the
Standards. Constructed by Troughton and Simms.
Each bar is supported on the eight rollers of the two lever-frames, which
are placed symmetrically under the bar, so that the upward pressure of each
of the eight different rollers is necessarily equal, and the length between the
defining points of the bar is not altered by its flexure. Equal intervals of
length of bar
supports = . > where n is the number of supports.
171. Double Micrometer Microscope for comparing the
smaller subdivisions of standards of length. Constructed by
Troughton and Simms.
It has a movable eye-piece with a double lens, sliding upon a horizontal
plate, and two micrometers ; and has two object-glasses, each with a double
I. SPECIAL COLLECTIONS. 43
lens, sliding on a horizontal plate parallel to the other plate. The measuring
field is about two centimetres in extent, or a little less than 1 inch. Value
of one division of each micrometer = '00003097 inch, or 0'0007866 milli-
metres.
172. Apparatus for determining the Expansion of
Standard Bars. Constructed by Troughton and Simms.
The trough containing the steel bar with projecting points, distant 1 yard
and 1 metre respectively, is filled with melting ice to secure constant length
at the temperature of C. The standard bar is placed in the lower trough,
with two standard thermometers, and is raised gently against the points. Their
impression shows the constant length on the bar at its noted temperature in
ordinary air. Next fill the lower trough with melting ice, and take impressions
to show the constant length on the bar when at C. Then fill the lower
trough with water, and raise to boiling point, or other less high temperature,
by the heat from the gas jets underneath, and take impressions to show the
constant length on the bar when at 100 C., &c. From the difference of
these lengths accurately measured under micrometer microscopes, the rate of
expansion of the bar is deduced.
173. Large Callipers for measuring diameter and depth of
cylindrical or other measures. Constructed by Troughton and
Simms.
These are made on the same principle as the instruments used for measuring
shot and the bore of guns at Woolwich. They measure diameters up to
24 inches and within O'OOl inch by the aid of a vernier.
174. Model of Sub-divided Yard with comparing appa-
ratus, for Ihe use of local inspectors of weights and measures.
Constructed by Troughton and Simms.
The tested yard measure is placed with its zero defining line immediately
under that of the standard. By running the eye-piece along the upper guide
bar, each defining line is accurately compared and differences determined to
less than O'Ol inch by means of the small supplementary sub-divided inch
measure placed also under the eye-piece. This apparatus is described and
illustrated in Appendix III., 7th Annual Report of Warden of the Standards,
1873.
175. Spherometer for measuring spherical curves, with true
gun-metal plane. Used for measuring the flexure of the middle
of the glass disc placed upon the Imperial Standard bushel. Con-
structed by Troughton and Simms.
When the horizontal plane is made to rest with its three triangular flattened
points upon the true plane, the central screw with its micrometer head is
accurately adjusted in the same plane, and its reading noted. By substituting
for the plane the surface to be tested, its convexity or concavity is determined
from the difference of the reading of the micrometer, either or +. Value
of one revolution of the screw = 0' 01 inch, and of one division of the mi-
crometer=0 % 0001 inch. By interposing a bright beam of light between the
point of the screw and the surface tested, and by estimation of 0' 1 division,
accurate measurements have been made to 0' 00001 inch. This instrument
is described in Appendix X., 6th Annual Report of Warden of the Standards,
1872.
44 SEC. 3. MEASUREMENT.
176. Cathetometer for vertical measurements. Constructed
by Troughton and Simms.
For example, for accurately reading a barometer or manometer: place
the cathetometer at a convenient distance, and adjust the cross wire of the
upper telescope to the level of the mercury in the glass tube, and that of the
lower telescope to the level of the mercury in the reservoir. The difference
of the two readings on the graduated scale of 42 inches gives the length of
the column of mercury to 0' 001 inch, by aid of the vernier.
177. Stereometer for ascertaining the density of bodies by
determining their volume. Constructed by Troughton and Simms.
This instrument was invented by M. Say ( Annales de Chimie,t. xxiii. p. 1 ,1 797),
for determining the specific gravity of gunpowder, and was used with some
improvements by Professor W. H. Miller (See Phil. Trans. 1856, part hi. p. 800.)
for determining the density of the platinum Kilogramme des Archives, during
his work of restoring the imperial standard pound. The solid body tested is
placed in the receiver communicating with the upper end of a vertical glass
tube, the lower end of which communicates with that of a second glass tube
having its upper end open to the air. The body should nearly fill the receiver,
which is screwed up air-tight in its place. Mercury is poured into the second
tube, and can be discharged by a stopcock at its lower end. Differences in
the relative height of the mercury in the two tubes are noted by means of the
cathetometer, as indicating the volume of compressed air under the two condi-
tions, when the body is in the receiver and when it is removed. The volume
of the body is deduced from the volume, of the mercury contained in the
tube between the different heights noted.
178. Balance of new construction oscillating with steel
springs. This has been recently constructed by Oertling from a
design of Mr. Ar tings tall.
Its principle is, that, instead of the beam and pans being suspended on
knife-edges, thin elastic steel springs are used, and adjustments of knife
edges from time to time are thus avoided. It is similar in construction to
Steinheil's silk ribbon balance. Its advantages as a balance for weighings,
where extreme scientific accuracy is not required, consist in its simplicity and
durability ; but it appears to be wanting in the sensibility and stability re-
quisite for a balance of precision.
179. Model Kit of Apparatus for Local Inspectors of
Weights and Measures. Constructed by Oertling.
This portable collection of all the necessary apparatus for comparing
imperial weights and measures has been taken from the Necessaire des
Verificaleurs, employed in France for verifying metric weights and measures,
with a view to its adoption in this country. It includes a Septimal Balance
by means of which a weight of 56 Ibs. is compared against 8 Ibs., the sum of
the standard weights contained in the kit.
ISO. Experimental Gasholder for determining the internal
temperature. Constructed by Messrs. Wright & Co.
By raising and lowering the bulb of the thermometers, the tubes of which
are made to slide through the top of the gasholder, the temperature of the
gas or air at various heights inside the bell can be read off through the glass
side, and the mean temperature determined.
I. SPECIAL COLLECTIONS. 45
181. King's Pressure Gauge, showing mechanical pressure
of gas or air. Constructed by Mr. Sugg.
Standards Department, Board of Trade.
The amount of the mechanical pressure of gas or air contained in a gas-
holder is shown by this pressure gauge, when it is put in communication
with the gasholder by an air-tight tube. The surface of the water in the
cistern of the pressure gauge is depressed by the force of the gas or air, and
alters the level of a metal cup floating on it. A cord is attached to the float,
and passes over a pulley, the spindle of which, aided by friction rollers,
carries a pointer moving on a graduated dial, and thus indicates the amount
of pressure in huudredths of an inch.
Specimens of Standard Weights and Measures.
182. Copy of Standard Weight, 112 Ibs., of Queen
Elizabeth.
One of two similar bronze weights deposited in one of the old Treasuries of
the Exchequer, and fully described in App. IV. to the 7th Annual Report of
the Warden of the Standards.
183. Gilt Steel Yard, line measure, of the same form as the
imperial standard yard. Constructed by Troughton and Simms.
Well-holes are cut down to the mid-depth of the bar, where the defining
lines are cut upon gold studs, thus ( V ! ; i the measure being taken
at the middle portion of the central transverse line, intercepted between the
two longitudinal lines. These lines, including the two transverse guide lines,
one on each side of the defining Hue, are 0*01 inch apart.
184. Steel Yard End Measure, showing the form of end-
standard yard adopted by the Standards Commission. Con-
structed by Troughton and Simms.
The form of the defining ends is that of a spherical surface, whose centre is
the centre of the division-line at the middle of the bar's length. The material
of the defining end is a highly polished plug of agate, shrunk into a slightly
conical hole at the end of the steel bar.
185. Steel Foot End-Measure. Constructed by Troughton
and Simms.
186. Two Steel 6-inch End-Measures, one finished and
one unfinished. Constructed by Troughton and Simms.
187. lO-Poot Measuring Rod, of pine wood, bound with
brass. Constructed by Troughton and Simms.
188. 3-Foot Measuring Bod, of pine wood, bound with
brass. Constructed by Troughton and Simms.
46 SEC. 3. MEASUREMENT.
189. 1 Ib. Avoirdupois Weight, of gun-metal, electro-
plated with nickel.
Constructed as an experiment of coating brass or bronze with unoxidisable
metal. Oxidation, however, is found to occur at points on the surface of the
bronze under the nickel coating.
190. 1 Kilogram Weight, of gun-metal, nickel-plated.
191. Set of Glass Avoirdupois Weights, from 7 Ibs. to
1 oz ; , made experimentally of green bottle glass, not subject to
hydroscopic influences. The larger weights adjusted with lead
shot.
192. Set of Metric Weights, from 1,000 grammes to
] gramme. Constructed by Salleron, Paris, of opaque glass,
adjusted with mercury to the density of brass weights, and her-
metically sealed.
193. Specimen of an Enamelled Iron Weight of
56 Ibs*, made to resist oxidation, by De Grave, Short, and Co.
194. Specimen of a Patent Brass-cased Iron Weight
of 14 Ibs.
195. Section of a Patent Brass-cased Iron Weight
of 14 Ibs., showing mode of construction.
196. Copy of Standard Cubic Foot nickel-plated, with
filling apparatus. Constructed by G. Glover & Co.
This is a copy of the standard cubic foot bottle, the primary unit from which
the gas-measuring standards were derived. It was verified by weighing its con-
tents of distilled water = 62'321 pounds avoirdupois, according to Sir G. Shuck-
burgh's determination of the weight of a cubic inch of water. It is used as a
direct transferrer of a cubic foot of gas or air, which is driven out from it
by raising the cistern and thus introducing water from underneath up to the
defining line of a cubic foot. By this arrangement, the nearly undisturbed
surface of the water is carried upwards and gradually through the entire
height of the bottle, without risk of forming air bubbles.
197. Copy of five cubic feet Gas-measuring Standard,
made of anti-corrosive metal, by G. Glover and Co., with scale of
capacity graduated in feet and minute fractional parts.
The bell is equipoised when at various depths of its immersion in the water
of the cistern by a balance, a portion of which hangs from a cord working in
a groove in the circumference of a cycloidal wheel, and attached to the axis
of the wheel from which the bell is suspended.
198. Copy of a Standard Test Dry Gas Meter, with
testing table. Constructed by G. Glover & Co.
Such test gas meters are authorised to be used for testing stationary meters,
where the larger gas measuring standards cannot conveniently be used. The
accompanying testing table shows it fitted with thermometers and pressure
gauges, and with stand pipes for outlet and inlet communications.
I. SPECIAL COLLECTIONS. 47
199. Model of a Petroleum Testing Apparatus, for ascer-
taining the temperature at which its inflammable vapour ignites.
Designed by T. W. Keates, Ksq., and proposed as a standard for use
in accordance with authoritative uniform regulations. Constructed
by How & Co.
200. Brass Scale of 41 inches, divided into tenths, and of a
metre divided into millimetres ; both scales at 62 Fahr. Con-
structed by Dollond, tind now the property of Mr. Petrie.
This possesses some scientific interest, having been compared several times
with Shuckburgh's scale by Capt. Kater. He found in 1830, and again in
1831, that 36 inches of the scale = 35' 99893 inches of the imperial
standard yard, afterwards destroyed in 1834; and assuming the scale of
inches to be perfectly correct, that the metre = 39 '37045 inches.
Compared at the Standards Office in February 187 6, with the bronze official
yard, which has a standard metre at C. marked on the same bar. From the
mean of six comparisons, 36 inches of the scale = 35 '99961 inches of the
new imperial standard yard, and the metre = 0*999684 metre, being 0'316
millimetre less than the Metre, dcs Archives at the normal temperature
of C.
223b. Fraudulent Balance, seized from a butcher's shop
by an inspector of weights and measures.
Standards Department, Board of Trade.
An illustration of the principle of the balance. One of the suspending
hooks of an ordinary equal-armed balance is bent outwards thus lengthening
that arm of the beam, and enabling the butcher to make about 14 oz. of meat
counterbalance a 1 Ib. weight on the other end of the beam.
SET OF OLD STANDARD MEASURES LENT BY THE MAYOR AND
CORPORATION OF THE CITY OF WINCHESTER.
201. Very old Steelyard Weight, date unknown. Found
at Hyde Abbey, Winchester.
202. Set of Standard Troy Weights, from 256 oz. to
1 oz., of Queen Elizabeth. Dated 1588, being the year in which
she granted a charter to the city.
203. Set of Standard Weights (avoirdupois), 56 Ibs., 7 Ibs.,
8 Ibs., 2 Ibs., 1 Ib., of Queen Elizabeth, dated 1588, being the year
in which she granted a charter to the city. From the Muniment
Room, Winchester.
204. Standard Weights (56 Ibs., 28 Ibs., 14 Ibs., and 7 Ibs.).
Supposed to be of the date of Edward III. From the Muniment
Room, Winchester.
205. Standard Yard Measure. Henry VII. From the
Muniment Room, Winchester.
206. Standard Quart and Pint of William III. Dated
1700. From the Muniment Room, Winchester.
48 SEC. 3. - MEASUREMENT.
207. Standard Gallon, Quart, and Pint of Queen
Elizabeth, dated 1601. From the Muniment Room, Winchester.
208. Standard Winchester Bushel, given to the Cor-
poration by Henry VII. in the year 1487.
209. Standard Winchester Gallon, given to the Cor-
poration by Henry VII., in the year 1487.
SET OF MEASURING INSTRUMENTS CONTRIBUTED BY SIR J. WHIT-
WORTH, BART., D.C.L., F.R.S.
217. True Planes. The true plane is the foundation and
source of all truth in mechanism.
The patent hexagonal surface plate is constructed so as to be supported and
suspended from three points, and remains true in either position. The original
true planes first exhibited by Sir Joseph Whitworth at the meeting of the
British Association at Glasgow, in 1840, were rectangular, and were ribbed,
so as to allow of their being supported on three points ; but when large rect-
angular surface plates were suspended from the two handles a perceptible
alteration took place, and they were no longer as true as when supported on
the three points.
212. Whitworth's Workshop Measuring Machine, for
making difference gauges from correct cylindrical standards of
size.
One division of the micrometer wheel represents l6 ^ 00 of an inch, one
quarter of a division, viz., ?0 -^ 00 of an inch can be distinctly felt and gauged.
No proper size of bearing can be made for an axle to work in without
having a difference gauge of such size as experience has proved to be best.
214. External and Internal Standard Cylinder Gauge,
1 inch in diameter.
The standard gauges are usually made from y^th to 2 inches diameter, but
they are also made for larger diameters.
They are a necessary adjunct to the workshop measuring machine when
making difference gauges.
21O. Box of Standard Lengths, of end measure, 1 inch to
12 inches.
Either these standard lengths of end measure or the cylindrical standard
gauges are used for adjusting the workshop measuring machine ; for large
dimensions these are preferable.
213. Box of Cylindrical External and Internal Dif-
ference Gauges, differing by ^Vo^ 1 of an inch in diameter.
By means of these a workman can feel his way step by step and so make
the bore of any number of barrels or tubes exactly the same diameter. They
illustrate the importance of small differences in size ; while one fits, another
3-jJ;-^ of an inch less in diameter appears not to fit at all.
A tight fit is not a proper fit, there must be a certain difference in diameter
between an axle and the bearing in which it has to work ; what the difference
should be depends on a variety of circumstances which experience alone can
determine.
I. SPECIAL COLLECTIONS. 49
213a. Ten Standard Plat Surface Gauges, from ^th of
an inch to T ^th of an inch varying xoV^th of an inch.
They are standards for the thickness of sheet metal and the diameter of
small wire ; they serve for the correction of the wire gauge.
t Cylindrical standards are not made less than -j\jth of an inch in diameter.
216. Standard Screw Gauge of Whit worth thread.
This gauge is to show the form of the Whitworth standard thread. The
two cylindrical parts give the exact diameter of the top and the bottom of
the screw threads in universal use ; and the angle of the thread is 55, and
is rounded off th of its depth.
211. Millionth Measuring Machine.
The screw of this machine has 20 threads to the inch, the screw wheel 200
teeth, and the micrometer wheel is divided into 250, therefore each division
represents the one-millionth of an inch.
TJie end of the fast headstock and the end of the movable headstock are
true planes parallel to each other ; the ends of the piece to be measured
must also be parallel true planes ; the feeling piece is a piece of steel about
T %ths thick, its sides being parallel true planes, and it is introduced between
the standard to be measured and the true plane at the end of the fast head-
stock ; when the proper adjustment has been made the movement of the
micrometer wheel one division, viz., one millionth of an inch, will cause the
feeling piece to be suspended friction overcoming gravity.
The power of measurement and the true plane are the two great elements
in practical mechanics.
An idea may be formed of the millionth of an inch, from the fact that
if a sheet of foreign letter paper were divided into 4,000 thicknesses, each
thickness would represent the millionth of an inch.
APPARATUS USED BY DR. JOULE, F.R.S., FOR ASCERTAINING THE
MECHANICAL EQUIVALENT OF HEAT.
218. Revolving Electro-magnet, used in 1843 for ascer-
taining the Mechanical equivalent of Heat.
Part of the apparatus used in 1843 for the determination of the mechanical
equivalent of heat : viz., a revolving piece, holding a glass tube filled with
water, and containing an electro-magnet. This worked between the poles of
a powerful magnet ; and the heat evolved by the rotating electro-magnet was
measured by the rise of temperature of the water. In this manner the quan-
tity of heat lost by the circuit was ascertained when the machine worked as
an engine ; and, on the other hand, the quantity of heat produced when work
was done on the machine was also measured. 833 ft. Ibs. was the mechanical
equivalent of a degree Fahr. in 1 Ib. of water, as determined by these first
experiments.
219. Calorimeter, containing a revolving agitator. This
was employed in the experiments on the heat evolved by the
friction of water, made in 1849. The equivalent arrived at was
772 ft. Ib.
40075. D
50 SEC. 3. MEASUREMENT.
220. Cast-iron Vessel, containing Friction Disk, to
revolve under mercury. Used in 1 849 to determine the mecha-
nical equivalent of heat by the, friction of cast-iron against cast-
iron. The equivalent arrived at was 775 ft. Ib.
221. Electro-magnet consisting of a broad plate" of half-
inch iron, .having a bundle of copper wires coiled round it. Em-
ployed in the first determination of the mechanical equivalent of
heat.
222. Apparatus for determining the temperature of water
at its maximum density.
Used in the experiments on atomic volume and specific gravity by Play fair
and Joule (Memoirs of the Chemical Society, vol. iii., 1846). It consists of
two tall vessels, connected together by a stop-cock at the bottom, and a trough
at the top. A minute difference of the temperature of the water in one of the
vessels from that of the maximum density, determines a flow through the
trough to the vessel still nearer the temperature of maximum density.
The temperature of water at maximum density was thus shown to be 39 1 .
223. Paddle Apparatus, by means of which Dr. Joule
determined the dynamical equivalent of heat. Described in Philo-
sophical Transactions for 1850. page 65. Sir William Thomson.
II. MEASUREMENT OF LENGTH.
A, STANDARD SCALES.
223a. Model of an Ancient Egyptian Standard Cubit,
dated in the reign of King H^rus, 9th Pharaoh of the 18th dynasty
(1657 B.C.). Mrs. Chisholm.
The ancient standard measure, of which this is a copy, was found in the
ruins of Memphis, and is now in the Royal Museum at Turin. It is a Royal
cubit of seven palms : or 28 digits. The total length of this end standard
measure is 523 5 millimetres or 20 6 inches, and agrees very nearly with that
of several other ancient Pharaonic cubits still existing, as well as with the
length of the Royal cubit as deduced by Sir Isaac Newton from the dimensions
of the Great Pyramid, the mean length being 525 millimetres. The original
natural cubit, or cubit of a man, of 6 palms is also marked upon this measure,
being equal to 463 millimetres or 18-24 inches, and also the ancient Egyptian
foot of 16 digits, or f of the natural cubit, and equal to 12' 16 inches, or 1-013
English foot. The great span of 14 digits and the small span of 12 digits are
also marked.
227. Standard Scale , in porcelain, showing the relations of
modern British and ancient Great Pyramid inches.
Prof. Piazzi Smyth.
This scale was prepared to order by M. Casella, of London. It exhibits
side by side 25 modern British inches and the same number of ancient Great
Pyramid inches, similarly subdivided.
II. LENGTH. 51
The .0 divisions of both sets of inches coincide at the left hand exactly,
but from thence the gradual growth of the difference of 0*001 of an inch per
inch in favour of the Great Pyramid scale may be traced, until at the 25th
inch the difference amounts to 0-025 of the British inch. At that point,
however, it is to be noted that 25 Great Pyramid inches are just one 10
millionth of the earth's semi-axis of rotation, or the nearest earth commensur-
able and most scientific unit ever yet proposed as a standard of length.
228. Standard rive-Inch Scale, in smoky agate, for micro-
scope sight. Prof' Piazzi Smyth.
The material, which came from Brazil, and was worked up and divided
to order by M. Jules Salleron, Paris, was chosen as being a natural product
of almost infinite age, and therefore settled condition, harder than steel and
utterly unoxidisable. The particular standard length adopted is shown for
microscopic sight. It depends not on one pair only, but on 20 available pairs
- of lines, each five inches apart, drawn with a fine diamond point, and is in-
tended to typify both one fifth of the sacred cubit of Israel and one 50
millionth of the earth's semi-axis of rotation.
229. Standard Five-Inch Scale, in white chalcedony, for
microscope sight. Prof. Piazzi Smyth.
This material, which came out of some ancient Roman palace, is chosen
for the same reasons as that last described. The scale is divided on the same
system.
230. Standard Five-Inch Scale, in red porphyry, for
microscope sight. Prof. Piazzi Smyth.
This material came from an Imperial Roman palace to which it had been
taken under the Caesars from some far more ancient Egyptian temple. It was
originally quarried by the Egyptians of 3,500 years ago in the rich porphyry
district between Thebes and the Red Sea, and it has been adopted for the same
reasons as the preceding examples, and the scale is divided on the same
system.
232. Standard of Length, derived from the earth's polar
axis, which is unique and common to all terrestrial meridians.
Prof. Hennessy.
This standard, proposed by Professor Hennessy, is a bronze bar, which, at
15 of temperature centigrade, is equal to the fifty millionth part of the
earth's axis.
233. Steel Chain, of fifty links, whose total length is the
millionth part of the earth's axis, or very nearly 500*5 English
inches. It is nearly equal to the half chain of two perches in Irish
plantation measure. Prof. Hennessy.
235. Standard Yard Measure, German Silver, with one
chamfer divided to inches and lOths, for temperature 60 Fahr.
Elliott Brothers.
239. Steel Tape Measure, 66 ft. For testing tapes, divided
to feet and inches on one side and links on the other.
Elliott Brothers.
D 2
52 SEC. 3. MEASUREMENT.
247. Measure of Length, according to natural principles.
Hans Baumgartner, Basle.
250. Half Metre, maple, with points.
Geneva Association foi* the Construction of Scientific In-
struments.
251. Brass Metre. (Grand Duchy of Baden Model.)
Geneva Association for the Construction of Scientific In-
struments.
252. Steel 2-Metre Standard, with points. (German
Model.)
Geneva Association for the Construction of Scientific In-
struments.
253. Brass Standard Metre. (Swiss Model.)
Geneva Association for the Construction of Scientific In-
struments.
The Geneva Association for the Construction of Scientific Instruments
possesses in its laboratories a machine for the division of straight lines, to
the construction of which it has endeavoured to apply all the improvements
of modern science. These efforts have been crowned with success, and the
increasing reputation of this machine, which may be considered as the most
complete at present existing, has obtained for the Geneva Association orders
for metrical standards from several European Governments.
The machine is worked automatically, that is, all the process of dividing is
done mechanically. Thus, apart from the inaccuracy consequent on the tem-
perature of the operator, it avoids the errors proceeding from inattention
or fatigue on his part. Mechanical action has, moreover, the advantage of
being more regular, seeing that the motive power is always equal.
An ingenious contrivance enables the correction of errors due to a change
of outward temperature during the process of division, to be effected ; thus, at
any temperature a correct graduation corresponding to is obtained. By
the same means, a division of any length may be made, although the pitch
of the thread of the screw of the machine, and the length of the division re-
quired, may be incommensurable.
The pitch of the screw has been thoroughly examined and corrected, so as to
guarantee accuracy to the -^^ of a millimetre.
This machine for dividing straight lines has been used to effect the normal
division of the large machine for dividing circles which stands by its side on
the same bed of concrete. This application has been the means of exactly
ascertaining the coefficient of dilatation of the machine for dividing straight
lines. The maximum of error found in the division of the normal circle was
less than a second. It is impossible to expect greater accuracy when it is
remembered that the arc of a second on the circumference of the divided
circle represents about -^^ of the millimetre.
259. Standard Metre, with rack motion to be used as a
machine for dividing other metres.
Geneva Association for the Construction of Scientific In-
struments.
II. LENGTH. 53
This instrument may be used both as a comparing apparatus, and as a
machine for dividing fractions of the metre, for the use of comptrollers of
weights and measures. A small pointer or cutter is traversed, by means of
a rack, along the meter, while a very simple lock action enables the milli-
metric displacements of the indicator to be registered without reading the
divisions.
259b. Iridio -platinum Standard Metre, in course of
manufacture. Johnson, Matthey, and Co.
259c. Section of Metre when finished, showing the form
determined upon by the International Commission.
Johnson, Matthey, and Co.
26O. 6-foot Measuring Hod, for uneven ground, for en-
gineering and scientific purposes. .Designed by the exhibitor, and
made by Messrs. T. Cooke & Sons. Edward Crossley.
The apparatus consists of a wooden rod 6 ft. in length, with metal ter-
minations containing spherical cups fitting on to spherical heads upon tripod
stands. Three tripod stands are required. Each terminates in a flat ring
npon which the base of the short pillar carrying the spherical head is hori-
zontally adjustable, and to which it can be clamped. The rod is supported
by two tripod stands, while the third is set forward to receive the rod in
its next position. The inclination of the rod is read off to half-a-minute
in each position by means of a level and arc attached to the centre of the rod.
The true horizontal distance is then obtained by applying a tabulated cor-
rection for each inclination of the rod.
This instrument will give an accuracy of 1 in 10,000 on any sort of
ground, even with a gradient of one in four.
266. Ivory Pocket Measures. T. Hawksley.
Containing the Fahrenheit and centigrade temperature scales ; English
inches divided to $ in., and centimetres divided into millimetres ; designed
for the purpose of introducing into everyday use the decimal system of
measurement.
269. Poot-scale-plate. A rectangular brass-plate containing
twenty different foot-scales, made in 1769 by Adam Steitz in
Amsterdam. It is a copy from the original deposited in the Town
Hall of Amsterdam. Prof. Buys- Ballot, Utrecht.
269a. Meter Diagram. A. and F. Stanley, Neiv York.
289. Meter Scale with double divisions, for and 20 C.,
by Breithaupt and Son, in Cassel.
Mathematical and Physical Institute, Marburg {Prof.
Dr. Melde).
295. 2-Meter Standard Measure in steel.
F. W. Breithaupt and Son, Cassel.
54 SEC. 3. - MEASUREMENT,
This normal 2-meter standard is an end measure, as well as a line
measure, with divisions throughout in centimeters, and on both the end deci-
meters in millimeters. It was graduated on the longitudinal dividing machine,
constructed by George Breithaupt in the year 1850, for the temperature of
Celsius, as far as 0-01 mm. precision.
Such normal double meters have been made in large numbers on steel, as
well as simple normal meters on brass, for the Imperial Commission of Normal
Weights and Measures.
.With, this longitudinal dividing machine a length of one meter may be
graduated uninterruptedly even to the smallest subdivisions.
296. Star dard Scales in Bock Crystal, viz. :
a. Scale of 10 cm.
b. Scale of 15 cm.
c. Scale of 20 cm.
The scales are cut parallel to the axis of the crystal and are.
divided into millimeters ; the first and the last millimeters are.
divided into ten parts. The graduation has been carried out by
Mr. Brauer in St. Petersburg.
Hermann Stern, Ober stein, Principality of Birkenfeld.
299. Meter in Steely line measure divided into millimeters.
L. Steger, Kiel.
. a, i:*ji .1 ij;..'j {. ; ;-'< !;- ju-.t'>. ; afi
301. Apparatus for comparing Standard Measures of
Length, by Stollenreuther.
University of Munich (Prof, von Jolly).
302. Meter in the form of a ruler with subdivisions.
M. Meyer, Teacher of Mathematics at the Gymnasium,
Halle.
In order that the subdivisions of the meter should be clearly understood
by the scholars, one side of the square has no divisions, that side is of the
exact length of a meter ; the second side is divided into decimeters only, the
third into centimeters, and the fourth into millimeters.
303. Schonemann's Measuring Wedge, reading to '01
mm. Gewerbe Schule at Halle (Director, Kohlmann).
304. Schonemann's Measuring Wedge, reading to '01
mm. Kleemann, Mechanical Engineer, Halle.
, ,
3O6. Meter-scale in Brass.
.,. ;0 - Prof* Baron von Feilitzsch, Greifswald.
This scale was constructed at the workshops of Messrs. F. W. Breithaupt
and Son in Cassel (Province Hesse), and is remarkable for its great accuracy.
It is divided, on silver-plated brass, into centimeters, and at both ends
into millimeters.
309. Original Meter Scale, iron. One of the forty speci-
mens which were delivered to the members of the Meter-Corn-
H. LENGTH. 55
mission in the year vii. of the French Republic ; formerly in the
possession of Tralles. Prof* D r - -Dove, Berlin.
Original Meter Scale by Tralles (of iron). One of the 40 standards which
were delivered to the Commissioners.
Iron Meter a touts. This meter, which was presented to Hapler by Tralles,
was one of the three which the latter had made at the same time, by Lenoir,
with the 15 which were distributed among the members of the Commission.
After the completion of the new measurement of degrees performed by
Delambre and Mechain, the real length of the meter was determined by the
Commission, consisting of, Swinden, Tralles, Laplace, Legendre, Cizcar,
Mechain, and Delambre, in their report of the 6th Floreal year 7, to be
443 - 295936, and the distance of the Pole, by assuming an oblateness of ^fa,
from the equator having been calculated to be 5130 js toises, it was legally
accepted as " metre oral ct definitif" at 443-296.
" Cette unite uornmee metre qui est le dixmillioneme partie du quart du
meridian revient selon les anciennes mesures & 3 pieds 1T296 lignes^ en em-
ploy ant la toise du Peron a 13 degres du thermometre & mercure divise en
80 parties."
312. Standard Meter on brass in mahogany case.
Ed. Sprenger, Berlin.
313. Standard Meter on Steel. Ed. Sprenger, Berlin.
314. Standard Meter on Wood. Ed. Sprenger, Berlin.
315. Standard Tape Measure, 20 meters.
Ed. Sprenger, Berlin.
315a. Standard Stirling Ell, believed to be a copy of the
standard Scottish ell adjusted at Edinburgh, 26th of February
1 755. The Burgh of Stirling.
315b. Standard Meter. Bock and Handrick, Dresden.
Two Standard Meters (boxwood).
Bock and Handrick, Dresden.
2-Meter Standard Measure.
Bock and Handrick, Dresden.
B. TELEMETERS.
'226. Telemeter. For measuring the distance of inaccessible
obj ects. Patrick i Adie .
This instrument, the first of its name, was patented by Mr. Adie in 1863.
It consists of two powerful telescopes at the ends of a fixed base ; the united
rays, by total reflection, give simultaneous observation in the eye-pieces.
234. Telemeter, for determining distant inaccessible points
by one observation. Manufactured by Adie & Son, Pall Mall.
Prof. Pigot.
56 SEC. 3. MEASUREMENT.
242. Nolan's Range Finder.
1. Two-angle measures. Right and left.
2. Two Y supports.
3. Two tripods.
4. Two tripod buckets.
5. Two leather boxes with straps to contain items 1 and 2.
6. A 50 yards measuring tape.
7. A metal calculating roller.
8. Two magnifying glasses.
9. A leather case with strap to contain items 6, 7, 8.
10. A leather numnah which fits under the saddle of item 1, and
on which the two boxes, item 5, are strapped.
.-,;> War Office.
243. Two Instruments for Measuring Distances.
Constructed by Dr. Meyerstein.
Prof. W. Klinkerfiies, Gottingen.
262. Telemeter with prism by Col. Goulier for the rapid
measurement of distance. M. Tavernier Gravel, Paris.
263. Pocket Telemeter. By M. Gautier.
M. Tavernier Gravet, Paris.
264. Telemeters. Fortin Hermann Bros., Paris.
285. Collection of War Telemeters. These instruments,
which are based on the speed of transmission of sound, are
intended for measuring distances in the field.
Le Boulenge, Liege.
3O7. Instrument for Measuring Distances, according to
the systems of Kleinschmidt and Breithaupt.
Royal Museum, Cassel (Dr. Pindcr, Director).
The instrument for measuring distances was constructed entirely of brass
by J. C. Breithaupt during the second half of the 18th century. It consists
of a rail of 0-978 m. in length, serving as measuring-base, on both ends of
which is attached a movable telescope for sighting the object the distance
of which is to be determined. From the known length of the base, and the
indicated angles which the adjusted telescopes form with the base line, the
distance sought is ascertained by trigonometrical calculation.
C. GAUGES AND CALLIPERS.
11. Set of Gauging Instruments. Dring and Fage.
Head rod. For ascertaining the head diameter of a cask, and working out
the contents.
Bung rod and slide. For finding the bung diameter and diagonal of a cask.
The rod is divided into inches and tenths, with a line of imperial area and
diagonal line ; this last gives the approximate content without calculation,
and is computed on the assumption that most casks are similar to one another
in form, and therefore vary as the cubes of their like dimensions.
II. LENGTH. 57
Long callipers used for fmuing the internal length of a cask from head to
head.
Cross calliper. Used for finding the external diameter of a cask.
Stave gauge. For finding the thickness of the stave in a cask.
236. Sliding Calliper Gauge, with tangent screw and
vernier for reading TW<j tn ^ an ^ ncn ms ide an d outside measure-
ment. Elliott Brothers.
237. Decimal Gauge, German silver, with screw and ratchet
motion for measurin to ^h of an inch. Elliott Brothers.
246. Aerial Spider Line Micrometer of great delicacy,
measuring an object to the 100,000th of an inch.
Dr. Royston-Pigott, F.R.S.
The image of sets of spider lines of a recording micrometer placed beneath
the stage, is formed by a half inch objective, five inches from the spider
lines. This image is in fact a miniature diminished exactly seven times.
The micrometer reads to the l-20,000th of an inch, a ^ oa /r ; consequently
the image is measured seven times more minutely. This would be the
l-140,000th, or -j^i^^th of an inch (English). On the whole, therefore,
the instrument may be said to measure to the l-100,000th, i.e., l66 * 06o th of an
inch.
These aerial spider lines are made to move about the object to be measured
at the will of the observer, and come into the focus of the microscope by
regulating the plane of the aerial spider lines.
246a. Wollaston's Single Lens Micrometer.
Wollaston Collection, Cavendish Laboratory, Cambridge.
(Phil. Trans., 1813, p. 119.)
256. Callipers, for clock and watch making.
Geneva Association for the Construction of Scientific In-
struments.
Much used in clock and watch making for measuring thicknesses. This
instrument gauges to ^V tn f a nne > or TlM n f a millimetre.
The divisions traced on the steel arc are not equal, but are calculated to
measure equal increments of the interval between the two nibs. They
increase therefore with the chords.
257. Curious Steel Callipers for very accurate measure-
ment, by Paull of Geneva, 1777. Royal Society.
267. Apparatus for measuring the exterior diameter of the
Gun Barrel and the interior diameter of the rings to be shrunk
on the same ; constructed by G. Brauer.
Arsenal of St. Petersburg.
The apparatus consists of a bar, with two adjustable arms, which is sus-
pended across the cannon ; one arm being brought into contact on one side
with the surface of the cannon, the other arm with its contact lever is brought
into contact with the surface of the cannon on the other side, in such a
manner that this contact lever at its upward and downward motion, by means
of the vertical screw at the greatest diameter, indicates zero. In order to
exactly determine the diameter, the divided movable scale is adjusted, after
58 SEC. 3. MEASUREMENT.
taking off the apparatus from the barrel of the cannon, between the two
arms, so that the contact lever again indicates zero. The same scale serves
also for measuring the interior diameter of the rings. The apparatus has
been constructed and made by G. Brauer at St. Petersburg.
267a. Photograph of an Apparatus for measuring the
eccentricity of the chamber and the curve of the bore of cannons.
G. Brauer, St. Petersburg.
The apparatus consists of two parts :
1 . A body, wHich is pressed into the mouth of the cannon by means of
an endless screw. In this screw a telescope is fixed which can be turned
about its own axis, and is provided with a filar micrometer and a position
circle.
2. A piece, which can be slided along the barrel, being turnable about the
axis of the bore, and in whose centre is a glass plate with engraved cross.
This cross is viewed through the telescope before mentioned, and the deter-
mination of the position of the cross on the filar micrometer indicates the
elements for determining the curve of the bore and the eccentricity of the
chamber.
The apparatus was constructed by the exhibitor for the Russian Marine
Artillery Department.
267b. Instrument for Measuring the Bore of Cannons
(Etoile Mobile). G. Brauer, St. Petersburg.
This instrument consists of a ring, in which two parallel rods slide longi-
tudinally side by side, and one of which carries the scale, the other its
vernier. The sliding rods are pressed asunder by means of springs, so that
their exterior steel ends touch the side of the bore to be measured. As this
contact must not take place during adjustment, the sliding rods are brought
together by a bolt. A screw perpendicularly under the sliding rods is in-
tended for adjusting them according to the greatest diameter, which has to
be done afresh at each measurement. If the chamber of a breech-loading gun
is to be measured with the apparatus a set of two rings has to be added, of
which the one in front carries a telescope for viewing the scale. The two
exterior rings are joined to each other by four bars, and these bars have a
movement in the centre ring, which during the operation of measuring L
pressed into the back part of the cannon bore by means of four screws, and
the whole apparatus is then moved as required.
267c. Apparatus constructed for measuring the exterior
diameter of small cylinders with an accuracy of 0' 001 inch.
G. Brauer, St. Petersburg.
This apparatus, which was employed in the experiments on the elasticity
of gun-metals, steel, cast-iron, &c., in Bussia, is provided with an immovable
pillar and a contact-lever, which can be adjusted by means of a screw-move-
ment. The cylinder to be measured is placed between the two, and the screw
turned until the lever points to zero, and then the reading is effected by the
vernier of the longitudinal scale.
267a. Apparatus for Measuring the Breeches of
Large Guns. M. Gadolin, St. Petersburg.
II. LENGTH. 59
267d. Apparatus for Measuring the Length of the
Impressions made by the Rodman Scale.
Technological Institute at St. Petersburg.
The copper plate, on which is the impression to be measured, is placed on
the slide of the apparatus, and then one end of the impression after the other
is brought under the cross thread of the microscope by means of the screw of
the slide, when the reading can be made on the head of the screw. By-
means of a micrometer eyepiece also smaller dimensions can be measured.
The apparatus belongs to the Technological Institute at St. Petersburg.
267e. Micrometer for Guns and Tubular Objects.
Samuel B. Allport.
This is a tube, provided with three spring arms, radially disposed round its
end, between which a cone is inserted. The cone is connected with a screw
at the other end of the tube, whereby it is projected or withdrawn, and so con-
tracts or expands the spring arms.
The angle of the cone bears such a relation to the pitch of the screw tha 4
the expansion or contraction of the arms when inserted in a tube will indicate
the variations in its bore in thousandths of an inch by suitable divisions on
the head of the screw.
267e. Apparatus for measuring the eccentricity of the pivots
of a polar or transit axis, with an approximation of * 00001 inch.
A. Hilger.
271. Calliper, with Dial, of the English inch measure,
divided into eighths. M. Isvardfils.
272. Calliper, with Dial of two centimetres, divided into
tenths of a millimetre." M. Isvardjfils.
283. Cylindrical Gauges differing in diameter by one ten
thousandth of an inch. Other gauges and specimens of surfaces.
Royal School of Mines.
284. Universal Calliper, with slide and reverse action.
Geneva Association for the Construction of Scientific In-
struments.
Instrument of measurement, for ascertaining equally the thickness, the
inner diameter, and length of tubes.
286. Apparatus for measuring accurately the Diameter
of Wires, for testing whether pivots and other turned objects are
perfectly circular in form, and for the determination of the error
when they are not truly circular.
Landsberg and Wolpers, Hanover,
287. Apparatus for measuring the Thickness of thin
metal plates, sheets of paper, &c.
Landsberg and Wolpers. Hanover.
288. Calliper-Compasses for larger measurements.
Landsberg and Wolpers, Hanover.
60 SEC. 3. MEASUREMENT.
233a. Photographs, showing two kinds of machines i'or
measuring with great precision the alterations in shape produced
in metals by tension and compression. Dumoulin Froment, Paris.
291. Calliper Apparatus, for accurately determining dia-
meters and lengths up to 150 mm.
A. Meissner (ff. Muller and F. Reinecke), Berlin.
^L millimeter can be obtained by direct reading by means of a microscope,
and the T | 7 part of a millimeter by estimation.
293. Collection of Timber Callipers for the use of
foresters. C. Staudinger and Co. (F. W. von Gehren), Giessen.
A collection of tree-callipers (" Baumkluppen "), mostly in use for the pur-
pose of comparison with those of Staudinger's construction, by many autho-
rities recognised as the best. A list of the names is added to the collection.
298. Calliper Compasses, with plane contact lever.
Physical Institute of the University of Kiel (Prof. Dr.
G. Karsteri).
This appai-atus, which is in the possession of the Physical Science Institute
of the University of Kiel, was constructed in 1832 by liepsold, and made use
of by Schumacher for comparing the platinum kilogramme of the archives
with the Danish.
(See Schum. Astronom. Jahrbuch, 1836, p. 243.) 9
A description by G. Karsten of the instrument will be found in " Vom
Maasse und vom Messen," vol. I. of the " Encyclopedic der Physik," p. 506
and following.
308. Apparatus for measuring the Thickness of Thin
Plates. R. Fuess, Berlin.
308a. Improved Patent Measuring Gauge, with
patent releasing arm. Wm. Henry Laidler.
This gauge is constructed to enter a hole drilled in a plate ; the arm will
clear any rough edge or burr, and when the measurement is taken the arm
can be released, and the instrument withdrawn, without altering or interfering
with the indication. Each division on the vernier shows 1 - 1 00 part of an inch.
3O8b. Improved Ivory Calliper Gauge, with Engi-
neer's Slide combined. Wm. Henry Laidler.
D. CATHETOMETERS.
241. Differential Cathetometer, an apparatus designed
for measuring variations in the length of solid bodies, particularly
of rods and wires. Dr. Heinrich Streintz, University of Gratz.
The principle on which this apparatus is based is, reading by reflection from
two mirrors. Two levers, having small mirrors ss attached to them perpendi-
cular to their axis, are turned by the flat ends of the bar to be measured as
indicated in the drawing. If a telescope and a scale are placed, at some
distance, in such a position that the image of the scale reflected by the mirror
II. LENGTH.
Gl
is visible through the telescope, each variation in the position of the point at
the end of the lever will be magnified to a degree indicated by the quotient,
the numerator of which represents the double distance of the mirror from the
scale, and the denominator that of the point from the axis of rotation.
As the latter distance can be diminished to one centimeter in the apparatus,
and as, moreover, the telescope with the scale can be placed at any distance
within which distinct images will be seen, say five metres, a shifting of the
reflected image by one millimeter will be equal to displacement of the end-
surface of the bar to be measured by O'OOl millimeter. As, however, the
tenths of the millimeter even can be pretty accurately determined, the reading
will be correct as far as the 10,000th part. '
There is no doubt that the correctness of the reading with this apparatus
can be carried still further, if mirrors of superior quality and powerful
telescopes are employed.
In measuring the variations in the length of a wire a flat surface must be
given to that part to which the wire is to be suspended, as well as to the part
OH which the weights are placed, and to which the levers are to be applied.
62 SEC. 3. MEASUREMENT.
The arrangement of the apparatus is as follows :
To a solid brass pedestal, which rests on three adjusting screws, a strong
glass tube a 1^ meter long is cemented, to which two brass bars bb are
clamped. Each of these brass bars consists of two parts, of which one
moves or slides in the other in such a manner that it can be either lengthened
or shortened. The set screw c serves for fixing the chosen length. By means
of the joint d a horizontal rotatory or veering movement of the fore-part of the
bar can be effected. Close to its free end there is on each side a steel point
the two forming together an axis which is held by a bow ff carrying two
cups, in such a manner that the bow can be easily but surely turned round
this axis.
The lever gg which must be firmly connected with the bow, has longitu-
dinally a slit, or slide, with two sliding pegs placed in a level position with
the axis and fastened to the bow, along which the lever can be moved, so that
at whatever distance from the axis the extreme end of the lever may be fixed
it must always turn with the bow around the axis.
In order not to be obliged to take the measurement of the length of the
lever afresh at each experiment, it is provided at its upper surface with
conical-shaped cavities in which the screws hh catch. These conical-shaped
cavities would be, properly speaking, visible only in a drawing of a vertical
section, but not in a front view, as represented in the sketch, but they have
been marked in the drawing for the purpose of rendering the description more
intelligible.
The measurement of the length of the lever at the different cavities is
accomplished by means of a spherometer. The lower bar b is arranged in
a manner quite similar to the upper bar.
In order to meet the requirement that the levers should but lightly press
against or touch the end surfaces in the manner indicated in the drawing, small
balancing blocks II can be attached at any point to the levers.
For the purpose of reading, two telescopes with vertical scales are required,
which must be placed in juxtaposition, that is to say, by the side of each
other. Presuming the staff to move upwards and downwards without varying
its length, the difference in the reading in the upper and in the lower mirror
will naturally be of the same value in every position of the staff.
A glass tube has been chosen to serve as a column a, because glass possesses
a very small coefficient of expansion. Moreover, in using the instrument,
the tube must be filled with water and two thermometers placed in it, by means
of which any change in the temperature that may take place during the
process of measuring can be accurately determined.
A similar, although less perfect, apparatus has been employed by the
exhibitor in two experiments already, namely, " as regards the variations in
" the elasticity and the length of a wire under the influence of a galvanic
" current." See Transactions of the Academy of Sciences at Vienna,
Vol. LXVIL, Part II. , April 1873 ; and " respecting the moderation of
" the torsion oscillations of wires." See Transaction of the Academy of
Sciences at Vienna, Vol. LXIX., Part II., March 1874. Extracts of both
treatises have also been published in Pogg. Ann.
The apparatus can be employed in measuring the coefficients of expansion,
coefficients of elasticity, the after effects of elasticity, the expansion produced
by magnetism, &c., and will secure in every case an accuracy not hitherto
attained, not only by reason of the correctness of the readings, but also
on account of the correction of temperature rendered possible through the
employment of the glass column.
The measurement is likewise very easy of accomplishment, since a manipu-
lation such as is the case with ordinary cathetometers is not required, as the
II, LEXGTtf. 63
variations taking place in the wire can be perceived through the telescope
directly magnified and projected on the scale.
In most cases it will only be necessary in making such experiments to know
exactly the absolute length of the body to be measured in equal per cents, as
well as the elongation, for measuring which a good scale, or a very simple
cathetometer, is all that will be required.
24 la. Original Cathetometer by D along.
Polytechnic School, Paris.
241 b. Cathetometer, with two Levelling Micrometer
Telescopes.
Physical Science Cabinet of the Imperial Academy of
Sciences, St. Petersburg.
241 c. Drawing of a small Cathetometer, used by Prof.
Mendeleeff in his investigations on the tension of gases.
Prof. Mendeleeff.
In order to eliminate a source of many errors the eyepiece is fixed in the
telescope, and the whole cathetometer has to be put at the required distance
from the object to be observed.
The telescope is provided with a micrometer screw.
253. Great Cathetometer, for reading differential levels
more than a metre apart.
Geneva Association for the Construction of Scientific In-
struments.
This instrument is composed of a tripod supporting a central rod, which
bears on its upper part the brass column, or prismatic piece, along which
the telescope moves in a right line. The dimensions of the column are great,
so as to avoid all flexure. The division on the silver plate is in millimeters,
and the vernier of the slide gives readings to the 50th of a millimeter. This
instrument has two levels ; the one placed between the rings that support
the telescope, the other placed perpendicularly to the first upon the table
situated at the base of the column.
The universities of Berlin, Rome, Dorpat, Neuchatel, &c. have instruments
of this pattern.
273. Cathetometer, by Casella. The telescope moves on a
girder-shaped brass bar, to which the scale is attached, and is
furnished with a micrometer eyepiece, by means of which readings
can be taken without moving the telescope. The instrument is
supported by a massive iron frame- work.
Prof. A. W. Rucker, Leeds.
292. Cathetometer. C. Bamberg, Berlin.
The principal division of the instrument is executed on silver to centi-
meters. The division into single millimeters has been made on a scale con-
nected with the principal slide, whose divided surface is on a level with that
of the centimeter graduation. The millimeter-scale moves with the principal
slide, which carries the means for reading and adjustment (microscope and
^elescope). The reading of the meter-division is effected (as far as O'OOl
64 SEC. 3. MEASUREMENT.
mm.) by means of the eyepiece-micrometer of the microscope. The micro-
metrical displacement of the principal slide,; which is balanced in all posi-
tions round the longitudinal axis of the scale column, takes place by a pecu-
liar contrivance, which avoids all one-sided pressure. The slide with the
clamp is balanced by a counter-weight suspended from the ceiling or a trestle,
so that its ascending and descending motion is effected with great facility.
294. Photograph of a Cathetometer, constructed by
Staudinger and Co.
C. Staudinger and Co. (F. W. von Gehren}, Giessen.
The peculiarities of the construction may be learned from the photo-
graphs. The instrument has an available graduated length of one meter ;
the column with the counter-weight turns completely around the long ver-
tical axis, and is provided with adjustments, reversing telescope, and water-
level.
305. Cathetometer.
Prof. Baron von Feilitzsch, Greifswald.
The Cathetometer consists of a central axis, and a prism turning round
the same. For placing the central axis in a vertical position a cylindrical
water-level, indicating to 10 seconds, is employed. A scale on silver one
meter in length, and divided throughout into millimeters, is inlaid into the
prism. Sliding along this is a telescope, likewise fitted with a cylindrical
water-level, the supporter of which is provided with a vernier indicating
3 V mm -
There is also a water-level, for regulating the direction of the prism.
310. Cathetometer, so arranged as to be used for horizontal
measurement. Prof. Dr. Dove, Berlin.
311. Cathetometer, by Breithaupt and Son, Cassel, with
riding level. Polytechnic School, Cassel (Dr. E. Gerland).
The following improvements, contributing partly to more minute readings
with the apparatus, partly affording means of correction of the several parts,
have been added to the well-known constructions.
The firmly placed central axis, around which the long frame and prism
turns, can be placed vertically by a special cylindrical water-level, indicating
to 10 seconds, and which is fastened to the frame independently of
other parts, in order that the vertical position of the axis required in very
fine measurements may be readily ensured ; the more so, as all othe*r
observations are based on the correct adjustment of this water-level. The
vertical position of the axis is effected in the same manner as with an
ordinary levelling instrument, and any deviations of the water-level are cor-
rected half on the adjusting screw of the same, and half by the regulating
screws of the tripod.
The prism, the inlaid silver scale of which, 1 meter in length, is through-
out divided into millimeters, and fitted with a vernier for -J- mm., can be
placed in a horizontal position and parallel to the face of the scale. By means
of adjusting screws, and a reversible riding level, the telescope can be placed in
the required position.
If this is done, the bubble of the telescope water-level will remain unchange-
ably in the centre during the rotation of the whole instrument on its central
axis, as well as during the upward and downward motion of the slider.
II. LENGTH. 65
A very severe proof consists in sighting a distant object with the telescope,
which is then reversed in its sockets, and the apparatus turned round 180,
at which the object should be intersected again by the eyepiece cross.
The immovable cross in the ocular is cut on glass, in order to prevent
hygroscopical and other interruptions. For the purpose of obtaining the
rectangular position of the telescope, the supporter may also be placed with
one end between points, while an elevation screw is fixed to the other. The
essential point for effecting the before-mentioned correction by employing the
attaching or adjusting water-level consists simply in adjusting the water-level
axis exactly to the leaning face by means of the correction arrangement
marked a in the drawing. The proof is effected by reversing the angle
vertically, the water-level thus turning between its. points. If after the
proper attachment the bubble deviates from the centre, half of this deviation
must be corrected by the regulating screws of the tripod, and the other by the
correction arrangement a. It is, however, to be mentioned that, previous to
the above proof, the parallel position of the water-level axis towards its
points of attachment is to be examined, which can effected by reversing
between its two points, and thereby a deviation of the bubble, if there be any,
Avill be removed half by the adjusting screw b, and the other half by the
arrangement a. Finally, there remains the examination and correction of the
water-level sideways to be made, which is done in the usual manner by the
screw c. This attaching or adjusting water-level may also be recommended
for other purposes, for instance, in mounting of machines, &c.
Regarding the peculiar construction of the aforesaid adjusting water-level,
the suspension between two points, in general, it may be remarked that the
same has been derived from the compensation-level constructed by F. W.
Breithaupt and Son some years ago (vide Dingler's Polytechn. Journal,
vol. CLIV. p. 401). In what manner this principle has been adopted in other
mechanical workshops, and represented partly as an invention of their own,
has been proved by an article in Carl's Repertorium, vol. IX., p. 127, by the
addition of an arrangement or simplification totally at variance with the
construction.
E. DIVIDING ENGINES.
248. Instrument for dividing Mathematical Scales or
Rules.
H. M. Commissioners of Patents
This instrument is to be used for dividing scales according to the French,
Swiss, or English measures of length, and is provided with a vernier for
obtaining the smaller divisions of the scale. It can also be adapted to
the production of diagonal scales.
248 a. Dividing Engine, made by the late Mr. Bryan
Donkin, F.R.A.S., in the year 1828. Bryan Donkin.
The principle involved in the construction of the machine is the employ-
ment of a compensating arrangement, by which great accuracy is obtained,
notwithstanding the inequalities of the screw used in the machine for advancing
the cvitting tool. The machine consists, first, of a table moving upon wheels
on a railway. To the under side of the table is attached a clasp nut in two
parts, moved by the main screw, which is below the table, and exactly
parallel with the line of motion. To effect the compensation the table con-
sists of an upper and lower plate, the upper one being capable of a small
40075. B
66 SEC. 3. MEASUREMENT.
motion independent of the lower plate. The lower plate carries the fulcrum
of a bent lever, whose arras are at right angles and as 50 to 1. This lever
moves in a vertical plane, so that the longer arm lies by gravity alone on the
undulating edge of the compensation bar. The upper plate is pressed end-
ways against the shorter arm of the bent lever by means of a spring keeping
them always in contact. By a kind of parallel motion the two plates are
attached so as to allow of the very small motion required in the upper plate
independently of the lower. The compensating bar, which is of the length
of the screw, has 50 narrow slips of metal placed upon it, each having an
adjusting screw by which the ends of the pieces may be placed in a continuous
line, or above or below the line, as required by the mode of adjustment. This
bar is carried by a pivot at one end, and the other end is raised or depressed
by a screw, which adjusts the compensating bar to the total length moved
through by the guide screw.
In the case of dividing a scale, the swing frame carrying the cutter or
diamond point is attached to the framing of the machine, the scale to be
divided being placed upon the upper plate.
In the case of cutting a screw, the tool holder is fixed upon the upper plate
and the screw to be cut is placed between centres parallel to the motion of the
table and to the guide screw, having motion imparted to it by a train of
wheels connecting it with the screw of the machine. The compensating bar
being adjusted for total length, and the small pieces of metal upon the same
being adjusted to the intermediate errors of the guide screw, it will be seen,
that by the passage of the longer arm of the lever over the edge of the com-
pensating bar, a slight motion will be imparted to the upper plate independent
of the lower, so that, in other words, if by the error of the screw the lower
table is moved through too great a space, the upper table is made to move
(by the action of the lever) through a space equal thereto in the contrary
direction, and ewe versa.
Note. A description somewhat more in detail and of the manner of
adjustment will be found in " Holtzapffel's Turners' and Mechanics' Manufac-
tures," 2nd vol., p. 651 et seq.
Many scales were divided and many screws cut by this machine, of which
some were given to various scientific friends, and Sir ,T. Whitworth, amongst
others, had a scale and a screw about the year 1843 which have served him a&
standards.
265. Machine for dividing right lines, by Nicholas Fortin.
MM. Fortin Hermann Bros., Paris.
This machine is the one constructed by the celebrated inventor in 1787,
and used in the works connected with the adoption of the metrical system.
The pitch of the screw is exactly one millimetre. (Fortin's machine for
dividing circles, as well as this machine, was presented to the Conservatoire
des Arts et Metiers by MM. Fortin Hermann Bros., in 1876.)
297. Micrometer Dividing Machine.
Voigt and Hochgesang (Gust. Voigi), Gottingcn.
The pitch of the screw is mm., its head is divided into 200 parts ; each
part, therefore, corresponds to -gfa mm., reading by the vernier to ^ of this
value. By a spring fixed in the nut " loss of time " is completely removed.
The tracing appliance is constructed in the simplest manner possible. The
tracing point a diamond is lifted by a mechanical contrivance, and let
down again.
The slide allows of drawing a line of 30 millimeters in length.
II. LENGTH. 67
The slide which carries the tracing point moves without greasing between
six finely polished carnelian plates ; by this arrangement any errors, which
might be caused by clotted grease, will be rendered absolutely impossible.
F. TIDE REGISTERS.
327b. Patent Indicator, for tanks or reservoirs.
John Nicholas.
This gauge is similar to that last described, but the atmosphere giving
comparatively a constant pressure the stand pipe can be dispensed with.
The brass tube referred to in the previous description may be seen in the tank
attached. It is not necessary to pierce or employ a tank when attaching one
of these gauges, and the small pipes can be laid in the walls in a similar
manner to gas tubes. In some cases one tube is sufficient, the water column
being balanced by mercury in a metal tube at the back of the gauge. This
gauge is suitable for tanks upon the roofs of mansions or hotels, where engines
are used for pumping.
255. Registering Water-mark, of new construction, which
records the curve of the water-level and its mean height.
Lieutenant- General Baeyer, President of the Geodetic
Institute at Berlin.
Invented by F. H. Reitz, civil engineer, of Hamburg. The apparatus
was made in the factory of Pape and Dennert. The clockwork is by
Knoblich.
278a. Magneto-Electric Water Level Indicator.
Siemens and Halskc, Berlin.
A float which rises or falls with the level of the water in the reservoir or
tank communicates motion by a metallic chain to a magneto inductor, which^
generating electric currents, works at any distance an indicator connected by
a cable or insulated wire.
1695. Apparatus for making contact to show the height of
water with float, rod-chain, counterpoise, and water tube.
C. # E. Fein, Stuttgart.
This is self-acting, and registers at any distance the water-level in a
reservoir, &c.
It consists of five parts :
(1.) The float with chain and counter weight which when acted on by the
rise or fall of the water impart their motion to the contact arrange-
ment
(2.) The contact arrangement which communicates the motion of the float
to the recording instrument by opening or closing the circuit.
(3.) The recording instrument ; this shows the level of the water at all
times, the pointer being acted on by the motion to and fro of two
electro-magnets.
(4.) The conducting wire.
(5.) The battery.
279. Three Gauges, in enamel cast iron, for registering the
height of a river or lake. De Dietrich and Co., Niederbronn.
E 2
68 SEC. 3. MEASUREMENT.
The first of these on the Niederbronn pattern is in black and white and
graduated to centimetres, the second on the Nancy pattern is graduated in
black and white for every two centimetres, and the third on the Paris pattern
is in blue and white graduated to five centimetres.
These water-mark plates are fixed by means of iron clamps to piers, vertical
embankments, &c., and serve for the observation of the level of the water in
rivers, canals, lakes, and reservoirs.
Placed at proper distances from one another in the chief water-courses and
its tributaries, they enable the rise of the water to be observed, and conse-
quently timely warning to be given, by telegraph or otherwise, to the inhabi-
tants of the districts concerned.
28O. Recording Tide Gauge, with self-acting indications of
the mean height of the water (system of F. H. Reitz, Hamburg) ;
executed by Dennert and Pape, in Altona.
Royal Prussian Geodetic Institute, Berlin.
The tide-measuring system exhibited by the Royal Prussian Geodetic
Institution of the European measurement of a degree, at the instance of its
president, General Baeyer, and constructed by Dennert and Pape of Altona,
with clock by T. Knoblich, of Hamburg, has a graphic apparatus for regis-
tering the tide-curve and an arrangement by which the mean water-level is
indicated automatically. The registration of the water-level is effected bj r
means of diamond points upon a cylinder placed horizontally for the accurate
division of the arc.
The mean water-level is indicated by means of two agate rollers with di-
visions, which slide upon a horizontal glass disc turned by the clock of the
tide-measurer, moved to and fro by the rising and falling water, and by the
rotation of the glass disc, and may be read off at any desired intervals of
time.
The calculation otherwise necessary of the mean water-level (the true level
of the sea) from the indications of the registering apparatus is saved by the
above-mentioned mechanical arrangement, and effected automatically with
very great accuracy by the tide-measurer.
The determination of the form and dimensions of the earth undertaken by
the European Committee for re-measuring degrees of longitude and latitude,
also contains the determination of the mean sea level at points on different
coasts, and its comparison by means of accurate levellings. During the last
few years the Committee has endeavoured, in consequence of these examina-
tions, to study the different apparatus and to promote a more exact observa-
tion of the tide corresponding to the exact levellings recently taken.
These circumstances were the cause of a eommissiou from his Excellency
General Baeyer, President of the Central Office of the European Committee
for higher geodetic purposes, and the Royal Prussian Geodetic Institution,
to F. R. Reitz, instructing him to prepare a tide apparatus according to his
system. The instrument now exhibited was made by Dennert and Pape, of
Altona. and the clockwork by Theodor Knoblich, of Hamburgh. It is in-
tended by the Imperial German Admiralty to place this new instrument,
after the close of the Exhibition, on the Isle of Sylt, Schleswig.
The commission given by his Excellency General Baeyer referred to the
construction cf a new instrument, combining a registering apparatus and
mechanical means of determining the mean level of the sea. The apparatus
here described is therefore a combination of both objects.
A buoy A, moved up and down by the tide in a vertical shaft, turns a disc
C, about a horizontal axis, by means of a copper wire B. During the ebb
the wire B descends and turns the disc C; during the flood the same is
II. LENGTH.
69
effected in the opposite direction by a weight D turning the disc E, connected
with the disc C upon the same axis. In order to reduce the movement of
the buoy A in a certain proportion, a pinion F, on the axis of the disc C
and E, moves a rack G, in a horizontal direction. On one end of G a
diamond-point H is fixed, on the other end two rollers J, J, with a horizontal
axis.
Fig. 1.
The clock of the instrument turns the cylinder round its axis in 24 hours by
means of a combination of wheels, and the glass disc M in six hours.
The tide-curves are engraved upon the cylinder L with the diamond-point
II. The rollers J, J move en the glass disc M by the combined action of the
buoy A, the weight D, and the clockwork.
All the different parts of the apparatus are fixed upon the same plate N, N
of cast iron, planed at the necessary points to insure their invariable position.
The plate N rests on three columns of cast iron, placed upon the coping of
the shaft.
The cylinder is covered with blackened chalk paper, whereon the diamond
engraves the tide-curves as white fine lines on a black ground.
The paper on the cylinder L is divided in half hours, and from meter to
meter of height. For this purpose a proper self-acting apparatus is con-
structed, by which both divisions are made with great exactness. Diamond-
points are used for this purpose also. It is necessary, for the sake of distinct-
ness, to renew the covering paper of the cylinder once a month. To avoid
waste of time a second exactly similar cylinder is prepared and carefully
divided, to replace the former cylinder.
For the observation of the constants of the apparatus, it is necessary to
note complete revolutions of the disc C and glass disc M. For this purpose
two indices are applied.
The circumference of the disc C, measured on the axis of the copper wir
B, is exactly two meters in length.
70
SEC. 3. MEASUREMENT.
The apparatus for the determinations of the mean height of the sea is
explained by the following remarks :
It is the question how to define the mean height of the water for a certain
period.
This height would be the arithmetical mean between high and low water,
supposing a regular form of the tide-curves. In fact, the real observed tide-
curves differ very much from this theoretically-defined regular form (curve of
sines). To show this the tide-curves of Cuxhaven, Southampton, and Ipswich
will suffice as examples. The irregularities in these curves are evident and
easily to be seen in figure 2, where the curve of sines is drawn for the purpose.
MEAN
MITT
SOUTHAMPTON. f 6 IPSWICH.
Fig. 2.
If h be the difference between high and low water, the mean height is
for Cuxhaven 0*527^, for Southampton 0'567/J, and for Ipswich 0'47lA
instead of 5 h, the amount of the mean height, supposing a regular form of
the curve. The mean height of the sea is one of the most important result*
of the tide observations. It is the only datum by which to define the invaria-
bility, or the measure of the variation, of height of the continent and islands.
The line of mean height acgi must be in such a position that the areas
abc and gfi (figure 2) together equal the area edge. This is to be found by a
tedious calculation of areas of the tide-curves drawn on the cylinder L.
The apparatus here described gives the requisite data for an easy deter-
mination of the mean height by means of two rollers ( JJ) (one of them con-
II. LENGTH. 71
trolling the other) moving in accordance with the level of the water on a disc
of glass (M). This disc is turned round its axis by the clockwork in 6 hours.
The axis of the rollers J, J is parallel to the direction of their motion on the
disc M. The number of the revolutions of the rollers is noted in certain
periods by means of the divided rim (the rim is divided in 100 parts, tenths
being estimated) and a numerical apparatus showing revolutions up to 100.
The height of the water may be taken from the point when the roller J
stands in the centre of the disc M.
If the height of the water taken from this point be x, and the diminution of
the movement of the buoy by the pinion F be -
.... (I.)
Is the expression for the movement of a point in the circumference of the
roller J in a period during which the disc M revolves through an arc </>.
The expression jx8<f> is the area of a figure with the ordinates x and the
base </> (x representing the height of the water and <f> the time). The mean
value of .r or the height of a rectangle of equal area with this figure and the
base </> is found by dividing by (j>. This mean value of x is the mean height
to be found, equal m suppose. Then
J^_ (2 .)
The movement of a point of the circumference of the roller J is equal to
-JxSQ. This is equal to the product of the circumference of the roller J
called p and the difference of readings on the margin of the roller J at the
beginning and end of the period. Hence, if the readings are called a l and Oj,
.-I**-'* .... (3.)
If z is the number of seconds corresponding to the arc </>, and b the con-
stant arc through which the disc M revolves in a second:
(4.)
Finally, if ~ =
the mean height of the sea.
The single constant c is easily to be determined by experiment and also
with great exactness without the knowledge of the dimensions of the appa-
ratus, as follows : In a certain position of the roller J a number of revolutions
is made by the disc M, representing a number of seconds z l (a revolution is
made in 21,600 seconds). At the beginning and end of these revolutions the
readings (a x and a 2 ) of the roller J are noted. After this a certain length (/)
of the copper wire upon the disc C is unrolled (measured by means of the
circumference of the disc C, equal 2 meters, and the index, or directly). In
the new position of the roller J a number of revolutions of the disc M again
is made, representing a certain number of seconds (z 2 ), and also the corre-
sponding two readings (a 3 and cr 4 ) of the position of the roller at the beginning
and end of these revolutions are now observed. All the requisite data for the
determination of c are now obtained. If the two values of m corresponding
72
SEC. 3. MEASUREMENT.
to the two positions of the roller are m 1 and
from equation (I.),
and their difference is equal /,
therefore :
a, a.
(II.)
When the constant c for both rollers is calculated, the constant difference
in 'the results for m is fixed by a number of revolutions of the disc M in the
same position of the rollers. The difference of m found in this way, of course,
is constant.
The equations (I.) for the apparatus exhibited, calculated as described, are :
For the roller on the left side :
m = 8656 -632 a2 ~ ai meters.
For the roller on the right side :
m = 8655* 983 -^^ meters.
The roller on the right side gives a constant difference for the value m
given with the roller on the left side equal 1'3252 meter. Respecting the
correction of the apparatus, it is only necessary to make the axis of the rollers
parallel with the direction of the movement on the disc M. In this parallel
position this movement, of course, has no influence on the revolution of the
rollers. The parallel position of the axis of the rollers may be tried by ex-
periment, by moving them on the disc M, turning the disc C. During this
experiment the disc M must remain at rest. No motion of the rollers will
then be observed. It seems requisite, at first sight, that the roller J move
through the centre of the disc M. But this is not necessary, an approxima-
tion only being needed for practical purposes. By a sidewards position no
difference in the revolution of the rollers is effected. This is proved in the
following way :
Fig. 4.
II. LENGTH.
73
As to the two positions I. and II. of the rollers, it needs be shown that a
motion d<j> of the disc M causes the same effect.
In the position I. the motion of the roller is :
pq = a8<f>.
In the position II. the motion of the roller is not equal nm.
But:
mo = nm cosj
consequently :
cos j = -- and nm=a l
therefore :
Fig. 5.
The motion of the rollers, therefore, in the two positions is equal.
To connect the distance of the points from which the mean height is
measured by the instrument to a point given by levelling, the height of a
point P of the buoy over the water is carefully measured.
This may be very exactly done by putting the buoy into a vessel filled with
water. The buoy afterwards is lifted a little by the weight D (Figure 1).
This is easy to calculate from the area of the buoy, the weight D, and
74 SEC. 3. MEASUREMENT.
the radius of the discs C and E. The buoy then is fixed at a certain height
by a wire O. In this position the height of P. below a point given by
levelling is carefully measured. The absolute height of the water represented
by the chosen position of the buoy is now known. After this the mean
height corresponding to the same position (viz., the constant height of this
position) is calculated according to the result by a number of 10 or more
revolutions of the disc M. If the measured height corresponding to the
position of the buoy be equal h, and if the height given by the instrument
be equal m, h m is the absolute height (according to the levelling) from
which the mean height given by the instrument is taken.
The diamond-point can then be fixed in a position to get a corresponding
diagram on the cylinder L to the absolute height given by levelling.
F. H. EEITZ,
Hamburgh, May 1876. . Civil Engineer in Hamburgh.
281. Self-recording Tide-gauge, improved.
H. C. Ahrbecker.
In this instrument the whole of the paper can always be seen, and requires
renewal only once a month. The clock goes for 32 days.
This instrument was designed to obviate the disadvantages which occur in
working the ordinary pattern.
A float which rises and falls with the tide in an iron tube is attached to
one end of a chain that passes over a wheel, at the other end a counterpoise
hangs. When the float rises or falls it communicates its motion (by means
of the before-mentioned wheel) to a sliding pencil that moves across a strip
of paper drawn under it by the clock.
In the model exhibited the distance between two lines across the paper,
= 2 hours, = 1 ft. in the length.
This instrument can be made to work without any attention whatever for
12 months if necessary.
282. Mareegraphe," or tide-gauge. Van Rysselberghe.
G. MISCELLANEOUS LENGTH -MEASURING INSTRUMENTS.
238. Measuring Wheel for determining distance by regis-
tering the number of revolutions ; the upper index pointing out
every single and the lower every 100 revolutions.
Elliott Brothers.
238a. Odometer or Way Measurer in gilt metal case
elaborately chased, an early example, probably made in the second
half of the 16th century. " Alexander Nesbitt.
In Beckmann's History of Inventions there is a description of two instruments
resembling this, which belonged to the Emperor Rudolph II. (1576-1612).
415b. Pare and Distance Indicator for Street Cabs.
Robert Foster s Sunderland.
This is an instrument for measuring the distance travelled by a cab or
other vehicle to which it may be attached. A driving band taking its motion
from the road wheel actuates counting wheels, and so pointers are made to
II. LENGTH. 75
indicate on dials the distance passed over and the fare. There is also an
appliance for registering on a slip of paper all the fares taken during the day.
The pointers can be brought back to zero by the driver, but they cannot be
moved forward except by the motion of the vehicle.
240. Improved Measuring Wheel or Mile Meter.
Elliott Brothers.
24Oa. Micrometrical Divisions in English and Metric
Measure. Dumoulin Froment, Paris.
27O. Holt's Diagr ammeter. This instrument is specially
made for measuring the ordinates of indicator-diagrams 6" long,
and is used much after the manner of a parallel rule, the register-
ing nut on the screw being first placed at zero ; when it is required
to register a measurement the break key is depressed, and when
all the measurements have been taken the distance the nut has
travelled gives the mean ordinate. Henry P. Holt.
274. Spherometer (by Salleron), to read to *001 mm.
The Council of the Yorkshire College of Science, Leeds.
276. The Wealemefna, E. R. Morris's patent. A pendant
for the watch-chain.
The Morris Patents Engineering fVorks, Birmingham.
To measure, it is merely necessary to advance the Wealemefna over the
object, when the large hand will register the inches and fractions of an inch,
and the small one the feet. The instrument registers to 25 feet.
276a. Schlagenheit's Measurer for Curved and Straight
Lines. S. J. Hawkins.
This instrument has a small wheel A, the periphery measuring one inch
and divided into five equal parts, indicated by fine points, marking when in
use each length by a slight indentation upon the map or plan. At each revolu-
tion of the wheel a small spring B is struck, indicating that one inch has been
traversed. Attached to the instrument is a small scale C, th of an inch in
lergth, divided into 10 parts for measuring distances less than one division
of the wheel.
276b. Opisometer. Instrument ordinarily used for the above
purpose. S. J. Hawkins.
277. Measuring Instrument, E. R. Morris's patent. (Silver
medal awarded at Manchester, 1875.) For the use of architects,
surveyors, builders, contractors, timber merchants, &c., &c., and
for general measuring purposes, in place of the rule or tape. It
measures to 100 ft., and weighs under 3 oz.
The Morris Patents Engineering Works, Birmingham.
To use the instrument it is merely necessary to advance it along the object
to be measured, when the large hand will register the inches and fractions of
an inch on the outer dial, the smaller hand on the inner dial, the feet and the
smallest hand on the recessed dial, the tens 'of feet travelled over. The in-
strument registers to 100 feet. Price, electro-silver, in leather case, 16s. 6d.
76 SEC. 3. MEASUREMENT.
278. Chartometer, E. K. Morris's patent. (Silver medal
awarded at Manchester, 1875.)
The Morris Patents Engineering Works, Birmingham.
The only instrument that measures and registers distances on maps, plans,
scaled drawings, &c., and that is adapted for various scales. By guiding the
small steel wheel along any route on a map, the hand registers the actual dis-
tance in miles, yards, &c., according to the dial in use and the scale of the
map, which should correspond. To deal with a map of a difficult scale, the
glass front is opened by pressing a spring ; the dial removed, and another
corresponding to the fresh scale slipped into its place. A set of dials adapted
to the scales of all the Ordnance maps, and the usual scales of travelling
maps, &c., &c., is contained in a recess of the leather case, beneath the
instrument.
277 a. Pedometer, of the latest and most approved form.
J. and W. E. Archbutt, Westminster.
This instrument has pendulum action, and is worn suspended in the waist-
coat pocket ; it is provided with a regulator whereby it can be set to accu-
rately record distances walked.
277b. Improved form of Pedometer, by Dollond, in which
the direct chain action is substituted for the lever ; made in the
early part of the nineteenth century.
J. and W. E. Archbutt, Westminster.
277 c. Pedometer or instrument for accurately register-
ing distances walked. This instrument was invented and made
by Spencer and Perkins in the latter part of the eighteenth
century. /. and W. E. Archbutt, Westminster.
290. Scale for Measuring Curves, Eschenauer's patent.
Hermann Schafer, Darmstadt.
The curve scale is intended for engineers, steam boiler makers, surveyors,
architects, and others, for copying maps, plans, &c.
It will be of great advantage in the projection of railway lines, the
curve scale requiring only to be adjusted to the situation in order to ascer-
tain how the line can be most favourably traced, and expensive cuttings
avoided. In regard to such surveys, as well as in the control or examination
of railway lines already traced and sketched (for which purposes either the
curves, cut of certain radii, or compasses, are used at present), the employ-
ment of the curve scale will save the trouble of trial, since the correct one can
be immediately determined and read by means of this instrument.
Boiler manufacturers, also, and almost all engaged in technical pursuits, will
find the curve scale very useful for determining the radius of an arc of a
circle, of which three points are given, as, for instance, in curved steam
boiler bottoms.
In fact, in all cases where part of an arc of a circle, or three points of the
samei are given, the radius can be read direct, and without loss of time, in a
manner hitherto unknown.
If it be desired to take the radius of a given curve by means of the scale,
the middle bar of the same is placed on the curve line, and the scale is then
III. AREA. 77
moved so far upwards or downwards until the curve line meets in three com-
niensurably described points of the scale. The number indicated gives the
radius of the curve in centimeters, if the curve is drawn in its natural size.
If, however, the drawing of which the radius of the curve is to be deter-
mined is, as is usually the case, on a reduced scale, the radius indicated must
be multiplied with the proportional number of the reduced scale.
For example, if the drawing should be to the scale of -^^ of the natural
size, and the curve radius on the curve scale is indicated with 52 5 cm., the
actual radius of the curve will be 52 '5 x 2,500 = 131,250 cm., or 1,3 12* 5 meters;
or, should the drawing be to the scale of -gfa, and the curve scale indicates
43 cm., the radius of the curve will be 43 x 500 = 21,500 cm., or 215 meters.
The curve scale can likewise be used as a reduction scale of every other
measure which is to be calculated in meter measure, as the radius in meters
can always be read directly, no matter in what scale the drawing is made.
This is a great saving of labour, which is very much facilitated if, as often
is the case, old maps and drawings are to be made use of.
In using the curve scale it will sometimes happen that the curve to be
ascertained does not exactly meet the line drawn on the scale, but will fall
between two lines. In this case the smaller division can, as the radii are
marked progressively by 0'5 cm., be easily estimated by eye after a little
practice.
For example, the curve of the radius of 1,110 meters, at a proportionate
scale of ^ 5 1 6 6 ., lies between 88 5 and 89 * of the curve scale, and amounts to
nearly 88 -9.
As, however, in most cases, round numbers, without fractions, are chosen
for the radii, the radius can always be determined with the greatest accuracy,
109 3 a. Ellipsometer.
Before the eyepiece of the glass, a double refracting prism is made to turn
until a wire, moving perpendicularly to the principal section of the prism.
passes through the two intersecting points of the two reflections of the ellipse.
An index shows at the moment the position of the prism.
Graphometer of Botti.
The Royal Institute of " Studii Superiorly Florence.
III. MEASUREMENT OF AREA. *
316. Amsler's Flanimeter, for calculating with perfect
accuracy the areas of plans, maps, or other plane surfaces, in
square inches and metrical measure. Elliott Brothers.
317. Folarplanimeter. Ott and Coradi, Kcmpten, Baviera.
By means of the polarplanimeter the superficial contents of any kind of
figures drawn on paper, no matter what their outline may be, can be ascer^
tained by mere tracing more exactly and quickly than by any other method.
The inventors of this instrument are respectively J. Amsler, Schaffhausen,
and Ch. Starke, Vienna. Ott and Coradi's construction is a combination
of both, embracing the excellences of each. It differs from Amsler's instru-
ment by the pole (axis) of the instrument not being formed by an inserted
point of a needle, but by a steel ball embedded in a metal cylinder, thus
78 SEC. 3. MEASUREMENT.
giving it a firmer position ; and, moreover, by the axis of the roller being
lodged in a horizontal frame, and the dividing circle of the roller as well as
the indicating wheel being free at the top, thereby affording much easier and
more accurate reading than Amsler's instrument. This arrangement has the
advantage that for simple calculation the zero point of the roller can be placed
exactly on the zero point of the vernier, when the tracing pencil is at the
commencement of the figure. The weight can be separated from the instru-
ment, by withdrawing the bolt, and placed in the case by itself. The runner
carrying the axis of the polar arm can be moved along the whole length of the
quadrangular bar, by which means at every longitudinal scale desired a
round number can be obtained for the value of the vernier unit (for example,
scale 1 * 500 vernier unit, 2 square meters, or scale 1 1440 vernier unit, 5 square
fathoms). The tracing bar is divided into \ mm., and the runner sliding on
the same carries on one side a vernier, on the other an index. For adjustment
with the index, the most usual or specially desired longitudinal scales are
marked with lines on the bar ; by means of the vernier and the divisions on the
bar, proportions of measure not previously given can be easily inserted and
noted down ; in the same manner, in the case of plans which have been drawn
on shrunk paper, the area can be retained in its actual size by a corre-
sponding movement of the runner, and the position of the vernier noted down
for a certain amount of shrinking.
318. Planimeter, divided on a glass plate.
F. W. Breithaupt and Son, Cassel.
The planimeter consists of a network marked on a glass plate for a certain
scale of the meter measure.
319. Wetli's Planimeter.
Physiological Institute of the University of Halle (Prof.
Bernstein, Director).
The planimeter is fitted together by placing the six-toothed movement into
the centre of the divided disc, whilst the central point of the small glass disc
moves at the other end in the screw of the ring encircling the divided disc.
Next, the slide with the large glass disc is placed on the three-railed track
in such a manner that the horizontal glass disc comes underneath the smaller
vertical one ; the latter is then, by means of the screw which is fixed on the
ring, regulated in such a manner that it is easily carried along with the hori-
zontal disc by friction.
The pointer moving on the same axis with the divided disc indicates the
superficial contents of the figure in square millimeters. The small toothed
wheel records every 1,000 square millimeters of the surface.
IV. MEASUREMENT OF VOLUME.
STANDARD MEASURES.
319a. Casts of a Collection of Roman Measures to hold
liquids. Archaeological Museum, Madrid.
The originals, of alabaster, are preserved at the Archaological Museum of
Madrid. They were discovered at the end of the last century in the Torre del
Mar, Province of Malaga, Spain.
IV. VOLUME. 79
322a. Series of Standard Measures of Capacity, in
copper, with glass discs, from the centilitre to the double
decalitre. (11 measures.)
Messrs. Collot Brothers, Boulevard de Montrouge, Paris.
324. The Standard Pint, popularly known as " The Stirling
Jug." The Smith Institute, Stirling.
This measure was entrusted to the town by Act of (the Scottish) Parlia-
ment, in the year 1437. Sometime previous to 1745 it had been borrowed
by a coppersmith for the purpose of making others, and as he joined the
insurgents in " 45 " it was lost sight of. On his not returning, his effects were
sold, with the exception of a few that were thrown into a garret as rubbish ;
among these, in 1752, the Stirling Jug was found, after some years of patient
and unwearied search (by Rev. A. Bryce, of Kirknewton). It is made of
brass, and is in the shape of a hollow truncated cone, weighing 14 Ibs. 10 oz.
1 dr. 18 grs. Scottish troy. Diam. of mouth 4.17 English in., of the bottom
5-25 in., and depth 6 in. On the front, near the mouth, is a shield in relief,
bearing a lion rampant, the Scottish national arms, near the bottom is ano-
ther, bearing an ape passant gardant, supposed to be the arms of the foreign
maker.
324a. Russian Standard Measures of Capacity (Vedro,
V., \ V., T \J- V., T ^ V.). Siemens and Halske, Berlin.
These measures, made of bronze, have a coni-
cal shape, newly adopted in Russia, for standard
and trade measures of capacity. In these mea-
sures the inner diameter, A B, of the bottom
is equal to an inner side, A C, and double
diameter, C D, of the orifice. By very sim- /
pie contrivance, such trade measures might /
be verified, approximately, by (linear) mea- / jj
surement of A B, A C, and C D.
325. Set of Standard Measures for Alcohol, conical
shaped, in order to diminish the possibility of evaporation of the
liquid. Siemens and Halske, Berlin.
322. Measures of Capacity, according to natural principles.
Hans Baumgartner, Basle.
WATER METERS.
321. Schmid's New Water Meter. A. Schmid, Zurich.
This meter consists of two of Schmid's patent hydraulic motors, coupled
at right angles, and enclosed in a water-tight casing. They are set in motion
by the force of the fluid they have to measure. At each revolution a volume
equal to the contents of four cylinders must pass. The pressure required to
keep tight the oscillating surfaces of the cylinders is furnished by the
difference of pressure at inlet and outlet, which is thus self-regulating. The
80 SEC. 3. MEASUREMENT.
meter is also kept in motion by the difference of pressure. The frictional
resistance is the same with all pressures of the fluid under measurement, and,
according to the size of the meter, is represented by a water head of 3 to
16 ft. The different parts of the meter are constructed of materials not
liable to chemical influence.
The chief advantages of this meter are :
1. The velocity of the engine is exactly in proportion to the quantity
flowing through the meter.
2. According to the most careful experiments, the error, if any, does not
exceed 1 per cent.
321a. Siemens' and Adamson's Patent Water Meter.
Guest and Chrimes, Rotherham.
This meter has a great resemblance to the motive-power machine known as
Barker's Mill. The water passes down through a funnel into the measuring
drum, and in passing outward through the curvilinear channels of the 'same
causes it to revolve, delivering a certain quantity of water at each revolution
of the drum, and this is indicated by worm wheel and gearing, in gallons, feet,
or any other units required, on a dial plate properly divided and prepared
for the purpose.
The meter is exhibited in section, so that the internal arrangements and its
action can be seen. This meter has been extensively used for upwards of 20
years.
32 lb. Half-inch Patent Water Meter, for the water supply
for domestic and trade purposes on the constant supply system.
J. Tylor and Sons, London.
326. Water-meter, for cold water, for 26 mm. width of
tube. Dreyer, Rosenkranz, and Droop, Hanover.
327. Water-meter, for domestic use.
Dreyer, Rosenkranz, and Droop, Hanover.
331. Model of a Gas Meter of ancient construction, with
glass sides.
School for Industry, Halle (Dr. Kohlmann, Director).
329. Apparatus for determining the capacity of Car-
tridge-cases as far as 20 cub. mm. A. Bonsack, Berlin.
330. New Volumeter, consisting of A. Sauer's burette,
a second glass piece, stands and tubes.
(Compare Fresenius, " Zeitschrift fur analytische Chemie," xiv.
heft. 3 and 4).
Berggewerkschafts-kasse, Bochum, Dr. Heintzmann.
V. MASS. 81
V. MEASUREMENT OF MASS.
A. BALANCES.
333. Balance, with double column, 20-inch beam, fitted with
steel knife edges working on agate planes, to carry 5 Ibs. in each
pan, and turn distinctly with '01 grain. Fitted with apparatus
for moving sliding weight without opening glass case. As made
for the Warden of Standards, for comparison of standard weights.
L. Oertling.
334. Balance, with double column, very light beam, 10 inches
long, fitted with agate knife edges and agate planes, to carry
30 grains in each pan, and turn distinctly with 001 grain, with
apparatus for moving sliding weight. L. Oertling.
335. Balance, with 14-inch beam, fitted with agate knife
edges and agate planes, to carry 1,500 grains in each pan, and
turn distinctly with *001 grain. L. Oertling.
336. Balance, with 16-inch beam, fitted with agate knife
edges and agate planes, to carry 2 ibs. in each pan, and turn
distinctly with 02 grain. L. Oertliny.
337. Balance, with triangular beam, 6J inches long, fitted
with agate knife edges and agate planes, to carry 3,000 grains, and
turn distinctly with 01 grain. L. Oertliny.
338. Balance, with beam 6 inches long, fitted with agate
knife edges and agate planes, to carry 2,000 grains in each pan,,
and turn distinctly with '02 grain. L. Oertling.
339. Portable Assay Balance, with 6-inch beam, to carry
30 grains in each pan, and turn distinctly with '001 grain.
L. Oertling.
34:0. Balance, constructed by H. Qlland, of Utrecht, to
weigh bodies up to 40 kilogrammes.
Prof. Dr. P. L. Rijke, Leyden.
This instrument is furnished with a double system of " fourchettes,"
directed by a rod 6 m. long. A difference of 1 in the pointer corre-
sponded to a difference in weight of
9 5 m. gr. when the weight was 20 kilogrammes.
10-5 50
13-8 73
With weights of about 50 kilogrammes, in a series of experiments under
favourable conditions, between each of which the balance was set at rest,
numbers not differing in the average by more than 0'03 were obtained.
When conditions were less favourable, the differences amounted to 0'26, and'
only reached 0> 94 when the conditions were altogether unfavourable.
40075. F
82 SEC. 3. MEASUKEMENT.
341. Analytical Balance, charge up to 500 grammes in
each pan ; sensible to -^ part of a milligramme with its full charge.
Beckers Sons, West Zeedyk, Rotterdam.
This balance is furnished with agate knife edges, and all bearings rest on agate
planes ; it has a rest for pans and beam, and apparatus with adjustable shelf
for taking specific gravities. The beam is divided in -J- parts of a milligramme.
Sets of weights from 500 grammes down to 1 milligramme. Three riders.
342. Analytical Balance, on plan suggested by Professor
Dittmar, Andersonian University, Glasgow, for a charge up to
100 grammes in each pan.
Beckers Sons, West Zeedyk, Rotterdam.
This instrument shows a new method for displacing the centre of gravity of
the beam, and for weighing up to 110 milligrammes by means of riders. The
two riders form a part of the balance, with plunger for displacing exactly
10 grammes of water at 15 C. for taking specific gravities of liquids. Sets
of weights.
343. Balance, with drawer and eccentric for lifting, movable
pans, set screws and level, charge up to 1^ kilos, in each pan,
sensible for 20 milligrammes with its full charge.
Beckers Sons, West Zeedyk, Rotterdam.
344. Balance, charge up to 1 kilo, in each pan, sensible for
20 milligrammes with its full charge.
Beckers Sons, West Zeedyk, Rotterdam.
344a. New description of Balance of Precision, designed
by M. Mendeleef, Professor of the University of St. Petersburgh,
and constructed by Oertling. It is more particularly described
in Appendix 10 to the Ninth Annual Report of the Warden of the
Standards. H. W. Chisholm.
The peculiarity of this balance is that it has very short arms, and thus
occupies very little room, and by its more rapid motion time is saved in weigh-
ings, whilst it gives results quite as 'accurate as those given by balances of
precision with arms of greater length as ordinarily used.
Though constructed to carry a kilogram in each pan, the total length of
the beam of this balance is less than 4f inches, whilst it is intended to give
results within one tenth of a milligram. The balance beam to carry a kilogram
is ordinarily 20 inches in length.
It can be used as a vacuum balance, as well as for weighings in air.
344b. Balance of Precision for minute weighings of 10
grains and under in each pan, constructed by Oertling.
H. W. Chisholm.
The beam is made as light as possible, and unusually so. The pans and
suspending wire are of aluminium. The balance works upon fine points.
A single action lowers the support of the beam and the supports of the
pans.
348-9. Frerich's analytical Balance, capable of carrying
2,000 grnis. with riders and *a set of gramme weights.
F. Sartorius, Gottingen.
V. MASS. 83
350. Analytical Balance, capable of carrying 500 grms., and
a set of gramme weights. F. Sartorius, Gottingen.
351. Analytical Balance, capable of carrying 200 grms.,
with a set of gramme weights. F. Sartorius, Gottingen.
352. Frerich's Analytical Balance, with contrivance for
weighing by means of torsion. F. Sartorius, Gottingen.
353. Pair of Russian Scales. Bennct Woodcraft, F.R.S.
354. Test Balance capable of carrying 20 grammes in each
scale. Edouard Sacre, Brussels.
The bearings are taken off the knife edges when the balance is at rest. With
20 grammes the balance is affected by the 750th part of a milligramme.
With 2 grammes it is affected by the 7,000th part of a milligramme.
354a. Model Balance, with 'two columns, specially intended
for verifying the standard kilogram weights, mounting and tongue
of aluminium bronze, tires and scales of aluminium, riders,
carriage for shifting the weights from one scale to the other,
rests for four weights, rules for the use of small sliding weights
replacing the divisional series of the gramme, such as the deci-
gramme, centigramme, milligramme, 10th of milligramme, hand
of aluminium with double dial, parallel mirror for reading the
oscillations at a distance, spherical level, two " Baudin " ther-
mometers.
Messrs. Collot Brothers, Boulevard de Montrouge, Paris.
354b. Model Balance, with two columns, charge 300 grammes
range, for chemical analysis, mounted on cast-iron tripod, mount-
ing and tongue of bronze, platina tires, riders showing tenths
of the milligramme, spherical level.
Messrs. Collot Brothers, Boulevard de Montr ouge, Paris.
357. Printing Beam for Weighing Machine, admitting of
the registration of each weighing. M. Chameroy, Paris.
This method of checking is applicable to all weighing machines of the
nature of the steelyard. It would be found useful at custom houses, depdts,
markets, railway stations, works, and other similar places.
Its advantages are :
1. The affording of a record, by means of a printed impression on a special
ticket, of the exact amount of the weight as determined by the machine itself.
2. The facilitating of the reading of the weights, either on the ticket or on
the scale beam.
3. The preservation of an exact record^ of weighings, the authenticity of
which is thus ensured.
358. Physical Balance, weighing up to five kilogrammes.
Hugo Schickert, Dresden.
F2
84 SEC. 3. MEASUREMENT.
359. Physical Balance, weighing up to 200 grammes.
Hugo Schickcrt, Dresden.
363. Fine Assay Balance for weighing 20 grammes, turning
with I/ 100 nig. G. Westphal, Celle.
364. Large Balance for determining the specific gravity of
liquids. G. Westphal, Celle.
365. Large Balance used in the Manufacture of Sugar.
G. Westphal, Celle.
366. Small Balance for determining the specific gravity of
liquids. G. Westphal, Celle.
367. Pharmaceutical Balance, for simple chemical opera-
tions. G. Westphal, Celle.
370. Balance for chemical and physical purposes.
C. Staudinger and Co. (F. W. von Gehreri), Giessen.
Balance of the exhibitors' construction ; capacity of weighing, one kilo-
gramme on each scale ; sensitive at this weight, to 0-4 milligr. The balance is
made of one piece of wrought (not cast) brass, and gilded. The centre and
terminating knife edges are of steel, and all supports of hard stone. The
weight of the beam with knife edges is = 793 grammes ; deflexion of the beam at
1 kilogr. weight on each scale = 0' 14 mm. ; at 1-500 kilo. weight=0'02S mm. ;
at 2-000 kil. weight = 0-042 mm.; at 3-000 kil. = 0*070 mm. A permanent
deflexion has not been observed at such a weight.
375. Ten Plates of Bock Crystal for Balances.
Hermann Stern, Oberstein.
376. Cheinico-physical Balance, executed by Ch. Jung,
in G iessen.
Collection of Physical Instruments of the University of
Giessen (Prof. Dr. Buff).
By shortening as much as possible the beam these scales offer the ad-
vantage of great sensitiveness and sufficient rigidity to weigh accurately from
250 grammes to -- milligrammes.
377. Analytical Balance, executed by Stollenreuther.
University of Munich.
379. Standard Weights in Glass, executed by Stollen-
reuther. University of Munich.
381. Model of a Balance for determining the quality of
grain, constructed according to the directions of the Imperial Ger-
man Commission for Standard Weights and Measures, with a
corn measure of 1 liter capacity. Reinhold Lohmann, Berlin.
The manner of adjusting the several parts, as well as the successive series
of applications of the same, is illustrated and facilitated by an explanation,
with sectional and cross-sectional drawings, accompanying the model.
V. MASS. 85
The practical employment and use of the apparatus for scientific and
technical industries, in the first instance, and next for the solution of national-
economical problems, will be demonstrated by two continuous memoirs,
published by the Imperial German Commission on Normal Weights and
Measures.
381a. Corn Balance, in box for showing the per-centage
in value of corn by weight as a means of fixing the price for pur-
chase or sale. L. Casella.
382. Model of a Centesimal Weighing Machine, with
glass platform. Dr. Kohlmann, Halle.
384. Model of a Decimal Weighing Machine, with glass
platform.
Physical Institute of the University of Halle (Prof.
Knoblauch, Director).
386. Beam Balance with equal arms, sensibility 1 : 200,000.
Kleemann, Mechanical Engineer, Halle.
390. Beam Balance, for educational purposes.
Alex. Bernstein and Co., Berlin.
The beam, for educational purposes, has contrivances for demonstrating
the different peculiarities of a scales-beam, or balance, namely, displacement
of the centre of gravity, lifting and grinding of the principal bearings, unequal
lengths of levers, non- parallelism of the knife edges, and position of one ter-
minal knife edge out of the level of the two other knife edges.
388. Small Decimal Balance, for educational purposes.
Alex. Bernstein and Co., Berlin.
The decimal balance for instruction in schools has on each prism a scale,
so that the influence of the weight on each prism can be shown by itself.
389. Analytical Balance.
Alex. Bernstein and Co., Berlin.
This analytical balance is capable of carrying 500 grammes, and when
fully weighted has a sensitiveness of -^ mgr. ; it has a perforated gilded
brass beam with axes of agate and pans with arrangement for releasing all
knife-edges, stop balance with pencil, and riders.
389a. New Balance for a Laboratory, carrying three
kilogrammes in each pan, and turning with five milligrammes.
Dcleuil, Paris.
When it is not in use, the beam is supported free of the knife edge, as in
other accurate balances ; vessels 25 centimetres in diameter can be placed on
the pans, also vessels with long necks, and flasks of 1-2 litres capacity. By
the aid of the second pan, the specific gravity of very bulky bodies can be
obtained.
389b. Balance in mahogany case.
Universitdts Laboratorium, Berlin,
86 SEC. 3. MEASUREMENT.
390a. Self-Acting Balance for Galvanic-plastic pur-
poses. Alex. Bernstein and Co., Berlin.
The balance for galvano-plastical purposes is so constructed that the con-
duction is interrupted automatically as soon as a deposit of a certain weight
has been obtained.
391. Balance for Blow-pipe Experiments, in a case,
with weights. Alex. Bernstein and Co., Berlin.
The scales are for blow-pipe experiments; they have steel axes, and
agate planes, two horn pans, two pairs of small gilded bowls, one bowl
with hook for the determination of specific gravities, and a set of weights from
1 gr. to 1 centigr. of silver ; from 1 centigr. to 1 milligr. of aluminium, and
the fraction milligr. of quills.
392. Gold Assay Balance.
Alex. Bernstein and Co., Berlin.
The gold-alloy scales have a carrying capacity of 5 grammes, and are
provided with bearings of agate, and indicate, when fully weighted, ^- milligr.
378. Balance for Weighing in Vacuo, on von Jolly's
principle. University of Munich.
392a. Bullion Scales. The property of the Conservatoire
des Arts et Metiers, 1866 ; constructed by Baron Seguier.
The late Baron Seguier, Membre de Tlnstitut.
419a. Spring Balance, with arrangement for suspending the
lever and the scales on steel springs.
Physical Institute of the University of Halle (Prof.
Knoblauch, Director).
428. Von Jolly's Spring-balance. University of Munich.
B. STEELYARDS.
332. Roman Steelyard or Stater a, of bronze. It was
found in the year 1855, during building operations at Watermoor,
a suburb of Cirencester, Gloucestershire.
Professor A. H. Church.
The beam, which is nearly 17 inches long, may be reversed, and it is con-
sequently divided along both its upper and under edges. When the fulcrum
nearer the head of the beam is employed objects can be weighed more than
twice as heavy as those which can be accommodated when the beam is sus-
pended by the other hook. To the head of the beam is attached a chain,
branching below into two parts, each terminated in bold hooks adapted for
grasping soft and bulky articles. This steelyard is a very good example of
its kind. The locality which furnished it was the site of the Roman city of
Corinium or Durocornovium, which has yielded an immense number of Roman
remains, many of which are preserved in the local museum.
V. MASS. 87
383. Model of a Roman Balance, with sliding weight of
To grammes, and stand.
Physical Institute of the University of Halle (Professor
Knoblauch, Director).
C. WEIGHTS.
346. Five Standard Weights derived from the polar stand-
ard of length. Prof' Hcnnessy, F.R.S.
One of these weights is equivalent at 15 centigrade to a cube of distilled
water whose side is the one hundred millionth part of the earth's polar
axis. The others are submultiples of this weight, and the Astern is
suggested in connexion with the polar standard proposed. See " Essay on a
Uniform System of Weights, Measures, and Coins of All Nations," by Pro-
fessor Henuessy.
346a. Series of Massive Copper Weights, standards of
I gramme up to 20 kilogrammes, with subdivisions in platina.
II Necessaire " for inspector of weights and measures on his rounds,
weighing about 10 kilos., and containing every requisite for testing
scales, of weights, measures of capacity, and of length, and
apparatus for stamping.
Messrs. Collot Brothers, Boulevard de Montrouge, Paris.
346b. Ancient French Standard Weight of the city of
Rouen, of brass, in the form of a series of cup weights in a
closed box of ornamental shape, weighing altogether 8 Ibs. of the
old poids de marc de Charlemagne. Presented to the Stan< lards
Department in 1869 by Colonel Le Contens, Viscount of Jersey.
H. W. Chisholm.
346c. Weight, wrought iron, ornamented with arabesques,
flowers, and masks. Made for the old Mint at Madrid in the 17th
century by the iron-master Salinas.
Archaeological Museum, Madrid.
360. Physical Weights. Hugo Schickert, Dresden.
361. Eight Sets of Weights, for analytical purposes.
G. Westphal, Celle.
The first of these weighs from 1 kilogramme downwards, the second from
500 grammes downwards, the third from 100 grammes, the fourth, fifth, and
sixth from 50 grammes, the seventh from 10 grammes, and the eighth from
5 grammes downwards.
362. Standard Weights. Each weight consists of one piece
of solid metal adjusted by the gilding process.
G. Westphal, Celle.
These consist of a 1 kilogramme weight, a set of weights weighing from
1 kilogramme downwards, and a set of standard weights with pin adjustment
weighing from 500 grammes downwards.
362a. Box of Weights, containing two kilos, and fractions of
a kilo. Deleuil, Paris.
88 SEC. 3. MEASUREMENT.
362a. Case of Weights and Measures. T. Oertling.
'Containing
Set of weights from 1 kilogramme to 1 milligramme.
Set of weights from 50 grammes to 1 milligramme.
Set of weights from 1,000 grains to -^ grain.
Set of weights for assaying silver, 1,000=1 gramme, in
circular ivory box.
Sets of weights of rock crystal (one spherical set), from 50
grammes.
Set of measures from \ litre down.
Dikes' hydrometer, as supplied to the Honourable Board of
Inland Revenue.
Bates' saccharometer, as supplied to the Honourable Board
of Inland Revenue.
Set of petroleometers for testing liquids of 650 to 900
specific gravity.
262b. Iridio-Platinum Standard Kilogram.
Johnson, Matthcy, and Co.
323. Standard Weights, according to natural principles.
Hans Baumgartner, Basle.
374. Sets of Weights and single Weights from 1 kilo-
gramme, made of rock-crystal ; amongst them some which have
been examined and marked with an index error by the Imperial
Commission for regulating Standard Weights and Measures at
Berlin. Hermann Stern, Oberstcin.
The weights, as well as the measures of quartz or rock-crystal, were
many years ago recognised as the best and most correct ; but no one has, up
to this time, executed them in such a manner as to afford institutes an op-
portunity of procuring them ; which want has now been supplied by the
exhibitor.
The other objects of agate are such as are produced by the Oberstein-Idar
grinding and polishing mill, and can be employed in different kinds of
machinery.
374a. Series of Spherical Standard Weights in Quartz,
from 1 kilogramme to 1 milligramme. A. Hilger.
374b. Standard Kilogramme Weight, quartz sphere, on
brass stand. A. Hilger.
374c. Standard Kilogramme Weight, of guaranteed value
1-0000019 kilo. A. Hilger.
387. Set of Pharmaceutical Weights from O'Ol grammes
to 200 grammes (19 pieces).
Kleemann, Mechanical Engineer, Halle.
Representation of the Weights and Measures used in
the time of Henry VII., as well as the mode of punishment of
fraudulent traders, copied from a painting on panel of the period
(doubtless official). Gardner Collection.
V. MASS. 89
D. INSTRUMENTS FOR DETERMINING SPECIFIC GRAVITY.
347. Tangential Balance for measuring the density of
liquids and solids by the angle of inclination, read on a divided
circle to two minutes, thus giving the third decimal of specific
gravity ; made by Oertling, of London.
Prof. Carl Wenzel Zenger, Prayue.
355. Hydrostatic Balance, by Ramsden; with Weights,
by Robinson, presented to the Royal Society by Lady Banks.
Royal Society.
368. Xylometer (cylindrical form), with brass cylinder.
Zimmer Brothers, Stuttgart.
369. Xylometer of Glass, prismatic form.
Zimmer Brothers, Stuttgart.
These instruments are chiefly used in the management of forests, and for
agricultural purposes.
They are employed for exact scientific examinations, especially for the
cubing of irregularly-shaped pieces of wood, and for determining the specific
gravity of wood.
Discs of wood which have been split out from the heart in the direction of
the pith rays, and therefore contain proportionate parts of all veins of wood,
can be quickly and exactly examined.
With both apparatus it is possible to read on the scale accurately down to
5 cub. centimeter (5 grammes water).
(See " Holzmessekunst," by Prof. Dr. Baur, Hohenheim.)
425. Hydrostatic Apparatus for ascertaining the specific
gravity of woods.
Prof. Dr. Nordlinger, Hohenheim, Wurttemberg.
372. Densimeter of Major Bode's construction, for determin-
ing the specific gravity of all sorts of powder.
A. and R. Hahn, Cassel.
The densimeter is the only existing instrument with which the specific
weight of all sorts of gunpowder (prismatic powder, powder-cakes, fine and
coarse grained powder, &c,), can be easily determined, in quantities of 50 to
250 grammes, with the most perfect accuracy.
It is constructed by Major Bode.
This apparatus consists of a reservoir with bolt, two gutta-percha tubes, and
a clamp.
1 . The reservoir is formed by a steel capsule, with lid fitting air tight.
By means of the bolt the lid of the steel capsule can be screwed fast on
this.
The contents of the reservoir are so measured in the clear that a prismatic
powder grain can be easily placed in it.
Lid and steel capsule are vaulted, in order to accelerate the exhaustion of
the air by pumping.
In the steel capsule in the upper part and in the lid in the lower
part, there is an air-tight cock. The reservoir communicates with these
90 SEC. 3. MEASUREMENT.
cocks by means of two channels, which, for fine-grained powder, are shut off
by a steel tinplate filter, the holes of which.have a width of 0'3 mm. The two
tubes, 1 and 2, are screwed air-tight on the plugs of the two cocks 1 and 2.
At the upper ends of both tubes funnels of glass are squeezed in for more
conveniently filling and emptying the mercury. The shorter tube, No. 1, of
about 600 mm. length, carries in the centre a glass-tube, about 200 mm. long,
divided into niillims, and can, just above this tube, be closed air-tight by
means of a screw cramp. The interior diameter of the tube No. I is about
9 mm., whilst that of tube No. 2, which is about 2,500 mm. long, measures
only about 5 mm. The gutta-percha tubes are spun over on the outside.
Reservoir and tube 1 are fastened in a wooden frame ; funnel 2 is in a
wooden- lining.
This precaution has been taken for the reason that the temperature of the
mercury and of the apparatus should be altered as little as possible during the
operation by the warmth of the hands. By means of two strings, which run
over rollers fastened in the ceiling of the room, funnel 1 and funnel 2 can be
pulled up or down at pleasure.
The auxiliary apparatus further required :
1. A thermometer, by means of which, previous to, during, and after the
filling in of the mercury, the temperature of the same will be ascertained.
2. A fine pair of scales indicating to 0*001 grammes, with a carrying
capacity of 6 kilos, (each scale 3 kilos.)
3. A barometer for determining the pressure of the atmosphere at the
place of operation.
4. A wooden scale, 1 m. long, with a steel point, and a slide for exactly
measuring the difference in the levels of the mercury meniscus in the two
tubes 1 and 2.
Theory of the Densimeter.
Let the weight of the reservoir, with the tubes screwed off, but inclusive
of the connecting piece screwing the capsule and the lid together, = R
grammes. After the reservoir has been exhausted, and filled with mercury,
let its weight at temperature t of the chemically pure mercury =T grammes.
Consequently the contents of the reservoir filled bythe mercury amount to
rp *D
cub. centim.
13-59(1 -0-00018 fr
If now P grammes of powder be placed in the reservoir, and the air exhausted
and the remaining space filled with mercury, the whole will weigh, at
temperature t, only T' grammes, hence if Y is the volume of the P grammes
powder, at t temperature,
T-T' + P
13-59 (1-0-00018 <)
consequently the specific gravity of the powder to be examined
* =spec ifi c g*y-r"*(*_-^"q-
The following examples will serve as illustration :
The specific gravity of chemically pure mercury amounts at
Gels. = 13-59; 10 Cels.= 13'5 n 19 Gels. = 13-55 ; 27 Cels.= 13'53
5Cels.= 13-58 ; 15 Cels. = 13'56 23 Cels. = 13'54.
V. MASS. 91
Example 1.
T=the reservoir filled with mercury weighs at 19 Cels.= 1091-6
K = the empty reservoir - = 329*6
Q = T li. Consequently mercury 762'0'grammes,
Consequently contents of the reservoir at 19 Cels.
T-R 762-0
= 13-59 (l-< 0-0018) = 13T5 ==56>236 Cub " Centim "
If now 60 grammes (= P) gunpowder is placed in the reservoir, and the
remaining space filled with mercury, we obtain
611-6 grammes ( = T t )
Reservoir empty =329 -6
60 grammes powder = 60-0
= 389-6 deducted,
remains Q = 222.0 grammes weight of the mercury filling the intervening
space, occupying at 19 Cels.
1 = 2^=16-444 CUD. centiin.
13'55
Consequently volume of the 60 grammes powder= 56-236 16*444
V= 39*792 cuh. centims.
p
S y = specific weight of the 60 grammes gunpowder
1.J07
39-792
Example 2.
If a powder prism weighs 42-0 grammes at 190 C. and weight of reservoir,
powder prism and mercury = 808-4 grammes.
Reservoir empty 329-6
42 grammes powder 42-0
371-6
consequently of 808-4
371-6 deducted,
= 436-8 grammes weight of mercury,
or - - = 32-236 cuh. centim. occupied hy these 436'8 grammes.
13*55
Consequently volume of the 42 grammes weighing powder prism =56-236
32-236 = 24-0 cub. centim.
Thus, specific weight of the powder prism= _I_ = 1-75
24-0
General Formula.
S _P_ F P _ __ Q
V I-I 1 T-R or -13-59(1-^0-0018),
13-59(1- t 0-0018)
g = P [13-59 (l-< 0-0018)] Since Q 1 = T' - R . - P
T-R-Qi . '
g _ P 13-59 (l-t 0-0018)
T-T' + P
92 SEC. 3. MEASUREMENT.
The extension of the examples 1 and 2, therefore, is essentially facilitated :
Example 1.
Given P= 60 gr. t= 19 C., consequently 13-59 (1 19 0-0318) = 13'53
T=1091-6 grammes, T' = 61 1-6 grammes.
Example 2.
Given P = 42 grammes <=190 C.,
consequently specific weight of mercury =13*55.
T= 1091-6 T'= 808-4
Because the expansion coefficient of the reservoir made of steel is different
for changing temperatures from that of the mercury, it will be necessary for
determining once for all empirically the weights of Tn for +0, +5, 10, 15,
20, 25, 30, 35 Gels., to calculate the required cubical contents of the reser-
voir = Vn, to interpolate them graphically, and to embody them from degree
to degree in a table.
DIRECTIONS FOR USE OF THE DENSIMETER.
The temperature of the mercury is determined and noted before, after, and
during the period of operation. For that purpose it is advisable to employ a
thermometer composed of a very fine glass tube, which admits of being
inserted in the gutta-percha tube No. 1, which has been filled up to the
aperture of the funnel.
The mercury in funnel 1 will show, on account of the friction and con-
sequent heating, 13 more heat than that in funnel 2. This difference is,
however, equalised in a very short time.
During the operation the apparatus must only be touched on the wooden lining,
in order to avoid as much as possible any variations in the temperature which
may be caused by the warmth of the hands. The powder to be tested must
be of nearly the same temperature as the mercury to be employed, for which
purpose it will be best to keep both before the testing operation for several
hours in the same room. The reading of the barometer which indicates the
pressure of the atmospheric air must be noted down.
The two tubes 1 and 2 are screwed air-tight to the reservoir, the two cocks
are opened, and the apparatus fastened in the wooden frame with vertical
position of the tube No. 1.
Thereupon the funnel T" is lifted to the level of T' (upon +760 mm.), and
chemically pure mercury poured into the funnel T", until both funnels are
filled with mercury to a height of about 20 mm. The mercury will then stand
760mm. high above the ( + 0) point of the reservoir; consequently the
pressure upon the highest point of the reservoir will be altogether two atmo-
spheres (1 atmosph. pressure corresponding in the mean to 7-fi.O mm. mercury.
Under this pressure the air in the reservoir will for the greatest part be
already forced up, and in fact in the direction towards funnel 1.
Now the cramp screw-piece is attached below the funnel 1, and above the
glass tube in the centre of the hose 1 filled with mercury, and the latter shut off
v. MASS. 93
air-tight at a height of about + 600 mm. Then funnel 2 is sunk to about
1,000 mm. below the zero point of the reservoir. The mercury level will
thereupon sink below the reservoir. In case reservoir and hose 1 were
already exhausted of air, the difference of the level of both the mercury
menisci will be exactly as much as indicated by the barometer, otherwise the
difference will be smaller. All the mercury then flows back from the reser-
voir, &c. into the funnel 2, for which reason the same must have a sufficiently
large capacity, and must be lowered carefully, not too quickly. Cock
No. 1 is then shut, funnel No. 2 lifted above the zero point of the reservoir,
and the latter, which in the most unfavourable case will contain only extremely
rarified air, filled by the same ; then cock 1 is opened, and the cramp at the
hose No. 1, so that the mercury in the funnel No. 1 can rise again. This
exhausting of the air is repeated a second time if necessary.
For testing whether the reservoir is entirely or sufficiently exhausted of air,
funnel 2 is sunk so far until its mercury level has reached about 400 mm.
below the zero point of the reservoir. Now occurs a Toricelli's vacuum in
hose 1, and the mercury meniscus is seen in the glass tube.
If there were still air in hose 1, the level-difference in the hoses 1 and 2 will
be smaller than the height indicated by the barometer for the day in milli-
meters. In this case the operation mentioned before is repeated. In all cases
at a position of funnel 2 at about 440 mm., the difference of the level of
both the mercury menisci will be, at the utmost, smaller by 2 3 mm. than
the indication of the barometer for the day. If the difference in the variation
of the levels should show itself equal to the height of the barometer, which
may be easily ascertained by the scale, by adjusting the slider fastened at
the height indicated by barometer at the upper meniscus in the glass tube ;
the pressure at the upper part of the reservoir will then be
1 atmosph. air pressure 1 =
1 atmosph. mercury pressure J
consequently the reservoir is exhausted of air.
But in order to employ a further powerfully-acting means for exhausting
the air, BO far as this should not have be'en accomplished already, the
funnel 2 is lifted as high as possible up to about 2, 760=1,900 mm., thereby
the very small quantity of air still present will be forced into the hose 1
under 2* + 1 =3* atmospheric pressure, and will ascend either towards the
hose 1, or occupy only a small and practically insignificant place, of O'OOl to
O'COOl cub. cent, by shutting off the cocks 1 and 2.
The raising and lowering of hose 1 and 2 is performed by pulling or
slackening the cords running over the rollers fastened into the ceiling of
the room.
It may now be supposed that the air is completely exhausted from the
reservoir, and that its vacuum is completely filled with mercury. At all
events the hydrostatic air pump of to 3' 5 atmosph. pressure, attached to the
apparatus in the simplest manner possible, will act much more powerfully
than any other air pump.
Finally, the two cocks 1 and 2 in the mercury are shut off, the temperature
of the latter being determined, the two hoses 1 and 2, which have previously
been carefully emptied, are unscrewed, the reservoir cleaned of the mercury
globules sticking to it (especially in the parts of the screw and the interior
channel-openings of the cocks), and the weight of the reservoir, including
bolt, determined with mercury.
94 SEC. 3. MEASUREMENT.
DETERMINATION OF THE SPECIFIC WEIGHT OF THE POWDER TO BE
TESTED.
The prisms or pieces of cake, or the coarse or fine-grained powder to be
tested, are accurately weighed on a scale.
The powder prisms of 25 mm. height, 40 mm. measured across the edges,
35 mm. on two sides, with channels each of 4-2 4 f mm. wide, or one chan-
nel 10 mm. wide, weigh, as a rule, at a specific weight of 1 '6 to 1'8, from 36
to 44 grammes.
Of grained powder so much is weighed that the steel lid can be easily fixed
on the reservoir, and fastened with the bolt, consequently about 50 grammes
in case of a small reservoir with about 76 cub. cent, capacity, or 200 gr. in
case of a larger reservoir of about 217 226 cub. cent, capacity. The
quantity of powder weighed is filled into the reservoir ; this is then closed,
the two hoses 1 and 2 are screwed on, and the operation is thereupon
proceeded with as detailed in the preceding explanations.
It must be observed that the operation is very simple and expeditious,
excluding every personal error, so that, consequently, the method, being
based on scientific principles, is a thoroughly rational one.
It should cause no surprise if the operations 1 and 2 must be repeated several
times, when the powder has been filled in, in order to raise the difference of
the level of the two mercury columns to the same height as the position of
the barometer, as the large capacities of the coal of the powder for absorbing
air is a notorious fact, and as also the moisture contained in the powder is
to a very great extent evaporated in the form of aqueous vapour, or ejected
by hydrostatic pressure and tension.
373. Mercurial Powder Balance, Major Bode's con-
struction, for determining the specific gravity of prismatic and
coarse-grained gunpowders. A. and R. Hahn, Cassel.
The mercurial powder scale replaces the alcohol or so-called " volumetrical
analysis method," and by means of this instrument the specific weight of
the different sorts of powder, prismatic, powder-cake, and coarse-grained
can be exactly determined with quantities of 40 to 50 grammes.
380. Balance for Weighing in Vacuo.
Paul Bunge, Hamburg.
The vacuum scale is a duplicate of a similar scale made by the exhibitor
for the Physiological Institute at Kiel. For facilitating exhaustion it has
been enclosed in a small receiver of 5 inches diameter and 10 inches in
height, which was only possible by the exhibitor's system of employing a
short beam. This is 69 millimeters long, and Avith a load of 50 gr. the
balance turns with -$ mgr.
The use of the scales is as follows : After the body which is to be weighed
in dried air or in a vacuum has been placed on the scales, and the exhaustion
or the desiccation has been effected, the scale can be arrested and released
by turning three studs fixed in the bottom plate. All weights of 20 gr. to
0-01 gr. can be placed on or lifted off the pan. Lastly, a rider can be tra-
versed the whole length of a beam in the line of the axis.
VI. VELOCITY. 95
VI. MEASUREMENT OF VELOCITY.
A. LOGS AND CURRENT METERS.
393. Patent Log, by Massey. For measuring speed at sea ;
in use in II. M. Navy.
Hydrograpldc Department of the Admiralty.
394. Patent Log, by Walker. For measuring speed at sea.
Hydrograpldc Department of the Admiralty.
394a. New Ship's Log. Benjamin Theophilus Moore*
In this log a revolving cylinder, furnished with screw blades, is placed
behind a tube, the front portion of which terminates in a solid pointed head.
The cylinder turns upon a spindle, in bearings inside the tube. Within the
revolving cylinder is a water-tight tube of glass containing the recording
mechanism. This tube is drawn out for the purpose of reading the dials.
The log line is attached near the centre of gravity of the whole instrument,
by which means the log is made to run horizontally, and below the surface of
the water, and as steadily as an arrow in the air.
The mechanism, being entirely protected from contact with sea water,
works smoothly, and cannot get out of order.
The glass tube is itself protected from any injury by the manner in which
it is contained within the revolving cylinder.
This log will indicate any distance, from one-tenth of a cable to one
thousand miles, with great accuracy.
394b. Massey's Patent Ship's Log. E. Massey.
Massey's Patent Frictionless Sounding Log.
E. Massey.
394c. Massey's Frictionless Propeller Conical End
Log. E. Massey.
394d. Massey's Patent Self-registering Ship's Logs.
L. P. Casella.
These logs are constructed on the rotating system devised by E. Massey,
and have registers and mile indices, to show distance run during the time the
log is overboard towing astern of ship.
394e. Reynold's Patent Pendent Log.
J. Cohen $ Co.
This log is composed of two parts ; first, the rotating log itself, and second,
the apparatus for registering the distance run while the log is overboard.
398. Ramsten's Patent Ship's Log. Elliott Brothers.
396. Current Meter, for measuring the velocity of currents
in rivers at different depths. Elliott Brothers.
An endless screw on a spindle turns two wheels at the same time, the one
recording every revolution of the blades by moving one division ; the other
indicating every complete revolution of the former.
96 SEC. 3. MEASUREMENT.
397. Bevy's Current Meter, constructed for measuring the
velocity of currents in larger rivers. Elliott Brothers.
The spherical boss is so determined that it will displace just as much water
as will balance the weight of all the parts which are fixed to the spindle, so
as to reduce friction to a minimum. Although the apparatus is covered
with glass, it has to be filled, before using it, with pure water to establish
similarity of pressure inside and outside. After every experiment the water
is removed and the spindle thoroughly dried. This form of current meter
was used by Mr. Bevy in the survey of the Parana and Uruguay rivers.
39 7a. Darcy-Pitot Gauge or Current Meter, for deter-
mining the velocity of streams of water. Prof- W. C. Unto in.
The velocity is obtained by a single measurement, and no time observation
is required. Used in Darcy and Bazin's researches on the flow of water in
pipes and canals.
399. Water Meter, based on the principle of measuring the
volume of water by recording its speed. J. A. Mutter, C.E.
This water meter consists principally of an air and water-tight chamber or
vessel, wherein moves a float, carrying two magnets of equal power, and fixed
with their dissimilar poles in juxtaposition to each other : the whole combina-
tion of the float and its spindle, together with the magnets, is made as near as
possible equal in density or specific gravity to the water. The water in pacing
through this measuring vessel is forced to take a rotary motion, by means of
a screen or a tongue, being a metal piece, put at a certain distance from the
inlet opening, and parallel with and lying along the inner circumference of
the measuring vessel. The top cover of the measuring vessel is p-operly
dished out, so a& to allow of two small soft iron armatures, fixed to a thin
metal arm or needle, to be brought outside the vessel, as near as can be to
the poles of the magnets inside; the metal arm or needle is fixed to a light
spindle, carrying an archimedean screw, which further gears with the regis-
tering parts of the apparatus. It is evident that the water in passing through
the measuring vessel, or rather alongside the same, communicates its motion
to the water inside the measuring vessel, which motion is also communicated to
the float and magnets, and lastly to the needle and worm spindle and further
gearing. It is plain that this meter really registers the true velocity of the
water, and taking, moreover, into consideration the lightness of its different
parts and the transmission of the speed of the float by means of magnets, it
will be found to be a very correct and sensitive meter, of simple and durable
construction.
399a. Current Meter, with electrical tell-tale apparatus',
according to Amsler's latest construction. (See description.)
Polytechnic School, Aix-la-Cliapelle, O. Intzc.
If the instrument makes 100 revolutions the electric current will be closed
by a contact, and the chime work will be kept in motion during some revolu-
tions of the instrument ; it will not be necessary, therefore, in measuring the
velocity in water-courses, to pull the instrument out of the water, but only to
note the time which passes from one signal to the other. By experiments it
must be ascertained what velocities of the current of the water correspond
to certain intervals of time between the electric signals.
400. Patent Electric Velocimeter, invented by Francis
Pastor elli, arranged for water currents, and for ascertaining the
speed of vessels. It consists of three parts. Francis Pastorelli.
VI. VELOCITY. 97
1. Four hemispherical cups are fixed to the end of four strong metal arms
that radiate at right angles from a central boss, mounted on a horizontal axis
at right angles to a framework of metal, or other material, BO that they may
freely revolve when placed iu the water. The horizontal axis has fixed to
it a point or piece of platina ; upon this work pressing points or surfaces,
which can he made of any form, circular or otherwise ; each revolution of the
axis causes a contact to be made.
2. The same receiving instrument, as used for the mining instrument, No.
.3388.
3. A Leclanche battery, as used for the mining instrument.
The receiving instrument can be placed in any convenient position on
board.
N.B. No. 1. This part of the instrument is intended to be fixed at any
desirable and convenient part of the vessel, or it may be arranged to throw
overboard ; under such conditions it will give more accurate indications than
the logs now in use, for it is not affected like them in their motion by depth,
or the increasing density of water ; assuming that corrections be applied for
force and direction of currents, with respect to the course or line of motion,
the errors would probably not be found to exceed 5 per cent.
402. Apparatus for indicating the Speed of a Ship by the
aid of Electricity. Be a net Woodcraft, F.R.S.
4O9. Hhysimeter, without frictioual parts, for measuring
the speed of water or other liquids whether in pipes or open
channels. Alfred E. Fletcher, Liverpool.
4O9a. Current Meter.
Benjamin Thcophilus Moore, M.A.
This instrument will measure the velocity of running water at any depth
below the surface, with accuracy and facility.
The frame is formed of thin brass bars united in front to a solid ogival
head, and terminating, in the opposite direction, iu a double vane or tail. It
is suspended in water by a cord attached to a stirrup.
The frame supports a hollow cylinder which is provided with six screw
blades, and is free to revolve upon fine pivots at its extremities. This cylinder
contains a water-tight glass tube within which is a simple train of mechanism
to record the number of revolutions made by the cylinder. This train of
mechanism is suspended in such a manner, that it remains at rest while the
cylinder revolves, and the dials which record the number of revolutions are
seen through the glass without opening the cylinder. When the instrument
is suspended iu running water by a cord attached to the stirrup, the frame
immediately takes up a position in which the axis of the revolving cylinder is
parallel to the direction of the stream. The cylinder is set in motion, and
stopped, at known instants, while under water, by means of a spring operated
upon by a light cord.
For use in very deep water a simple automatic starting and stopping
apparatus is placed inside the water-tight compartment of the cylinder, which
operates in such a way that while the instrument is descending or ascending
in water, the mechanism does not record the revolutions of the cylinder, but
only while it is at the depth at which the velocity is required. In this case
the* spring is removed and one cord only is used.
409b. Deep Sea Current Indicator.
Benjamin Theophilus Moore, M.A.
This instrument is intended to be used for the purpose of ascertaining the
direction of submarine currents.
40075. G
98 SEC. 3, MEASUREMENT.
It consists mainly of a water-tight globular shell of gun metal, pointed in
one direction, and terminating in the other in a long double vane, and is
carried by two pivots on a stirrup. Within the shell is a brass box,
suspended by girnballs in the manner of a ship's chronometer, and containing
a magnet with a graduated ring, and a train of clockwork. When the instru-
ment is lowered into deep water, its principal axis takes the direction of the
current, while the magnet settles itself in the magnetic meridian. After the
magnet and the instrument have taken up their respective positions, the
clockwork suddenly fixes the magnet at a known time. The instrument is
then drawn up out of the water and opened, when the fixed magnet shows
the direction, or bearing, of the current below.
This bearing is shown directly by the instrument when it is suspended from
a fixed platform, or from a ship at anchor, or otherwise at rest: When the
ship is in motion the instrument is to be used in combination with the deep
sea current meter, by which means the velocity and direction of the submarine
current can be determined simultaneously by a simple geometrical con-
struction.
409c. Recorder for Indicating Speed, Pressure, &c.
W. H. Bailey and Co.
B. ANEMOMETERS.
408. Anemometer, without frictional parts, suited to measure
the speed of air or gases, even when highly heated, or when
contaminated with smoke or corrosive vapours. Used by H.M.
Inspectors of Alkali Works. Alfred E. Fletcher, Liverpool.
41O. Lowne's Portable Air Meter, originally introduced
by Casella. JR. M. Lowne.
The indications of this instrument are obtained by means of a light fan
which communicates motion to indicating wheels ; the dial of the instrument
is placed at right angles to the fan, and is supported by three pillars on a base,
which also carries the tube containing the fan. The works are extremely
sensitive, the first centres running in jewels, and the indicating parts can be
thrown in or out of gear with the fan.
41Oa. Lowne's Patent Magnetic Air Meter, especially
adapted for measuring currents of air, gases, and fluids in positions
where delicate instruments would be subject to corrosion.
R. M. Lowne.
The peculiarity of this instrument is, that the registering works are en-
closed in an air-tight chamber, the connexion of the revolving fans with the
works being made through a sheet of brass by magnetism. The fans carry a
small bar magnet, and the first wheel of the indicating mechanism carries a
piece of soft iron, so that when the fans revolve outside the plate of brass the
soft iron revolves within by attraction and thereby moves the works.
41Ob. Lowne's Patent Colliery Air Meter, constructed
expressly for use in mines. R. M. Lowne.
The external aspect and form of this instrument is that of the well known
" Biram's Anemometer." The improvements consist of. 1st, a strong, light,
;aud anti-corrosive fan ; 2nd, a large clear dial ; 3rd, the indicating parts ~are
perfectly protected from dust and smoke ; and 4th, a lever is placed in a con-
venient position to enable the observer to throw the indicating wheels in or
out of gear with the fan.
VI. VELOCITY. 99
410c. Lowne's Patent Magnetic Anemometer and
Current Meter, for measurement of velocity of currents of air,
gas, and fluids. R. M. Lowne.
In this instrument the registering works are enclosed in an air-tight cham-
ber, the connexion of the revolving fans with the works being made through
a sheet of brass by magnetism. This instrument is mounted on gymbals,
with direction vane for use on board ship.
41Od. Lowne's Patent Ventilation Anemometer, origi-
nally introduced by Stanley. R. M. Lowne.
This instrument measures the air by means of a fan wheel placed in a clear
opening, without any obstruction from the registering apparatus, which is in a
separate chamber on the same plane as the fans, so that the instrument is quite
flat for the pocket ; the whole of the works are of extreme sensitiveness, and
the axes of the fans run in jewels, the indicating hands give the current that
passes the fans in feet (after correction), and a lever above the dial throws the
registering works in or out of gear with the fans.
410e. Mining Anemometer, for showing the velocity of cur-
rents in mines. Elliott Brothers.
410f. Biram's Anemometer. Improved for Coal Mines.
Francis Pastorelli.
It consists of a broad brass ring; fixed to it is a metal frame which carries
three divided circles ; in the interior and centre of the ring is a spindle
which carries eight vanes ; on one end is an endless screw ; this works a series
of wheels, which give motion to the hands on the dials, which record the
distance travelled by the air current every foot up to 100, 1,000, and 10,000
feet.
41Og. Dickinson's Anemometer.
Joseph Casartelli, Manchester.
This anemometer consists of a disc, or plate, made of light material, sus-
pended in a frame on delicate centres, having a balance weight attached to
the top of the fan. To one side of the frame is fixed on pivots a quadrant
opening out at right angles to the fan, and on it is marked the velocity of
the current in feet per minute, as indicated by the angular rise of the fan upon
which the current impinges. The advantage of the instrument consists in
the fact that it requires no timing as required by every other instrument, and
from actual experiment it is found as accurate as the most delicate instrument.
410h. Improved Biram's Anemometer.
Joseph Casartelli.
The improvement in this instrument consists in the fan being made of light
material, thus greatly diminishing the friction, and rendering it a delicate and
useful instrument.
41Oi. Biram's Patent Anemometer for ascertaining the
current of air in mines, air flues, &c. John Davis and Son.
This anemometer registers up to 1,000 feet. At the bottom there is a tube
in which a stick may be inserted, so that the experimenter can stand at a
distance from the instrument, otherwise the current of air would be deflected
by the body of the experimenter.
The vanes may at will be disconnected from the indices by means of a stud
at the side, thus rendering the process of timing more simple and exact.
G 2
100 SEC. 3. MEASUREMENT.
410k. Biram's Patent Anemometer for ascertaining the
current of air in mines, air flues, &c. John Davis and Son.
The 4" anemometer indicates up to 10 million feet. The size and angle of
the vanes are calculated from theory and corrected by experiment, each
instrument being corrected separately.
The registering apparatus consists in the 4 in. new anemometer of six small
circles, marked respectively X, C, M, X M, C M, and M, the divisions on
which denote units of the denominations of the respective circles ; in other
words, the X index in one revolution passes over its ten divisions and registers
10 x 10 or 100 ft. ; the C index in the same way 1,000 ft. ; and so on up to
10,000,000 ft.; so that an observer has only to record the position of the
several indices at the first observation (by writing the lowest of the two figures
on the respective circles between which the index points in their proper order),
and deduct the amount; from their position at their second observation, to as-
certain the velocity of the air which has passed during the interval ; this mul-
tiplied by the area in feet of the passage where the instrument is placed, will
show the number of cubic feet which has passed during the same period.
The novelty in this anemometer is in its extreme portability and substantial
workmanship ; it is supplied with a lever which disconnects, at will, the vanes
from the indices, thus rendering the process of timing more simple.
414. Edelmann's Anemometer with galvanic register.
M. Tli. Edelmann, Munich.
416. Anemometer for determining the velocity of the air,
and other gaseous currents in pipes and air passages.
Moritz Gerstenhofer, Freiberg.
C. CHRONOGRAPHS.
4O1. Apparatus for measuring the velocity of projectiles,
and capable of recording several measurements on one and the
same trajectory and of the same projectile.
Antoine Joseph Gerard, Liege.
403. Ballistic Chronoscope, with t\vo pendulums, for ascer-
taining the speed of a projectile at any point of its trajectory, by
measuring the time of flight of a portion of the trajectory ; also
for measuring portions of time between one tenth of a second and
25 seconds. Lieutenant- General Leurs, Brussels.
404. Electric Chronograph, for measuring the initial velo-
city of projectiles. Le Boulenge, Liege.
405. Electric Clepsydra, for measuring the time of flight
of projectiles. Le Bouletige, Liege.
405a. Electro-Ballistic Apparatus, for determining the
velocity of a projectile, with description of experiments and addi-
tional apparatus. M. Navez, Paris.
406. Electric Chronograph for the measurement of minute
portions of time, &c., &c. Lieut. H. Watkin, R.A.
This instrument consists of two upright cylinders resting on a base of wood ;
between them, suspended by an electro-magnet, is a weight with projecting
arms. The cylinders being connected with the secondary circuit of'an indue-
VI. VELOCITY. 101
tion coil, the circuit is complete with the exception of the small spaces on
either side of the weight. When taking velocities of shot, the primary
circuit is led through screens, constructed so that the current is broken and
immediately made again during the passage of the shot. The gun being
fired, the weight begins to descend ; the shot in passing the first screen causes
a spark to flash from one cylinder to the other through the weight which
having been previously smoked registers by a white spot the position of the
weight at that instant. As the weight continues to descend the same result
is obtained at the next screen, and so on. Adjacent to the cylinder is a time
scale divided into thousandths of a second, subdivided by a vernier of novel
construction into hundred thousandths of a second, by which the absolute
time taken by the shot between the screens is easily read off. For other uses
to which the instrument may be applied, see Royal Artillery Institution Papers.
407. Clock-Chronograph, contrived for the purpose of
measuring the time occupied by projectiles in passing over a
succession of equal spaces, with a view to determine accurately
the resistance of the air to their motion. Rev. F. Bashforth.
If the fly-wheel be spun by hand, and the markers be brought down,
they will trace two uniform spirals on the cylinder ; each marker is, however,
under the control of an electro-magnet. When the galvanic current is inter-
rupted, a record is made by the corresponding marker being suddenly drawn
aside. The circuit of the lower electro-magnet is interrupted once a second
by a clock beating half-seconds, which gives a scale of time. The circuit of
the upper electro-magnet passes along the tops of all the screens, as is
shown in the case of one screen. When one or more threads are broken
in any screen, a record is made on the cylinder. Thus, when an experi-
ment is to be made, the fly-wheel is spun briskly by hand, the markers
are brought down, and the gun is fired. The times of passing the screens are
recorded on one spiral, opposite a scale of time on the other. This instru-
ment was used in making all the experiments referred to in " Reports on
" Experiments made with the Bashforth Chronograph to determine the
" Resistance of the Air to the Motion of Projectiles, 1865-1870," published
by authority. Generally 10 screens were placed at intervals of 150 feet, but
in the experiments with the WhitAvorth gun (p. 162), 16 screens were placed
at intervals of 75 feet ; some of these records are shown. For a full descrip-
tion of the chronograph, see Proceedings of the Royal Artillery Institution,
Woolwich, for 1866, which description is also published separately.
407a. Chronograph for projectile experiments with the
recording apparatus of Deprez. Diimoulin fromcnt, Paris.
407b. Electric Chronograph. Dr. Werner Siemens.
This instrument, which was described in the year 1845 in Pogg. Ann.
(Bd. 66, p. 435), serves for the measurement of high velocities, especially
those of projectiles both along the barrel and in their further flight, and also
that of electricity.
It is based on the circumstance that an electric spark leaves a sharp mark
on polished steel, and that this mark can easily be discovered when the cylinder
has been previously blackened. The cylinder is turned rapidly by clock-
work, and each hundredth revolution is marked by the stroke of a small bell.
By means of a regulator the rapidity of rotation is so arranged that the
stroke of the bell coincides exactly with the beat of a second pendulum ; the
reading is made with a microscope with cross wires, the clockwork being
stopped. The graduation of the micrometer head gives 0-0001 of a revolu-
tion of the cylinder or millionths of a second if the cylinder rotates 100 times
a second.
102 SEC. 3. MEASUREMENT.
The measurement of the velocity of projectiles is effected by the passage of
an electric spark at the moment when the projectile touches an insulated wire
which reaches to the inside of the gun, and thus is free from retardation
caused by the inertia of matter or magnetism.
The same apparatus can be used for the measurement of the velocity of
electricity in suspended wires.
The complete apparatus comprises a Leydeu jar, induction coil, commutator,
gun barrel, chronograph, and two batteries.
407c. Recording Cylinder, with original marks by which
the speed of electricity in iron wires has been measured.
Dr. Werner Siemens.
Those marks which are surrounded by a halo or circle indicate the com-
mencement of the discharge, the successive series of small marks has been
formed by the electricity which has traversed the conductor ; the angular
distance between the first-mentioned mark and the first point of the series
gives the measurement of the speed of electricity. By measurement of the
time which the electricity requires to pass through lines of various lengths,
the electrostatic retardation, which is proportional to the square of the length
of the line, has been eliminated. By these researches it has been shown
that electricity is transmitted in conductors with a constant velocity which is
independent of the static retardation, and which for iron amounts to about
230,000 kilometres per second.
(See Monatsberichte der Kgl. Pr. Acad. der Wissenschaften, 6 Dec. 1875.)
411. Complete Apparatus for measuring the Velocity
of Projectiles in the bore of a gun, and for measuring the speed
of electricity. Siemens and Halske.
412. Vibration Chronograph, for measuring the time of
descent on an inclined plane, executed according to Beetz, by
M. Th. Edelmann, at Munich. (A description accompanies the
object.) Prof. Dr. Beetz, Munich.
413. Edelmann's Apparatus for the descent of a fall-
ing Body accessory to Beetz's chronograph.
M. Th. Edelmann, Munich.
413a. Chrono-Gonioxneter, with magnifier.
Le Vicomte Duprat, Consul- General of Portugal.
D. STROPHOMEJERS.
44. Counters and Speed Indicators.
T. R. Harding and Son.
(a.) Counters with reciprocating motion, as applied to marine and
stationary engines.
Counters with rotary motion, suitable for shafting, printing, and other
machinery.
Small counters with rotary motion applicable to spinning machinery and
various other purposes.
Pocket counters for ascertaining the speed per minute of spindles or quick
running machinery up to 10,000 revolutions per minute.
(6.) Counters actuated by pneumatic and electric apparatus at a distance
from the motion to be indicated.
(c.) Speed indicators, showing by the height of a column of mercury the
actual speed, at any moment, of engines and other machinery.
VI. VELOCITY. 103
44a. Mercurial Indicator and Counter.
T. R. Harding and Son.
The above instrument is a combination of Harding's integrating counter
and Brown's patent indicator, for which T. R. Harding and Son are sole
licensees in Great Britain.
The mercurial indicator shows the speed per minute of the shaft above
it ; the counter records AaZ/'the number of revolutions of the same shaft.
The principle of the mercurial indicator is very simple. The tubular arms
of the rotating U tube are connected with the central glass tube, and when
the instrument is at rest the mercury settles to a level in the glass tube and
arrives at the zero of the scale. When the instrument is rotated, the mercury,
owing to the centrifugal tendency, rises in the arms and sinks ill the central
tube to a greater or less extent according to the speed.
These indicators are of great importance for marine, stationary, and loco-
motive engines, as well as for various kinds of machinery.
By means of the counter and a watch, the accuracy of the mercurial
indicator can at any time be verified.
47. *' The Motometer," a machine to indicate the number
of revolutions made per minute, or other portion ,of time, by a
steam engine or revolving shaft, or any body having intermittent
motion, so that by simple inspection of a dial the rate of speed may
be seen. ff. Faija.
This instrument is constructed so as to indicate by a positive motion direct
from the engine or other moving body to which it is attached, and is of
purely mechanical construction independent of all centrifugal and other
forces of an indirect nature. The indication is consequently absolute and not
comparative.
The instrument is made in various forms to suit differences of speed, from
the slow stroke of a pumping engine to the high speed of a locomotive, &c.
The skeleton machine exhibited is suitable to indicate the ordinary speed
of a marine or stationary engine, while the one attached to the shafting is
adapted for very high speeds.
395. Hearson's Patent Strophometer or Revolution
Indicator, an instrument for showing at a glance, by the position
of a pointer on a graduated dial, the number of revolutions per
minute an engine is at the time making. Elliott Brothers.
395a. Working Model of Revolution Indicator, for
engines and machinery, by J. Wimshurst. J. F. Planner*/.
415. Mercurial Gyrometer, or " orbit meter."
Royal Polytechnic Academy {Prof. Reuleaux, Director},
Berlin.
The instrument indicates directly the angular velocity of an axle, shaft,
&c., in figures showing the rotations per minute. The reading takes place
on an alcohol column, which shows on one side a millimeter scale, and on
the other the rotation numbers. The instrument is so arranged that the
scale of the rotations has uniform graduation.
532b. Reuleaux's Ball-Gyrometer.
H. ffddicke, Engineer, Demmin, Pomerania.
The object of the instrument is to indicate the rotations made per minute
by any rotating body brought into connexion with the same. The number
104 SEC. 3. MEASUREMENT.
indicated will be read off a dial. As a peculiarity it may be mentioned that
the scale of the dial shows a uniform division, although the position of
the balancing balls moving the pointing hand depends according to a
complicated law on the velocity of the rotation of the spindle.
The motion is worked by means of straps and pulley, and can, as a matter
of course (on vessels, &c.), be effected by a fixed connexion with a shaft-
movement.
The winch-handle, however, will enable the spectator to put the instrument
in motion by the hand.
The accuracy of the indications of the instrument will be augmented if the
pointing hand is turned off a little with the finger in the direction of the pro-
gressive numbers, and then allows it to jerk back freely.
A forcible turning of the pointing hand in the opposite direction, toward O,
is not allowed.
41 5a. Revolution Indicator, to show the rate at which
machinery is working. Frederick Guthrie.
From the machinery an up-and-down motion is communicated to the piston
of a pneumatic forcing pump. The compressed air escapes through a fine
opening, and also exercises pressure on oil, water, or mercury, in a vessel
provided with a manometer tube. The height of the liquid in the tube
measures the rate at which the pump and machinery are working.
488 d. Drawings of a Simple Counter, and of a Registering
Counter.
(Sec Report of Baron Seguier to the Society of Encouragement,
1844.) M. Winnerel, Paris.
VII. MEASUREMENT OF MOMENTUM.
417. Model of the Ballistic Pendulum, erected in the
Royal Arsenal in 1814, and transferred to the Royal Military
Repository in 1836. Weight, 7,740 Ibs. Centre of gravity below
centre of suspension 10'97 ft.; centre of oscillation below centre
of suspension 1 1 88 ft. Scale Jth. Major M. L. Taylor, R.A.
418. Navez Electro-Ballistic Apparatus.
Major M. L. Taylor, R.A.
41 8a. Discussion on Electro-Ballistic Apparatus.
419. Model of Ballistic and Gun Pendulum, as erected
at Shoeburyness in 1858. Oscillating system of gun pendulum,
weighs 37 Ibs. 10-5 oz. ; that of the block pendulum weighs
31 Ibs. 8-25 oz. Scale, Jth. Major M. L. Taylor, R.A.
VIII. MEASUREMENT OF FORCE.
42 la. Attraction Meter. An instrument for measuring
horizontal attraction. j) Tt Siemens.
vni. FORCE. 105
This instrument consists of two horizontal tubes of wrought iron, ter-
minating at each end in a horizontal tube of cast iron. The first-named
horizontal tubes are partiall}* closed at their extremities, and communicate
with the transverse tubes below their horizontal mid-section. The transverse
tubes communicate also by means of a horizontal glass tube of 2 millims.
diameter at a superior level to the former.
The whole apparatus being mounted upon three levelling screws is filled
to the level of the half diameter of the transverse tubes with mercury, which
mercury also fills the whole of the longitudinal connecting tubes ; the upper
halvc-s of the cast -iron transverse tubes and the glass connecting tube are
filled with alcohol, comprising, however, a small bubble of air, which can be
made to occupy a central position in the glass tube b} r raising or lowering
the levelling screws.
If a weighty object is approached to either extremity of the connecting
tube, an attractive influence will be exercised upon the mercury, tending to
a rise of level in the reservoir near at hand, at the expense of the more
distant reservoir ; and this disturbance of level between the two reservoirs
must exercise a corresponding effect upon the index of air in the horizontal
glass tube, moving it away from the source of attraction. The amount of
this movement must be proportional to the attractive force thus exercised.
Variations of temperature have no effect upon this instrument, because the
liquids contained on either side of the bubble of air are precisely the same
in amount ; and the total expansion of the liquids is compensated for by
open stand tubes rising up from the centre of the connecting tubes through
which the apparatus can be easily tilled.
It is suggested that an instrument of this description may be employed
usefully for measuring and recording the attractive influences of the sun and
moon which give rise to the tides.
The instrument, which is of simple construction and not liable to derange-
ment from any cause, would have to be placed upon a solid foundation with
its connecting tube pointing east and \vest, records being taken either by
noting the position of the index upon the graduated scale below, or by means
of a self-recording photographic arrangement.
42 Ib. Bathometer. An instrument for measuring the depth
of the sea without the use of the sounding line. Dr. Siemens.
The total gravitation of the earth, as measured on its normal surface, is
composed of the separate attractions of all its parts, and the attractive
influence of each equal volume varies directly as its density, and inversely as
the square of its distance from the point of measurement.
The density of sea water being about i-026, and that of the solid con-
stituents composing the crust of the earth about 2'763 (this being the mean
density of mountain limestone, granite, basalt, slate, and sandstone), it
follows that an intervening depth of sea water must exercise a sensible
influence upon total gravitation if measured on the surface of the sea.
The bathometer consists essentially of a vertical column of mercury con-
tained in a steel tube having cup-like extensions at both extremities, so as to
increase the terminal area of the mercury. The lower cup is closed by means
of a corrugated diaphragm of steel plate, and the weight of the column of
mercury is balanced in the centre of the diaphragm by the elastic force derived
from carefully tempered spiral steel springs of the same length as the column
of mercury.
One of the peculiarities of this mechanical arrangement is, that it is para-
thermal, the diminishing elastic force of the springs with rise of tempera-
ture being compensated by a similar decrease of pressure of the mercury
106 SEC. 3. MEASUREMENT,
column, which decrease depends upon the proportions given to the areas of
the steel tube and its cup-like extensions.
The instrument is suspended a short distance above its centre of gravity in
a universal joint, in order to cause it to retain its vertical position, notwith-
standing the motion of the vessel, and vertical oscillations of the mercury are
almost entirely prevented by a local contraction of the mercury column to a
very small orifice. The reading of the instrument is effected by means of a
glass tube on the top, which connects the upper surface of the mercury with a
liquid of less density. In this is enclosed an air bubble, whose position on a
scale indicates the depth of water below the instrument.
Variations of atmospheric pressure have no effect upon the reading of this
instrument ; but a correction has to be made for variations of atmospheric
density as affecting the relative weight of the mercury column, which correc-
tion might be avoided, however, by excluding the atmosphere from both the
upper and lower surface of the mercury, and connecting the extremities of
the column. The only necessary correction is that for the effects of latitude,
which may be calculated as depths in fathoms, and tabulated for use with the
instrument.
The readings of the instrument have been checked by actual soundings
taken by means of Sir William Thomson's steel wire sounding apparatus ;
and the comparable results agree in all cases as closely as could be expected,
considering that the sounding line gives the depth immediately below the
vessel, whereas the bathometer gives the mean depth taken over a certain
area, depending for extent upon the depth itself.
It is thought that the bathometer may render useful service to the mariner in
warning him of changes of depth long before reaching dangerous ground ;
and the position of a vessel, when no astronomical observations can be taken,
may be ascertained by means of the instrument, provided the contour lines of
equal depths of oceanic basins were accurately laid down.
42 Ic. Graphical Bathometer , after von Jolly.
University of Munich.
42 Id. Gravimeter. An instrument for the measurement of
the variations of the earth's attractive force, invented by J. A.
Broun, F.R.S., and constructed from his drawings by Dr. C. F.
Miiller, of Stuttgart. J. Allan Broun, F.R.S.
The instrument consists of a weight suspended by two gold wires ; a single
wire fixed to the top of the weight and passing through its centre carries a
cylindrical lever ; when the lever is turned through 360 at the normal (say
southern) station, the torsion of the single wire thus produced carries the
weight round through an angle of 90. The forces then in equilibrium are,
the torsion force of the single wire and the attraction of the earth on the
weight, Avhich, as the two wires are no longer vertical, has been slightly raised
and seeks to attain its lowest point.
On proceeding from a southern to a more northerly station the earth's
attraction increases ; the amount of this increase may be measured in two
ways :
1st. The lever will require to be turned through more than 360 in order to
carry the weight to the height due to turning it through 90. (Had the station
been more southerly the lever would be turned through less than 360.) The
difference of the angle from 360 measures the increase (or diminution) of
weight.
2nd. By removing a small portion of the weight, equal to that due to the
increased attraction of the earth, the weight can be turned through exactly
VIII. FORCE. 107
90 by rotating the lever through ,360, as at the normal station. (On pro-
ceeding south weight has to be added.)
The following are the instrumental arrangements in order to make these
observations :
The weight has on each of three sides, at its base, a vertical mirror
silvered, not quicksilvered) ; the middle mirror makes an angle of exactly
90 with the other two. The lever also carries a vertical mirror, which when
there is no torsion in the suspension wire is immediately below and in the
same vertical plane with the middle mirror of the weight. A telescope,
having a glass scale at the focus of the eye-piece, is adjusted so that images
of the scale can be seen (one higher than the other) reflected from the middle
mirror of the weight and the lever mirror. When both of these mirrors arc
exactly in the same plane, the middle division on the scale seen directly with
the eye-piece, coincides with the same division in the two reflected images.
By a wheel and pinion (with endless screw and clamp for delicate movement)
placed below the instrument, a polished agate point can be made to act on a
similar agate point fixed to the lever, so as to turn the latter through any angle.
When turned through 360 the middle scale division again agrees with the
image from the lever mirror. If the image reflected from one of the side
mirrors of the weight does not agree also, the lever is turned through a greater
(or lesser) angle than 360, till this agreement is obtained ; the difference of
the angle through which the lever has been turned from 360 is obtained from
the scale reading, as seen on the lever mirror.
The following apparatus is employed for very small increases or diminutions
of the weight. Suspended to and vertically below the lever is a carefully
calibrated glass wire (1 millimetre diameter), which enters a glass tube fixed
below the instrument. At the lower end of this tube is a cistern containing
a liquid (distilled water, or as at present, chemically pure glycerine). This
liquid can be forced into the glass tube by a screw and piston (as in some
barometer cisterns). The liquid is then raised till such a diminution of weight
is produced by the immersion of the glass wire as to bring the mirror of the
weight through exactly 90, when the lever is turned through 360. The
length of glass wire immersed is read, by a micrometer microscope and scale,
to a thousandth of a millimeter.
Though finely polished agate points have been employed for turning the
lever so as to diminish the friction, there is an additional apparatus to ensure
that vertical friction has no effect on the observation at last. The lever
contains a magnet ; and two bar magnets, with rack-work adjustments for
height, are placed one on each side of the instrument, so that by a pinion and
rack movement they can be approached to the lever magnet till their force is
exactly equal to the torsion force of the single wire, and the agate points are
no longer in contact.
The instrument is made to serve for latitudes differing about 10 or 15,
but an auxiliary apparatus carries five platinum rings, which can be lowered
upon the weight, so as to make the instrument serve from the equator to the
poles, and to any height in the atmosphere.
There are special appliances for portability, by one of which the weight is
fixed ; another fixes the lever ; so that strain is removed from the suspension
wires> and the suspended pails cannot be shaken from their places. Levels,
a thermometer, and other details fit the instrument for the most accurate
observations. The suspension wires are fixed at their ends in a special
manner, so that the fixed points cannot vary. All the suspended apparatus is
electro-gilt.
42 Id. Photograph of Automatic Bathometer.
A. Gerard, Lie ye*
108 SEC. 3. MEASUREMENT.
In this instrument a lever of the second order supports a glass cylinder
containing 100 grammes of mercury by means of a spiral spring attached to
its extremity. The variation of the weight of the mercury, due to a change
in the altitude of the point of observation, produces a corresponding variation
in the length of the spring ; this is rendered apparent by means of a pointer
30 centimeters in length, worked by a watch chain passing round a pulley on
the axis of the pointer and attached to the lever.
42 le. Photograph of Pendulum of Altitude.
A. Gerard, Liege.
The pendulum consists of a glass rod mounted on knife edges ; the bob is
a cylinder of mercury attached to the glass rod by a spiral spring, thus
affording a perceptible variation in time of oscillation, due to variations of
gravity.
42 5 a. Drawing of a Registering Statical Gauge for
Pressure in Guns. System of W. Paschkiewitsh.
Captain W. Paschhiewitsh, St. Petersburg.
2828. Dynamic Anemometer for obtaining the horizontal
and vertical pressure of air in motion, upon inclined surfaces of
different forms and angles. Manufactured by John Browning.
The Council of the Aeronautical Society of Great Britain.
This instrument is intended simultaneously to determine the component
parts i.e., how much pressure is due to the horizontal, and how much to
the vertical of a current of air when directed against planes of different
areas, and of different forms, at angles varying from 15 to 90. The experi-
ments are tabulated in the Aeronautical Society's Keport for the year 1871
(Hamilton and Co.).
426a. Machine for measuring the slipping between hard
surfaces rolling in contact. Prof. Osborne Reynolds.
This machine was constructed for the purpose of verifying the conclusions
of the exhibitor respecting rolling friction, and the existence of a certain
amount of slipping between two smooth surfaces of different curvature, or diffe-
rent hardness, when the one rolls on the other under pressure. It has also been
used to measure the slipping between the surfaces, when the one is driving
the other against various resistances and at various speeds, as well as the
wear of the surfaces.
The large rolling surface is of cast-iron, supported so that it can rotate
freely, but otherwise rigidly fixed. For the smaller surface various materials
have been used, that exhibited being of steel ; this cylinder is supported so
that while its axis is always parallel to that of the larger cylinder, it can
be pressed against the latter with various degrees of pressure by means
of a lever acting through friction rollers. Arrangements are made for
recording the number of revolutions of both cylinders ; and connected with
"both spindles are driving pulleys and friction breaks on Appold's system, by
means of which the force to be transmitted can be regulated.
An amount of slipping of not more than the one hundred thousandth part
of the distance rolled can be measured with this machine.
The machine was constructed in Owen's College by Mr. Foster.
IX. WORK. 109
IX. MEASUREMENT OF WORK.
429. Dynamometer, graduated up to 100 kilogrammes by
intervals of 200 grammes, and showing dynams in kilogrammetres
up to 981, each interval measuring two dynams nearly in absolute
measure. P r f> Hennessy, Dublin.
430. Dynamometer graduated up to 10 kilogrammes, and
giving absolute dynams in kilogrammetres up to 98, each interval
measuring nearly one dynam in absolute measure.
Prof. Hcnnessy, Dublin.
Dynamometers similar to these are are employed at the Royal College of
Science. Dublin, as referred to in the College Directory for 1876-77, page 17.
" The dyuam or unit of force commonly employed throughout the course is
one kilogramme moving through one metre in one second of time."
430a. Photograph of Electrodynamometer. Made by
Professor H. A. Rowland, Johns Hopkins University, Baltimore,
on the model of that of the British Association.
Cavendish Laboratory, Cambridge.
431. Drawing of a Dynamometrical Apparatus, con-
structed in 1844 by the exhibitor, to measure the real horse-power
of steam-boats. Prof. Daniel Colladon, Geneva.
This apparatus, approved by the Academie des Sciences in 1843, was, in
the same year, adopted in the IJoyal Dockyard at Woolwich.
644. Surface Spring Indicator.
H. Hadicke, Demmin, Pomerania.
The indicator was constructed by the exhibitor, and executed from his
drawings by Messrs. Blanche and Co., in Merseburg. The piston has been
replaced by a surface spring, and the construction aims at
1. Avoiding the friction of the piston of the indicators hitherto in use.
2. Avoiding the slackness of the piston.
3. Avoiding the points of the diagram of machines in rapid motion
produced by the mechanical momentum of the piston.
432. Richard's Patent Steam Engine Indicator, with
Darke's Patent Detent and Cord Adjuster. Elliott Brothers.
By means of the detent, the paper cylinder is instantaneously set in motion
or stopped by the movement of the pencil arm, as it is being applied or with-
drawn, giving great facilities for taking a number of consecutive diagrams,
also rendering its application to oscillating engines much more convenient.
433. Cooper's Patent Slide Valve Indicator. An in-
strument for ascertaining the relative position between the piston
and slide valve of an engine at different points of the stroke.
Elliott Brothers,
1 1 SEC. 3. MEASUREMENT.
434. Flexion Pandynamometer. An instrument designed
to determine the work done by a stearn engine, by means of the
flexion of the beam. G. A. Him.
On the upper edge of the beam is a rigid wooden bar of the same length,
resting in the centre on a fork which prevents it from swerving, fastened to
one end of the beam with an iron rod, and free at the other end. To this
extremity is attached an inelastic cord, which passes round a pulley, fixed
at the head of the beam, and is carried thence towards the centre, where it is
wound round the axis of a very light needle.
It is evident, from this arrangement, that when the beam moves in either
direction, the end of the wooden bar which remains rigid approaches to or
recedes from the head of the beam. The cord consequently winds itself
round, or unwinds itself from, the axis of the needle, and the deviation of the
latter indicates the degree of flexion of the beam, multiplied if desired. At
the end of the needle is fixed a pencil, which works on a small board placed
above the beam. This pencil, at each double stroke of the piston, traces a
closed curve, of which the ordinates indicate the successive degrees of flexion
of the beam during the work. To determine, once for all, the degree of
flexion corresponding to a given load, the crank of the fly-wheel should be
fixed at the dead point, and steam at a known pressure should be introduced
into the cylinder.
435. Torsion Pandynamometer. This instrument is de-
signed to measure the power supplied by an engine to a factory,
by means of the torsion of the shafting through which the motive
power is transmitted. G. A. Him.
At the extremities of one length of the shafting are keyed two toothed
wheels of equal diameter, which gear, one directly and the other by an inter-
mediate wheel, into two smaller pinions. These pinions gear into the four
bevelled wheels of an ordinary differential movement. The two intermediate
wheels of this movement are loose on a shaft, which is prolonged in a vertical
direction, and made of a light steel rod. The result of this arrangement is,
that if the shaft twists, this rod deviates, and forms with a vertical line an
angle proportionate to the torsion to which the shaft is subjected. At the
upper and free extremity of the steel rod is seciyed, by means of a hinge, a
horizontal very light wooden bar, carrying at its extremity a roller, to which
is attached a recording apparatus. This roller, when the shaft is at rest, lies
in the centre of a wooden disc covered with paper, and revolving uniformly
on a vertical axis.
So soon as the steel rod deviates from a vertical line, in consequence of the
torsion of the driving shafting, the roller leaves the centre of the disc, and
begins to revolve. The turns registered by the recording apparatus are exactly
proportional to the torsion of the shafting.
The mean torsion of the shafting being thus known for a clay's work, two
parallel levers, placed in contrary directions, are securely fixed at the extre-
mities beyond the two toothed wheels, and the free extremities of the
levers, so as to determine the deviation caused in the vertical bar by a given
weight.
Simple proportion then gives the resistance, corresponding to the mean
angle obtained during a day's work, and it becomes easy to determine the
mechanical work which corresponds to this angle.
X. ANGLES. Ill
435b. Dynamometer Waggon, for marking and registering
the tractive power, and the distances travelled.
Eastern Railway of France Company, Paris.
436. Theoretical Pressure Diagram for calculating the
mechanical work in a steam cylinder.
H. Hadickc, Demmin, Pommerania.
X. MEASUREMENT OF ANGLES.
437. lO-inch Protractor, by Ramsden. Royal Society.
438. Clinometer of Precision, employed in 1865 by Pro-
fessor Piazzi Smyth in the interior of the Great Pyramid.
Prof. Piazzi Smyth.
This instrument was made to order by T. Cooke and Sons, of York, in 1864,
at the cost of Andrew Coventry, Esq., of Edinburgh, for measuring the
interior slopes of the Great Pyramid. When thus used it was further
mounted on a deep wooden beam, 120 inches long, armed with feet of gun
metal.
The angle measuring portion of the instrument is a complete circle, pro-
Tided with three pairs of opposite verniers, each reading to 10" in order to
eliminate errors of division as well as eccentricity, and the whole circle can
be moved and clamped on its centre so as to repeat any required angle all
round the circumference. On the voyage to Egypt a thermometer broke
inside the box, and the mercury tarnished the divided rim in parts. The
Pyramid angles thus obtained were printed in Vol. II. of " Life and Work
at the Great Pyramid," by Professor Piazzi Smyth, in 1867.
439. Smaller Clinometer of Precision, with improved
mounting, readers, and level. Prof. Piazzi Smyth.
This instrument was made to order by E. E. Sang, of Edinburgh, in 1869,
and intended for measuring Great Pyramid angles of slope. It carries its
own footbar, 25 inches long, has improved readers and illuminators, and a
chloroform level, as being more quick and frictionless than either ether or
alcohol. The circle can be rotated and clamped on its own centre for due repe-
tition of the angles round the circumference ; the verniers read to 1', and there
are supplementary verniers for investigating errors of division.
435a. Method of ascertaining Angles of Torsion by means
of instruments constructed by Professor Wischnegradski.
Laboratory of Mechanics, Technological Institute, St.
Petersburg.
This is composed of a support fixed with two horizontal screws in the
given section of the beam subjected to torsion. This support carries a
horizontal axle, upon which is fixed an arc, bearing the teeth, whose pitch
measures an angle of 2,440 seconds. This arc gears with an endless screw, the
head of which bears a circle divided into 244 equal parts, and furnished
with a fixed decimal vernier ; the arc also carries a very sensitive level, placed
at the beginning of the experiment in a horizontal position.
1J2 SEC. 3. MEASUREMENT,
The angle of torsion between the two given sections of the beam is calcu-
lated by two instruments exactly similar. The deformation of the twisted
beam causes an inclination of the levels of both instruments ; they are re-
stored to their original position by means of the endless screws, and then is
effected the reading of the angles described by the arcs of the two instru-
ments. The difference between these angles is the angle of torsion required.
In the Laboratory of Mechanics of the Technological Institute of St.
Petersburg the well-known apparatus of Wohler is used for the torsion
of trees, the photograph of which, taken together with the instruments for
measuring the angles of torsion, is exhibited. For demonstrating how to use
the instruments, a provisional apparatus is exhibited, wherewith the torsion
of the beam is effected by means of a simple lever.
442. Clinometers, devised by the Rev. Professor
Hen slow, one of which was used by Dr. Hooker in his
Himalayan journeys. J. I). Hooker, M.D., P.JR.S.
442a. Three Clinometers. G. W. Strawson.
443. Protractor, with scale, vernier, and magnifying glass.
Reads to 1 min. Prof. Baron von Feilitzsch, Greifswald.
443b. Instrument for the Measurement of Angles.
Dr. Fr. Holler, Selbo Drontheim, Norway.
440-1. Drawings and Photographs of Dividing Ma-
chinery. Messrs. Trougliton Simms.
Fig. 1. General view of dividing machine.
A. The circular table with racked circumference containing 4,320 teeth,
each tooth, therefore, equal to five minutes of arc.
B. The screw by which movement is communicated to Table A.
C. A ratchet wheel attached to the screw shaft.
D. A crank arm which during one half of a revolution gives a forward
movement to the screw ; during the remaining part of its revolution
the screw is at rest. The axis which carries the crank arm has a
bevelled wheel upon it, serving to communicate motion to the
cutting apparatus.
E. The cutting frame.
F. A cam to give movement to the dividing knife or other tool by which
the division is made.
The apparatus is so arranged that the division may be cut whilst
the circular table is at rest, the tool being lifted by a second earn (not
well seen in the drawing) when the table is in motion.
Fig. 2. Plan of cutting apparatus showing the relation it bears to the
circular table and screw.
Fig. 3. Section of table and axis.
Fig. 4. Drawings of cams and cutting frame, the cam " h " for lifting the
tool (just seen in Fig. 1) is here shown.
XI. TIME.
XLMEASUREMENT OF TIME.
Copy of the Drawing representing the first idea of the
Application of the Pendulum to the Clock ; dictated by
Galileo, then blind, to his son Vincenzo and his disciple Viviani.
Elucidated on the original of the Galilean manuscripts in the
Biblioteca Palatina.
The Royal Institute of ^ -Studii Super iori," Florence.
40075.
114 SEC. 3. MEASUREMENT.
In an account which he gave Prince Leopoldo de' Medici, Viviani, after
having described Galileo's experiments on the pendulum, and the way in
which he applied it to the measurement of time, continues thus : " But as
ff Galileo was most liberal in communicating his inexhaustible speculations,
" it frequently happened that the uses and newly discovered properties of
" his pendulum, spreading little by little, fell into the hands of persons who
" adopted them for their own ends or inserted them in publications, and
" by artfully passing in silence over the name of their true author, made
" such use of them that it was believed at least by those who knew nothing
" of the origin of the discoveries that the writers were the real authors of
" them. He next speaks of the observations of the ' Stelle Medicee,' of the
" tables relating to them prepared by the Padre Renieri, of the offering made
" by Galileo to the States General of Holland of his method for determining
" longitudes by means of the eclipses of Jupiter's satellites, and of Galileo's
" determination to send his son Viucenzo and the aforesaid Padre to Holland,
" since he himself, being old and blind, was unable to travel thither." He
then continues : " While, therefore, Padre Renieri was employed on the
" composition of the tables, Galileo gave himself up to meditations on his
" time-measurer; and I remember, one day in the year 1641, when I lived
" near him in the Villa d'Arcetri, that the idea struck him that it would be
" possible to adapt the pendulum to clocks with weights or springs, and
" make use of it instead of the usual regulator, hoping that the perfectly
" equable and natural motion of the pendulum would correct all the defects
" in the mechanism of the clocks. But as his blindness deprived him of the
" power of making plans and models of the designs he had formed in his
" mind, his son Vincenzo having arrived one day at Arcctri, from Florence,
" Galileo confided his ideas to him, and many times afterwards did they
" reason over the matter, and at last settled upon the method which is
" shown in the accompanying draAving, and then set to work' at once
in order practically to overcome those difficulties which for the most part
it is impossible to foresee. But Sig. Viucenzo intended to construct the
instrument with his own hand, in order that by this means the secret
of the invention should not be reported by the artificers before it had
been presented to His Serene Highness the Grand Duke, his master, and
to the States General (to be used for observing the longitude), but he
put off the execution of his work so frequently that a few months later
Galileo, the author of all these admirable inventions, fell sick, and on the
8th of January 1641, ' ab Incarnazione ' according to the Roman style, he
died ; and consequently Sig. Vincenzo's energies so cooled down that it
was not until the month of April 1649 that he actually began to make the
present clock upon the idea explained to him by his father Galileo. He
then managed to obtain the services of a young man who is yet living
named Donienico Balestri, a locksmith who had had some experience in
making large wall clocks, and he made him construct the iron frame, the
wheels and arbors, but the tooth-cutting and the remainder of the work he
executed with his own hands, constructing on the highest wheel called the
scape wheel (tacche) 12 teeth with as many pins (pironi} spaced between
the teeth, and with a pinion of six leaves on the same arbor, and another
wheel of 90 teeth which moves the above-mentioned. He then fixed on
one side of the support which is at right angles to the frame the detent
(scatfo) which rests on the scape wheel, and on the other side he fixed the
pendulum, which was made of an iron wire screwed at the lower extremity
for the attachment of a ball of lead, so that it could be lengthened or
shortened for regulating. When this much had been done Sig. Vincenzo
wished me (as one who was in the secret of this invention and who inde i
had urged him on to complete it) to see, by way of trial, the combine 0.
XI. TIME. 115
" working of the weight and the pendulum. I observed the mechanism in.
" operation more than once, and his workman was likewise present. When
" the pendulum was at rest it prevented the descent of the weight, but when
" it was raised and then let go, in passing beyond the perpendicular, Avith
" the longer of the two arms attached to the pivot of the pendulum, it raised
" the detent which fits into the scape wheel, which wheel drawn by the weight
" in rotating with its higher part moving towards the pendulum, pressed with
" one of its pallets on the other shorter arm, and gave it, at the beginning of
" its return, an impulse sufficient to cause it to swing to the height from
" which it had started, so that when it fell back naturally, and had passed
" the perpendicular, it returned once more to lift the detent, and immediately
" the scape wheel was set in motion and gave a fresh impulse to the pen-
" dulum, thus, the swinging of the pendulum was rendered continuous until
" the weight had reached the ground. We examined the operation together,
" connected with which, however, many difficulties arose ; but Sig. Vincenzo
" did not doubt but that he would be able to overcome them all, indeed he
" fancied that he would be able to apply the pendulum to clocks in a different
" manner and by means of other inventions ; but since he had got so far, he
" wished to finish it on this plan, as the drawing shows it, with the addition
" of hands to show the hours and even the minutes. For this purpose he set
" to work to cut another cog-wheel. But whilst engaged on this work to which
"' lie was unaccustomed, he was overtaken by a very acute attack of fever, and
" was obliged to leave it unfinished at this point, and on the 22nd day of his
" illness, 011 the 16th of May 1649, all his thoughts and aspirations, together
" with this most exact measurer of time, were for ever lost to him. He,
" their author, passed away to measure (let us hope) in the enjoyment of the
" Divine Essence, the incomprehensible moments of Eternity."
Dodecahedron, with eleven solar watches, made in Florence-
in 1587. The Royal Institute of u Studii Superiori" Florence.
Horizontal Solar Watch.
The Royal Institute of " Studii Superiori" Florence.
Horizontal Watch, at the latitude of 43 44', made by
Cammillo della Volpaja, Florentine, in the second hah 5 of the 16th
century. The Royal Institute of " Studii Superiori" Florence.
Vertical Watch, of boxwood, at the latitude of 43 30' r
made in Florence in 1590 by Girolamo della Volpaja.
The Royal Institute of " Studii Superiori" Florence.
Night Watch, at the latitude of 43 30', made in Florence in.
1568 by Girolamo della Volpaja.
The Royal Institute of" Studii Superiori" Florence*
483. Universal Dial, made in 1616 for Prince Charles.
The Royal United Service Institution.
Presented to the United Service Museum, in 1832, by Captain W. H.
Smyth, R.N., K.F.M., F.K.S., &c., &c.
485. Universal Dial, in use about 160 years ago.
The Royal United Service Institution*
Presented to the United Service Museum in 1838, by His Royal Highness
the Duke of Sussex.
H 2
116 SEC. 3. MEASUREMENT.
484. Timekeeper, which was twice carried out by Captain
Cook. The Royal United Service Institution.
This timekeeper is thus spoken of in Cook's Voyage to the Pacific, 1776,
Vol. I., p. 4 : "I had likewise in my possession the same watch or time-
" keeper which I had in iny last voyage, and which had performed its part
" so well. It was a copy of Mr. Harrison's, constructed by Mr. Kendall."
This watch was taken out again by Captain Bligh, 1787, and when the
crew of the " Bounty " mutinied it was carried by the mutineers to Pitcairn's
Island. In 1808 it was sold by Adams to an American, Mr. Mayo Fletcher,
who sold it in Chili, and in 1840 it was purchased for fifty guineas by Sir
Thomas Herbert. It was repaired and rated at Valparaiso, and taken by Sir
Thomas to China, and brought home in the " Blenheim" in 1843, having kept
a fair rate with the other chronometers for the space of three years.
Presented to the institution by Admiral Sir Thomas Herbert, K.C.B.
484a. Two Hour Glasses. These were used in Spanish
men-of-war at the beginning of the last century.
Ministry of Marine ', Madrid.
484b. Chronometer, the fifth made by the English maker
Arnold. It was used on board one of the Spanish ships at the
battle, of Trafalgar. Ministry of Marine ', Madrid.
491. Ancient Striking Clock.
H. M. Commissioners of Patents.
This clock is of Swiss manufacture, and supposed to have been made in the
year 1348. It was obtained from Dover Castle, and had never been removed
from there till the year 1872. It is interesting from the fact of its having the
verge escapement, which was used many years before the pendulum.
444. Clock Dial. The hours, six only, are indicated by
perforated Roman letters. The hand or pointer is formed of a
revolving disc, painted in oil, with the subject of Aurora and
the Hours ; it must have gone round four times in 24 hours.
The dial is fitted in the original carved door of the clock.
Italian. 17th century. Rev. J. C. Jackson.
445. Clock, in the shape of an orb of silver-gilt, covered
with silver filigree, suspended from a ring which is surmounted
by a cupid. The base of black marble is ornamented with
beads enriched with silver-gilt filigree, enamels, and precious
stones. German (Hamburg). Dated 1685.
Rev. J. C. Jackson.
446. Clock, in gilt ormolu case, engraved with figures of
soldiers and festoons of flowers and fruit. It has a single hand,
and strikes the hours. The present pendulum has been sub-
stituted for the old bob. English. Early 17th century.
Rev. J. C. Jackson.
XI. TIME. 117
462. Model of a Clock with four Faces, to be worked
by water. Major M. L. Taylor, R.A.
463. Sir W. Congreve's Clock, in which the action of
the pendulum is replaced by the motion of a small steel ball on an
inclined plane, which it descends in 30 seconds.
Major M. L. Taylor, R.A*
486. Month Equation Clock, with double pendulum and
dead-beat escapement by Quire, showing minutes and seconds both
sidereal and mean time, also sun fast or slow, and containing an
annual almanack, mentioned in Cooke & Maule's account of
Greenwich Hospital in 1789. Royal Naval College, Greenwich.
447. Two Chronometers, by Arnold. Royal Society.
These chronometers were taken round the world by Captain Cook.
447a. Chronometer, with Glass Balance Spring.
E. Dent and Co.
This is the invention and handiwork of the late Frederick Dent, of the Strand
and Royal Exchange, and the only specimen in existence. The spring requires
far less compensation for any given change of temperature than a steel spring
would, and the balance, which is composed of a glass disc, is compensated by
the two small compensation laminae mounted upon it.
448. Explanation of the principles of action of the Com-
pensation Balance, with four models showing the various
stages of construction. James Poole ? Co.
*' Cut open " for action of heat and cold ; ordinary construction without
auxiliary, in rough state from casting.
450. Silver Pocket Chronometer. James Poole $ Co.
451. Diagrams and Models of the method of winding and
setting watches without a key. James Poole fy Co.
452. Keyless Watch, complete, with fuzee.
James Poole fy Co.
452a. Dipleidoscope with Telescope. M. Littz, Paris.
453. Keyless Watch, complete, with centre seconds and
going barrel. James Poole $ Co.
454. Ship Chronometer (2 day), complete.
James Poole fy Co.
455. Ship Chronometer (2 day). Movement reversed, to
show workmanship. James Poole fy Co.
456. Chronometer Movement (2 day), as received from
the factories in Lancashire. James Poole ty Co.
456a. Six Chronometers with rates froni the Geneva Obser-
vatory, stating records of trials of the years 1875 and 1876.
H. R. Ekegren, Geneva.
118 SEC. 3. MEASUREMENT.
No. 16,175, gold, open face, 21 lines, keyless.
No. 16,873, 18
No. 16,144, Chronographs, 19 lines, keyless.
No. 16,534, hunter, 21 lines, keyless.
No. 16,576, 19
No. 16,525, 18
457. Regulator Clock, filled with the Exhibitor's new patent
gravity escapement, having no upward locking, and which cannot
trip or slip teeth. Alfred John Higham.
On the escape wheel there are two sets of teeth, one set longer than the
other ; the teeth of each set are arranged, and the pallets are formed and
placed, so that the shorter set of teeth only is used, except in case of tam-
pering or other disturbance, when the longer set comes into action. This
secondary locking entirely prevents irregularity in the clock rate, but the clock
can be allowed to " run," if it is desired to be so set to time, by removing two
extra stops which are adjustable. The action of the escapement is ordinarily
exactly the same as that of the gravity escapements invented by Mr. Denison
(Sir Edmund Beckett, Bart.), and the secondary locking can be applied to
those escapements. For further description, see the Horological Journal,
April 1876.
458. Regulator, with improved gravity escapement on the
Bloxamic principle, as arranged and patented by Mr. Higham ;
founded on the old pin- wheel escapement, and fitted with a gal-
vanic interrupter for chronographical and other astronomical
purposes. Charles Frodsham $ Co.
459. Marine Chronometer, fitted with a galvanic inter-
rupter for chronographical and other astronomical purposes.
Charles Frodsham fy Co.
459a. Two-day Marine Chronometer, fitted complete for
ship's use. Charles Frodsham.
460. Apparatus for demonstrating the application of the
pendulum to the clock, at the same time serving for audibly indi-
cating the minutes.
The Secondary Government School, Assen (Netherlands).
This apparatus is constructed by C. H. Van der Heydeu, watchmaker, at
Assen (Netherlands), in conjunction with Dr. A. Van Hasselt, teacher at
the school for middle-class education, Assen. Price about 4/. The escape-
ment may be pulled forward so as to allow the wheel to turn freely. In this
manner it may be demonstrated, that clockwork without a pendulum will
acquire an accelerated motion.
The escapement must be kept in a forward position, until the weight has
reached the ground.
The apparatus, as it audibly indicates the minutes, may also be used for
experiments to demonstrate the laws of the pendulum, the laws of hydro-
dynamics, &c.
460a. Wheat stone's Motor Magneto-Electric Clock
(in teak case). The British Telegraph Manufactory, Limited.
XI. TIME. 119
460b. Wheatstone's 'Sympathetic Magneto-Electric
Clocks (4). The British Telegraph Manufactory, Limited.
46Oc. 18-inch Wheatstone's Sympathetic Magneto-
Electric Clock.
The British Telegraph Manufactory, Limited.
461. New System of Electric Clocks.
Prof. Osnaghi, Imperial Central Meteorological Institute,
Vienna.
In these electric clocks the uncertainty of the action of the greater number
of electric pointers has been avoided by causing the electric current to flow
with almost unabated force, as if there were no other clocks present. This
is attained by giving the electro-magnets double coils of very unequal
resistance. The spirals with great resistance serve for the attraction of the
needle from a distance ; the spirals with little resistance for retaining the
already attracted needle. With every clock there is also a wire coil for the
general return current, through which the electric current can circulate until
the attraction of the needle is complete, when its course is diverted by certain
mechanism, and is forced to pass over to the next clock.
464. Model of a Protomotive Clock.
The Committee, Royal Museum, Peel Park, Salford.
An apparatus consisting of a dial with hour and minute hands, and a gutta-
percha tube 100 feet in length, the object of which apparatus is to demonstrate
how a number of such dials in distant situations may be made, by means of a
column of air at natural pressure, to indicate the same time as the clock with
which they are connected. Invented and made by the late liichard Roberts,
C.E., Manchester, about the year 1848.
465. Ley's Compensating Pendulum. Henry W. Ley.
An inexpensive pendulum compensation is to be obtained by the employ-
ment of zinc and flint glass.
466. Ley's Entirely Detached Gravity Escapement.
Henry W. Ley.
The object of this escapement is to cut off absolutely from the pendulum
the clock train with its variations, so that there may be nothing whatever to
disturb the arc of vibration. The arrangement of the escapement shown in
the Figs, permits the motions of the various parts to be clearly followed.
The scape wheel has six long teeth A, Figs. 1, 2, 3, and 4, by means of
which it is " locked," and six " impulse " pins B near its arbor. The arbor
carries a fly, not drawn. The pendulum receives its impulse at each alternate
beat ; at the beats from right to left in the Figures. The parts of the escape-
ment are : (1), a pallet C; (2), a lever D, having the same axis as C, and
resting normally against a fixed stop, from which it can lift, but below which
it cannot fall ; (it is in its normal position in Figs. 1, 3, and 4) ; (3), an arm
E, of which one end can turn on a pin in D, and the other end, which is free,
is lifted by the impulse pins, and rests on them successively ; (it is resting
on an impulse pin in Fig. 1) ; (4), a first detent F, against which C sets
when at the top of its lift; (C is thus set against F in Fig. 1); (5), a
second detent G ; and (6), set on a spring, a stop H, against which the scape
wheel locks.
120
SEC. 3. MEASUREMENT.
Fig. 1 The pallet against
the first detent.
Fig. 2. At the end of the pendulum
swing to the right.
The action of the escapement is as follows : Suppose (as represented in
Fig. 1) the scape wheel to be locked and that C has been lifted from its lowest
position through an angle a + ft to the top of its lift. Suppose also that
the pendulum is moving to the right from the end of its swing at the left.
First, a slot or a pin in the pendulum rod (a pin is supposed here for sim-
plicity sake, and the path of the pin is shown by the dotted curve in each
Fig.) lifts G, idly, which falls back to its normal position, that of Fig. 1,
immediately the pin has passed ; then the rod itself, towards the end of its
swing to the right, impinges against a "beat" pin c in C, and, still rising,
carries C with it through a further angle 7. In rising through 7, C takes
up D, and the free end of E, which was resting on the impulse pin by which
it was lifted, is carried clear of that pin (now see Fig. 2), and drops on to
B 1 , the^ impulse pin next below, depressing F in its drop, and afterwards
holding F down (see E and F in same Fig.). The pendulum now returns,
from right to left, and C with D falls back through 7, D being arrested at the
fixed stop ; the free end of its arm E still resting on B 1 , and still holding F
down. The pendulum continuing its descent, C falls back through B (the
detent F being out of the way), as far as the detent G (here see Fig. 3),
where it stops. In this fall through /3, C gives the impulse. The pendulum
now moves on by itself, until presently the pin in its rod once more lifts
G ; not, however, idly now, but releasing C, which falling back further through
a to its lowest position (shown in Fig. 4), unlocks the scape wheel from
H. The position of II with respect to that part of C which acts upon it is
XI. TIME.
121
Fig. 3. The pallet against
the second detent.
Fig. 4. The pallet at its
lowest position.
shown in plan in Figs 3a and 4a ; in Fig. 3a just before, and in Fig. 4a just
after the unlocking of the scape wheel. The pendulum having lifted G,
continues its swing to the extreme left, whence it was supposed started.
The scape wheel, free to move, lifts C and also E, the detent F, which is
weighted so as to rise of itself, following E's motion, and being in position
to hold C when the lifting is done, which is the case just before the next long
tooth of the scape wheel coming round and setting against H (which returned
to its normal position as C in lifting cleared it), the parts are again as
represented in Fig. 1.
Such being the action, it is evident that the escapement is not only a
detached one in the sense in which all properly so-called gravity escapements
are so, that is, the pendulum is free from the scape wheel between the un-
lockings, but that the detachment is entire, seeing that the pendulum is never
in connexion icith the clock -train at all, being out of the way for the unlock"
ings, as well as between whiles. There is therefore nothing whatever to
affect its rate.
The pressure of the scape wheel against the stop by which it is locked
varies. This variation, however, is altogether apart from the pendulum, as
unlocking is the work of the pallet.
In the arrangement drawn the impulse is not given across the line of
centres ; it can, however, be so given ; and other modifications of the escape-
ment as here arranged can be made within the limits of its principles of
action, which are (1.) that the lifted pallet shall be held independently of any
variations in the lift, and (2) that the unlocking shall be apart from the
pendulum.
122 SEC. 3. MEASUKEMENT.
46 6a. Jamin's Compensator. M. Lutz, Paris.
466b. Diagram representing the Great Westminster
Clock. E* Dent and Co.
This is by far the largest and most powerful clock in the world. The clock
frame is 15 feet 6 in. long, and 4 feet 10 in. wide. The escapement is the
double three-legged gravity, and the pendulum which controls it weighs
685 Ibs., is 14 feet 5 in. long, and vibrates once in two seconds. Its compen-
sation is effected by zinc and iron tubes. The dials, four in number, are 22|-
feet in diameter, and the bell on which it strikes, " Big Ben," weighs nearly
14 tons.
463c. Diagrams representing the New Standard Clock
of the Royal Observatory, Greenwich. E. Dent and Co.
One of these is a view of the back of the movement of the Greenwich
clock, showing the escapement, the galvanic contact springs, and the contri-
vances invented by Sir George Airy for altering the compensation of the
pendulum and for altering the rate of the clock without stopping it. The
other diagram shoAvs the barometric compensation.
466d. Collection of Compensation Balances.
E. Dent and Co.
No. 1. An early form of balrffice. Steel connexions are fastened near the
root of the rims of a plain brass balance ; the expansion or contraction of these
being less than that of the central brass arm, the rims are by any change of
temperature tilted towards or away from the axis of motion.
No. 2. An eariy form of balance. Loops formed of brass melted on to
steel are fastened upon each side of the axis of motion, in consequence of the
greater expansion or contraction of the brass, these open or close with the
change of temperature, and drag in or thrust out the small brass weights, to
which they are attached by wires.
No. 3. An early form of balance. The riuis are of brass melted upon steel,
the brass being outwards ; with any change of temperature the rims open or
close.
No. 4. An early form of balance. A flat steel bar has soldered to its
extremities underneath pieces of brass ; the ends of the steel bar carry uprights
bearing weights upon their summits, the brass pieces underneath having a
different rate of expansion to the steel, bend it either upwards or downwards,
and tilt the uprights carrying the weights towards or away from the axis of
motion.
No. 5. A balance of similar design, but having brass melted upon the
steel, instead of merely being soldered to its extremities.
No. 6. A balance of modern design, similar in its action to No. 5.
In order to obtain perfect compensation, it is found that for an increase of
temperature the compensation weights must advance more rapidly towards
the axis of motion, than for the same decrease of temperature they would
recede from it. This peculiarity necessitates what is called secondary com-
pensation. The following balances have been introduced to obviate this
error :
No. 7. Compensation pieces formed of brass melted upon steel receive such
curves, that with any increase of temperature the compensation weights move
towards the axis of motion more directly than they recede from it with any
decrease of temperature. (Dent's balance.)
XI. TIME. 123
No. 8. A compensation bar is formed, as in No. 5, by brass being melted
upon steel, and this bending upwards or downwards, with any change of
temperature, tilts the weights carried by the staples towards or away from
the axis of motion. But the staples are themselves compensation pieces, and
they lift the weights higher with any increase, and depress them with any
decrease of temperature, and in this manner increase the rate at which
they approach the axis of motion, and diminish the rate at which they recede
from it. (Dent's patent balance.)
No. 9. A balance of nearly the same form as No. 6, but the section of its
rim is somewhat in the shape of a prism ; the form of the rim offers less re-
sistance to the motion of the compensation weight inward than outward.
(Dent's registered balance.)
No. 10. A balance similar to No. 5 is mounted upon the arm of a balance
similar to No. 6. With any increase of temperature, the first balance can
assist the second, but with any decrease of temperature its motion is checked.
The whole combination, therefore, is more effective in the heat than in the
cold. (Glover's form.)
No. 11. An experimental balance, contrived for the purpose of removing
weight from the centre, both with an increase and decrease of temperature.
(Wetherill's form.)
No. 12. An auxiliary compensation is added to a balance similar in form
to No. 6. The auxiliary consists of two double compensation pieces, and the
effect is to carry weight towards the axis of motion, both for an increase and
decrease of temperature. The effect of the main compensation weights is
therefore increased in the heat and diminished in the cold. (Dent's balance.)
No. 13. A balance of similar design to No. 8, but arranged so that tho
secondary compensation can be altered with greater facility. (Dent's
balance.)
No. 14. A balance having the same general operation as No. 8, but the
effect is obtained by straight bars only. The secondary compensation can
also be altered without inconveniently disturbing the main compensation, and
both without producing any great alteration in the time of the chronometer.
(Dent's balance.)
467. Drawings of Compensation Balances, Escape-
ments, and other appliances connected with the construction of
Clocks and Watches. The British Horological Institute.
Lever Escape Wheel.
Lever Escapement.
Double Roller Lever Escapement.
Two Pin Lever Escapement.
Chronometer Escapement.
Duplex Escapement.
Club Tooth Lever Escapement.
Verge Escapement.
Horizontal Escapement.
Double Roller Lever Escapement with Compensation Balance.
Marine Chronometer Escapement.
Compensation Adjustment by Sir G. B. Airy, Astronomer Royal,
1875.
Double Three-legged Gravity Escapement as used in the West-
minster Great Clock.
124 SEC. 3. MEASUREMENT.
Dead Beat Clock Escapement.
Pin Wheel Clock Escapement.
Zinc and Steel Compensation Pendulum as used in the West-
minster Great Clock.
467a. Compensation Balance arranged in Two Groups.
GROUP I. Earnshaw's balance with circular rim (1795), and
modifications thereof to the present time.
Earnshaw's balance.
Modification of do.
Do. do.
Do. do., with extra adjusting screws.
Do. do., with screws for weights.
Do. do. do. do.
Do. do., with screws for more minute adjust-
ment.
Do. do. do. do. do.
Do. do., with double weights.
Do. do., with variation of weights.
Do. do., with auxiliary by Molyneux.
Do. do., do. do.
Modification of Molyneux's auxiliary.
Eifle's mercurial auxiliary:
Poole's auxiliary.
Example of recent auxiliary.
Do. do. do.
Do. do. do.
Compensation adjustment by the Astronomer Royal (Sir
G. B. Airy).
GROUP II. Balances of a form distinct from Earnshaw's, from
Hardy (1805) to the present time.
Hardy's balance.
Arnold's do.
Dent's do.
Balance with laminated arm and rim.
Hartnup's balance.
Do. do. cup.
Modification of Hartnup's balance.
Kullberg's flat rim balance.
Do. double-flat rim balance.
Cole's balance.
The British Horological Institute.
468. Enlarged Model of Compensation Watch Balance.
The British Horological Institute.
469. Ordinary Marine Chronometer Compensation
Balance. The British Horological Institute.
XI. TIME. . 125
471. Models (ten) of Compensation Balances, showing
various attempts to overcome what is known as the " Error " of the
ordinary Compensation Balance, by the late Thomas Hewitt.
The British Horological Institute.
472. Marine Chronometer by Earnshaw.
The British Horological Institute.
473. Marine Chronometer with Mudge's Escapement.
The British Horological Institute.
474. Grossmann's Micrometer.
The British Horological Institute.
475. Model of " Ferguson's Paradox."
The British Horological Institute.
476. Model of Cole's Resilient Escapement.
The British Horological Institute.
477. Callipering Engine, by the late Richard Roberts.
The British Horological Institute.
478. Models of English and French Repeating Motions
for Watches. The British Horological Institute.
479. Watch Movement.
The British Horological Institute.
480. Marine Chronometer Movement.
The British Horological Institute.
481. Collection of Watch and Chronometer Balance
Springs. The British Horological Institute.
482. Map showing allowance of time to be made for velocity
of sound as applied to the Westminster Clock Bell.
The British Horological Institute.
482a. Working Model, for educational purposes, of
a Chronometer Escapement, with a 6-inch compensation
balance. Ignaz Herrmann.
482b. Working Model, for educational purposes, of
a Lever Watch Escapement. Ignaz Herrmann.
Working Model, for educational purposes, of a Hori-
zontal Watch Escapement. Ignaz Herrmann.
Model for demonstrating the law of the compensation balance
or of any vibrating or rotating body. Ignaz Herrmann.
An arm carrying movable weights revolves about a vertical axis under the
action of a spring. The time taken for the spring to run down is propor-
tional to the square root of the distance of the weights from the axis.
126 SEC. 3. MEASUREMENT.
434a. Eight-day Marine Chronometer.
Parkinson fy Frodsham.
484b. Eight- day Marine Chronometer.
Parkinson Sf Frodsham.
484c. Chronometer, used by Captain Parry in the year
1819. Parkinson fy Frodsham.
This chronometer, used by Captain Parry in his voyage to the Polar Sea
in 1819, was specially compensated for extreme cold. Others of a similar
character were recently made for the Arctic Expedition under Captain Nares ;
also for Dr. Livingstone's Central African Expedition, the latter being com-
pensated for a higher range of temperature.
487. Pendulum Clock for marking the time according to
the time system of nature, thus forming the standard of a system
of measurement including time and space together, with decimal
subdivisions. The pendulum measures space by its length, and
time by its period of oscillation.
Hans Raumgartner, Basle, Switzerland.
The pendulum has the exact length of a longitudinal uuit of natural
measure, that is to say, of the one hundred thousandth part of a degree, of
which 540 go to a meridian, and measures the natural second, or the one
hundred thousandth part of a mean day.
487a. Pendulum. Professor Dr. A. Krucger, Helsingfors.
A barometer tube of about 350 mm length is attached to the pendulum rod
in the plane of swinging ; a little quantity of dry air is introduced in the upper
part of the tube: height of the mercury column about 150 mm . The rising
and falling of the mercury, depending on the variations of atmospherical
pressure, will affect the length of the pendulum and the clock-rate. It will
be very easy to calculate the distance from its centre, at which the tube is to
be attached ; then the barometrical variation in the clock -rate will be com-
pensated. A pendulum of this construction has been used with success at
the Helsingfors Observatory since 1866. See Astrononiische Nachrichten,
Vol. 62, No. 1482.
488. Clepshydral Escapement.
Prof. W. II. Miller, M.A., F.R.S.
By means of the fountain bottle of Berzelius, or Gay-Lussac's syphon
washing bottle, or any similar contrivance, a current of water is directed
into a capsule, from which it is transferred by a syphon to the mouth of an
inverted syphon partly filled with fine sand, one leg being rather more than
twice as long as the other. The upper end of the short leg is stopped with
a cork, in which is inserted a. short syphon about 0'29 inch (8 mm ) in diameter.
A compensated pendulum carrying near its upper end at a distance of 5-5
inches (140 ram ) an inverted funnel about 0-63 inches (IG" 11 --) long, 0'27
inches (7 mm ) wide at its base, and about 0-04 inches (l mm ) at the upper end.
The lower end of the upper syphon is supported at about 0-12 inch (3 mm )
above the top of the funnel carried by the pendulum when at rest. A tube of
about 0'08 inches (2 mnl ) in diameter, and 0'4 inches (10 mra ) long, is
supported with its upper end about 0- 12 inches (3 mm ) below the lower end
of the funnel at rest.
XI. TIME. 127
The pendulum being made to vibrate through a small arc before reaching
the upper syphon takes up a drop, and on arriving near its lowest point
delivers a drop to be carried off. The time is thus measured without allowing
the pendulum to come in contact with any solid body except the agate plane
on which it is supported.
The drop given off by the lower tube at the end of every two seconds, may
be used to record every alternate second of time by means of a timepiece
having a very light pendulum timed in accordance with the pendulum the
water clock.
No attempt has been made to exhibit the mechanism for counting the
seconds.
48 8a. Model of Compensation Balance, applicable to
watches and chronometers. (With a drawing.)
M. Winner -cl, Paris.
488b. Model of Escapement, applicable to the model
clock at the Paris Observatory. (With a drawing.)
M. lYinnerel, Paris.
488c. Model of Escapement, with simplified suspension,
applicable to clocks. (With a drawing.)
M. Winner el) Paris.
483e. Two Movements for Chronometers, one eight days
and one two days. Victor Kullbcrg.
489. Standing Pendulum Clock, in black wooden box with
silvered dial. Professor Buys-Ballot. Utrecht.
This is one of the first clocks made after Huygen's principle (i.e., provided
with cyeloidal pendulum). This peculiarity may be seen by opening the
door.
490. Two Conical Pendulum Clocks, for determining short
time intervals. Professor Buys-Ballot, Utrecht.
Each of these clocks is contained in a truncated wooden column covered
by a circular brass plate, by lifting which the dial may be seen. The foremost
part of the box can be removed to put the pendulum in motion, the spring
being woundup. In this condition only one hand moves. By pressing on the
button at the foremost part of the dial, the two other hands move until the
finger is withdrawn. In this manner very short lapses of time can be
measured. The instruments must be placed accurately horizontal. These two
specimens were used by Moll and van Beelt on the heath near Amersfoort
for determining the velocity of sound. They are constructed for the decimal
division of time, and indicate the ten millionth part of a day (24 hours).
491a. Very curious Timepiece, designed by Mudge.
E. Dent and Co.
The escapement is a true remoutoire ; two small pendulum springs are
wound up at every beat of the scape wheel, and these give impulse to the
balance. The balance is controlled by two pendulum springs, one above and
the other beneath it ; the first of these receives the action of the " compen-
" sation curb," the second is for ordinary regulation. TJie action of the
}28 SEC. 3. MEASUKEMENT.
Ji compensation curb " is analogous to the ordinary regulation by curb pins,
but the curb pins are advanced backwards or forwards along the spring by
the operation of the compensation pieces, which, being constructed of brass
melted upon steel, bend at every change of temperature. The whole time-
piece has been designed and got up with a surprising degree of refinement.
492. Working Model of Chronometer Escapement, with
two inch scape wheel. Philip John Butler.
493. Small Electric Pendulum. Striking seconds on
a bell, and thus capable of being used for astronomical studies.
Antoine Joseph Gerard, Liege.
494. Book containing plans of instruments, apparatus, and
machines. Antoine Joseph Gerard, Liege.
49 9a. Chronometrical Regulator, for putting in motion a
registering cylinder. Mr. Yvon Villarceau.
This system of regulator, the theory of which is due to Mr. Yvon Villarceau,
is represented by the model included among the objects exhibited by M. L.
Breguet.
500. Edelmann's Seconds Pendulum, with galvanic
attachment. M. Th. Edelmann, Munich.
501. Chronometric Comparateur, an instrument of coinci-
dences, for determining the difference of time between two distant-
clocks. M. Redier.
5Ola. Collection of Steel and Electro-gilded Pendu-
lum Springs. E. Dent and Co.
502. Clock employed in the Pantheon Experiment by M. L.
Foucault. Conservatoire des Arts et Metiers, Paris.
502a. Different applications of Metal Tubes of elliptical
section to instruments for measuring pressure, temperature,
weight, speed, and time.
1. Manometer for steam, air, or water pressure.
2. Barometer. Counterpoised barometer.
3. Thermometer.
4. Tacheometer, or speed indicator.
5. Balance for light and heavy weights.
6. Clock with pneumatic motor.
M. Eugene Bourdon, Paris.
502 a. Motor Clock and case, with two electric dials,
batteries, and fittings. T. Cooke $ Sons.
503. Electric Apparatus by M. Foucault, for keeping up
continuously the motion of the clock.
Conservatoire des Arts et Metiers, Paris.
XI. TIME. 129
503a. Marine Chronometers for ships' use. Manufactured
by Victor Kullberg, Liverpool Road, London, N.
South Kensington Museum.
503b. Two-day Chronometer, fitted complete. Two move-
ments reversed, to show the compensation balances.
South Kensington Museum.
503d. Chronometer and case 011 stand with glass shade.
The Royal Observatory, Greenwich.
509. Marine Chronometer, regulated at sidereal time, used
by the Scientific Commission of Noumea in observing the transit
of Venus. Messrs. Tondola and Co., Paris.
510. Marine Chronometer, suitable for distributing the
hour in quarter minutes to an unlimited number of electric
receivers, going for one year without being wound up. (System
applied for more than three years with complete success.)
Messrs. Tondola and Co., Paris.
511. Marine Chronometer, regulated to mean time. Speci-
men of ordinary construction. Messrs. Tondola and Co., Paris.
512. Geographical Clock, with revolving planisphere j
showing the time, longitude, and latitude, of all parts of the globe.
Messrs. Tondola and Co., Paris.
513. Astronomical Pendulum Clock.
W. Brooking, Hamburg.
514. Wheel-work of Clock. W. Brooking, Hamburg.
515. Astronomical Pendulum Clock with mercury com-
pensation pendulum. Th. Knoblich, Hamburg.
517. Chronometer-escapement, model.
Th. Knoblich, Hamburg.
518. Anchor-escapement, model.
Th. Knoblich, Hamburg.
519. Pendulum Clock belonging to the tide-gauge of Mr.
Reitz. Th. Knoblich, Hamburg.
519a. Clock worked by Water-power. T. Hankey.
520. Astronomical Pendulum Clock.
F. Dencker, Hamburg.
The Jiirgens compensation pendulum system has an isochronous sus-
pension spring, determined by calculation. It is, contrary to the formerly con-
structed repose pendulum, executed with sufficient stability. Not only is the
expansion coefficient of the separate bars exactly determined by the pyrometer,
40075. I
130 SEC. 3. MEASUREMENT.
but likewise the whole pendulum is directly controlled in the pyrometer. The
pyrometer employed is of quite a novel construction ; the observation takes
place in a liquid, without contact, under two micrometer microscopes. As
the observation through the microscope requires water of perfectly equable
temperature, the uniform^ of its temperature is ensured ; the bars likewise
must be quite homogeneous, as otherwise a bending of them will take place
by a change of the temperature, whereby the terminal ends will move out of
the range of vision. With regard to compound pendulums, the centre of
gravity is to be found by means of a balance the point of flexion of the spring
of which is known to the exhibitor, and then the point of oscillation by cal-
culation ; in a quite homogeneous and uniformly strong spring it is exactly in
the centre. By means of a bar, which is adjusted exactly to the length of the
pendulum,* the point of oscillation can be exactly fixed in the pyrometer, and
the whole pendulum examined with regard to extension and stability. The
working of the clock affords a check upon the accuracy of the measurement ;
if no error be made, the pendulum thus adjusted and fitted to a clock will
exactly vibrate seconds.
521. Model Escapement. F. Denckcr, Hamburg.
An anchor escapement, enlarged tenfold, with an impulse derived from
the chronometer and acting like the same from fork upon balance. This
requires no oil. The straight lines of the fork and the release stone
render a quite exact execution possible, and consequently an effect which
almost equals the direct impulse from wheel upon balance, without detracting
from the great insensibility of the anchor escapement. The lifting which
it is desired to give to the balance in this case is determined only by tbe
length of the fork, independent of the length of the lever. Arranged for
quarter seconds, it will be very useful for determining the time on journeys
and on sea. The last seconds are regulated by a curb, permitting only
little motion, but being securely guided by means of a screw. The last regu-
lation by the balance screws always disturbs the equilibrium of the balance,
and effects thereby a doubling of the errors at the change of the position.
The flat spiral spring has an inner and an external curve.
522. Gold Watch. F. Dencker, Hamburg.
The pocket watch has been executed exactly according to this model in
the exhibitor's establishment at Geneva. It is provided with a flat spiral
spring hardened in fire according to his invention. Up to the present time
no flat spiral springs hardened in fire are employed, as far as the exhibitor
knows.
523. Watch with spindle without spiral spring ; constructed
in the East in the first half of last century, indicating month, day,
and hour in Arabic figures. (JRemariable for its age and origin.)
Property of H.H. Prince Pless, Fiirstenstein.
The Breslau Committee.
V
523a. Watch, thickness of a crown piece, made for the late
Sir C. Wheatstone bv Mr. A. Stroh.
* The extension of the parts to be employed being known, a pendulum can be deter-
mined by calculations which swings in exactly one second.
131
SECTION 4, KINEMATICS, STATICS, AND
DYNAMICS.
WEST GALLEKY, GROUND FLOOR, ROOM K.
I. SPECIAL COLLECTIONS.
COLLECTION OF APPARATUS USED BY 'SGRAVESANDE TO ILLUS-
TRATE HIS PHYSICAL RESEARCHES.
524. 'sGravesande's Apparatus to demonstrate the
Laws of Centrifugal Force.
Professor Dr. P. L. Rijke, Ley den.
(See 'sGravesande's "Physices Elementa Mathematica," 3rd edition, Vol.
I., p. 153.)
525. 'sGravesande's Apparatus to demonstrate the
Theory of the Wedge.
Professor Dr. P. L. Rijke, Ley den.
526. 'sGravesande's Apparatus, to show, by means of a
pendulum furnished with weights and springs, that the same
quantity of Mechanical Work produces the same quantity of
Vis Viva.
Professor Dr. P. L. Rijke, Ley den.
527. 'sGravesande's Apparatus to demonstrate the Laws
of Falling Bodies.
Professor Dr. P. L. Rijke, Ley den.
528. 'sGravesande's Apparatus for Parabolic Motion.
Professor Dr. P. L. Rijke, Leyden.
I 2
132 SEC. 4. KINEMATICS, STATICS, AND DYNAMICS.
COLLECTION OF KINEMATIC MODELS, EXHIBITED BY THE KONIGL.
GEWERBE-AKADEMIE, BERLIN, PROF. KETILEAUX, DIRECTOR.
The models in this collection are connected throughout with Professor
Reuleaux's treatment of the theory of machines. Their nature will be found
fully discussed in his " Theoretische Kinematik " (Vieweg und Sohn). The
English edition of this work (Maciniilan), translated and edited by Professor
Alexander B. W. Kennedy, C.E., of University College, London, was pub-
lished in June. The English names of the mechanisms here given are those
used by Professor Kennedy in his translation.
551. I. Fairs of Kinematic Elements.
(a.) LOWER PAIRS.
1. Turning or cylinder pair, R+ R- or C + C~.
2. Sliding or prism pair, P+ P-.
3. Twisting or screw pair, S+ S~.
552. Fairs of Kinematic Elements.
(b.) HIGHER PAIRS.
4. Equilateral duangle in equil. triangle.
These models of the higher pairs of elements can be inverted ;
that is, the movable element can be fixed, and the fixed element
made movable. The centroids are shown in thick black or red
lines ; the roulettes, or point-paths, in thinner lines.
5. Expanded duangle in equil. triangle.
6. Equilateral curve-triangle in square.
7. Equilateral curve- triangle in rhombus.
8. Expanded isosceles curve-triangle (90) in square.
9. Expanded equilateral curve-triangle (90) in rhombus.
10. Regular curve-pentagon in square.
11. Symmetrical curve-pentagon in square.
553. II. Conic Axoids, with corresponding Spheric
Roulettes and Profiles.
12. Spheric epicycloid.
Katio 1 : 3.
13. Spheric cycloid.
A full cone rolling upon a plane cone (1:3).
14. Spheric hypocycloid.
A full cone rolling in an open one (2:1).
15. Spheric hypocycloid.
Ratio 1:3.
16. Spheric pericycloid.
The curve upon the rolling cone passes always through the de-
scribing point of the fixed one.
I. SPECIAL COLLECTIONS. 133
17. Spheric involute.
Katio 1:3.
18. Spheric involute.
Ratio 8:9 ; the curve in red is a curtate involute.
1 9. Apparatus for describing spheric cycloids.
Describes, among other curves, those here exhibited.
554. III. Simple Kinematic Chains and Mechanisms.
20. Quadric cylindric-crank chain.
21. Slider-crank chain.
22. Quadric conic-crank chain.
23. Reduced slider-crank chain.
The link c omitted.
24. Reduced slider-crank chain.
Links a and c omitted.
25. Reduced conic-crank chain.
The link c omitted.
26. Quadric crank chain with slot and sector.
27. Single crossed slide chain.
28. Double crossed slide chain.
29. Simple spur-wheel chain.
30. Simple spur-wheel chain with annular wheel.
31. Endless screw.
32. Stand for carrying the above models when in use.
555. IV. Crank Trains.
33. Double slider-crank.
34. Slider-crank.
With ceutroids.
35. Slider-crank.
With centroids.
36. Double slider-crank.
With centroids. (The centroids are here Cardan's circles.)
37. Slider-crank.
38. Skew double slider-crank.
39. Double slider-crank with curved slide.
40. Double slider-crank with skew slide.
41. Lever-crank.
42. Double slider-crank with curved slide.
With pin expansion.
43. Slider-crank.
Link b is here a disc.
44. Slider-crank.
With adjustable connecting rod.
45. Slider-crank.
With adjustable cross-head.
134 SEC. 4. KINEMATICS, STATICS, AND DYNAMICS.
46. Slider-crank.
In the form of a marine engine.
47. Slider- crank.
Slotted link gear.
48. Slider-crank.
Double slide gear.
49. Slider-crank (Norman Wheeler).
Three-fold.
50. Slider-crank, with pin expansion, 2 within 1.
51. Slider-crank, with pin expansion, 1 within 2.
52. Slider-crank, with pin expansion, 3 within 2.
53. Slider-crank, with pin expansion, 2 within 3.
54. Slider-crank, with pin expansion, 2 within 3.
Annular expansion.
55. Slider-crank, with pin expansion, 1 within 2 within 3.
56. Slider-crank, with pin expansion, 3 within 2 within 1.
57. Slider-crank, with pin expansion.
Adjustable stroke.
58. Swinging block (slider-crank).
59. Turning block (slider -crank).
60. Skew (turning) cross block.
61. Turning block (slider-crank).
With pin expansion (can be used also as a turning slider-crank).
62. Turning block (slider-crank).
With reduced centroids.
63. Double crank (drag-link coupling).
With reduced centroids.
64. Turning block (slider-crank), Redtenbacher's "Maskirte
Kurbelschleife."
Quick return motion ; the stroke is adjustable.
65. Swinging slider-crank.
650. Swinging double slider.
66. Swinging skew double slider.
67. Conic crank-train.
68. Isosceles double-crank (Galloway).
Mean velocity, ratio 1:2.
69. Isosceles double- crank (Galloway).
Mean velocity, ratio 1:2; arrangement for crossing dead points,
by Eeuleaux.
70. Anti-parallel cranks (Reuleaux).
Special arrangement for crossing dead points.
71. Anti-parallel cranks (Reuleaux).
With centroids, which are ellipses.
72. Anti-parallel cranks (Reuleaux).
With centroids, which are ellipses and hyperbola.
I. SPECIAL COLLECTIONS. 135
73. Double parallel crank train, used as a coupling.
For transmitting uniform rotation.
74. Double parallel crank train, used as a coupling (Reuleaux).
For transmitting uniform rotation.
75. Crank train for transmitting uniform rotation (Heilrnann).
76. Crank train for transmitting uniform rotation (Bohm).
77. Differential crank train (Romer).
Numbers of teeth, 56 and 56, with apparatus for tracing diagrams.
78. Differential crank train (Romer).
Numbers of teeth, 56 and 57, with apparatus for tracing diagrams.
79. Differential crank train (Romer).
Numbers of teeth, 30 and 90, with apparatus for tracing diagrams.
80. Hooke's joint.
81. Universal joint (Blees).
82. Universal joint (Polhein).
83. Universal joint (Reuleaux).
84. Universal joint (Klein).
85. Universal joint (Klein).
Simplified by Reuleaux.
86. Double Hooke's joint.
The velocity ratio here can be made constant.
556. TV ft. Mechanisms for describing Straight Lines
(exactly or approximately).
87. Roberts triangle, " parallel motion."
88. Triangle motion, inverted, by Reuleaux.
89. Elliptic linkwork (Nehrlich), 3rd form, inverted.
90. Elliptic linkwork (Nehrlich), 3rd form, inverted.
91. Hypocycloidal linkwork.
92. Hypocycloidal linkwork, inverted, by Reuleaux.
93. Epicycloidal linkwork, Reuleaux.
94. Elliptic linkwork, inverted.
With the whole motion.
95. TchebischefFs linkwork.
Arranged so that it can be inverted.
96. Conchoidal linkwork, 1st form.
97. Conchoidal linkwork, 3rd form (Reichenbach).
98. Conchoidal linkwork, 3rd form (Reuleaux).
99. Lemniscoidal linkwork, 1st form (Watt).
100. Lemniscoidal linkwork, 2nd and 3rd forms.
101. Lemniscoidal linkwork, 1st form, inverted (Reuleaux).
102. Lemniscoidal linkwork, 2nd and 3rd forms.
Steam engine model with Watt's planet wheels.
103. Sector mechanism (Reuleaux).
Involute.
136 SEC. 4. KINEMATICS, STATICS, AND DYNAMICS.
104. Sector mechanism (Reuleaux).
Cycloid.
105. Sector mechanism (Reuleaux).
Cycloid.
106. Cartwright's mechanism.
107. Mandsley's mechanism.
108. TchebischefPs mechanism.
109. Harvey's mechanism.
110. Harvey's mechanism.
111. Pantograph.
With elliptic Imkwork, 1st form.
112. Pantograph.
With prism guide.
113. Semi-pantograph.
With prism guide.
114. Semi-pantograph.
Steam engine model.
115. Rhombic linkwork.
557. V. Apparatus for describing Curves.
116. Ellipsograph.
117. Ellipsograph, by Slaby, on Haman and HempePs system.
Describes also cycloids. Dr. Slaby's construction contains very
essential improvements.
118. Elliptic chuck (Leonardo da Vinci).
119. Elliptic chuck (Delnest).
120. Sinoid and cardioid tracing gear.
121. Curve tracing apparatus.
122. Curve tracing apparatus.
123. Mechanism for describing Lissajous' figures.
Describes also ellipses.
124. Hastie's conoid gear.
125. Tricentric gear.
Tor the construction of three-grooved taps, &c.
126. (Form-) copying machine.
127. Rose-engine.
128. Rose-engine.
129. Rose-engine.
130. Rose-engine, special form.
558. VI Parallel or Translating Trains.
131. Parallel ruler.
Single and double.
132. Parallel ruler.
With crossed bars.
I. SPECIAL COLLECTIONS. 137
133. Complete lever parallel train.
Weighing machine, of Roberval.
134. Incomplete lever parallel train.
Weighing machine, of Milward.
135. Incomplete lever parallel train.
Weighing machine, of Farcot.
] 36. Incomplete lever parallel train.
Weighing machine, of Schwilgue.
559. VII. Compound Parallel Trains.
137. Feathering paddle-wheel, of Buchanan.
A combination of trains similar to parallel rulers. The floats
remain always vertical.
138. Feathering paddle-wheel, of Oldham.
The floats rotate about their axes as the wheel revolves.
139. Feathering paddle-wheel, of Morgan.
With eccentric ring.
560. VIII. Higher Couplings.
140. Uhlhorn's coupling.
141. Oldham's coupling.
142. Reuleaux's grooved disc coupling.
143. Kochlin's cylindric coupling.
144. Schiirinann's cylindric coupling.
145. Conic coupling.
146. Pouyer-Quertier's coupling.
561. IX. Toothed-wheel Trains.
147. Spur wheels (point-paths used for profiles).
148. Returning spur-wheel train.
149. Returning spur-wheel train, with annular wheel.
150. Returning spur-wheel train, with annular wheel.
151. Returning spur-wheel train, with two annular wheels.
152. Returning spur-wheel train, with two annular wheels.
153. Returning spur-wheel train, with intermediate wheel.
154. Returning spur-wheel train, with intermediate wheel.
Keuleaux's so-called halving spur-wheel train.
1 55. Returning spur-wheel train.
With Marlborough wheel.
156. Spur-wheel train.
The centroids are Cardan's circles.
157. Beylich's universal wheels.
Pin-wheels."
158. Cylindric friction wheels.
Held by axial pressure.
138 SEC. 4. KINEMATICS, STATICS, AND DYNAAIICS.
159. Screw wheels.
Working as spur-wheels.
160. Screw wheels.
Screw wheel and rack.
161. Bevel wheels.
Plane- (face-) wheel and full wheel.
162. Mangle-wheel train.
Automatic reversal.
163. Mangle-wheel train.
164. Mangle- wheel train.
With internal teeth.
165. Whitworth's feeding gear for drills.
The drill is under a constant pressure.
166. Re versing gear, claw coupling.
With bevel wheels.
167. Reversing gear, bevel wheels.
168. Reversing gear, returning wheel gear.
By Reuleaux.
169. Reversing gear, Sellers' arrangement.
Open and crossed belts.
170. Reversing gear, with three pulleys.
171. Face-wheel and runner (Rupp).
172. Speed changing gear (Sellers).
For lathes.
173. Speed changing gear with double pulleys.
174. Reversing and disengaging train (radial).
Wheels of 103 and 53 teeth respectively.
175. Reversing and disengaging train (Fairbairn's).
1 76. Reversing and disengaging train (Brown's) ;
177. Engaging and disengaging train (Plait's).
178. Engaging and disengaging train (Curtis').
Globoid Gearing.
179. Globoid screw wheels ; spheric screw and wheel.
Reuleaux.
180. Globoid ring, screw, and wheel.
Reuleaux.
181. Skew globoid ring, conic screw and tooth.
Reuleaux.
182. Globoid ring, cone, and wheel.
Used by Stephenson in locomotive reversing gear,
183. Crossed globoid ring, screw, and tooth.
Reuleaux.
184. Crossed globoid ring, screw, and tooth.
Reuleaux.
I. SPECIAL COLLECTIONS. 139
185. Globoid screw aud screw wheel.
Endless screw.
186. Globoid screw.
Applied in horse gins ; velocity ratio 1 : 12.
Parallel Wheels.
187. Parallel wheels with 24 teeth.
Reuleaux. The teeth are revolutes.
188. Parallel wheels with 6 teeth.
Reuleaux. Would work also with 3 teeth. The teeth are ping.
189. Parallel wheels with 5 teeth.
Reuleaux. One wheel annular.
190. Parallel wheels with 24 (pin) teeth. -
Reuleaux. The parallelism is destroyed by displacing the axes.
Planet Wheel Chains.
191. Planet wheel chain.
192. Planet wheel chain, a==oo .
With excanching wheels.
193. Planet wheel chain, a=&=oo .
194. Planet wheel chain, with annular wheel.
195. Planet wheel chain, b=c=<x> .
196. Hyperboloidal endless screw.
562. X. Belt-trains.
197. Eeturning belt- train.
Shows the alteration of velocity due to the slipping of the belt.
198. Skew belt- train.
Acts in one direction only.
199. Belt-train with crossed guide pullies.
The necessary tension is given to the belt at the instant it is thrown
into gear.
563. XI. Slider-cam Trains.
200. Sinoidic cams. Cardioids.
Open cam with roller, pair-closure.
201. Sinoidic cams. Cardioids.
With second disc and centroid.
202. Sinoidic cams. Cardioids.
Pair-closure.
203. Sinoidic cams. Polar sinoid.
With centroid.
204. Sinoidic cams. Polar sinoid.
With centroid.
140 SEC. 4. KINEMATICS, STATICS, AXD DYNAMICS.
205. Cams with discontinuous profiles. Curve-triangle in skew-
curved slot.
With centroid.
206. Cams with discontinuous profiles. Equilateral curve-quad-
rangle.
With centroid.
207. Cams with discontinuous profiles. Equilateral curve-penta-
gon in straight slot.
208. Cams with discontinuous profiles. Equilateral curve-penta-
gon in adjustable slot.
Both parts are adjustable.
209. Cams with discontinuous profiles. Curved disc in curved
slot.
Both parts are adjustable.
210. Cams with discontinuous profiles. Curved disc.
For the motion of a slide valve.
211. Cams with discontinuous profiles. Disc with looped slot.
With shuttle, used in printing presses.
212. Slider-cam, two-lobed cylindric sinoid.
Force-closure.
213. Slider-cam.
Force-closure.
214. Slider-cam, cylindri 
