On the measurement of an international arc of meridian through the Ameri-

can continent, from Cape Horn to the Arctic regions. By TRELAWNEY

SAUNDERS. (Title)

Results of observations and experiments with an almucantar of four inches

aperture, at the Harvard College Observatory. By S. C. CHANDLER, jr.

(Title)

The geodetic work of the U. S. coast and geodetic survey. By J. HOWARD

GORE. (Title)

A criterion for the rejection of doubtful observations. By MANSFIELD MER-

RIMAN. (Title)

Harmonic motion in stellar systems. By PLINY EARLE CHASE. (Title)

On the mean temperature of the two hemispheres of the earth. By H. HEN-

NESSY. (Title)

On the constitution of the earth and planets. By H. HENNESSY. (Title)

On an international standard for measurements. By H. HENNESSY. (Title)

Systematic errors in stellar magnitudes. By E. C. PICKERING. (Title)

On the magnitude of the errors which may be introduced in the reduction of

an observed system of stellar coördinates to an assumed normal system

by graphic methods. By WM. A. ROGERS. (Title)

Analysis of the formula for the moon's latitude as affected by the figure of the

earth. By JOHN N. STOCKWELL. (Title)

On an indirect solution of the equation

d3 T

a = a+da+da 2 + 1. fd= 3 + etc.

ατ

da

ατ

is a function of four variables.

to the 6th power of the time, in which

By WM. A. ROGERS. (Title)

A brief account of some preliminary experiments in the construction of clocks

of precision. By LEONARD WALDO. (Title)

A collection of formulæ for the area of a plane triangle. By MARCUS BAKER.

(Title)

The products of vectors. By SAMUEL EMERSON. (Title)

Temporary stars. By DANIEL KIRKWOOD. (Title)

On the visibility of faint objects under red illumination. By G. W. HOUGH.

(Title)

78

78

78

Mechanical arithmetic, illustrated by the averaging machine. By W. S. AU-
CHINCLOSS. (Title)

ADDRESS OF VICE PRESIDENT JOHN TROWBRIDGE
On the Fritts selenium cells and batteries. By C. E. FRITTS
Relation between the electromotive force of a Daniell cell and the strength of
the zinc sulphate solution. By H. S. CARHART

Sensitiveness of photographic dry plate. By Wм. H. PICKERING

Photography of the infra-red region of the spectrum. By WM. H. PICKERING

Thunderstorms and their relations to "Low." By HENRY A. HAZEN
Notes on acoustics. By CHAS. R. CROSS

producing oxygen and hy-
By WM. A. ANTHONY

On a proposed method for ascertaining the least number of vibrations neces-

sary to determine pitch. By CHAS. R. CROSS

'Upon a generator in use at Cornell University for

drogen gas by means of the dynamo machine.

Determination of the coefficient of expansion of the speculum metal used for

Rowland's gratings. By WM. A. ROGERS

Additional observations confirming the relation: Metre des archives = Im-

perial Yard +3.37027 inches. By WM. A. ROGERS

A method for the practical examination of railroad employés as to color

blindness, acuteness of vision and hearing, with the results obtained by it

on the Pennsylvania railroad. By WILLIAM THOMSON

Notes on ancroids. By M. W. HARRINGTON

120

129

An absolute sensitometer. By G. W. HOUGH

An experiment for illustrating the conversion of mechanical energy into heat.

By CHAS. E. MUNROE

129

130

On the variation of the resistance of carbon under pressure. By T. C. MEN-

A possible method of electrical communication between vessels at sea. By

A. GRAHAM BELL

132

On the intensity of sound. II. The energy used by an organ

WEAD

134

.

135

136

136

A preliminary note on the action of acids upon iron in the magnetic field. By

EDWARD W. NICHOLS

Local and topical weather cards. By W. M. DAVIS

On a proof of contact theory of electricity. By A. E. DOLBEAR

On comparative cost of electric light, and oxycalcium light. By A. F. DOL-

BEAR.

Electric discharges in relation to the equilibrium of gaseous atmospheres. By

JAMES DEWAR

On the distribution of potential in conductors experiencing the electromag-
netic effects discovered by Hall. By WILLIAM THOMPSON. (Title)

On a standard tangent galvanometer. By SILVANUS THOMPSON. (Title)

On the government of electric motors. By SILVANUS THOMPSON. (Title)

Change in rainfall of Virginia. By J. R. PURDIE. (Title)

The Princeton Meteorological Observatory. By WILLIAM LIBBEY, jr. (Title)

A form of apparatus for determining the diathermacy of air and gases. By

JOHN R. PADDOCK. (Title) .

A proposed method of determining the magnetic dip by means of a magnetic

pendulum. By MARCUS BAKER. (Title)

Description of a galvanometer for demonstrating the internal current trans-

mitted through the liquid within a voltaic cell. By CONRAD W. COOKE.

(Title).

Thermal belts. By J. W. CHICKERING, jr. (Title)

Geometrical methods in the theory of refraction at one or more surfaces. By

JAMES LOUDON. (Title)

137

137

137

Some relations of positive and negative electricity. By H. W. EATON. (Title)

A method of distributing weather forecast by means of railroad trains, etc.

By JOHN A. MILLER. (Title)

Note on the periodic modification of electro-static induction. By H. S. CAR-

HART. (Title)

On the sensitiveness of the eye to colors of a low degree of saturation. By

E. L. NICHOLS. (Title)

A spectrophotometric study of pigments. By E. L. NICHOLS. (Title)

First steps toward a general system of observations of atmospheric electricity.

By CLEVELAND ABBE. (Title)

Organization of seismological observations. By CLEVELAND ABBE. (Title)

Methods of verifying weather probabilities. By CLEVELAND ABBE. (Title)

Standards of barometry and thermometry. By CLEVELAND ABBE. (Title)

On the rotation of the equipotential lines of an electric current by magnetic

action. By E. H. HALL. (Title)

138

138

138

138

138

138

138

SECTION C. CHEMISTRY.

ADDRESS OF VICE-PRESIDENT JOHN W. LANGLEY

Optical methods of estimating sugar in milk. By H. W. WILEY

On chlorpropiolic acid and certain substituted acrylic and propionic acids.

By C. F. MABERY

Continuous etherification. By L. M. NORTON and C. O. PRESCOTT

Anthracene from water-gas tar. By ARTHUR H. ELLIOTT

On the chemistry of fish. By W. O. ATWATER

141

163

163

164

170

170

A preliminary report on the composition of the coals of Kansas. By E. H. S.

BAILEY

Fermentation without combined nitrogen. By ALFRED SPRINGER
Examination of methods proposed for rendering the lighter petroleum oils in-
explosive. By CHAS. E. MUNROE

The chemistry of the roller milling process. By CLIFFORD RICHARDSON

Analysis of a mural efflorescence. By CHAS. E. MUNROE

A study of the phenomenon of deliquescence. By CHAS. E. MUNROE (Dia-

gram)

171

172

174

175

177

179

An explanation of Gladstone and Tribe's 2-3 law in chemical dynamics. By

JOHN W. LANGLEY

185

Preliminary analysis of the bark of Fouquieria splendens. By HELEN C. DE

S. ABBOTT

The density of solid carbonic acid. By JAMES DEWAR

The composition and methods of analysis of human milk. By ALBERT R.

LEEDS

190

Modifications of Ruffle's Method for the absolute determination of nitrogen.
By H. C. WHITE. (Title).

On the assimilation of atmospheric nitrogen by plants. By W. O. ATWATER.
(Title)

Notes on Reinsch's test. By HENRY LEFFMANN. (Title)

Apparatus for the determination of nitrogen by the copper oxide method. By

CHARLES W. DABNEY, jr. (Title)

A convenient apparatus for determining nitrogen in duplicate. By CHARLES

W. DABNEY, jr. (Title).

Anhydrobenzoamidosalicylic acid. By CHARLES W. DABNEY, jr. (Title)

Torsion balances. By ALFRED SPRINGER. (Title)

Discussion on fermentation. By ALFRED SPRINGER. (Title)

On a substitute for litmus, and simple processes for estimating alkalies, acids,

temporary hardness of water, etc. By J. F. HEYES. (Title).

A new form of gas regulator. By F. P. DUNNINGTON. (Title)

Simple lecture illustrations. By F. P. DUNNINGTON. (Title).

Production of argentic hydrate. By F. P. DUNNINGTON. (Title)

Improvements in apparatus for rapid gas analysis. By A. H. ELLIOTT. (Title)

SECTION D. MECHANICAL SCIENCE.

ADDRESS OF VICE PRESIDENT ROBERT H. THURSTON

The production of optical surfaces. By JOHN A. BRASHEAR (Illustrated)

The Giant's causeway and Portrush electric tramway (Ireland). By WIL-

LIAM A. TRAILL

Electric tramways. By M. HOLROYD SMITH

Are the advantages of a trip gear worth its greater cost than excentrics? By

ARTHUR RIGG

The strength of cast iron. By W. J. MILLAR

261

262

262

A mode of heating from a central source. By SIR FREDERICK BRAMWELL

Flood regulator. By JAMES DILLON

On a new method of producing screws of standard length and uniform pitch.

By WM. A. ROGERS.

275

Development of the philosophy of heat engines. By R. H. THURSTON

Three problems in river physics. By J. B. JOHNSON

Steam engine practice in the United States in 1881. By J. C. HOADLEY

289

The Missouri Coteau and its moraines. By J. E. TODD (Map)

A study of one point in the Archæan-palæozoic contact line in southeastern

Pennsylvania. By PERSIFOR FRAZER. (Map)

Identification of Green Mountain gneisses in eastern New England. By C. H.

HITCHCOCK

The horizons of petroleum and inflammable gas in Ohio. By EDWARD OR-

ΤΟΝ

The correlation of the lower coal measures of Ohio and eastern Kentucky.
By EDWARD ORTON

The salt well at Humboldt, Minnesota. By N. H. WINCHELL.

A review of the geology of Delaware. Results of a survey now in progress.
By FREDERICK D. CHESTER.

The geological age, character and origin of gypsum beds of Cayuga Co., New
York. By S. G. WILLIAMS

A great trap dyke across southeastern Pennsylvania. By H. CARVILL LEWIS,

Evidences of local glaciers in the Catskill Mountain region. By JOHN C.

SMOCK

An attempt to determine the amount of chemical erosion taking place in the
limestone (Calciferous to Trenton) valley of Centre Co., Pa., and hence
applicable to similar regions throughout the Appalachian system. By
A. L. ERVING.

Notice of an important work on the origin of the crystalline schists, by Dr. J.

Lehmann, Professor of Geology at Breslau, illustrated by an atlas of 28

photographic plates. 4to, Bonn, 1884. By GEO. H. WILLIAMS

363

381

394

396

397

398

399

400

402

402

403

404

405

407

408

413

415

On a section of the strata of the cretaceous and tertiary formations of Ala-
bama. By EUGENE A. SMITH, and LAWRENCE C. JOHNSON
Musical sand, its wide distribution and properties. By H. CARRINGTON BOL.
TON and ALEXIS A. JULIEN (Illustrated)
Notice on the microscopical examination of a series of ocean, lake, river and
desert sands. By ALEXIS A. JULIEN and H. CARRINGTON BOLTON
A study of "Eozoon canadense." By ALEXIS A. JULIEN

Note on the intimate relations of the Chemung group and Waverly sandstone
in northwestern Pennsylvania and southwestern New York. By JAMES
HALL (Section)

Geographical and physical conditions as modifying fossil faunas. By HENRY
S. WILLIAMS

Note on the Eurypteridæ of the Devonian and carboniferous formations of
Pennsylvania; with a supplementary note on Stylonurus excelsior. By
JAMES HALL

420

422

On some fish remains recently discovered in the Silurian rocks of Pennsylva-
nia. By E. W. CLAYPOLE

424

Geographic classification, illustrated by a study of plains, plateaus and their
derivatives. By W. M. DAVIS

The genesis and conservation of volcanic energy. By J. J. PIKE
British earthquakes and their seismic relations. By RICHARD OWEN (Dia-
gram)

432

438

The ultimate results of converting the basin of Sahara into an inland lake.
By P. H. VAN DER WEYDE

On the relative level of the Atlantic Ocean and Gulf of Mexico, with remarks
on the gulf stream and deep sea temperatures. By J. E. HILGARD
Recent improvements in apparatus and methods of sounding ocean depths.
By DANIEL AMMEN

Deep sea-soundings in the Caribbean sea. By J. R. BARTLETT

The pilot chart of the north Atlantic Ocean. By J. R. BARTLETT

On the erosive action of ice. By J. S. NEWBERRY. (Title)

On some large and peculiar fossil fishes from Ohio and Indiana. By J. S.
NEWBERRY. (Title)

By GEORGE H. COOK. (Title)

By J. W. SPENCER. (Title)

On the geological survey of New Jersey.
Sand boulders in drift at Columbia, Mo.
Occurrence of boulders of decomposition at Washington, D. C., and else
where. By J. W. SPENCER. (Title)

Cause of motion in glaciers. By CHARLES WHITTLESEY. (Title).
Native antimony from York, Prince William Co., New Brunswick. By GEORGE
F. KUNZ. (Title)

451

451

451

451

451

451

Note on cassiterite from King's Mountain, N. C. By CHARLES W. DABNEY, jr.

(Title)

451

North Carolina phosphates. By CHARRES W. DABNEY, jr. (Title)
On the physical condition of the interior of the earth.

(Title)

Second geological survey of Pennsylvania. By CHARLES A. ASHBURNer.

(Title)

Deflection in the direction of the ice-flow in Maine during the last part of

the glacial epoch. By G. H. STONE. (Title)

On the two series of kame or osar gravels which appear to cross each other

like an x. By G. H. STONE. (Title)

Additional facts concerning the glacial boundary in Kentucky, Indiana and

Illinois. By G. FREDERICK WRIGHT.. (Title)

Exhibition of a geological map of the United States, and a geological map of

New York, New Jersey, and Pennsylvania. By J. W. POWELL. (Title)

Metamorphism in the Huronian of the northwest. By R. D. IRVING. (Title)

The supposed Taconic formation near Philadelphia. By H. CARVILL Lewis

(Title)

The life and scientific work of Arnold Guyot. By WILLIAM LIBBEY, jr.

(Title)

A brief account of the remarkable explorations in Tibet, Mongolia, and the
frontiers of India and China recently made by Krishna, or A. K., a native
surveyor trained under the trignometrical survey of India. With the of-
ficial map. By TRELAWNEY SAUNDERS. (Title)

New identifications in biblical geography based on the recent survey of
Western Palestine made for the Palestine exploration fund. With the
great map of the survey 18 feet in length, and the reduced map of the Old
Testament, Apocrypha, and Josephus, derived therefrom. By TRELAW-
NEY SAUNDERS. (Title)

Some recent observations about the caves at the Giant's Causeway and in the

Island of Staffa, with especial reference to Fingal's cave. By F. COPE

WHITEHOUSE. (Title)

452

452

452

452

452

452

452

452

452

452

SECTION F. BIOLOGY.

ADDRESS OF VICE PRESIDENT EDWARD D. COPE

455

The relations between the theromorphous reptiles and the monotreme mam-

malia. BY EDWARD D. COPE (Plate)

On the structure of the feet in the extinct Artiodactyla of North America. By
EDWARD D. COPE

482

Structure of the siphon in the Endoceratidæ. By ALPHEUS HYATT

Larval theory of the origin of tissue. By ALPHEUS HYATT

Structure and affinities of Beatricea. By ALPHEUS HYATT

The osteology of Oreodon. By W. B. SCOTT

Historical view of the fossil flora of the Globe. By LESTER F. WARD

Geological view of the fossil flora of the Globe. By LESTER F. WARD

Botanical view of the fossil flora of the Globe. By LESTER F. WARD

The torsion of leaves. By W.J. BEAL

492

493

495

496

498