Now throw away the operand Nv.cH, and we get the velocity equation pure and simple, and the index equation (3) then comes by s = Nv-1

But, although the above manipulation of the characteristic equation has some analytical interest, the process cannot be always recommended on the score of simplicity. It is, on the contrary, usually easier and simpler to work upon the component equations upon which the characteristic is founded.

Transactions.

Presents, January 18, 1894.

Baltimore :-Johns Hopkins University. Circulars. Vol. XIII. No. 108. 4to. Baltimore 1893; Studies in Historical and Political Science. Eleventh Series. Nos. 11-13. 8vo. The University.

Baltimore 1893.

8vo.

Medical and Chirurgical Faculty of the State of Maryland.
Transactions of the Ninety-fifth Annual Session.
Baltimore 1893.

The Faculty.

Berkeley :-University of California. [University Publications for the year 1892-93.] 8vo. 1892-93.

Berlin :-Deutsche Chemische Gesellschaft.

Nos. 9-18. 8vo. Berlin.

The University.

Berichte. 1893.
The Society.

Brussels :-Académie Royale de Médecine. Bulletin. Tome VIII.

Nos. 5-9. 8vo. Bruxelles 1893. Académie Royale des Sciences. Bulletin. 5-11. 8vo. Bruxelles 1893.

The Academy. Tome XXVI. Nos.

The Academy.

Bucharest :-Societätii de Sciinte Fizice.
Nos. 9-10. 8vo. Bucuresci 1893.
Buitenzorg :-'s Lands Plantentuin. Mededeelingen.
8vo. Batavia 1891.

Buletinul. Anul II.
The Society.
Nos. 8-9.
The Director.
Proceedings.
The Society.
Bulletin.

Cambridge: Cambridge Philosophical Society.
Vol. VIII. Part 2. 8vo. Cambridge 1894.
Cambridge, Mass.:-Museum of Comparative Zoology.
Vol. XXV. Nos. 2-3. 8vo. Cambridge 1893.

The Museum.

Copenhagen:-Kongelige Danske Videnskabernes Selskab. Skrifter.
Bd. VII. Nos. 8-9. 4to. Kjöbenhavn 1893; Oversigt.
1893. No. 2. 8vo. Köbenhavn.
The Society.
Cracow :-Académie des Sciences. Bulletin International. No-

vembre, 1893. 8vo. Cracovie 1893. Davenport :-Academy of Natural Sciences.

Part 2. 8vo. Davenport, Iowa 1893. Dublin :-Royal Irish Academy. Transactions.

The Academy. Proceedings. Vol. V. The Academy. Vol. XXX. Parts

Transactions (continued).

6, 9. 4to. Dublin 1893; Proceedings.
III. No. 1. 8vo. Dublin 1893.

Third Series. Vol.
The Academy.

Dulwich :-Science Society, Dulwich College. Report, 1892-93.

8vo. Sydenham 1893.

The Society.

Edinburgh :-Geological Society. Transactions. Vol. V.

8vo. Edinburgh 1888.

Royal Scottish Society of Arts. Transactions.

Part 3. 8vo. Edinburgh 1893.

Florence:-Biblioteca

Part 4.

The Society.

Vol. XIII.

The Society.

The Library.

Nazionale Centrale. Bolletino. 1893.

Num. 180-192. 8vo. Firenze. Frankfort-on-the-Oder :-Naturwissenschaftlicher Verein. Helios. Jahrg. XI. Nos. 6-9. 8vo. Frankfort a.0.1893; Societatum Litteræ. Jahrg. VII. Nos. 8--12. 8vo. Frankfort a.0. 1893.

Geneva :-Société de Physique et d'Histoire Naturelle.
Tome XXXI. Partie 2. 4to. Genève 1892-93.

The Society.
Mémoires.

The Society Vol. XXIV.

The Society.

Glasgow:-Philosophical Society. Proceedings. 8vo. Glasgow 1893. Irkutsk :-East-Siberian Section, Imperial Russian Geographical Society. Izvestiya. Vol. XXIV. Nos. 3-4. [Russian.] 8vo. The Society. Jena:-Medicinisch-Naturwissenschaftliche Gesellschaft. Jenaische Zeitschrift für Naturwissenschaft. Bd. XXVIII. Heft 2. 8vo. Jena 1893. The Society.

Irkutsk 1893.

Kew Royal Gardens.

Bulletin of Miscellaneous Information. 1893. Nos. 82-83. 1894. Appendix I. 8vo. London 1893-94. The Director. Leipsic:-Königl. Sächs. Gesellschaft der Wissenschaften. Abhandlungen (Math.-Phys. Classe). Bd. XX. Nos. 3-4. 8vo. Leipzig 1893. The Society. Liége:-Société Géologique de Belgique. Annales. Tome XX.

Chemical Society. Journal. July-December. 8vo. London;
Proceedings. Nos. 127-130. 8vo. London 1893.

The Society.

East India Association. Journal. Vol. XXVI. No. 1. 8vo.

London 1893.

Entomological Society. Transactions.

London 1893.

The Association. 1893. Part 4. 8vo.

The Society.

Geological Society. Abstracts of the Proceedings. Nos. 611

615. 8vo. [London 1893.]

The Society.

Transactions (continued).

Imperial Institute. Annual Report, 1893. 8vo. London 1893.
The Institute.
Institution of Civil Engineers. Abstracts of the Proceedings.
Session 1893-94. Nos. 1-5. 8vo. [London.]

Institution of Electrical Engineers.

No. 107. 8vo. London 1893.
Institution of Mechanical Engineers.

No. 3. 8vo. London.

The Institution.

Journal. Vol. XXII.

The Institution.

Proceedings. 1893.
The Institution.

Mineralogical Society. The Mineralogical Magazine. Vol. X

No. 47. 8vo. London 1893.

Odontological Society.

The Society.
Transactions. Vol. XXVI. Nos. 1—2.
8vo. London 1893.
The Society.
Pathological Society. Transactions. Vol. XLIV. 8vo. London
1893.
The Society.
Pharmaceutical Society of Great Britain. Pharmaceutical Journal
and Transactions. July-December, 1893. 8vo. London.
The Society.
Photographic Society. Journal and Transactions. Vol. XVIII.
No. 4. 8vo.
Royal Agricultural Society. Journal. Third Series. Vol. IV
Part 4. 8vo. London 1893.
Royal Astronomical Society. Monthly Notices. Vol. LIII.
Nos. 6-9. Vol. LIV. No. 1. 8vo. London 1893.

London 1893.

The Society.

The Society.

The Society.
Royal Geographical Society. The Geographical Journal. July
-December, 1893. 8vo. London.
The Society

The Institute.

Royal Institute of British Architects. Journal of Proceedings.
July-December, 1893. 4to. London.
Royal Institution of Great Britain. Reports of the Weekly
Evening Meetings. January-June, 1893. 8vo. London.
The Institution.

Royal Microscopical Society. Journal. 1893.

London 1893.

Part 6. 8vo.

The Society.

Royal Statistical Society. Journal. Vol. LVI. Part 4. 8vo.
London 1893.

The Society.

Vol. XXXVII.

The Institution.

Royal United Service Institution. Journal.
No. 190. 8vo. London 1893.
Society of Arts. Journal. July-December, 1893. 8vo. London.

The Society.

Society of Chemical Industry. Journal. Vol. XII. Nos. 6—11.
8vo. London 1893.
The Society.

Victoria Institute. Journal. Vol. XXVII. Part 1. London
The Institute.

1893.

Transactions (continued).

The Academy.

Madison :-Wisconsin Academy of Science, Arts, and Letters.
Vol. IX. Part 1. 8vo. Madison 1893.
Manchester:-Geological Society. Transactions.

Part 13. 8vo. Manchester 1893.
Mexico-Sociedad Científica "Antonio Alzate."

Revista. Tomo VII. Nos. 3-4.

Vol. XXII.
The Society.
Memorias y

8vo. México 1893.

Moscow-Société Impériale des Naturalistes.

1893. Nos. 2-3. 8vo. Moscou 1893.

The Society.

Bulletin. Année
The Society.

New York:-Academy of Sciences. Annals. Vol. VIII. Nos. 1—3. 8vo. New York 1893; Transactions. Vol. XII. 8vo. New York [1893].

American Museum of Natural History.
Pp. 305–336. 8vo. [New York] 1893.

The Academy.

Bulletin. Vol. V.

The Museum.

Paris:-Académie des Sciences. Comptes Rendus. JuilletDécembre, 1893. 4to. Paris; Bulletin du Comité International Permanent pour l'Exécution Photographique de la Carte du Ciel. Tome II. Fasc. 2. 4to. Paris 1893.

The Academy. Ecole Normale Supérieure. Annales. Tome X. No. 12. 4to.

Paris 1893.

Société de Biologie. Comptes Rendus.

1893. Svo. Paris.

The School.

Juillet-Décembre,
The Society.

The Society.

Société de Géographie. Comptes Rendus des Séances. 1893.
Nos. 12-18. 8vo. Paris.
Société d'Encouragement pour l'Industrie Nationale. Bulletin.
Mai-Juillet, 1893. 4to. Paris; Compte-Rendu des Séances.
Juin-Décembre, 1893. 8vo. Paris.
The Society.
Société Française de Physique. Séances. Avril-Juillet, 1893.
8vo. Paris 1893; Bulletin Bimensuel. 1892-93. Nos. 26—
28, 30-33. 8vo. Paris.
The Society.
Société Géologique de France. Compte-Rendu des Séances.
1893. Nos. 13-18. 8vo. [Paris.]
The Society.
Société Mathématique. Bulletin. Tome XXI. Nos. 7-8. 8vo.
Paris.

The Society.

1892-93.

Paris.

Société Philomathique. Compte-Rendu des Séances.
Nos. 17-18, 20. 1893-94. Nos. 1-5. 8vo.

Philadelphia :-Academy of Natural Sciences.
Parts 1-2, and Pp. 217-312, 345-376.

The Society. Proceedings. 1893. 8vo. Philadelphia. The Academy.

July-December, 1893. 8vo.

The Institute.

Transactions (continued).

Pisa-Società Toscana di Scienze Naturali.
Vol. VIII. Pp. 233-241. 8vo. Pisa.
Rome:-Reale Accademia dei Lincei. Rendiconti.

Processi Verbali.
The Society.

Serie 5. Vol. II.

Semestre 1. Fasc. 10-12. Semestre 2. Fasc. 1-11. 8vo. Roma 1893. The Academy. San Francisco:-Californian Academy of Sciences. Proceedings. Second Series. Vol. III. Part 2. 8vo. San Francisco 1893; Occasional Papers. No. 4. 8vo. San Francisco 1893.

Santiago :-Sociedad Nacional de Mineria.

The Academy.

Boletin.

Año. X. The Society.

Livr. 1-2. The Society.

Nos. 59-60. 4to. Santiago de Chile 1893. Société Scientifique de Chili. Actes. Tome III. 8vo. Santiago 1893. Stavanger:-Museum. Aarsberetning. 1892. 8vo. Stavanger

Stockholm 1893.

The Museum.

1893.
Stockholm :-Kongl. Svenska Vetenskaps Akademie. Bihang till
Handlingar. Band 18. 8vo. Stockholm 1893; Öfversigt.
Årg. 50. No. 8. 8vo.
The Academy.
Sydney :-Linnean Society of New South Wales. Proceedings.
Vol. VIII. Part 1. 8vo. Sydney 1893; Abstract of Pro-
ceedings. May-November, 1893. 8vo. Sydney; The Macleay
Memorial Volume. Edited by J. J. Fletcher. 4to. Sydney
1893.
The Society.
Tokyo:-Imperial University of Japan. Calendar. 1892-93. 8vo.
Tokyo 1893; Mittheilungen aus der Medicinischen Facultät.
Bd. II. No. 1. 4to. Tokio 1893.
The University.
Toronto:-University. Calendar. 1893-94. 8vo. Toronto 1893.
The University.

Turin:-Reale Accademia delle Scienze. Memorie. Tome XLIII.
4to. Torino 1893.
The Academy.
Vienna-Kais. Akademie der Wissenschaften. Sitzungsberichte.
Bd. CII. Abth. 2b. Heft 8. 8vo. Wien 1893; Anzeiger.
Jahrg. 1893. Nos. 23-27. 8vo. Wien 1893. The Academy.
Washington-Smithsonian Institution. Miscellaneous Collec-
tions. Vol. XXXIV. 8vo. Washington 1893.

The Institution.
Surgeon-General's Office. Index-Catalogue of the Library.
Vol. XIV. 4to. Washington 1893. The Surgeon-General.

Observations and Reports.

Bombay :-Meteorological Office. Brief Sketch of the Meteorology of the Bombay Presidency in 1892-93. 4to. Bombay.

The Office.