A Treatise on Levelling, Topography, and Higher Surveying

William Mitchell Gillespie

D. Appleton, 1870 - 171 pages

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ART INTRODUCTION 1 Levelling in General	1

Direct Levelling 3 Indirect Levelling 4 Barometric Levelling 5 Topography	2

Special Objects and Difficulties 7 Underground Surveying 8 Water Surveying	3

Location	4

PART I	5

Curvature	6

Refraction CHAPTER II PERPENDICULAR LEVELS 16 Principle 17 Plumbline Levels	7

Reflecting Levels	8

Forms of Ground	90

Sketching Ground by Contours	91

Conventionalities	92

BY LINES OF GREATEST SLOPE 155 Their Direction	93

Degree of Shade	94

Shades by Contourlines	95

Diapason of Tints	97

CONVENTIONAL SIGNS 166 Signs for Natural Surface 98 888	98

WATERLEVELS ART PAGE 19 Continuous Waterlevels	10

Visual Waterlevels	11

AIR BUBBLE OR SPIRIT LEVELS 21 The Spiritlevel	12

Blocklevel	13

Level with Sights	14

The Telescope Level	15

The Y Level	16

The Crosshairs	17

Supports	18

First Adjustment	19

Second Adjustment	20

Centring the Objectglass and Eyepiece	21

Adjustment by the Peg Method	22

Verification by another Telescope	23

Gravatts Level	24

Tripods	25

Target	26

Verniers	27

Speaking Rods	28

Fieldnotes CHAPTER VI THE PRACTICE	30

First Form of Fieldbook	33

Second Form of Fieldbook	35

Third Form of Fieldbook	38

Best Length of Sight 58 Equal Distances of Sight 59 Datumlevel	39

Benchmarks 61 Testlevels	40

Limits of Precision 63 Flyinglevels 64 Levelling for Sections 65 Profiles	41

Crosslevels	42

DIFFICULTIES 67 Steep Slopes	43

When the Rod is too low 69 When the Rod is too high 70 When the Rod is too near	45

Levelling across Water 72 Across a Swamp or Marsh	46

Problem II 16	51

Vertical Surveying	53

Burniers Level	62

Through Underwood	73

Over a Board Fence	74

Over a Wall	75

Through a House	76

The	77

Wind	78

Idiosyncrasies	79

Reciprocal Levelling	80

Its Nature	81

Difficulties CHAPTER VIII LEVELLING LOCATION	82

Staking out Work	83

To Locate a Level Line	84

Applications	85

To run a Grade Line	86

On a Single Hill	87

Interpolation	88

Ridges and Thalwegs	89

Signs for Water	99

Signs for Miscellaneous Objects	101

Scales	103

PART V	105

The Old Method	106

When the Height of the Signal cannot be Measured	108

The Mining Transit 177 Mapping	109

LOCATING NEW LINES 178 Second Object 179 When the Mine is entered by an Adit	110

When the Mine is entered by a Shaft 181 To Dispense with the Magnetic Needle	111

Reducing Several Courses to One 183 Third Object 184 Problems	113

PART VI	115

THE INSTRUMENTS 186 Description of the Sextant	117

The Box Sextant 188 The Reflecting Circle 189 Adjustments of the Sextant	118

How to Observe 191 Parallax of the Sextant	120

Conversely	121

To Measure a Line one end being inaccessible	122

Otherwise	124

Artificial Horizon	125

Mountain Barometers	126

The Aneroid Barometer	127

Boilingpoint Barometer	128

Accuracy of Barometric Observations	129

Simultaneous Observations	130

Definition	131

Systems PART IV	132

General Ideas	133

Plane of Reference	134

Vertical Distances of the Horizontal Sections	135

Methods for determining Contourlines	136

Instrumental Solution	137

Between Stations	138

The Soundingline	139

TIDEWATERS ART 220 Tides	140

Difference on Atlantic and Pacific Coast 222 Mean Level of the Sea 223 High and Low Water 224 Establishment of a Place 225 Tide Gauges	141

Tide Tables	142

Gauges in Bends 228 Beacons and Buoys	144

THE CHART	145

Methods of Fixing Points on the Chart 230 Conventional Signs	146

PART VIII	147

Outline of Operations	148

Measuring the Base 235 Corrections of the Base 236 Reducing the Base to the Level of the	152

A Broken Base 238 Base of Verification	153

Choice of Stations	154

Signals	157

Observations of the Angles	159

Reduction to the Centre	160

The Angles 244 Spherical Excess 22	162

Correction of the Angles 246 Interior Fillingup	164

Lees Formulas 17	170

Other editions - View all

A Treatise on Levelling, Topography, and Higher Surveying
William Mitchell Gillespie
Full view - 1870

A Treatise on Levelling, Topography, and Higher Surveying
William Mitchell Gillespie
Full view - 1871

TREATISE ON LEVELLING TOPOGRAP
William Mitchell 1816-1868 Gillespie,Cady 1840 Staley
No preview available - 2016

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Common terms and phrases

adjustment angular attached axis back-sight barometer bisect the target bottom bubble-tube centre CHAPTER circle clamp column compass contour-lines coördinates correction cross-hairs curvature desired height determined difference of heights direction Dumpy Level equal error eye-piece feet fore-sight formula gamboge given ground hill hold the rod horizon-glass horizontal inch latitude length level line line of collimation line of sight lower one end main socket means measured mercury method miles millimetres mirror move object object-glass observed angle perpendicular plane of reference plate-screws plumb-line precisely reading represented right angles scale screws set the instrument sextant shade shaft side signal slope spherical spherical excess stakes starting-point station subtract surface Surveying taken temperature thalwegs theodolite tint tion transit triangle tripod tube turn the telescope turning-points upper usually vernier vernier-plate vertica vertical angles vertical plane zenith distance

Bibliographic information

Title	A Treatise on Levelling, Topography, and Higher Surveying
Author	William Mitchell Gillespie
Editor	Cady Staley
Publisher	D. Appleton, 1870
Original from	Harvard University
Digitized	18 Oct 2007
Length	171 pages

Export Citation	BiBTeX EndNote RefMan

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A Treatise on Levelling, Topography, and Higher Surveying

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