Book contents
- Frontmatter
- PREFACE
- Contents
- ART. 79 On the Determination of the Ohm [B. A. Unit] in Absolute Measure
- ART. 80 Experiments to Determine the Value of the British Association Unit of Resistance in Absolute Measure
- ART. 81 On the Specific Resistance of Mercury
- ART. 82 The Use of Telescopes on Dark Nights
- ART. 83 On a New Form of Gas Battery
- ART. 84 Acoustical Observations. IV
- ART. 85 Further Observations upon Liquid Jets, in Continuation of those recorded in the Royal Society's ‘Proceedings’ for March and May, 1879
- ART. 86 Address to the Mathematical and Physical Science Section of the British Association
- ART. 87 On the Tension of Mercury Vapour at Common Temperatures
- ART. 88 On the Absolute Measurement of Electric Currents
- ART. 89 On the Duration of Free Electric Currents in an Infinite Conducting Cylinder
- ART. 90 On the Equilibrium of Liquid Conducting Masses charged with Electricity
- ART. 91 On an Instrument capable of Measuring the Intensity of Aerial Vibrations
- ART. 92 Comparison of Methods for the Determination of Resistances in Absolute Measure
- ART. 93 On the Dark Plane which is formed over a Heated Wire in Dusty Air
- ART. 94 Experiments, by the Method of Lorenz, for the Further Determination of the Absolute Value of the British Association Unit of Resistance, with an Appendix on the Determination of the Pitch of a Standard Tuning-Fork
- ART. 95 On the Mean Radius of Coils of Insulated Wire
- ART. 96 On the Invisibility of Small Objects in a Bad Light
- ART. 97 On Maintained Vibrations
- ART. 98 The Soaring of Birds
- ART. 99 Distribution of Energy in the Spectrum
- ART. 100 Investigation of the Character of the Equilibrium of an Incompressible Heavy Fluid of Variable Density
- ART. 101 On the Vibrations of a Cylindrical Vessel containing Liquid
- ART. 102 On the Crispations of Fluid resting upon a Vibrating Support
- ART. 103 On Porous Bodies in Relation to Sound
- ART. 104 Suggestions for Facilitating the Use of a Delicate Balance
- ART. 105 On the Imperfection of the Galvanometer as a Test of the Evanescence of a Transient Current
- ART. 106 On Laplace's Theory of Capillarity
- ART. 107 On the Measurement of Electric Currents
- ART. 108 On the Circulation of Air observed in Kundt's Tubes, and on some Allied Acoustical Problems
- ART. 109 The form of Standing Waves on the Surface of Running Water
- ART. 110 Acoustical Observations.—V
- ART. 111 On the Measurement of the Electrical Resistance between Two Neighbouring Points on a Conductor
- ART. 112 On the Electro-Chemical Equivalent of Silver, and on the Absolute Electromotive Force of Clark Cells
- ART. 113 Presidential Address
- ART. 114 A Lecture Experiment on Induction
- ART. 115 On Telephoning through a Cable
- ART. 116 On a Galvanometer with Twenty Wires
- ART. 117 On Clark's Standard Cells
- ART. 118 On the Constant of Magnetic Rotation of Light in Bisulphide of Carbon
- ART. 119 Optics
- ART. 120 Über die Methode der Dämpfung bei der Bestimmung des Ohms
- ART. 121 On the Theory of Illumination in a Fog
- ART. 122 A Monochromatic Telescope, with application to Photometry
- ART. 123 Self-induction in Relation to Certain Experiments of Mr Willoughby Smith and to the Determination of the Ohm
- ART. 124 Professor Tait's “Properties of Matter”
- ART. 125 A Theorem relating to the Time-Moduli of Dissipative Systems
- ART. 126 On the Accuracy of Focus necessary for Sensibly Perfect Definition
- ART. 127 On an Improved Apparatus for Christiansen's Experiment
- ART. 128 Optical Comparison of Methods for Observing Small Rotations
- ART. 129 On the Thermodynamic Efficiency of the Thermopile
- ART. 130 On Waves propagated along the Plane Surface of an Elastic Solid
- ART. 131 On Prof. Himstedt's Determination of the Ohm
- ART. 132 On the Clark Cell as a Standard of Electro-motive Force
- ART. 133 Testing Dynamos
- ART. 134 The Reaction upon the Driving-Point of a System executing Forced Harmonic Oscillations of Various Periods, with Applications to Electricity
- ART. 135 On the Self-Induction and Resistance of Straight Conductors
- ART. 136 On the Colours of Thin Plates
- ART. 137 Notes, chiefly Historical, on some Fundamental Propositions in Optics
- ART. 138 On the Intensity of Light Reflected from Certain Surfaces at Nearly Perpendicular Incidence
- ART. 139 Notes on Electricity and Magnetism. I. On the Energy of Magnetized Iron
- ART. 140 Notes on Electricity and Magnetism. II. The Self-Induction and Resistance of Compound Conductors
- ART. 141 Notes on Electricity and Magnetism.—III. On the Behaviour of Iron and Steel under the Operation of Feeble Magnetic Forces
ART. 96 - On the Invisibility of Small Objects in a Bad Light
Published online by Cambridge University Press: 05 December 2011
Book contents
- Frontmatter
- PREFACE
- Contents
- ART. 79 On the Determination of the Ohm [B. A. Unit] in Absolute Measure
- ART. 80 Experiments to Determine the Value of the British Association Unit of Resistance in Absolute Measure
- ART. 81 On the Specific Resistance of Mercury
- ART. 82 The Use of Telescopes on Dark Nights
- ART. 83 On a New Form of Gas Battery
- ART. 84 Acoustical Observations. IV
- ART. 85 Further Observations upon Liquid Jets, in Continuation of those recorded in the Royal Society's ‘Proceedings’ for March and May, 1879
- ART. 86 Address to the Mathematical and Physical Science Section of the British Association
- ART. 87 On the Tension of Mercury Vapour at Common Temperatures
- ART. 88 On the Absolute Measurement of Electric Currents
- ART. 89 On the Duration of Free Electric Currents in an Infinite Conducting Cylinder
- ART. 90 On the Equilibrium of Liquid Conducting Masses charged with Electricity
- ART. 91 On an Instrument capable of Measuring the Intensity of Aerial Vibrations
- ART. 92 Comparison of Methods for the Determination of Resistances in Absolute Measure
- ART. 93 On the Dark Plane which is formed over a Heated Wire in Dusty Air
- ART. 94 Experiments, by the Method of Lorenz, for the Further Determination of the Absolute Value of the British Association Unit of Resistance, with an Appendix on the Determination of the Pitch of a Standard Tuning-Fork
- ART. 95 On the Mean Radius of Coils of Insulated Wire
- ART. 96 On the Invisibility of Small Objects in a Bad Light
- ART. 97 On Maintained Vibrations
- ART. 98 The Soaring of Birds
- ART. 99 Distribution of Energy in the Spectrum
- ART. 100 Investigation of the Character of the Equilibrium of an Incompressible Heavy Fluid of Variable Density
- ART. 101 On the Vibrations of a Cylindrical Vessel containing Liquid
- ART. 102 On the Crispations of Fluid resting upon a Vibrating Support
- ART. 103 On Porous Bodies in Relation to Sound
- ART. 104 Suggestions for Facilitating the Use of a Delicate Balance
- ART. 105 On the Imperfection of the Galvanometer as a Test of the Evanescence of a Transient Current
- ART. 106 On Laplace's Theory of Capillarity
- ART. 107 On the Measurement of Electric Currents
- ART. 108 On the Circulation of Air observed in Kundt's Tubes, and on some Allied Acoustical Problems
- ART. 109 The form of Standing Waves on the Surface of Running Water
- ART. 110 Acoustical Observations.—V
- ART. 111 On the Measurement of the Electrical Resistance between Two Neighbouring Points on a Conductor
- ART. 112 On the Electro-Chemical Equivalent of Silver, and on the Absolute Electromotive Force of Clark Cells
- ART. 113 Presidential Address
- ART. 114 A Lecture Experiment on Induction
- ART. 115 On Telephoning through a Cable
- ART. 116 On a Galvanometer with Twenty Wires
- ART. 117 On Clark's Standard Cells
- ART. 118 On the Constant of Magnetic Rotation of Light in Bisulphide of Carbon
- ART. 119 Optics
- ART. 120 Über die Methode der Dämpfung bei der Bestimmung des Ohms
- ART. 121 On the Theory of Illumination in a Fog
- ART. 122 A Monochromatic Telescope, with application to Photometry
- ART. 123 Self-induction in Relation to Certain Experiments of Mr Willoughby Smith and to the Determination of the Ohm
- ART. 124 Professor Tait's “Properties of Matter”
- ART. 125 A Theorem relating to the Time-Moduli of Dissipative Systems
- ART. 126 On the Accuracy of Focus necessary for Sensibly Perfect Definition
- ART. 127 On an Improved Apparatus for Christiansen's Experiment
- ART. 128 Optical Comparison of Methods for Observing Small Rotations
- ART. 129 On the Thermodynamic Efficiency of the Thermopile
- ART. 130 On Waves propagated along the Plane Surface of an Elastic Solid
- ART. 131 On Prof. Himstedt's Determination of the Ohm
- ART. 132 On the Clark Cell as a Standard of Electro-motive Force
- ART. 133 Testing Dynamos
- ART. 134 The Reaction upon the Driving-Point of a System executing Forced Harmonic Oscillations of Various Periods, with Applications to Electricity
- ART. 135 On the Self-Induction and Resistance of Straight Conductors
- ART. 136 On the Colours of Thin Plates
- ART. 137 Notes, chiefly Historical, on some Fundamental Propositions in Optics
- ART. 138 On the Intensity of Light Reflected from Certain Surfaces at Nearly Perpendicular Incidence
- ART. 139 Notes on Electricity and Magnetism. I. On the Energy of Magnetized Iron
- ART. 140 Notes on Electricity and Magnetism. II. The Self-Induction and Resistance of Compound Conductors
- ART. 141 Notes on Electricity and Magnetism.—III. On the Behaviour of Iron and Steel under the Operation of Feeble Magnetic Forces
Summary
In a former communication to the Society (March 6, 1882) [Art. 82, vol. II. p. 92] I made some remarks upon the extraordinary influence of apparent magnitude upon the visibility of objects whose ‘apparent brightness’ was given, and I hazarded the suggestion that in consequence of aberration (attending the large aperture of the pupil called into operation in a bad light) the focussing might be defective. Further experiment has proved that in my own case at any rate much of the effect is attributable to an even simpler cause. I have found that in a nearly dark room I am distinctly short-sighted. With concave spectacles of 36 inches negative focus my vision is rendered much sharper, and is attended with increased binocular effect. On a dark night small stars are much more evident with the aid of the spectacles than without them.
In a moderately good light I can detect no signs of short-sightedness. In trying to read large print at a distance I succeeded rather better without the glasses than with them. It seems therefore that the effect is not to be regarded as merely an aggravation of permanent short-sightedness by increase of aperture.
The use of spectacles does not however put the small and the large objects on a level of brightness when seen in a bad light, and the outstanding difference may still be plausibly attributed to aberration.
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- Information
- Scientific Papers , pp. 187Publisher: Cambridge University PressPrint publication year: 2009First published in: 1900