Chapter VI: Sect. 1. Instruments.--2. Clocks

IN page 473, I have described the manner in which astronomers are able to observe the transit of a star, and other astronomical phenomena, to the exactness of a tenth of a second of time. The mode of observation there described implies that the observer at the moment of observation compares the impressions of the eye and of the ear. Now it is found that the habit which the observer must form of doing this operates differently in different observers, so that one observer notes the same fact as happening a fraction of a second earlier or later than another observer does; and this in every case. Thus, using the term _equation_, as we use it in Astronomy, to express a correction by which we get regularity from irregularity, there is a _personal equation_ belonging to this mode of observation, showing that it is liable to error. Can this error be got rid of?

It is at any rate much diminished by a method of observation recently introduced into observatories, and first practised in America. The essential feature of this mode of observation consists in combining the impression of sight with that of touch, instead of with that of hearing. The observer at the moment of observation presses with his finger so as to make a mark on a machine which by its motion measures time with great accuracy and on a large scale; and thus small intervals of time are made visible.

A universal, though not a necessary, part of this machinery, as hitherto adopted, is, that a galvanic circuit has been employed in conveying the impression from the finger to the part where time is measured and marked. The facility with which galvanic wires can {566} thus lead the impression by any path to any distance, and increase its force in any degree, has led to this combination, and almost identification, of observation by touch with its record by galvanism.

The method having been first used by Mr. Bond at Cambridge, in North America, has been adopted elsewhere, and especially at Greenwich, where it is used for all the instruments; and consequently a collection of galvanic batteries is thus as necessary a part of the apparatus of the establishment as its graduated circles and arcs.

END OF VOL. I.

HISTORY OF THE INDUCTIVE SCIENCES.

VOLUME II.

HISTORY OF THE INDUCTIVE SCIENCES, FROM THE EARLIEST TO THE PRESENT TIME. BY WILLIAM WHEWELL, D. D., MASTER OF TRINITY COLLEGE, CAMBRIDGE. _THE THIRD EDITION, WITH ADDITIONS._ IN TWO VOLUMES.

VOLUME II.

NEW YORK: D. APPLETON AND COMPANY, 549 & 551 BROADWAY. 1875.

CONTENTS

OF THE SECOND VOLUME.

_THE SECONDARY MECHANICAL SCIENCES._

BOOK VIII.

HISTORY OF ACOUSTICS.

PAGE
Introduction. 23

CHAPTER I.--PRELUDE TO THE SOLUTION OF PROBLEMS IN ACOUSTICS. 24

CHAPTER II.--PROBLEM OF THE VIBRATIONS OF STRINGS. 28

CHAPTER III.--PROBLEM OF THE PROPAGATION OF SOUND. 32

CHAPTER IV.--PROBLEM OF DIFFERENT SOUNDS OF THE SAME STRING. 36

CHAPTER V.--PROBLEM OF THE SOUNDS OF PIPES. 38

CHAPTER VI.--PROBLEM OF DIFFERENT MODES OF VIBRATION OF BODIES IN GENERAL. 41

BOOK IX.

HISTORY OF OPTICS, FORMAL AND PHYSICAL.

Introduction. 51 {8}

_FORMAL OPTICS._

CHAPTER I.--PRIMARY INDUCTION OF OPTICS.--RAYS OF LIGHT AND LAWS OF REFLECTION. 53

CHAPTER II.--DISCOVERY OF THE LAW OF REFRACTION. 54

CHAPTER III.--DISCOVERY OF THE LAW OF DISPERSION BY REFRACTION. 58

CHAPTER IV.--DISCOVERY OF ACHROMATISM. 66

CHAPTER V.--DISCOVERY OF THE LAWS OF DOUBLE REFRACTION. 69

CHAPTER VI.--DISCOVERY OF THE LAWS OF POLARIZATION. 72

CHAPTER VII.--DISCOVERY OF THE LAWS OF THE COLORS OF THIN PLATES. 76

CHAPTER VIII.--ATTEMPTS TO DISCOVER THE LAWS OF OTHER PHENOMENA. 78

CHAPTER IX.--DISCOVERY OF THE LAWS OF PHENOMENA OF DIPOLARIZED LIGHT. 80

_PHYSICAL OPTICS._

CHAPTER X.--PRELUDE TO THE EPOCH OF YOUNG AND FRESNEL. 85

CHAPTER XI.--EPOCH OF YOUNG AND FRESNEL.

_Sect._ 1. Introduction. 92 _Sect._ 2. Explanation of the Periodical Colors of Thin Plates and Shadows by the Undulatory Theory. 93 _Sect._ 3. Explanation of Double Refraction by the Undulatory Theory. 98 _Sect._ 4. Explanation of Polarization by the Undulatory Theory. 100 _Sect._ 5. Explanation of Dipolarization by the Undulatory Theory. 105 {9}

CHAPTER XII.--SEQUEL TO THE EPOCH OF YOUNG AND FRESNEL.--RECEPTION OF THE UNDULATORY THEORY. 111

CHAPTER XIII.--CONFIRMATION AND EXTENSION OF THE UNDULATORY THEORY. 118

1. Double Refraction of Compressed Glass. 119 2. Circular Polarization. 119 3. Elliptical Polarization in Quartz. 122 4. Differential Equations of Elliptical Polarization. 122 5. Elliptical Polarization of Metals. 123 6. Newton's Rings by Polarized Light. 124 7. Conical Refraction. 124 8. Fringes of Shadows. 126 9. Objections to the Theory. 126 10. Dispersion, on the Undulatory Theory. 128 11. Conclusion. 128

BOOK X.

HISTORY OF THERMOTICS AND ATMOLOGY.

Introduction. 137

_THERMOTICS PROPER._

CHAPTER I.--THE DOCTRINES OF CONDUCTION AND RADIATION.

_Sect._ 1. Introduction of the Doctrine of Conduction. 139 _Sect._ 2. " " " Radiation. 142 _Sect._ 3. Verification of the Doctrines of Conduction and Radiation. 143 _Sect._ 4. The Geological and Cosmological Application of Thermotics. 144 1. Effect of Solar Heat on the Earth. 145 2. Climate. 146 3. Temperature of the Interior of the Earth. 147 4. Heat of the Planetary Spaces. 148 _Sect._ 5. Correction of Newton's Law of Cooling. 149 _Sect._ 6. Other Laws of Phenomena with respect to Radiation. 151 _Sect._ 7. Fourier's Theory of Radiant Heat. 152 _Sect._ 8. Discovery of the Polarization of Heat. 153 {10}

CHAPTER II.--THE LAWS OF CHANGES OCCASIONED BY HEAT.

_Sect._ 1. Expansion by Heat.--The Law of Dalton and Gay-Lussac for Gases. 157 _Sect._ 2. Specific Heat.--Change of Consistence. 159 _Sect._ 3. The Doctrine of Latent Heat. 160

_ATMOLOGY._

CHAPTER III.--THE RELATION OF VAPOR AND AIR.

_Sect._ 1. The Boylean Law of the Air's Elasticity. 163 _Sect._ 2. Prelude to Dalton's Doctrine of Evaporation. 165 _Sect._ 3. Dalton's Doctrine of Evaporation. 170 _Sect._ 4. Determination of the Laws of the Elastic Force of Steam. 172 _Sect._ 5. Consequences of the Doctrine of Evaporation.--Explanation of Rain, Dew, and Clouds. 176

CHAPTER IV.--PHYSICAL THEORIES OF HEAT.

Thermotical Theories. 181 Atmological Theories. 184 Conclusion. 187

_THE MECHANICO-CHEMICAL SCIENCES._

BOOK XI.

HISTORY OF ELECTRICITY.

Introduction. 191

CHAPTER I.--DISCOVERY OF LAWS OF ELECTRIC PHENOMENA. 193

CHAPTER II.--THE PROGRESS OF ELECTRICAL THEORY. 201

Question of One or Two Fluids. 210 Question of the Material Reality of the Electric Fluid. 212 {11}

BOOK XII.

HISTORY OF MAGNETISM.

CHAPTER I.--DISCOVERY OF LAWS OF MAGNETIC PHENOMENA. 217

CHAPTER II.--PROGRESS OF MAGNETIC THEORY.

Theory of Magnetic Action. 220 Theory of Terrestrial Magnetism. 224 Conclusion. 232

BOOK XIII.

HISTORY OF GALVANISM, OR VOLTAIC ELECTRICITY.

CHAPTER I.--DISCOVERY OF VOLTAIC ELECTRICITY. 237

CHAPTER II.--RECEPTION AND CONFIRMATION OF THE DISCOVERY OF VOLTAIC ELECTRICITY. 240

CHAPTER III.--DISCOVERY OF THE LAWS OF THE MUTUAL ATTRACTION AND REPULSION OF VOLTAIC CURRENTS.--AMPÈRE. 242

CHAPTER IV.--DISCOVERY OF ELECTRO-MAGNETIC ACTION.--OERSTED. 243

CHAPTER V.--DISCOVERY OF THE LAWS OF ELECTRO-MAGNETIC ACTION. 245

CHAPTER VI.--THEORY OF ELECTRODYNAMICAL ACTION.

Ampère's Theory. 246 Reception of Ampère's Theory. 249

CHAPTER VII.--CONSEQUENCES OF THE ELECTRODYNAMIC THEORY. 250

Discovery of Diamagnetism. 252 {12}

CHAPTER VIII.--DISCOVERY OF THE LAWS OF MAGNETO-ELECTRIC INDUCTION.--FARADAY. 253

CHAPTER IX.--TRANSITION TO CHEMICAL SCIENCE. 256

_THE ANALYTICAL SCIENCE._

BOOK XIV.

HISTORY OF CHEMISTRY.

CHAPTER I.--IMPROVEMENT OF THE NOTION OF CHEMICAL ANALYSIS, AND RECOGNITION OF IT AS THE SPAGIRIC ART. 261

CHAPTER II.--DOCTRINE OF ACID AND ALKALI.--SYLVIUS. 262

CHAPTER III.--DOCTRINE OF ELECTIVE ATTRACTIONS.--GEOFFROY. BERGMAN. 265

CHAPTER IV.--DOCTRINE OF ACIDIFICATION AND COMBUSTION.--PHLOGISTIC THEORY.

Publication of the Theory by Beccher and Stahl. 267 Reception and Application of the Theory. 271

CHAPTER V.--CHEMISTRY OF GASES.--BLACK. CAVENDISH. 272

CHAPTER VI.--EPOCH OF THE THEORY OF OXYGEN.--LAVOISIER.

_Sect._ 1. Prelude to the Theory.--Its Publication. 275 _Sect._ 2. Reception and Confirmation of the Theory of Oxygen. 278 _Sect._ 3. Nomenclature of the Oxygen Theory. 281

CHAPTER VII.--APPLICATION AND CORRECTION OF THE OXYGEN THEORY. 282 {13}

CHAPTER VIII.--THEORY OF DEFINITE, RECIPROCAL, AND MULTIPLE PROPORTIONS.

_Sect._ 1. Prelude to the Atomic Theory, and its Publication by Dalton. 285 _Sect._ 2. Reception and Confirmation of the Atomic Theory. 288 _Sect._ 3. The Theory of Volumes.--Gay-Lussac. 290

CHAPTER IX.--EPOCH OF DAVY AND FARADAY.

_Sect._ 1. Promulgation of the Electro-chemical Theory by Davy. 291 _Sect._ 2. Establishment of the Electro-chemical Theory by Faraday. 296 _Sect._ 3. Consequences of Faraday's Discoveries. 302 _Sect._ 4. Reception of the Electro-chemical Theory. 303

CHAPTER X.--TRANSITION FROM THE CHEMICAL TO THE CLASSIFICATORY SCIENCES. 305

_THE ANALYTICO-CLASSIFICATORY SCIENCE._

BOOK XV.

HISTORY OF MINERALOGY.

INTRODUCTION

_Sect._ 1. Of the Classificatory Sciences. 313 _Sect._ 2. Of Mineralogy as the Analytico-classificatory Science. 314

_CRYSTALLOGRAPHY._

CHAPTER I.--PRELUDE TO THE EPOCH OF DE LISLE AND HAÜY. 316

CHAPTER II.--EPOCH OF ROMÉ DE LISLE AND HAÜY.--ESTABLISHMENT OF THE FIXITY OF CRYSTALLINE ANGLES, AND THE SIMPLICITY OF THE LAWS OF DERIVATION. 320

CHAPTER III.--RECEPTION AND CORRECTIONS OF THE HAUÏAN CRYSTALLOGRAPHY. 324 {14}

CHAPTER IV.--ESTABLISHMENT OF THE DISTINCTION OF SYSTEMS OF CRYSTALLIZATION.--WEISS AND MOHS. 326

CHAPTER V.--RECEPTION AND CONFIRMATION OF THE DISTINCTION OF SYSTEMS OF CRYSTALLIZATION.

Diffusion of the Distinction of Systems. 330 Confirmation of the Distinction of Systems by the Optical Properties of Minerals.--Brewster. 331

CHAPTER VI.--CORRECTION OF THE LAW OF THE SAME ANGLE FOR THE SAME SUBSTANCE.

Discovery of Isomorphism.--Mitscherlich. 334 Dimorphism. 336

CHAPTER VII.--ATTEMPTS TO ESTABLISH THE FIXITY OF OTHER PHYSICAL PROPERTIES.--WERNER. 336

_SYSTEMATIC MINERALOGY._

CHAPTER VIII.--ATTEMPTS AT THE CLASSIFICATION OF MINERALS.

_Sect._ 1. Proper Object of Classification. 339 _Sect._ 2. Mixed Systems of Classification. 340

CHAPTER IX.--ATTEMPTS AT THE REFORM OF MINERALOGICAL SYSTEMS.--SEPARATION OF THE CHEMICAL AND NATURAL HISTORY METHODS.

_Sect._ 1. Natural History System of Mohs. 344 _Sect._ 2. Chemical System of Berzelius and others. 347 _Sect._ 3. Failure of the Attempts at Systematic Reform. 349 _Sect._ 4. Return to Mixed Systems with Improvements. 351

_CLASSIFICATORY SCIENCES._

BOOK XVI.

HISTORY OF SYSTEMATIC BOTANY AND ZOOLOGY.

Introduction. 357 {15}

CHAPTER I.--IMAGINARY KNOWLEDGE OF PLANTS. 358

CHAPTER II.--UNSYSTEMATIC KNOWLEDGE OF PLANTS. 361

CHAPTER III.--FORMATION OF A SYSTEM OF ARRANGEMENT OF PLANTS.

_Sect._ 1. Prelude to the Epoch of Cæsalpinus. 369 _Sect._ 2. Epoch of Cæsalpinus.--Formation of a System of Arrangement. 373 _Sect._ 3. Stationary Interval. 378 _Sect._ 4. Sequel to the Epoch of Cæsalpinus.--Further Formation and Adoption of Systematic Arrangement. 382

CHAPTER IV.--THE REFORM OF LINNÆUS.

_Sect._ 1. Introduction of the Reform. 387 _Sect._ 2. Linnæan Reform of Botanical Terminology. 389 _Sect._ 3. " " " Nomenclature. 391 _Sect._ 4. Linnæus's Artificial System, 395 _Sect._ 5. Linnæus's Views on a Natural Method. 396 _Sect._ 6. Reception and Diffusion of the Linnæan Reform. 400

CHAPTER V.--PROGRESS TOWARDS A NATURAL SYSTEM OF BOTANY. 404

CHAPTER VI.--THE PROGRESS OF SYSTEMATIC ZOOLOGY. 412

CHAPTER VII.--THE PROGRESS OF ICHTHYOLOGY. 419

Period of Unsystematic Knowledge. 420 Period of Erudition. 421 Period of Accumulation of Materials.--Exotic Collections. 422 Epoch of the Fixation of Characters.--Ray and Willoughby. 422 Improvement of the System.--Artedi. 423 Separation of the Artificial and Natural Methods in Ichthyology. 426

_ORGANICAL SCIENCES._

BOOK XVII.

HISTORY OF PHYSIOLOGY AND COMPARATIVE ANATOMY.

Introduction. 435 {16}

CHAPTER I.--DISCOVERY OF THE ORGANS OF VOLUNTARY MOTION.

_Sect._ 1. Knowledge of Galen and his Predecessors. 438 _Sect._ 2. Recognition of Final Causes in Physiology.--Galen. 442

CHAPTER II.--DISCOVERY OF THE CIRCULATION OF THE BLOOD.

_Sect._ 1. Prelude to the Discovery. 444 _Sect._ 2. The Discovery of the Circulation made by Harvey. 447 _Sect._ 3. Reception of the Discovery. 448 _Sect._ 4. Bearing of the Discovery on the Progress of Physiology. 449

CHAPTER III.--DISCOVERY OF THE MOTION OF THE CHYLE, AND CONSEQUENT SPECULATIONS.

_Sect._ 1. The Discovery of the Motion of the Chyle. 452 _Sect._ 2. The Consequent Speculations. Hypotheses of Digestion. 453

CHAPTER IV.--EXAMINATION OF THE PROCESS OF REPRODUCTION IN ANIMALS AND PLANTS, AND CONSEQUENT SPECULATIONS.

_Sect._ 1. The Examination of the Process of Reproduction in Animals. 455 _Sect._ 2. " " " " in Vegetables. 457 _Sect._ 3. The Consequent Speculations.--Hypotheses of Generation. 459

CHAPTER V.--EXAMINATION OF THE NERVOUS SYSTEM, AND CONSEQUENT SPECULATIONS.

_Sect._ 1. The Examination of the Nervous System. 461 _Sect._ 2. The Consequent Speculations. Hypotheses respecting Life, Sensation, and Volition. 464

CHAPTER VI.--INTRODUCTION OF THE PRINCIPLE OF DEVELOPED AND METAMORPHOSED SYMMETRY.

_Sect._ 1. Vegetable Morphology.--Göthe. De Candolle. 468 _Sect._ 2. Application of Vegetable Morphology. 474

CHAPTER VII.--PROGRESS OF ANIMAL MORPHOLOGY.

_Sect._ 1. Rise of Comparative Anatomy. 475 _Sect._ 2. Distinction of the General Types of the Forms of Animals.--Cuvier. 478 _Sect._ 3. Attempts to establish the Identity of the Types of Animal Forms. 480 {17}

CHAPTER VIII.--THE DOCTRINE OF FINAL CAUSES IN PHYSIOLOGY.

_Sect._ 1. Assertion of the Principle of Unity of Plan. 482 _Sect._ 2. Estimate of the Doctrine of Unity of Plan. 487 _Sect._ 3. Establishment and Application of the Principle of the Conditions of Existence of Animals.--Cuvier. 492

_THE PALÆTIOLOGICAL SCIENCES._

BOOK XVIII.

HISTORY OF GEOLOGY.

Introduction. 499

_DESCRIPTIVE GEOLOGY._

CHAPTER I.--PRELUDE TO SYSTEMATIC DESCRIPTIVE GEOLOGY.

_Sect._ 1. Ancient Notices of Geological Facts. 505 _Sect._ 2. Early Descriptions and Collections of Fossils. 506 _Sect._ 3. First Construction of Geological Maps. 509

CHAPTER II.--FORMATION OF SYSTEMATIC DESCRIPTIVE GEOLOGY.

_Sect._ 1. Discovery of the Order and Stratification of the Materials of the Earth. 511 _Sect._ 2. Systematic Form given to Descriptive Geology.--Werner. 513 _Sect._ 3. Application of Organic Remains as a Geological Character.--Smith. 515 _Sect._ 4. Advances in Palæontology.--Cuvier. 517 _Sect._ 5. Intellectual Characters of the Founders of Systematic Descriptive Geology. 520

CHAPTER III.--SEQUEL TO THE FORMATION OF SYSTEMATIC DESCRIPTIVE GEOLOGY.

_Sect._ 1. Reception and Diffusion of Systematic Geology. 523 _Sect._ 2. Application of Systematic Geology.--Geological Surveys and Maps. 526 _Sect._ 3. Geological Nomenclature. 527 _Sect._ 4. Geological Synonymy, or Determination of Geological Equivalents. 531 {18}

CHAPTER IV.--ATTEMPTS TO DISCOVER GENERAL LAWS IN GEOLOGY.

_Sect._ 1. General Geological Phenomena. 537 _Sect._ 2. Transition to Geological Dynamics. 541

_GEOLOGICAL DYNAMICS._

CHAPTER V.--INORGANIC GEOLOGICAL DYNAMICS.

_Sect._ 1. Necessity and Object of a Science of Geological Dynamics. 542 _Sect._ 2. Aqueous Causes of Change. 545 _Sect._ 3. Igneous Causes of Change.--Motions of the Earth's Surface. 549 _Sect._ 4. The Doctrine of Central Heat. 554 _Sect._ 5. Problems respecting Elevations and Crystalline Forces. 556 _Sect._ 6. Theories of Changes of Climate. 559

CHAPTER VI.--PROGRESS OF THE GEOLOGICAL DYNAMICS OF ORGANIZED BEINGS.

_Sect._ 1. Objects of this Science. 561 _Sect._ 2. Geography of Plants and Animals. 562 _Sect._ 3. Questions of the Transmutation of Species. 563 _Sect._ 4. Hypothesis of Progressive Tendencies. 565 _Sect._ 5. Question of Creation as related to Science. 568 _Sect._ 6. The Hypothesis of the Regular Creation and Extinction of Species. 573 1. Creation of Species. 573 2. Extinction of Species. 576 _Sect._ 7. The Imbedding of Organic Remains. 577

_PHYSICAL GEOLOGY._

CHAPTER VII.--PROGRESS OF PHYSICAL GEOLOGY.

_Sect._ 1. Object and Distinctions of Physical Geology. 579 _Sect._ 2. Of Fanciful Geological Opinions. 580 _Sect._ 3. Of Premature Geological Theories. 584

CHAPTER VIII.--THE TWO ANTAGONIST DOCTRINES OF GEOLOGY.

_Sect._ 1. Of the Doctrine of Geological Catastrophes. 586 _Sect._ 2. " " " Uniformity. 588 {19}

_ADDITIONS TO THE THIRD EDITION._

BOOK VIII.--ACOUSTICS.

SOUND.

The Velocity of Sound in Water. 599

BOOK IX.--OPTICS.

Photography. 601 Fluorescence. 601

UNDULATORY THEORY.

Direction of the Transverse Vibrations in Polarization. 603 Final Disproof of the Emission Theory. 604

BOOK X.--THERMOTICS.--ATMOLOGY.

THE RELATION OF VAPOR AND AIR.

Force of Steam. 606 Temperature of the Atmosphere. 607

THEORIES OF HEAT.

The Dynamical Theory of Heat. 608

BOOK XI.--ELECTRICITY.

General Remarks. 610 Dr. Faraday's Views of Statical Electrical Induction. 611

BOOK XII.--MAGNETISM.

Recent Progress of Terrestrial Magnetism. 613 Correction of Ships' Compasses. 616 {20}

BOOK XIII.--VOLTAIC ELECTRICITY.

MAGNETO-ELECTRIC INDUCTION.

Diamagnetlc Polarity. 620 Magneto-optic Effects and Magnecrystallic Polarity. 621 Magneto-electric Machines. 623 Applications of Electrodynamic Discoveries. 623

BOOK XIV.--CHEMISTRY.

THE ELECTRO-CHEMICAL THEORY.

The Number of Elementary Substances. 625

BOOK XV.--MINERALOGY.

Crystallography. 627 Optical Properties of Minerals. 629 Classification of Minerals. 630

BOOK XVI.--CLASSIFICATORY SCIENCES.

Recent Views of Botany. 631
" " Zoology. 634

BOOK XVII.--PHYSIOLOGICAL AND COMPARATIVE ANATOMY.

VEGETABLE MORPHOLOGY. 636 ANIMAL MORPHOLOGY. 638 Final Causes. 642

BOOK XVIII.

GEOLOGY. 646

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