The Colliery Manager's Handbook ... Second edition, revised, with additions

Front matter

*. i ■^m.' ■»•.■ ADVERTISEMENTS. I TELEGRAPHIC ADDRESS.— " THORNEWILLS, BURTON-ON-TRENT." O o )— ( E-h PU( >— *< P^ o GO w PC! ILLUSTRATED CATALOGUES ON APPLICATION. ESTABLISHED 1732. ADVERTISEMENTS. II WALKER BROTHERS, ENGINEERS, IRONFOUNDERS. AND BOILER MAKERS, WIGAN, LANCASHIRE. Telegraphic Address :— " PAGEFIELD, WIGAN." Telephone .*- .No. 14. (Bforii Bmripitott of $ftimtt0 WALKERS' PATENT AIR COMPRESSING ENGINES, As supplied to the principal COLLIERIES, also GOLD, SILVER and DIAMOND Mines, in all parts ofthe World. GAS COMPRESSING ENGINES. WALKERS' PATENT "INDESTRUCTIBLE" VENTILATING FANS For Mines, Collieries, Tunnels, Sewers, &c, with Simple or Compound Condensing Engines, Direct Acting, or by means of Belt or Rope Gearing. WALKERS' PATENT ANTI-VIBRATION SHUTTER FOR FANS. "Guibal " and "Schiele " Ventilating Fans.

Underground or Surface Haulage Machinery, COMBINED WITH THE FISHER AND WALKER PATENT FRICi'lGh CLUTCH, Unequalled for SIMPLICITY, ECONOMY in Working, and ENDURANCE ofthe Machinery and Haulage ROPES. COAL, SORTING MACHINERY. ADVERTISEMENTS. III In preparation, and will be published shortly. Crown 8vo, about 600 pages, with about 300 Illustrations. A HANDBOOK ON MACHINERY FOR METALLIFEROUS MINES. BEING A COMPANION VOLUME TO MR. D. C. DAVIESS "METALLIFEROUS MINERALS AND MINING" AND "EARTHY MINERALS AND MINING." BY E. HENRY DAVIES, M.E., F.G.S. WITH A CHAPTER ON MODERN AMERICAN PUMPING MACHINERY i:y PHILIP ARGALL, M.E OF DENVER, COLORADO. In this work will be found full descriptive particulars of Modern Mining Machinery, written from the point of view of an experienced Mining Engineer, the work being specially adapted for the use and instruction of Students, as well as a Book of Reference for Engineers and others engaged or interested in Mining Undertakings.

The volume will be fully illustrated by carefully selected Diagrams and Drawings, many of which are now published for the first time. • • WORKS OF MR. D. C. DAVIES ABOVE REFERRED TO. r a A TREATISE ON METALLIFEROUS MINERALS AND MINING. By D. C. Davies, F.G.S., M.E. Fifth Edition, thoroughly Revised and much Enlarged, by his Son, E. Henry Davies, M.E., F.G.S. With about 150 Illustrations. Crown 8vo, 12s. dd. cloth. " Neither the practical miner nor the general reader, interested in mines, can have a better book for his companion and his guide." — Mining Journal. " A book that will not only be useful to the geologist, the practical miner, and the metallurgist ; but also very interesting to the general public." — Iron. A TREATISE ON EARTHY AND OTHER MINERALS AND MINING. ByD. C. Davies, F.G.S., M.E. Third Edition, Revised and Enlarged, by his Son, E. Henry Davies, M.E., F.G.S. With about 100 Illusts.

Preface

. Even a slight acquaintance with the duties and responsi bilities of a Colliery Manager will lead to the conclusion that he had need be almost omniscient within his own province. Besides his responsibility for satisfactory results in the opening out and working of a colliery, under the ever-varying conditions of coal-mining enterprise, there rests upon him a heavy legal as well as moral responsibility which no true man would wish to shirk, and in the discharge of which he has to prepare for that which happens more often, perhaps, in his career than in that of most professional men — viz., the unexpected. It becomes him, therefore, to fit himself beforehand in every possible way for the discharge of his onerous duties. In so doing he will have to acquire the rudiments of Geology, Chemistry, and Electrical Engineering ; a good deal more than the rudiments of Mechanical Engineering, Survey ing, and Plan-making ; and to make himself master of the mysteries comprised in the comprehensive terms Practical Mining and Ventilation.

Further, he must be thoroughly versed in the obligations imposed upon him and his sub ordinates by the Acts of Parliament bearing on the subject of Coal Mining, and by the Special Rules in force in any given district.

PREFACE.

. VI The Author is well aware, after twenty years' experience, that the best and indeed the only satisfactory preparation for the efficient discharge of the duties of the Colliery Manager is that which is to be gained in the laborious school of experience ; but he knows also that the wise use of a carefully prepared and comprehensive Handbook — such as he ventures to believe the volume now in the reader's hand will be found to be — would have been to him an incalculable boon in the earlier years of his course, and hardly less so subsequently as a book of reference and of practical guidance. No doubt excellent handbooks already exist, dealing with various branches of the subject ; but the Author's aim has been in the following pages to prepare a work more complete in itself than any of its predecessors, and one comprising the most recent information as to the ever-progressing science and art of Coal Mining.

In the use of the work by students, it is believed that the questions and answers given on the various subjects will be found specially helpful. The Author gratefully acknowledges the assistance which has been given him in preparing this work for the press by his friends Mr. J. T. Robson, H. M.'s Inspector of Mines for South Wales, and the Rev. J. E. Flower, M.A., of Wands worth ; and also the courtesy shown by the Council of the Mining Institute of Scotland in granting him permission to quote the result of their Commission of Mining Engineers, as given in their Transactions (vol. iii., pp. 51 to 124). Besides much valuable information which has been obtained from the Transactions of the North of England and South Wales Institutes of Mining Engineers, he has also received con-

PREFACE.

. VII siderable assistance from the columns of the Practical Engineer and the Colliery Guardian, and from other sources, reference to which will be found in various pages of the work. The greatest care has been taken to ensure accuracy in every respect, but if any mistake has escaped notice the Author will be thankful to have it pointed out to him. The preparation of this Handbook — which for several years has occupied such time as the writer has been able to give to it — has been to him a most congenial task ; and he ventures, in sending it forth, to express the hope that the work may be found as useful -to the student, and to those engaged in the management of collieries, as the preparation of it has been pleasant and profitable to himself. Pontypridd, January. 1891.

PREFACE.

TO SECOND EDITION. The rapid exhaustion of the First Edition of this work — which has found a ready sale not only in Great Britain but in the Colonies and in America — has made it necessary to prepare a Second Edition, a demand to which the Author cheerfully and gratefully accedes. In doing so he has revised the book throughout, bringing it where necessary up to date, and he has taken the opportunity of adding three new chapters, dealing respectively with Mineral Leases and other Holdings ; with the Priestman Oil Engine and Petroleum and Natural Gas ; and with Colliery Explosions. With the additional matter in the present edition — including about 20 new illustrations — the work has been enlarged by nearly ioo pages ; and these additions the Author confidently hopes will greatly enhance the value of the Handbook to students and managers of mines. Pontypridd, June, 1893. CONTENTS.

Chapter I. Geology

PAGES Stratified and Unstratified Rocks — Dip — Rise — Outcrop — Strike — Diversified arrangement of Rocks — Faults — Classification of the Rocks into Systems — Igneous Rocks — Description of the different systems of Stratified Rocks 1-8

Chapter II. Search For Coal

In untried Districts by the Application of Geological Knowledge — Search n both an Unknown and Proved Coalfield by Boring — The operation of Hand-boring by the use of Rigid Rods — Boring with the Diamond Drill — Particulars of Deep Bore-holes — Application of the Result obtained by a Series of Bores — Search for Coal in South Staffordshire — Search for Coal in Kent 9-29

Chapter III. Mineral Leases And Otfier Holdings

Ownership of Minerals in the British Isles — Severance of Mineral and Surface Ownership — Freehold Properties — Copyhold Tenure — Minerals worked by Owners or Leased to Others — Take-notes or Licences to Search — Arranging a Mining Lease — Effect of Severance of Ownership in Working — Responsibility for Surface Damage and for Local Rates and Taxes — Theoretical Perfect Lease — Terms of Leases in Northumberland and Durham — Royalties — Annual Certain Rent — Short Workings — Second Royalty Rent under Copyhold Land — Surface Wayleaves — Underground Wayleave — Under-Sea Coal — Outstroke — Instroke Rent — Shaft Rent — Aircourse and Watercourse Easements — Buildings reverting to Lessor at Termination of Lease — Free Houses and Coal for Miners in Northumberland and Durham — Building Leases for Cottages— Arbitration — Farms included in Mining Lease — Renewal of Lease — Reduction of Rent in Bad Times — Joint-ownership of Minerals — Terms of Leases in West Yorkshire ; in South Yorkshire ; in Derbyshire, Nottinghamshire and Leicestershire ; in the Cannock Chase District ; in West Cumberland ; in Lancashire ; in Scotland ; in South Wales ; in Somersetshire ; in North Wales — Forest of Dean Coalfield — Crown Grants in the Forest — Free Miners — Gaveller of CONTENTS.

X PAGES the Forest of Dean — Certain Rents and Royalties in the Forest — Sale of Gales by Free Miners — Forfeiture of Gales — Ancient Mining Customs in Derbyshire — Licences to Search, and Leases from the Crown, in Isle of Man — Terms of Leases in Kilkenny and Tyrone Coalfields — State Minerals in Spain— Leases from Concessionaires — State Minerals in France — Coal and Iron in Belgium — State Control of Coal and Iron in Germany— Ownership of Lands in United States — Experimental lease of Lead and Copper Mines by Federal Government — Mexican Grants— Patents Granted by United States Government — Effect of the Discovery of Gold and Silver in California — Boundaries of Mineral Grants — Price of Coal Lands on the Public Domain — Wayleaves over Public Land — Mining Laws of Separate States — Classifica tion of Coal Mines in the United States — Minerals in Newfoundland — Royalties on Crown Lands in British Columbia — Ownership and Working of Minerals in New South Wales — Crown Licences and Leases in Queensland— in South Australia — in Victoria — in Western Australia — in New Zealand — in Tasmania — Ownership and Working of Minerals in India 30-63

Chapter IV. Shaft-sinking

Forms of Shafts — Mode of keeping them truly Vertical during the Sinking — Circumstances calling for consideration in Selecting their Sites — The Tools and Appliances used in Sinking — Timbering as it proceeds — Walling — Tubbing — Machine Drills to Expedite Sinking — Piling through Quicksands — Sinking through Quicksands by hollow Cylinders of Cast-iron — Poetsch's Freezing System of Sinking through Quicksands — - The Kind-Chaudron System of Sinking — Explosives used for Blasting in Sinking — Deep Shafts I 64-85

Chapter V. Fitting Up The Shaft And Surface Arrangements

Arrangement of Pit Bottom for Small and Large Trams — Shaft Gates — Conductors — Buntons — Keeps — Pit Cages — Safety Cages — Detaching Hooks — Pit Head-gear — Pulleys — Ropes — Capping Round and Flat Ropes — Observations for Users of Ropes — Tables of different qualities of Round and Flat Ropes and of Chains — Method of Splicing Ropes — Shaft Signals — Pit Stage — Tipplers — Screens and under Railways — Winding Engines — Conical and Spiral Drums — Steam-brake to prevent over-winding — Counterbalancing the Load in Shaft — Rules for Winding Engine — Calculations of Sizes required under given Conditions — Questions and Answers on Steam and Steam-engines — Systems of Winding Coal up Shafts without using Drums 86-137

Chapter VI. Surface Arrangements

(continued). STEAM BOILERS AND THEIR FITTINGS. Ordinary Forms of Colliery Boilers, " Egg-ended," Cornish, and Lancashire — General Construction and Flue Arrangements — Galloway Tubes for Cornish and Lancashire Boilers — Details of Construction — Riveting, Punching, and Drilling — Caulking — Welded Shell Joints — Attachment of Flat Ends — Expansion Joints for Internal Tubes —Relative Strengths of Different Riveted Joints — Diagonal Seams — Complete Shell CONTENTS. XI PAGES Rings — Means of Strengthening Apertures cut in the Shell — Seating a Lancashire Boiler — Faulty Methods of Seating — Seating Blocks and Crown Tiles— Means of Preventing Radiation of Heat — Position on the surface in which to place Boilers — Boiler Fittings— Mechanical Stokers— Hydraulic Test— Steam-pipe Connection— Steam-pipe Expansion Joints— Heating the Feed-water before it enters the Boilers — Feed-pumps and Injectors — Chimneys and Chimney Flues — Galloway Breeches- Flued Boilers— Babcock and Wilcox Water-tube Boilers — Arnold's Boiler — Vertical Boilers — Safeguards against Explosions — Grooving, &c. — Necessity for Care in Tending Boilers — Water Impurities — Analysing and Purifying Feed-water by the Addition of Chemicals —The Hotchkiss Boiler-Cleaner — Seale's Patent Water Purifier — Sanderson's Patent Feed-water Purifier and Heater — Periodical Examination of Boilers by Experts — Causes of Explosion — Dangerous Practices when Cleaning Boilers — Warming Surface Buildings by Steam —Rules relating to Boilers — Separators, Steam-traps, and Burnam's Steam Loop — Feed-water Heaters and Economisers — Warning Whistles, &c 138-197

Chapter VII. Timbering And Walling

The kind of Timber used at Collieries — Storing it Underground — Method of fixing Props and Lids — Temporary Props and Lids — " Dog" for drawing Props — " Sets" of Timber and their fixing in Main Roadways — Timber for Collars — Sills under Props — Timbering for a bad Roof, where the Floor and Sides are good — Lagging — Timbering for a bad Roof and Side, the other Side and Floor being good — Timbering for a bad Roof and Sides, with a good Floor — Timbering for a bad Roof, Floor and Sides — Lagging of Trees and Brushwood — Sizes of Timbers and their distance apart — "Cogs" or " Chocks " — Methods of Timbering in France — Notching the Timber — Cast-iron Props —Wrought-iron and Steel Supports — Storing the Timber on the surface — Creosoting as a means of preserving Timber from decay — Customs as to Setting and Drawing the Timber — Walling the Main Roads from the Shaft — Material used in Walling — Semicircular arched Roadway — Invert under Side Walls — " Horse-shoe" Arch — Elliptical Arch for Roadway — Process of building Arches —Necessity of removing all Timber, and tightly packing behind the Walls of Arches — Packing the Top and Sides with Sand 198-21 1

Chapter VIII. Narrow Work And Methods Of Working

Shaft Pillars — Water-Levels — Cross-measure Drifts from Shafts sunk through inclined strata — Stone Drifts through faults — Longwall Method of Working — Post and Stall System — Different Arrangements of Single Road Stall Working— Double Road Stall Method and its Modifications — Method of Working and Timbering adopted at the following Collieries : — Celynen, Risca, and the Ocean — Wicket System of North Wales — The Bank System of South Yorkshire— Method of Working and Timbering adopted at the following Collieries : — Lundhill, Kiveton Park, High Park, Wearmouth, Silksworth, Florence, Great Fenton, Cannock and Rugely, Pemberton, Clifton Hall, Pendlebury, Sovereign, Radstock, Kingswood, Allanshaw, Cowdenbeath — Working thin seams in Northern France and Belgium — Square-work Working of the Staffordshire thick coal seam — Working the thick coal seams of Poland, Upper Silesia, and Bohemia — Dealing with excessively thick coal seams by Longwall and Post and Stall — Questions and Answers bearing on the subjects of the Chapter . . . 212-297 CONTENTS. XII

Chapter IX. Underground Conveyance

TAGES Rails used on Main and Minor Roads — Construction of Tubs — Inclination suitable for Main Levels and Self-acting Inclines — Arrangement of Rails and i riction Rollers on Inclines— Blocks at the Bank-head— Ramean's Safety Catch for Inclined Planes — Mortier's Safety Catch — Method of Fixing the Incline Drum — The " Seizer " placed at the Foot of Inclined Planes — Accidents on Self-acting Inclines — Arrangement for Stopping Run-away Tubs down Inclines — Cut-chain Haulage on Inclines — Counterbalance Tram for Inclines — Different Systems of Engine Planes — Direct Haulage— Tail-rope— No. I Endless Rope — No. 2 Endless Rope — Endless Chain — Signals on Engine Planes — Size of Hauling Engines necessary — Compressed air as a Motive Power — Compound Hauling Engines — Determination of Gradient for Horse Road and Inclined Plane — Calculating the Friction of Tubs ...... 29S-330

Chapter X. Drainage

Winding AVater up Shafts — Lifting and Forcing Pumps — Making Pipe Joints Watertight — Balance Bobs — The Windbore — Clack-piece — Fish-piece — The Working Barrel — Action of the Pumps — Water Speed in Pipes — Construction and Method of securing Pumps — Preserving Pipes from the Action of Mineral Water — Pump Rods : Their Material ; Method of Joining ; Steadying ; Safety Catches — Attachment of Bucket to Spears — Hanging Clack and Bucket Doors — General Arrangement of Lifting and Forcing Sets of Pumps — Determination of Weight Necessary for Balance Bobs — Use and Action of the Air Vessel — Bunton and Plank Brattices to form compartment in Shaft for Pumps — Arrangement for a Sinking Set of Pumps — Sliding Suction for Sinking Set — Messrs. Thornewill and Warham's Details of Pump Work — The " Deane" Sinking Pumps — The Cornish Pumping Engine — The Cornish Double-beat Valve — Davey's Differential Valve Gear for Cornish Engine — Davey's Compound Differential Pumping Engine — Relative Advantages of placing Pumping Engines Above and Underground — Steam Pumps — The Compound Differential Engine as arranged Underground — The Worthington Pumping Engine — Compressed Air for underground Pumping Engines — Hydraulic Pumps — Moore's Hydraulic Mine Pump — Wire Rope Systems of Pumping — Electrical Pumping Plant at the Trafalgar Colliery — Syphons for Drainage of Underground Roadways — Memoranda — Powers of Engines forgiven work — The Pulsometer, its Action and Use — Pulsometer arrangement for Draining Underground Workings — Calculation of Contents of Water Barrels . 331-369

Chapter XI. The Gases Met With In Mines

: VENTILATION. The Atmosphere — Specific Gravity — The Symbols of Gases — Atomic Weight - — Oxygen — Nitrogen — Carbonic Acid, or Carbonic Anhydride — Carbonic Oxide — Sulphuretted Hydrogen or Hydrogen Sulphide — Proto-carburetted Hydrogen Blowers — Outbursts — Pressure of Firedamp in the Solid Coal — Effect of Earthquakes in Liberating Gas — After-damp — Explosions of Fire-damp The Diffusion of Gases — Natural Ventilation — The Furnace — The Waterfall The Steam Jet — The Struve Ventilator — Nixon's Ventilator — The Fabry Ventilator The Lemielle Ventilator — Cook's Ventilator — Root's Ventilator — Guibal Fan Waddle Fan — The Schiele Fan — The Capell Fan — The Medium Fan — Fan Arrangement for a Winding Shaft — Two Separate Engines to Drive Fan — Duplicate Fan and Engine CONTENTS. XIII PAGES Ascensional Ventilation — Stoppings to Direct the Underground Air-currents — Advan tages of Air-splitting — Regulators — Doors on Travelling Roads — Air-crossings — Brattice— Velocities of Air-currents in the Roads and Shafts— Relative Sizes of Downcast and Upcast Shafts — Anemometer and Measuring the Volumes of Air — Ther mometer — Hygrometer — Barometer — Effect of Diminished Atmospheric Pressure in Seams yielding Firedamp — Barometric Rules — Water-gauge — Motive Column and Rule to ascertain it — Horse-power of Ventilation — Useful Effect of Ventilating Fans — Theoretical Quantities of Air displaced by Fans — Rules for Total Volumes of Air required at Collieries ........... 370-414

Chapter XII. On The Friction Of Air In Mines

The Pressure necessary to overcome Friction — Rate of Increase or Decrease — Power necessary to produce Ventilation — Rate of Increase or Decrease — Best Form of Airway — Examples on Pressures and Powers of Different Shaped Airways — Questions and Answers on Ventilation .......... 415-453

Chapter XIII. The Priestman Oil Engine

; PETROLEUM AND NATURAL GAS. Application of the Oil Engine to Mining — Description of its Action — Cost of Working — Its Advantages in certain Positions — Rules for the Prevention of Accident from its Use — Particulars of its Application as a Hauling Engine — Different Nature of Work performed by Oil Engines — Quality of the Oil Used — Character of Petroleum — Geological Formations in which Found — Possibility of a Boring first Tapping Petroleum, Water, or Gas — A Theoretical mode of Production — Professor Mendeleeff's Theory of Petroleum Formation — Comparison of Manufactured and Natural Petroleum — Possibility of the Exhaustion of Coalfields and Continuance of Oil-fields — Chemical Composition of Petroleum — Natural Gas in Commercially Profitable Quantities — Where found— Particulars of the Findlay Gas Well — Increase of Capital employed in the Use of Natural Gas — Shrinkage in its Supply — Burning the Gas on the Surface of River Water andon the Ground — Analysis of Pittsburg Natural Gas — Its Occurrence in the United Kingdom — Petroleum in Europe with the Number of Wells bored and their Depth in the Baku Oil-field — Known Oil Regions of the United States, Canada, and Mexico — Number of Wells Bored and their Average Depth in America — Oil-fields of South America, Australia, New Zealand, North Africa, South Africa, Persia, Burmah and India— Petroleum in China, Sumatra, Java, Borneo, and Japan . 454-463

Chapter XIV. Surveying And Planning

General Use of Working Plans — Chaining Distances — Construction of the Spirit Level — Method of Taking Levels — Ordnance Bench Marks — The Adjustments of the Spirit Level — Forms of Levelling Book — Mr. Wells's Hints on Levelling Operations — The Miner's Dial — Davis's Improved Hedley Dial — The Hoffman Joint — Method of Needle Surveying — Vernier or "Fast" Needle Surveying — Reducing Angles to an Original Base Line — Declination, Diurnal Fluctuation, and Dip of the Needle — Construction of the Transit Theodolite— Method of Using the Theodolite Underground — The Adjustments of the Theodolite — The Protractor and its Use — The Parallel Ruler CONTENTS. PAGES and its Use — Scales — Survey Book — Paper for Colliery Plans — Meridianal Lines on Plans — Separate Plan of each Seam's Workings — Desirability of Placing Full Infor mation on Colliery Plans — Plotting the Surveys — " Tieing " Surveys — Plotting Sections — Colouring Colliery Plans — Computation of Areas and Produce of Coal from them — Setting out Railway Curves — Making Geological Sections — Louis's Improved Davis's Clinometer — Practical Questions and Answers 464-5 n

Chapter XV. Safety-lamps And Firedamp Detectors

The Davy Lamp — The Clanny — Morgan's — Protector — Pieler — Gray's — Hepplewhite- Gray — Marsaut — Mueseler — Evan Thomas — Clifford — McKinless — Cryptograph Lock — Cuvelier's Patent Lock — Examining and Testing Safety-Lamps before going into the Mine — Patterson's Testing Apparatus — Primary and Secondary Portable Electric Safety-lamps — Garforth's Firedamp Detector — Liveing's Firedamp Detector — Maurice's Firedamp Indicator 512-532

Chapter XVI. Sundry And Incidental Operations And Appliances

Carbonic Acid Gas Detector — Coal Dust — Watering the Underground Roadways — Explosives and Blasting Operations — Gunpowder — Gun-cotton — Tonite — Nitro-glycerine — Dynamite — Bellite— Useful work performed by Explosives — Blown-out Shots — Tohnson's Tamping Plug — Charging, Stemming and Firing Shots — Shot-firing Safety- Lamps — The Lauer Detonator — Experiments with Wooden Plugs for Tamping — The Water Cartridge and Accessories — Sand and other means of Protecting Cartridges — Tamping with Wet Moss — Roburite — Carbonite — Securite — Lime Cartridges — Wedges for Coal getting — Macdermott's Rock and Coal Perforators — Ingersoll Hand-power Rock Drill — Ingersoll Machine-power Rock Drill — Gillott and Copley Rotary Coal-cutting Machine — Bower, Blackburn and Mori Electrical Coal-cutting Machine — Stanley's Coal Heading Machine — Caging Appliances and Drop Staples — Pit Horses, their Food and Work — Fleuss Apparatus for Breathing in Noxious Gases — Fleuss Lamp — Exploring for Water — Underground Dams — Water-blasts — Underground Fires — Testing the Roof — Driving through Faults — Watt's Steam Indicator — Richards's Indicator — Use of Indicator Diagrams — Continuous Diagrams — The Thompson Indicator — Schaffer and Budenberg's Double Indicator — Bourdon's Pressure Gauge — Schaffer and Budenberg Bourdon Gauges — Steel Tube Gauges for Very High Pressures — Duplex Gauges — Graduating Ordinary Pressure Gauges — Graduating Steel Tube Pressure Gauges — Bourdon Vacuum Gauges — Schaffer Diaphragm Gauge — Testing Vacuum Gauges — Lightning descending Shafts — Dunford and Emen's Patent Automatic Tub-greaser— Self-lubricating Pedestals for Colliery Tubs 533~6oi

Chapter XVII. Colliery Explosions

Early Explosions— First accurate Statistics — Early Investigations into Causes of Explosions —Table of some Notable Explosions — Public Inquiry into the Cause of an Explosion and Reports to Parliament thereon — Possibility of some Coal-dusts being Inflammable — Different Ways in which Firedamp is Ignited — Pressure resulting from an Explosion CONTENTS.

XV PAGES and its Effect— Absence of Force at Point of Origin — Later Development — Relief at Shafts, usually— Direction taken by Blast— Deposits of Coked Coal-dust left by Explosion— Charred Timbers and other Evidence of its Passage left by Explosion- Damage at Downcast Shaft from large Explosion— Derangement of Ventilation by Blast— Work Necessary for Recovery of Workings— Anomalies of Evidence—Con flicting Evidence— Disagreement of Experts as to Cause and Direction of an Explosion — Complex Explosions— Evidence of great Force exerted by some Explosions—Under ground Fires Caused by Explosions— Coal-dust a Source of Danger— Its Influence in Intensifying an Explosion — Explosions restricted to Mines containing Firedamp- Reasons for Supposing Coal-dust has aggravated Explosions — Necessity for systematic Damping of Dusty Roadways— Prevention of Accumulations of Coal-dust on Main Roads— Influence of very Slight per centage of Firedamp on Atmosphere impregnated with Coal-dust— Prohibition by Mines Act, 1887, of firing Gunpowder Shots in Dusty Mines unless previously watered— Accumulations of Coal-dust in Longwall and in Pillar and Stall Working— Where most Dangerous Coal-dust is found— Chemical Changes from Exposure of Coal-dust to Atmosphere— Difficulties in Conducting Experiments with Coal-dust — Necessity for the extension of knowledge on Coal-dust — Coal-dust Explosions on the Surface — Some Particulars of the Altofts Explosion- Difficulty to Dogmatize as to a Coal-dust Explosion— Possibility of Firedamp reaching Roadways in a Longwall Working through Fissures and so causing Explosion — Explosions in wet Mines— Possible Uninflammability of the Coal-dust in the Radstock and Forest of Dean Mines— The most likely part for an Explosion— Order of Firing a Series of Shots— Firing Shots between Shifts — Remedial Measures . . 602-622

Chapter XVIII. Miscellaneous Questions And Answers

Denudation — Meeting of Cages in a Shaft with Flat Winding Ropes — Outstroke and Wayleave — Pressure of Water against a Barrier — Applying the Result obtained from Boring —Discharge of Water from a Bore-hole — Pressure per Square Inch produced by an Air-Compressing Engine — Description of Anthracite, Semi-Bituminous, Bituminous, Cannel, and Lignite Coals — Dynamometer — Elements of Rocks — Relative Hardness of " Rock Masses " — Beds and Veins of Minerals — Difference of Vein, True Fissure Vein, and Lode 623-634

Appendix

. SUMMARY OF REPORT OF HER MAJESTY'S COMMISSIONERS ON ACCI- DENTS IN MINES 635-646 INDEX 647-676 FIG. I. Stratified and Unstratified Rocks PAGE I 2. Horizontal and Inclined Strata .......... 2 3. Unconformable, Bent and Contorted Strata ....... 2 4-9. Head-Gear and Windlass for Boring, Ordinary Bore-Rod, Chisel, Wimble, Beche and Rounder . . . . . . . . . . . 10 10-14. Bracehead, Brake or Lever for Boring, Runner, Topit, Key . . . .II 15. Shoe-Nose Shell, with Valve, for bringing up loose stuff. Wrought-iron screwed Well Bore Pipes. Auger for clay and stiff soil. V-Nose chisels for hard ground. Shell-auger with valve for loose and wet soil. Bell-shell, with Valve, for loose gravel. Listing Dog for raising Rods. Pair of Rod- Wrenches for screwing and unscrewing Rods. Levers for turning Rods.

Spring Dart for drawing Pipes in Bore-Holes. Bell-Box for bringing up broken bits. Spiral Worm for extracting broken Rods. Worm Auger for loosening stuff in Bore-Holes. Square-Nose Chisel. S-Nose Chisel for Hard Strata. T-Nose Chisel for Hard Strata. Rods with Screw Joints in 5 and 10-foot lengths . 12 16. Method of Boring with the Diamond Drill 16 17. Plan showing position of Bore-Holes ........ 22 17A. Sketch showing possible position of Land held on a Mining Lease with respect to Railways, &c 38 18-20. Spring Hook, Curbs or Cribs for Sinking 65 21-23. Ring-Crib. Combined Wedging and Ring Crib 68 24-25. Segment of Metal Tubbing .......... 69 26. Timber, Walling and Tubbing in a Sinking Shaft . . . . . . 71 27. Piling through Quicksand in a Sinking Shaft 72 28-29. Poetsch's Sinking Process 73-74 30.

The Kind-Chaudron system of sinking Shafts ....... 75 31-33. Kind-Chaudron system — Large Trepan ••...... 76 34-37. Do. do. Small Trepan ....... 77 37A-370 Sketches illustrating the method of sinking the Ashton Moss Colliery Shafts through the Drift overlying the Coal Measures ... gz 38. Double-Decked Cage ........ gg 39. Treble-Decked Cage go 40-41. Broadbent's Safety Cage ....... q0 42. Calow's Safety Cage ......... QO FIG. 43-46. Ormerod's Safety Link PAGE 91 47. Arrangement of Catch-Plate in Headgear for Ormerod's Safety Link . . . 92 4S. Forster & Brindle's Detaching Hook 93 49. Pulley-Frame 94 50. Iron Pit-head Frame at the New Hall Park Collieries 95 51-53. Wire-Rope Capping 99 54. Repairing broken Wire Rope 104 55-58. Rope Splicing 104-105 59-60. Cone and Spiral Drums 107 61. Pair of High- Pressure Winding Engines 109 61 A. Diagram showing work done by Winding Engine ill 6lB.

Pendulum Counterbalance 112 62. Counterbalance Chain for Winding . . . . . . . . 113 62A. Inclined Plane Counterbalance 113 63. Marcet's Boiler 120 64. Illustrating the action of a Winding Engine 1 2S 65. Lancaster Piston Block 130 66-67. Lancaster Piston Rings and Spiral Spring 131 3 68-69. Lancaster Piston Rings and Serpent Coil Spring . . . . . .132 70. Joy's Valve Gear 133 71-72. Craven's Winding Gear 135 73. Common Cylindrical Boiler 139 74. Cornish Boiler 139 75- Lancashire Boiler with Galloway Tubes ........ 140 76-79. Boiler Plate Joints 141 80-81. Zig-zag and Chain Riveting 142 82. Punched Holes 142 83-84. Split Caulking 143 85-86. Attachment of Front and Back End Plates 144 87. Bowling Hoop Expansion Joint .......... 144 88. Adamson's Flanged Seam 145 89. Paxman's Flue Joint ............ 145 96.