^1 1*

C tfc

5^ n

SIlic 39, it ii\ii Xtbniru

ZX'orth (Carnliita ^tatc College

TP927 ♦«• P7

I

S00601527 L

THIS BOOK IS DUE ON THE DATE INDICATED BELOW AND IS SUB- JECT TO AN OVERDUE FINE AS POSTED AT THE CIRCULAilPION DESK. /^

APR 1 B 1984

OCT 1 01984

APR - 9 1986

Digitized by tine Internet Arcliive

in 2010 witli funding from

NCSU Libraries

littp://www.arcliive.org/details/practicalbricktiOOdobs

)iiiL:»^2. «
	iC	■'H	1	!
i	4*.	*

[[

RNAMENTAL BRICKWORK. -V". 43, St. Martin's Lane, London.

TRE PRACTICAL

BRICK AND TILE BOOK

COMPRISINO

I.— A RUDIMENTARY TREATISE ON

BRICK AND TILE MAKING

By EDWARD DOBSON, A.I.C.E., M.I.B.A.

II.— THE RUDIMENTS OF

PRACTICAL BRICKLAYING

By ADAM HAMMOND

iii.-BRICKWORK

A PRACTICAL TREATISE ON

BRICKLAYING, CUTTING, AND SETTING

By F. WALKER

. smith ohtx %^o ISttuireb ani) Stbtxxt^ iiiustratwns

LONDON

CROSBY LOCKWOOD AND CO.

7, STATIONERS' HALL COURT, LUDQATE HILL

^^

THE

PRACTICAL BRICK AND TILE BOOK

PART I. A RUDIMENTARY TREATISE ON

BRICK AND TILE MAKING

By EDWAED DOBSON, A.I.C.E., etc.

\ Q> "o O

A RUDIMENTARY TREATISE

ON THE MAXUfACTt'RE OF

BRICKS AND TILES

CONTAINING AN OUTLINE OF THE

PRINCIPLES OF BRICKMAKING By EDWARD DOBSON, A.I.C.E., M.I.BA.

AUTnOR OP "the art op BtllLDrMG," "MASONRY AND STO;<K-CUTTI-\0," " FOUXDATIOXS AND COXCRKTE WORK," ETC., ETC.

HE VISED AXD COSRECTED BY CEARLES TOMLINSON, F.R.S.

EIGHTH EDITION

WITH ADDITIONS BY EOBEKT MALLET, A.M., F.R.S., M.I.C.E., Etc.

SHith numerous illustrations

LONDON CROSBY LOCKWOOD AND CO.

7, STATIONERS' HALL COURT, LUDGATE HILL

1886

THE AUTHOE'S PEEFACE.

The preparation of this little work has necessarily es. tended over a considerable period of time, and, although our limits preclude anything like an attempt at a com- plete view of the principles and practice of Brick- making, it will be found to contain much practical information which has never yet been published, and descriptions of processes which are little known be- yond the localities where they are practised. The whole of the illustrations have been drawn expressly for the work, and the descriptions of tools and pro- cesses have been written from personal observation, no dependence having been placed on verbal descrip- tion, even by experienced workmen. Working brick- makers are mostly illiterate men, imable to describe correctly their own operations, and still less to explain their meaning. I have therefore considered it necessary to have every process here described carefully watched throughout, either by myseK or by some one on whose accuracy of observation I coidd place dependence.

In the course of last autumn I drew up several papers of questions, embracing a variety of points on which it was found difl&cult to obtain correct information, but which were distributed amongst those of my friends who were likely to have opportunities of ascertaining what was required.

b

iv THE author's PREFACE.

Many of these papers in course of time were returned, accompanied by valuable details, and I have to express my thanks and obligations to many gentlemen per- sonally unknown to me for the assistance thus afforded. i\jnongst those from whom I have received valuabio assistance during the progress of the work, I may especially mention the names of Mr. Arthur Aikin ; Mr. John Lees Brown, of Lichfield ; Mr. William Booker, of Nottingham ; Mr. Richard Prosser, of Bir- mingham ; and Mr. Frederick Ransome, of Ipswich.

Mr. Richard Prosser has kindly contributed a valuable accoimt of the practice of Brickmaking in Stafford- shire, which will be read with much interest, and it will be worth the reader's while to compare the processes described in this chapter with those made use of in the neighbourhood of iN'ottingham, described in Chapter III.

The details given in Appendix I. respecting the manu- facture of Suffolk bricks Mere Idndly furnished by Mr. Frederick Ransomc, to vv'hom I am also indebted for drawings of a Suffolk kiln, which were intended by him as a contribution to the work, but which, un- fortunately, were committed to the post for transmis- sion, and never reached their destination.

In collecting the information requisite for writing the accounts of Brickmaking and Tilemaking as practised in the neighbourhood of London, I am under great obli- gations to Mr. Adams and ^Ir. Itandcll, of the Maiden Lane Tileries, and to Mr. Samuel Pocock, of the Cale- donian Fields, Islington, for the kindness with which they afforded me facilities for inspecting and sketching their works, and for the liberal manner in ^hich they furnished me with details of prices and quantities.

Although much time and pains have been bestowed upon the work, there is so much difficulty in writing o

THE AUTHOR S TllEFACE. V

strictly accurate account, even of a simple operation, that I cannot hope that it is perfectly free from errors ; but I trust that they are only of a trivial nature, and I shall be greatly obliged to any reader who will point out any omissions or mis-statements, that I may be able to correct them in a future edition.

There has long been a want of rudimentary treatises on the Materials of Construction, published in a cheap form, and written in a simple and practical style, divested of scientific technicalities, which render such books nearly useless to those by whom they are most needed. I venture to express a hope that this work may be of service in supplying this deficiency with regard to one very important class of building materials. At the same time it must be observed that the Science of Brick- making is as yet untrodden ground, comparatively little being known of the manner in which different sub- stances mutually act upon each other when exposed to furnace heat, or of the relative proportions of silica, alumina, lime, and other usual ingredients of brick- earths, which are best calculated to produce a sound, well-shaped brick, of a pleasing colour. All that I have attempted here, therefore, is to give a clear description of the actual manufacture of bricks and tiles, and to explain the leading difierences which exist in the manner of conducting the several operations of Brickmaking iu various parts of this country. How far I have succeeded in this attempt the reader alone can determine.

EDWARD D0B80N.

PEEFACE TO THE FOUETH EDITION.

This work was revised by Professor Tomlinson in 1863, and some matter become useless by time and the altera- tion of the Excise laws judiciously expunged. A chapter was at the same time appended on making bricks by machinery, but since that period many improvements and new inventions have necessitated a supplemental chapter, in which the editor has endeavoured to give an outline of that part of the subject reaching to the present day. lie has also added a sketch of that which was properly called by the author of the work the Science of Brickmaking. A few notes, revising the text gene- rally, will be found in the Appendix, and to which the alphabetical index now given affords easy reference.

Though small and elementary, this work may pro- bably claim to be the most complete upon its siibjcct in the English language.

ROBEPvT MALLET.

Auyu:t, IStiJJ.

CONTENTS.

ti.B. — Th' Xicibcis refer to the Farar/rapJis and mt to (he prtgcs, except tchcre otherwise stated.

INTRODUCTION (Pages 1-12.)

I. Early history of the art -would not add to our practical know- ledge, li. Burnt brick used in the building of the Tower of Babel ; in the walls of Babylon ; both biuiat and sun-dried bricks used in ancient Egypt. III. Bricks extensively used by the Romans ; the art of brick- making abandoned at the decline of the Roman Empire ; subsequently revived in the middle ages. IV. Early and extensive use of bricks in Holland and the Netherlands. V. Brickmaking introduced into England by the Romans ; arrived at great perfection at the time of Henry VIII. ; only used for large mansions in the time of Queen Elizabeth. VI. Brick generally introduced as a building material in London after the great fire of 1666; many fine specimens of brickwork still extant, executed at the beginning of the 18th century. VII. Enumeration of the duties suc- cessively imposed upon bricks and tiles ; abolition of the distinction between common and dressed bricks, by 2nd and 3rd Vict. c. 24. VIII. The new act a great boon to the public. IX. Nimiber of bricks uiade yearly in Great Britain. X. Differences in the processes employed in brickinaking in differents parts of England. XI. Average strength of various kinds of bricks. XII. Comparison between the crushing strength cf hand-made and machine-made bricks.

CHAPTER I.

GENERAL PRINCIPLES OP THE MANUFACTURE OF BRICKS AND TILES.

I. Bricks. (Pago 12.)

1. Classification of the various operations of the bnckmaker.

Peepaeation of Brick-eaeth. (Pages 12 — 2b.)

2. Enumeration of qualities to be aimed at in making bricks. 3. Suc- cess depends principally on the selection and preparation of brick-earth. 4. Br'ck-carths may be divided into three principal classes; viz., pure clays, marls, and loams ; few earths fit for brickmaking without some

i3

VI U CONTENTS.

mixtui-c. 5. ^Vlumina the principal ingredient in britk-carth ; cracka in drying, after being moulded, and will not stand firing ; necessary to add sand to strong claj's, to diminish their contraction ; lime and sifted orecze used near London for the same purpose. 6. Composition of firo clay; mode of making the Dinas fire brick. 7. Fire clay generally mixed with burnt clay, broken crucibles, &c. 8. Enumeration of prin- cipal localities where fire bricks are made ; relative cost of Windsor, Welch, and Stourbridge fire bricks. 9. Bricks made of refractory clay, ia/iYf^ rather than burnt. 10. Composition of fusible earths. 11. London bricks not made of clay, but of loams and marls. 12. Bricks may be divided into two classes, hahccl and hurnt ; difficulties in treating the fusible earths. 13. Catting bricks made from sandy loams, eitlicr natural or artificial. 14. Colour depends not on the natural colour of the clay, but upon its chemical composition. 15. Bricks might be made of various colours by the employment of metallic oxides. 16. Floating bricks. 17. Unsoiliug. 18. Clay digging and iceathering. 19. Stones must be picked out by hand ; injurious effect of limestone in the clay. 20. Grind- ing. 21. IFashing. 22. Cutters made of washed earth mixed with sand. 23. Sufficient attention not generally paid to the preparation of brick- earth.

Temperi^-o. (Pages 25—28.)

24. Object of tempering ; is effected in various ways ; treading, grind- ing, pugging, 2-5. Briclcmaking on the Nottingham and Grantham

railway. 26. Use of the pug-mill.

MouLDiNO. (Pages 28—35.)

27. Slop moulding and pallet moulding. 28. Description of sli)p moulding. 29. Description of pallet moulding. 30. Description of moulding table. 31. Brick moulds, their varieties. 32. Diiferenee in rate of production per stool, according to the process employed. 33. Slop and pallet moulding sometimes combined. 34. Moulding by machinery. 35. Disadvantages of dense bricks. 36. Method invented by Mr. Prosscr of moulding in the dry state. 37. Defects of pressed bricks. 38. Dif- ficulties in making moulded bricks, arising from warping in the kiln. 39. Dimensions of bricks. 40. Bricks made of various shapes in country yards, but not generally in London. 41. Bricks with hollow beds. 42. Ventilating bricks.

Drying. (Pages 35—38.)

43. Slop-moulded bricks dried on flats, and liacked under cover. 44. Bricks hacked in the open air where brickmaking is conducted on a large scale. 45. Clamp bricks hacked at once, and not dried on flats. 46. Recapitulation of differences between slop moulding and pallet mouldirg. 47. Different clays require different treatment.

BunNiNO. (Pages 38—42.)

48. Bricks burnt in clamps and in /ciliis. 49. Peculiarities of clamp burning. 50. Three classes of kilns. 51. Management of a kiln. 52. Impossible in a rudimentary tix'atisc to describe all the proecssei>

CONTENTS. IX

II. Tiles. (Pages 42— 47.)

53. Differences in the manufacture of bricks and tiles, 54. Three classes of tiles, viz., paving (tics, roofing tiles, and draining tiles. 55, Business of a tilery includes the making of pottery. 56. Tiles burnt ia the countiy together with bricks ; in London in separate kihis. 57. Drain- ing-tiles principally moulded by machinery. 58. Importance of making di-ain tiles a /lome manufaeture. 59. Concluding observations.

CHAPTER II.

ON THE MANUFACTURE OF BRICKS AND TILES IN HOLLAND. BY HYDE CLARKE, C.E.

I. Bricks. (Pages 47— 48.)

Bricks extensively used in Ilolland. — Dutch clinkers made at Moor, near Gouda. — Materials for making them; — river slime and sand; localities from whence obtained. — For Flemish bricks the sand is brought from the river Scheldt. — The slime and sand are mixed and kneaded together by treading. — Dimensions of paving bricks and Dutch clinlvs. — House bricks and tiles made at Utrecht from brick-earth formd in the neiKhbourhood. — Dimensions of house bricks.

II. Brick-kilns. (Pages 48 — 51.)

Sometimes made to burn upwards of a million of bricks. — Fii'c holes left in the side walls. — Doorway made in the breadth of the kiln. — Sheds erected on each side of the kiln to shelter the fii'es.— ^Mode of setting the kiln. — Mode of filing.

III. Tiles. (Page 52.)

Varieties of tiles made in Ilolland. — Clay ground in a pug-mill. — Kueaded by women before moulding. — Two moulders, viz., a rough moulder and a finisher. — Tiles diied tirst in sheds and afterwards in the sun. — Moulding of flat paving tiles. — Iron moulds used in Switzerland.

IV, TiLE-KiLNS. (Pages 53—55.)

Tiles burnt in covered kilns with arched furnaces. — Setting. — Burn- ing.— Cooling. — Mode of giving a grey colour. — Glazing. — Utrecht the principal seat of the tile manufactui-e. — Gouda celebrated for pottery and tobacco-pipes.

CONTENTS.

CHAPTER III.

BiaCKJIAKING AS PRACTISED AT NOTTINGHAM.

(Pages 55—59.)

1. Peculiarities in manufacture of bricks near Nottingham. 2. Use of brass moulds not confined to Nottingham. 3. Object of crmhiiig the brick-earth between rollers. 4. Advantages and disadvantages of the use of rollers. 5. Description of brickmaking at Nottingham applies, ^vith slight variations, to the practice of the neighbouring counties. 6. Brick-earth from the marls of the new red sandstone ; abounds with layers of skerry and veins of gypsum. 7. Colour of Nottingham bricks. 8. Common bricks made without picking the clay. 9. Preparation of clay for making front bricks. 10. ilanufacture of rubbers. 11. Clay at Nottingham not generally suited for making roofing tiles. 1 2. Size of old and modem bricks.

General Arrangemext or .\ Brickwork.

(Pages 59—80.)

13. Locality of existing yards. 14. Eental and cost of clay. 15. Ar- rangement of buildings. 16. Description of clay-mill. 17. Addition of a setond set of rollers a great improvement. 18. Keference to engravings of clay-mill ; mode of boxing up the machinery. 19. Improvement to conceal machinery. 20. Duty performed. 21. Length of time a clay- mill will remain in working condition. 22. Description of Wash-mill. 23. The PMi7-»ii7/ not used at Nottingham. 2\. Moulding sand. 25. Mould- ing table, description of. 26. Brick mould, description of. 27. Use of copper moulds confined to small articles. 28. Mould placed on the moulding table and not upon a stock-boaid. 29. Plane, description of. 30. The Flats, how prepared; size of. 31. The Hovel, description of; sometimes provided with flues. 32. Best bricks dried wholly under cover in fined hovels. 33. The Clapper, description of; use of. 34. Dressing bench and dresser. 35. Machinery for pressing bricks ; points to be attained in making machinery. 36. Machine-pressed bricks cheaper than those dressed by hand. 37. Kiln, detailed description of. 38. Difierent mode of constructing the walls. 39. Comparison of the two moth -ids. 40. Reference to engravings. 41. Stops to the tops of the kilns. 42. Sizes of kilns. 43. Duration of kilns.

Process of Brickmaking. (Pages 80 — 87.)

44. Claij dinging. A5. Tempering. 46. Cost of. 47. J/omWi'w^, descrip- tion of process. 48. Drying ; laying on flats; hacking. 49. Time that should be allowed for drying'. 50. Cost of mouldimg and drying. 51. Tressed bricks. [2. Folishcd bricks. 63. Size of brick-moulds. 54. Rate of production. 55. Burning; management of the firing. 56. Cost of fuel. 57. Effect of the fire upon the colour of the bricks. 58. Cost of setting and drawing the kiln. 59. Cost of labour in firing. 60. Enumeration of the varieties of britksvare manufactured at Not- *vagham,

CVSTESIS. XI

Cost of MAxrFAcrvRE. (Pages S7— 94.)

61. Land and brick-earth ; difficulty of estimating rental ; cost of clay. 62. Buildings and machinery ; difficijlty of ascertaining best relative sizes of \rorking floors, horels, and kilns. 63. Approximate estimate of extent of buildings and plant required for a weekly production of 46,800. 64. Additional biiildings required in a yard, where all kinds of brickware are made. 65. Enumeration of iooJs required. 66. labour, how paid for. 67. Summary of cost of production. 68. Eelatire value of dif- ferent qualities of bricks. 69. Seferenre to Ulustiationa, figs. 1 to 18.

CHAPTEE IT.

BRICKMAKIXG AS PRACTISED IN THE STAFFORDSHIRE POTTERIES. BY R. PROSSER, C.E.

Bricks. (Pages 95—96.)

1. ^/-iV^-s ; enumeration of kinds of brick manufactured. 2. Drab bricka chiefly used for furnace work. 3. Tiles. 4. Clay. 5. Xames of strata in the pottery district. 6. Two examples given of the process of brick and tile making.

First Example — Brick:xiaki>"g. (Pages 97 — 101.)

7. Buildings and plant. 8. Hates of production. 9. Tempering. 10. Moulding. 11. Drying. 12. Loss of weight whilst drying. 13. Burn- ing. 14. Cost of manufacture. 15. Rental.

Desckiptiok of Illistratioxs. (Pages 102 — 105.)

16. Clay-null. 17. Moulding table. 18. Brick mould. 19. The oven or cupola.

Second Example — TiLE->LVK.rxG. (Pages 105 — 111.)

20. Enumeration of articles made at Basford. 21. Weathering and tempering. 22. Moulding. 23. Drying. 24. The Set. 25. Quarries and Dust Bricks. 26. Drain tilei. 27. Tile machines. 28. Tiring; detailed description of. 29. Selling prices of difi"erent articles.

Descriptiox of IllvstpvAtioxs. (Pages 111 — 117.)

30. Moulding bench. 31. Mode of drying tiles. 32. Tile-block and horse. 33. Mode of setting lower part of oven. 34. Mode of setting upper part of oven. 35. Desirability of improving the mode of conduct- ing the manufacture of bricks. 36. Expense of carriage. 37. Analysis of clays, &c.

Xll CONTEXTS.

Bbicsuakcco on the Socth Stajtokdsbibe Railway.

(Pages 117—119.)

38. Bricks made for this line Ly Mr. George Bro\m, of "Walsall Wood. — Material not clay, but marl. — Description of strata. — Description 0/ processes employed.-— Cost of bricks at the kiln.

CHAPTER Y.

BRICEMAKIXG IX THE VICIXITY OF LONDON.

(Page 119.)

1. Subject divided into three heads.

I. ^L\TERiALS ANT) Plaxt. (Poges 119—133.)

2. Brick -earth divided into three qualities. Z. Strong clay. i. Loom. b. MaJin. 6. Different modes of preparation. 7. Object of adding chalk. 8. Soil. 9. Sand. 10. General arrangement of a BricJitcork. 11. ChaLt and Clay MU!s. 12. The Fuo-mUl. 13. The'CuckhoM. 14. The Mould- ing Stool. \o. The Brick Mould. \^. The Stock-board. \1. The Strike and Pallets. 18. Tlu Hack Barrow. 19. The Sack Ground.

II. Process of ^Iaxvpactciie. (Pages 138 — 158.)

20. Claij digging. 21. Quantity of clay rcqiiired per 1,000. 22. Maiming. 23. Soiling. 24. Tempering. 25. Tugging. 26. Moulding. 27. Hacking. 28. Clamping, requires skill. 29. General principles of. 30. Foundation. 31. Upright. 32. Xecks. 33. Firing. 34. Breeze. 35. Proportion required depends on the nature of the clay. 36. Time allowed for burning. 3". Upright and Outside. 38. Variations in the mode of clamping. 39. Table of the qualities and prices of bricks made for the London market. 40. Brickmaking at Chtshunt. 41. Brick- making practised generally all round London.

III. Cost of Maxtfacttbe. (Page 150.)

42. Cost divided imdcr three heads.

43. Clay. 44. atnJk. 45. Sand. 46. Brceu. 47. SoU. 48. Coalt and icood. 49. Water.

Matebuls a>d Fuel. (Pages 159—161.)

. 45. Sand. 46. Brceu. 47. Soil. 48. Coalt

3Iachi>iby and Tools. (Page 161.) 50. Cost of plant.

Labour. (Page 162.) 61. Details of cost.

CONTENTS. xiii

BuiCKMAKIXG AT THE COPENHAGEN TuNNEL, ON THE GrEAT

Northern Eatlway. (Pages 162 — 164.) Description of rollers, drying sheds, and kilns.

Reference to Illustrations. (Pages 164— 1G7.) 52 to 59. Description of figures 1 to 21.

CHAPTER VI.

LONDON TILERIES.

Introductory. (Pages 167 — 169.)

1. The present chapter confined to a description of the manufacture of pantiles. 2. List of principal articles made at the London Tileries.

Buildings and Plant. (Pages 170 — 183.)

3. Pug-mill. 4. Sling. 5. The Moulding Shed. 6. The Pantile Table. 7. The Block and Stock-hoard. 8. The Tile Mould. 9. The Poll. 10. The Washing-off Table. 11. The Splager. 12. The Thwacking Frame. 13. The Tile Kiln.

Process of Manufacture. (Pages 183 — 186.)

14. Clay getting and weathering. 15. Tempering. 16. Slinging. 17. Moulding. 18. Thwacking. 19. Kilning.

Cost of Manufacture. (Pages 186 — 188.)

;ost. 21. Selling prices. 22. Differe le manufacture of various articles.

23. Description of Illustrations. (Pages 188 — 189.)

20. Tabular view of cost. 21. Selling prices. 22. Differences in the processes employed in the manufacture of various articles.

CHAPTER Yll.

ON THE MANUFACTURE OF ENCAUSTIC TILES.

(Pages 189—191.:

1. Eevival of the manufacture of encaustic tiles. 2. Difficultk's ariaing from the unequal shrinkage of differently-coloured clays.

Process of Manufacture. (Pages 191 — 195.)

3. Clay. 4. Moulding. 5. Inlaying. 6. Drying, firing, and glazing. 7. Manufactui-e of tcssercc. 8. Tessclated pavements.

XX7 CONTENTS.

CHAPTEE YIII.

ON THE MANUFACTURE OF BRICKS AND DRAlN-l'U'ES HV MACHEN'ERi'. (Pages 195—209.)

Object to deal with principles rather than with minute details. Various patents for making tricks by machinery. Description of Oates's brick- making machine. Crushing strength of bricks made by this machine. Machine can utilise materials unser^-iceable to the haind brickmaker. Cost of machine. Description of drain-pipe making machine. Hollow bricks also made by it. Various forms of hollow bricks.

CHAPTEE IX.

ADDITION.AL REMARKS ON THE M.^NUFACTURE OF BRICKS BY MACHINERY. (Pages 210-244)

By Robert Mallet, A.M., F.E.S.

Improvements in brickmaking since 1863. 'Wliitehead's improved clay cnishing and grinding roller-mill. Whitehead's pug-mill. Whitehead's perforated pug-mill. Portable clay-mill. Composite machines, in which crushing rollers and horizontal pug-nuUs are combined. Brickmaking machines, by Whitehead, M. Jardin, Clayton & Co. Machine for working with plastic clay. Brick-pressing machines, by Longley, Whitehead, and Bradley and Craven. Dry-clay brickmaking machines, by Hersiy and Walsh, Bradley and Craven, and Wilson of Campbell- field. Tile-making machines, by Page & Co., and Whitehead. Hoffiuann'a brick-kiln.

APPENDIX I.

By Charles Tomlinson, F.R.S.

(Pages 245— 261. ^

On the plasticity and odour of clay. On diying bricks. On the use ol ccal-dust in making clamp bricks. Brickmaking at Great Grimsby. Brickmaking in Suffolk. On the making and burning of drain-tiles.

APPENDIX II.

By Rofert Mallet, A.M., F.R.S.

(Pages 262—272.)

The science of brickmaking. CJoloured bricks. Infusorial sUiceoui materials. Plasticity and odour of clay. Water chemically combined o< mechanically present.

RUDIMENTS

kWY OF MAKING BRICKS AND TILES.

INTRODUCTION.

I. It would 1)6 impossible, in a little volume like the present, to enter at any length upon the early history of the Art of Brickmaking, nor would such an investi- gation, however interesting in a historical point of view, add much to our practical knowledge of the subject. It is, however, desii'able that we should give a few par- ticulars relative to the progress of the manufacture in this country ; and we propose at the same time to give a brief sketch of the legal restrictions which have been imposed from time to time upon the mode of conduct- ing the operations of the brickmaker.

II. The use of brick as a building material, both burnt and unburnt, dates from a very early period. Burnt brick is recorded in the Bible to have been used in the erection of the tower of Babel ; and we have the testi- mony of Herodotus for the fact, which is confirmed by the investigations of travellers, that burnt bricks, made from the clay thrown out of the trench surrounding

B

a INTRODUCTION.

the cityj were used in building the walls of tlie city of Babylon. These very ancient bricks were of three kinds ; one of which was very similar to the modern Avhitc Sufiblk bricks^ and another to the ordinary red brick of the present day.

Sun-dried bricks were extensively used in ancient times, especially in Egypt, where their manufacture was considered a degrading employment, and, as such^ formed the principal occupation of the Israelites during their bondage in Egypt after the death of Joseph. Yery interesting ancient representations of the processes employed are still in existence, and throw much light on various passages of Scripture. Thus, the passage in Psalm Ixxxi. C, '^I removed his shoulder from the burden; his hands were delivered from the (ivater) pots," is strikingly illustrated by pictures still preserved to us, in Avhich labourers are carrying the tempered clay on their shoulders to the moulders, whilst others are engaged in carrying vessels of water to temper the clay. The Egyptian sun-dried bricks were made with clay mixed with chopped straw, which was furnished to the Israelites by their Egyptian taskmasters before the application of Moses to Pharaoh on their behalf, after which the obligation was laid on them to provide their own straw, which appears to have been a grievous addi- tion to their labour. It would appear from the details given, that the Israelites worked in gangs, under the superintendence of an overseer of their own nation, who was provided with all necessary tools and mate- rials, and who was personally responsible for the labour of the gangs.

Burnt bricks were, howererj also used in Egypt for river walls and hydraulic works, but, probably, not to any very great extent.

INTRODUCTION. 3

It is recorded in 2 Samuel xii. 31. that David put tlie cliildren of Ammon under saws^ and harrow s^ and axes of iron, and made them pass through the brick- kiln : without entering on the question whether the Ammonites were made to labour in the brickfields as the Israelites had themselves previously done during the time of their bondage in Egypt, or whether we are to understand that they were put to death with horrible tortures, as supposed by most commentators, there is a strong presumption that the implements here spoken of in connection with the brick-kiln were employed in the preparation of the clay ; and if this view be correct, the passage is interesting as evidence of the use of machinery in making bricks at a very early period of history.

III. The Romans used bricks, both burnt and ua- burnt, in great profusion ; all the great existing ruins at Rome being of brick. At the decline of the Roman Empire, the art of brickraaking fell into disuse, but was revived in Italy after the lapse of a few centuries. The mediaeval ecclesiastical and palatial architecture of Italy exhibits many fine specimens of brickwork and ornamental work in terra-cotta; cornices and other decorations of great beauty being executed in the latter material.

IV. In Holland and the Netherlands, the scarcity of stone led, at an early period, to the extensive use of brick, not only for domestic but for ecclesiastical build- ings, and these countries abound in fine specimens of brickwork, often in two colours, combined with great taste, and producing a very rich effect, as in the cele- brated examples at Leeuwarden in Friesland. ■ It is worthy of remark, that in the fens of Lincolnshire and Norfolk, where we should naturally liave expected to

B 2

4 INTRODrCTIOX.

have found the same material made use of, the churches, many of -which are exceedingly fine specimens of archi- tecture, are built of small stones, said to have been brought from a great distance on pack-horses.

V. Brickmaking appears to have been introduced into England by the Romans, who used large thin bricks or wall tiles as bond to their rubble construc- tions ; and such wall tiles continued to be used in England until rubble work was superseded by regular masonry, about the time of the Norman Conquest. Brick does not appear to have come into general use as a building material until long afterwards.

In the reign of Henry VIIL, however, the art of brickmaking had arrived at great perfection, and the remains of many buildings erected about this time exhibit some of the finest known specimens of oma- mental brickwork.

The following is a list of some of the principal brick buildings erected at the period of which we speak : —

VXytE. WHEX BOLT.

Horetmonceaax Castle, Sussex . Early in the reig^i of Ilcnry VL

Gate of the Bjehouse in Hertfordshire Ditto.

Tanershall Castle, Lincolnshire . . a.d. 1440.

Lollards* Tower, Lambeth Palace . ad. 1454.

Oxborongh Hall, Norfolk . . . About x.v. 1482.

Gatc-wav, Rf-c!on-, Hadleigh, Suffolk . Close of loth centurr.

Old part of Hampton Court . . ad. 1514.

HengraTe Hall, Suffolk . . . Finished a. d. 1538.

Manor House, at East Barsham, Norfolk During the reign of Henry VIL

Thorpland Hall, Norfolk . . . Ditto.

Parsonage Hcase,Great Snoring, Norfolk During the reign of Henrj- VIH.

Many of these buildings have been engraved in Pugiu's " Examples of Gothic Architecture," to which we would refer the reader. The decorative details of the Manor House at East Barsham, and of the Parsonage House at Great Snoring, are particularly worthy of notice ;

INTRODUCTION. 0

the panelled friezes^ cornices, and other ornamental work, being constructed of terra-cotta moulded to the required form. The use of terra-cotta for decorative panels and bas-reliefs appears to have been common during the reign of Henry VIII. The gateway of York Place, Whitehall, designed by Holbein, was de- corated with four circular panels, which are still pre- served at Hatfield Peveril, Hants.

The gateway of the Rectory in Hadleigh churchyard is very similar in character to that at Oxborough Hall, engraved in Pugin's work, above referred to. It has been lately restored very carefully, the terra-cotta work for the purpose being made at the Layham Kilns, near Hadleigh, in moulds of somewhat complicated con- struction.

In the time of Queen Elizabeth, brick seems only to have been used in large mansions, rCl common build- ings, timber framework, filled in with lath and plaster, was generally used, and this construction was much employed, even when brickwork Avas in common use, the brickwork, up to a late period, being merely intro- duced in panels between the wooden framing.

VI. On the rebuilding of London after the great fire of 1666, brick was the material universally adopted for the new erections, and the 19th Car. II. c. 11, regu- lated the number of bricks in the thickness of the walls of the several rates of dwelling-houses. One of the resolutions of the corporation of the city of London, passed about this time, is interesting ; it is as follows : — " And that they (the surveyors) do encourage and give directions to all builders, for ornament sake, that the ornaments and projections of the front buildings be of rubbed bricks; and that all the naked parts of the walls may be done of rough bricks, neatly wrought, or all

0 INTRODUCTION.

rubbed, at the direction of the builder, or that the builders may otherwise enrich their fronts as they please."

Much of the old brickwork still remaining in London^ in buildings erected at the end of the 17th and be- ginning of the 18th century, is very admirably executed. The most remarkable feature of the brickwork of this period is the introduction of ornaments carved with the chisel. A fine example of this kind of work is shown in the Frontispiece,* which is a sketch of 'So. 43, St. Martin's Lane, one of a block of houses built by a person of the name of ^lay, who about the same time erected Clay's Buildings, to which the date of 1739 is affixed. The house in question is said to have been intended by Mr. jNIay for his own residence. Its deco- rations consist of two fluted Doric pilasters, supporting an entablature, the avIioIc executed in fine red brick- work ; the mouldings, flutings, and ornaments of the metopes having been carved with the chisel after the erection of the walls. f

A'll. It w^as not till the close of the last century that bricks were subjected to taxation. The 21th Geo. III. c. 21', imposed a duty of 25. Gd. per thousand on bricks of all kinds. By the 34th Geo. III. c. 15, the duty was raised to 45. per thousand. By the 43rd Geo. III. c. G9, bricks were divided into common and dressed bricks, and separate rates of duty were imposed on each kind. These duties and those on tiles were as follows : —

* The author is indchtcd to the kindness of Mr. Edis for tliis sketch of one of the most interesting sjicciincns of ornamental brickwork in the mctrorolis.

T This fact was discovered some years ago, wheu the house waa imdcrt^oing a thorough repair, and the scaffolding afforded facilities for a close inspection of the ornamentation. Cast terra-cotta imitations of carved stone for architectural decoration were sent by Mr, Blanchard to the Exhibition of 1851, and were strongly recommended in the Jury licfort, Class XXYIII,

liNTRODUCTlON. /

SCHEDULE (A)— DUTIES.

BEICKS AKD TILES.

£ V. d.

For cveiy tliousand bricks which shall be made in Great Bri- tain, not exceeding any of the following dimensions, tliat is to say, ten inches long, three inches thick and five inches wide 050

For every thousand of bricks which shall be made in Great Britain exceeding any of the foregoing dimensions . . 0 10 0

For every thousand of bricks which shall be made in Great Britain, and which shall be smoothed or polished on one or more side or sides, the same not exceeding the superficial dimensions of ten inches long by five inches wide . . 0 12 0

For every hundred of such last-mentioned bricks, exceeding 7 The duiies on the aforesaid superficial dimensions ... J pa\iug-tilcs.

For every thousand of plain tiles which shall be made in

Great Britain 0 4 10

For every thousand of pan or ridge tiles which shall be made

in Great Britain 0 12 10

For every hundred of paving tiles which shall be made in

Great Britain not exceeding ten inches square . . .025

For every hundred of paving tiles whicli shall be made in

Great Britain exceeding ten inclics square . . . 0 4 10

For every thousand tiles which shall be made in Great Bri- tain, other than such as are hereinbefore enumerated or described, by whatever name or names such tiles are or may

be called or known 0410

N.B. — The said duties on bricks and tiles to be paid by the maker or makers thereof respectively.

Bv the 3rd William IV. c. 11 (1833), the duties on tiles* were wholly repealed, and two years afterwards the duty on bricks was again raised, making the duty on common bricks 55. lOd. per thousand.

The brick duties formed the subject of the 18tli Report of the Commissioners of Excise Enquiry, 1836; and in 1839 these duties were repealed by the 2nd and 3rd Vict. c. 24, and a uniform duty of 5^. 10^/. per thou-

* By a curious oversight, this Act, whicli was intended to put roofiny tiles on the same footing as slates, also repealed the duties on paving tiles, whilst briclis used for paving remained sul)jcct to duty as before. Tliue a lump of clay put into a mould of 10 in. X 5 in. X 3 paid duty, but the same qiiantiiy of clay put into a mould 10 in. square was duty free, because it came under the denomination of a tile. The manufacturer, and nr ' the public, reaped the advantage thus given

o INTRODUCTION.

sand imposed on all bricks of -ohich the cubic content did not exceed 150 cubic inches^ without any distinc- tion as to shape or quality.

Till. The ncTT Act Avas a great boon to the public as well as to the trade, as, in consequence of the removal of the restrictions on shape, bricks might be made to any required pattern ; and moulded bricks for cornices, plinths, string-courses, &c., could be manufactured at a moderate price. Under the old regulations, also, the brickmaker was precluded from correcting any defect which might arise from warping or twisting in the process of drying, without making himself liable to pay the higher rate of duty. In 1850 the duty ou bricks was entirely repealed.

IX. The number of bricks annually made iu Great Britain is very great ; just before the duty was repealed, a charge was made on about 1,800,000,000 bricks annually. In 1854 the number manufactured was estimated to be over 2,000,000,000, of which about 130,000,000 were made in the brickfields in and around Manchester, and about a similar number by the London brickmakers. The weight of this annual produce is upwards of 5,400,000 tons, representing a capital employed probably exceeding £'2,000,000. Comparatively few bricks are made in Scotland, on account of the abundance of stone in that country. Those who are not practically connected with engineer- ing works may find some difficulty in forming a clear conception of the immense number of bricks annually made for railway purposes ; and which may be roughly estimated at from GOO to 800 millions annually. In 1821, before the introduction of the railway system, the number of bricks charged M'ith duty in England and Scotland amounted to 913,231,000. * In 1831 the

INTRODUCTION, 3

number was 1,153^048,581. In 1840 the number rose to 1,725,628,333.

A common turnpike road bridge over a railway requires for its construction, in round numbers, 300,000 bricks ; and the lining of a railway tunnel of ordinary dimensions consumes about 8,000 for every yard in length, or in round numbers about 14,000,000 per mile.

X. The processes employed in the manufacture of bricks differ very greatly in various parts of the country. In some districts the clay is ground between rollers, and the pugmili is never used. In others, both rollers and pugmills are employed. In the neighboui'hood of London the clay is commonly passed through a wash- mill. Equal differences exist in the processes of mould- ing and drying. Lastly, the form of the kiln varies greatly. In many places the common Dutch kiln is the one employed. In Essex and Suffolk the kilns have arched furnaces beneath their floors; in Staffordshire bricks are fired in circular domed ovens called cupolas ; whilst near London kilns are not used, and bricks are burnt in clamps, the fuel required for their vitrifica- tion being mixed up with the clay in the process of tempering.

XI. Bricks vary very much in their strength, a point to which, although of considerable importance, very little attention is paid. There is a striking difference in this respect between modern and ancient bricks ; a differ- ence very much in favour of those made centuries ago; and, perhaps, the weakest bricks made are supplied by London makers. In some experiments by 'Mv. Hawkes (a detailed account of which is given in the Builder for 1861) it was found that of thirty-five kinds of bricks which were tested, the average strength of the strongest

B 3

10 INTRODUCTION.

was 2j8o5 lbs. ; of those of medium tenacity, 2,125 lbs. ; and of those of least strength, 1557 lbs. These bricks were of the ordinary form^ and varied in thickness from 325 to 1'7 inches. It was also found that the thinner kinds of bricks were proportionally stronger than those which were thicker ; the greatest, mean, and least strengths of the former being respectively 4,088 lbs., 2,054. lbs., and 2,070 lbs.

In comparing weight with strength, it was found tliat the average weight of twenty-five bricks from dif- ferent districts, was 7*85 lbs., and that the heaviest bricks were usually the strongest. The results of the following experiments are calculated according to a uniform standard : — Tipton blue bricks, weighing 10 lbs., gave 5,555 lbs., 3,975 lbs., and 2,801 lbs., as the greatest, mean, and least degree of strength. Boston bricks, weighing 988 lbs., gave 4,133 lbs., 3,198 lbs., and 2,616 lbs., as the value of the same items. Roman hypocaust tiles from the ancient city of Uriconium, near 'V^'roxetcr, gave 4,670 lbs., 3,567 lbs., and 2,630 lbs. The Leeds bricks, weighing 9- 17 lbs., gave 4,133 lbs., 3,198 lbs., and 2,616 lbs. Dutch clinkers, with a weight of only 6'56 lbs., gave the respec- tive strength of 4,006 lbs., 3,345 lbs., and 2,542 lbs. This is an exception to the general result of the heaviest bricks being the strongest. Lastly, the lightest London bricks, weighing 6*19 lbs., gave 1,496 lbs., 998 lbs., and 366 lbs. The experiments also gave evidence of the fact that bricks were unable to sustain for any length of time a weight considerably less than that which was originally required to break them ; for example, a Bal- timore brick, which required 850 lbs. to break it, car- ried a weight of 735 lbs. for ten hours only, and then broke. It must be borne in mind that the second

IXTRODUCTIO.V. 11

result is represented in terms of the whole brick, for the sake of rendering the comparison more easy, although, of course, the experiment could only be made on the half brick.

XII. Now that machine-made bricks are getting into general use, notwithstanding that some opposition has been made to their introduction, the following table may be interesting. It is a report of the results of some experiments on hand-made and machine-made bricks, with Messrs. Burton and Co.^s hydraulic press. All the bricks were bedded upon a thickness of felt, and laid upon an iron-faced plate.

Pressure to crack. Pressure to crush,

tons. tons.

Good London grey Stocks . . . 1200 . . . U-00

Best paviours to be got ... 1400 . . . 23-00

Bed bricks, not fully bunit . . . 13-75 ... 25 05

Ditto, ordinary quality .... 1300 . . . 26-25

Three white bricks made by Cl&y- ) ,» „. ., n-

ton and Co. s machineiy . j

Ditto, second best, with four bricks 1625 . . . 41-00

In the following pages we have described at con- siderable length the practice of brickmaking as carried on in Nottinghamshire, Staffordshire, Suffolk, and in the neighbourhood of London j and although the prac- tice of almost every county presents some local pecu- liarity, the reader who has carefully gone through these accounts will be enabled to understand the object of any processes not here described, and to form a toler- ably correct judgment as to whether the process of manufacture in any district is conducted in a judicious manner; or whether the brickmaker has merely fol- lowed the practices handed down bv lis predecessors without any consideration as to the possibility of im- proving upon them. Before, however, enteriuj^ npon the practical details of the subject, it is necessarj '.hat

12 RUDTMEXTS OF THE

the reader should have some knowledge of the general principles of brickmaking, and of the nature of the processes employed; and these we shall proceed to consider in the following chapter.

CHAPTER I.

V

GE>'EK^VL PrJNCIPLES OF THE MANLTACTURE OF BRICKS AND TILES.

1. BRICKS.

1. Tl.j- whole of the operations of the brickmaker may be classed under five heads^ viz. : —

\ preparation of brick earth. ■;! Tempering.

•^ ^Moulding.

^ Drying. V- Burning.

We propose in this chapter to describe these opera- tions one by one, pointing out the object to be effected by each, and comparing at the same time the different processes employed in various parts of this country for the same end.

PREPARATION OF BRICK EARTH.

2. The qualities to be aimed at in making bricks for building purposes may be thus enumerated :— Sound-

'^ jiesSj_thatis, freedom from cracks and flaws ; Laidaes*, r to enable them to withstand pressure and cross strain ; ^ regularity of shape, that the mortar by which they are miited may be of uniform thickness to insure unifor- mity of settlement ; uniform itj:_of size, that all the bricks in a course may be of the same beiglit ; uni-

^

ART OF MAKING BlUCKS AND TILES.

13

_iiw^mily of tuloui'j which is of importance only in ornamental work ; facility of cutting, to enable the bricklayer to cut themTo any given shape, as required in executing all kinds of gauged -work; lastly, for furnace-work, and all situations exposed to intense heat, infusibility.

3. Success in attaining the desired end depends chiefly on a proper selection of brick earths; their judicious preparation before commencing the actual process of brickmaking, as well as on the drying and

jDurning of the bricks. / The other operations are matters of minor importance. Brickmaking may be viewed in two lights — as a science, and as an art. The former has been little studied, and is imperfectly under- stood ; whilst the latter has been brought to great perfection.

4. The argillaceous earths suitable for brickmaking may be divided into three principal classes, viz. : —

Pure clays, composed chiefly of alumina^^ndsilieii, but containing a small proportion of other substances — as iron, lime, &c.* (See Appendix II., page 263.)

* The following analyses of various kinds of clay are given in the second volume of the English translation of " Knapp's Technological Chemistry."

	Cornish washed Kaolin.	Stour- bridge fire clay.	Pipeclay.	Sandy clay.	Blue clay.	Brick clay.
Silica Alumina Oxide "1 of iron j Lime Magnesia Potash \ 8c soda Water .	46-32 39-74 0-27 0-36 0-44 ) 12-67	6410 23-15 1-85 0-95 1000	53-66 32-00 1-35 0-40 trace 12-08	66-68 26-08 1-26 0-84 trace 5-14	46-38 38-04 1-04 1-20 trace 13-57	49-44 34-26 7-74 j 1-48 5-14 1-94
99-80	10005	99-49	100-00	100-23	100-00

14 RUDIMENTS OF THE

Marls, ■whicli may be described as earths coutaiiiing u considerable proportion of lime.

Loams, -u-hich may be described as light sandy clays.

l/j It very seldom happens that earths are found which

H are suited for the purpose of brickmaking without some

y admixture. The pure clays require the addition of

sandj loam, or some milder earth ; whilst the loams are

often so loose that they could not be made into bricks

without the addition of lime to flux and bind the earth.

Even when the clay requires no mixture^ the difference

in the working of two adjacent strata in the same field

is often so great that it is advisable to mix two or three

sorts together to produce uniformity in the size and

colour of the bricks.

5. It appears, then, that a chemical compound of silica and alumina is the principal ingredient in all brick earth.* This silicate of alumina, or pure clay alone, or those clays which contain but little sand, may, when beaten up with water into a stiff paste, be moulded with great ease into any shape ; but will shrink and crack in drying, however carefully and slowly the ope- ration be conducted ; and will not stand firing, as a red heat causes the mass to rend and warp, although it becomes very hard by the action of the fire.

The addition of any substance which will neither combine with water, nor is subject to contraction, greatly remedies these defects, whilst the plastic quality of the clay is not materially affected. For this reason the strong clays are mixed with milder earth or with sand. The loams and marls used for brickmaking in the neighbourhood of London are mixed with lime and sifted breeze for the same purpose, and also to effect the fluxing of the earth, as will be presently described. • Some remarks on the plajiitity of clay w ill be found iu the Afijendi*

AUT OF MAKING BllICKS AND TILES. 15

G. Fire clays or refractory clays are compounds of Bilica^ alumina^ and water, or liydrated silicates of alu- mina represented by tlie formula AlgO 3, 2Si03 + 2H0. Sucli clays owe their refractory qualities to their com- parative freedom from lime, magnesia, metallic oxides, and similar substances which act as fluxes. Pew clays, however, exist in nature according to this pure type. The composition and quality of clays in con- tiguous beds in the same pit, and even of clay from the same contiguous horizontal bed, may vary. ''If we compare difterent clays together in respect to elementary composition, we find the relation between the silica and alumina to be extremely variable, and accordingly, the formulae which have been proposed to express their rational constitution are very discordant. This is in great measure to be explained by the fact, that in many clays a large proportion of silica exists uncombined either as sand, or in a much finer state of division. The grittiness of a clay is due to the presence of sand.'^* Fire-bricks are used in those parts of furnaces where the heat would soon destroy ordinary bricks. They are made of various shapes and sizes as required, and are often produced, as in the iron works of South Wales, on the spot. The clay is ground between rolls, or under edge stones, and kneaded by treading. The bricks are made by hand in moulds ; they are carefully dried in stoves, and burnt at a high temperature in closed kilns. Burnt clay in powder is sometimes mixed with the raw clay. Stourbridge clay is celebrated for the manufacture of fine bricks, but clay from the coal-measures is also largely used. All these bricks have a pale brownish colour, but they are sometimes mottled with dark spots,

* " irctallurgy," by John rcicy, M.D., F.R.S., Lecturer on Mctnllurgjr at the Goverumcnt School of Mines. London, 1861.

16 RUDIMENTS OF THE

whicli Dr. Percy refers to the presence of particles of iron pyrites. The Dinas fire-brick consists almost entirely of silica, the material being obtained from the rock of that name in the Vale of Neath. It lies on the limestone, and occasionally intermixes with it, and contains probably about 5 per cent, of calcareous matter. The bricks have extraordinary fire-proof qualities. The material had long been used as a sand, and many attempts ^ere made to form it into bricks, without success, until a method was contrived by the late Mr. W. TT. Young, when in 1822 a company was formed for the manufacture of these bricks. The mode of making the Dinas brick was long kept secret, but a number of original details concerning it are given in Dr. Percy's work. The material which is called clay is found at several places in the Vale of Xeath in the state of rock, and disintegrated like sand. The colour when dry is pale grey. The rock is crushed to coarse powder between iron rolls ; it softens by exposure to the air, but some of it is too hard to be used. '* The powder of the rock is mixed with about 1 per cent, of lime and sufficient water to make it cohere slightly by pressure. This mixture is pressed into iron moulds, of which two are fixed under one press, side by side. The mould, which is open at the top and bottom, like ordinary brick-moulds, is closed below by a moveable iron plate, and above by another plate of iron, -which fits in like a piston, and is connected with a lever. The machine being adjusted, the coarse mixture is put into the moulds by a workman, whose hands are protected by stout gloves, as the sharp edges of the fragments would otherwise \round them : the piston is then pressed down, after which the moveable bed of iron on which the brick is formed is lowered and taken away with the

AKT OF MAKING BRICKS AND TILES. 17

brick upon it, as it is not sufficiently solid to admit of being carried in the usual manner. The bricks are dried on these plates upon floors warmed by flues passing underneath ; and ivhen dry they are piled in a circular closed kiln covered with a dome, similar to kilns in which common fire bricks are burned. About seven days of hard firing are required for these bricks, and about the same time for the cooling of the kiln. One kiln contains 3.2,000 bricks, and consumes 40 tons of coal, half free-burning and half binding. The price (1859) is 605. the thousand/'* The fracture of one of these bricks shows irregular particles of quartz, and the lime which is added acts as a flux, causing them to agglutinate. These bricks expand by heat, while bricks made of fire clay contract. Hence they are useful for the roofs of reverberatory furnaces, and for parts where solid and compact lining is required. These siliceous bricks must not be exposed-^ to the actibn of slags rich in metallic oxides.

7. Fire clay, being an expensive article, is frequently mixed with burnt clay, often as much as two parts by weight to one of Stourbridge clay. Broken crucibles, old fire bricks, and old glass-pots ground to powder are also mixed with fire clay.

8. Fire clay is found throughout the coal measures, but that of Stourbridge is considered to be the best, as it will bear the most intense heat that can be produced without becoming fused. Next in esteem to those of Stourbridge are the "Welsh fire bricks, but they will not bear such intense heat. Excellent fire bricks arc made at Newcastle and Glasgow. Fire bricks are made near Windsor, at the village of Hedgerly, from a sandy

• In this year bricks were much cheaper than they have been since.

18 RUDIMENTS OF THE

loam known by the name of Windsor loam, and much used in London for fire-work, and also by chemists for luting their furnaces, and for similar purposes.

The relative merits of Windsor, Welsh, Stourbridge, and other fire bricks, are best shown by their commer- cial value. The following items, extracted from the '^ Builders' and Contractors' Price Book for 1868," edited by G. E. Burnell, exhibit their relative cost : —

Per 1000.

£ s. d. Windsor fire bricks . . . .54.0

Wcljh ditto .5 4 0

Stourbridge ditto 7 0 0

Kewcastle ditto 5 5 0

Alloa ditto 5 8 0

Dorset ditto 4 16 0

9. Bricks made of refractory clay, containing no lime or alkaline matter, are baked rather than burnt ; and their soundness and hardness depend upon the fineness to which the clay has been ground, and the degree of firing to which it has been exposed.

10. It is very seldom that the common clays arc found to be free from lime and other fluxes ; and wlien these are present in certain proportions, the silica of the clay becomes fused at a moderate heat, and cements the mass together. Some earths are very fusible, and, when used for brickmaking, great care is requisite in firing the bricks to prevent them from running together in the kiln.

11. The earths used for brickmaking near London arc not clays, but loams and marls. To render these earths fit for brickmaking, they are mixed with chalk ground to a pulp in a wash -mill. This eficcts a double purpose, for the lime not only imparts soundness to the bricks, acting mechanically to prevent the clay from shrinking and cracking, but also assists in fusing the

ART OF MAKING BllICKS AND TILES, 19

siliceous particles ; and Avlien present in sufficient quan- titjj corrects the evil effects of an overdose of sand^ as it takes up the excess of silica that would otherwise remain in an uncombined state.

12. It -will be seen from these remarks that we may divide bricks generally into two classes — baked bricks

^a^L£_ii:Qm_ the refractQiy clays^ and burnt or vitrified bricks made from the fusible earths.

The fusible earths are the most difficult of treatment^ as there is considerable practical difficulty in obtaining a sufficient degree of hardness without risking the fusion of the bricks ; and it will be found that ordinary kiln-burnt bricks, made from the common clays_, are for the most part of inferior quality, being hard only on the outside, whilst the middle is imperfectly burnt, and remains tender. The superior quality of the London malm bricks, which are made from a very fusible com- pound, is chiefly due to the use of sifted breeze, -!= which is thoroughly incorporated with the brick earth in the pugmill, so that each brick becomes a kind of fire ball, and contains in itself the fuel required for its vitrifica- tion. In building the clamps the bricks are stacked close together, and not as in ordinary kiln-burning, in which openings are left between the bricks to allow of the distribution of the heat from the live holes. The effect of these arrangements is to produce a steady uni- form heat, which vitrifies the bricks without melting them. Those bricks which are in contact with the live holes or flues melt into a greenish black slag.

13. Cutters, that is, bricks which will bear cutting and rubbing to any required shape, are made from sandy loams, cither natural or artificial. In many

• Breeze is a casual mixture of cinders, small coal, and ashes, such as Is collected by the dustmen.

20 RUDIMENTS OF THE

districts cutters are not made, there being no suitable material for the purpose. Bricks made from pure clays containing but little silica are hard and tough, and will not bear cutting.

14. We now come to the consideration of colour, which depends on the varying proportions of the hydrated oxide of iron in the clay, which change according to the amount of heat to which the bricks are subjected, and not on their natural colour before burning. This should be borne in mind, because brick- makers often speak of clays as red clay, white clay, &c., according to the colour of the bricks made from them, without any reference to their colour in the unburnt state.

If iron be present in clay without lime or similar substances, the colour produced at a moderate red heat will be red, the intensity of colour depending on the proportion of iron. The bind or shale of the coal mea- sures burus to a bright clear red. If the clay be slightly fusible, an intense heat vitrifies the outside of the mass and changes its colour, as in the case of the Staffordshire bricks, which, when burnt in the ordinary way, are of a red colour, which, however, is changed to a greenish blue by longer firing at a greater heat. The addition of lime changes the red produced by the oxide of iron to a cream brown, whilst magnesia brings it to a yellow. Few clays produce a clear red, the majority burning of different shades of colour, varying from reddish brown to a dirty red, according to the propor- tion of lime and similar substances which they contain. Some clays, as the plastic clays of Suffolk, Devon- shire,* and Dorsetshire, burn of a clear white, as may

* The plastic clay of Devonshire and Dorsetshire forms the basis of the English stone waic. It is composed of about seventy-six parts of

ART OF MAKING BRICKS AND TILES. 31

be seen in the SuflFolk white bricks, which are much esteemed for their soundness and colour. The London malms have a rich brimstone tint, which is greatly assisted by the nature of the sand used in the process of moulding.

15. By employing metallic oxides and the ochreous metallic earths, ornamental bricks are made of a variety of colours , This, however, is a branch of brick- making which has as yet received very little attention, although, with the rising taste for polychromatic deco- ration, it is well worthy of consideration. (See note, page 270.)

Yellow clampt burnt bricks are made in the vicinity of the metropolis, and in other* situations where similar material and fuel are readily obtained. White bricks are made from the plastic clays of Devonshire and Dorsetshire, and also Cambridgeshire, Norfolk, Suffolk, and Essex, as well as in other counties. Red bricks are made in almost every part of England ; but the fine red or cutting brick is not generally made. Blue bricks are made in Staffordshire, and are much used in that part of England.

Sound and well-burnt bricks are generally of a clear and uniform colour, and when struck together will ring with a metallic sound. Deficiency in either of these points indicates inferiority.

16. Bricks suflficiently light to float in the water were known to the ancients. This invention, however, was completely lost until rediscovered at the close of the

silica and twenty-four of alumina, with some other ingredients in very small proportions. This clay is very refractory in high heats, a property which, joined to its whiteness when burned, renders it peculiarly valuable for pottery, &c.

* Yellow clampt burnt bricks are made at Margate, in Kent, from the patches of plastic clay lying in the hollows of the chalk. The older part of Margate is built of red bricks said to have been brought from Canter- bury.

22 RUDIMENTS OF THE

last century by !M. Fabbroni, who published an account of his experiments. M. Fabbroni succeeded in making floating bricks of an infusible earth called fossil meal^ which is abundant in some parts of Italy. Bricks made of this earth are only one-sixth of the weight of common clay bricks, on which account they would be of great service in vaulting church roofs, and for similar pur- poses. Ehrenberg, the eminent German microscopist, showed that this earth consists almost entirely of the frustules or siliceous skeletons of vnrious kinds of minute water plants. (See note, page 271.)

Having thus briefly sketched the leading principles which should be our guide in the selection of brick earth, we will now proceed to describe the several pro- cesses by which it is brought into a fit state for use.

17. Unsoilwg. — Xlie first operation is to remove the mould and top soil, which is wheeled away, and should be reserved for resoiling the exhausted workings when they are again brought into cultivation. In London the vegetable mould is called the encallow, and the operation of removing it, cncallowing .

18. Clay -dig fjing and Wcatliering. — The brick earth is dug in the autumn, and wheeled to a level place pre- pared to receive it, when it is heaped up to the depth of^ several feet, and left jthrough the winter months to be mellowed by the frosts, which break up and ci'umble thejumps. ^SFtHe commencement of the brickmaking seasonTwTiich generally begins in April, the clay is turned over with shovels, and tempered either by spade labour or in the pugmill ; sufficient water being added to give plasticity to the mass.

19. J)uring these oi^crations any stones which may be found must be carefully picked out by hand, which is a tedious and expensive operation, but one which

ART OF MAKING BRICKS AND TILES. 23

cannot be neglected with impunity^ asjjie-^reeeace of a pebble in a brick gejiprnllY rnnsps^ \% t,o pynnl^ ip ^^y^'^g:j anJ makes it shaky and unsound when burnt. If the earths to be used are much mixed with gravely the only remedy is to wash them in a trough filled with water, and provided with a grating sufficiently close to prevent even small stones from passing through, and by means of which the liquid pulp runs off into pits prepared to receive it, where it remains until, by evaporation, it becomes sufficiently firm to be used. This process is used in making cutting bricks, which require to be of perfectly uniform texture throughout their whole sub- stance J but it is tedious and expensive.

In working the marls of the midland districts, much trouble is experienced from the veins of skerry or im- pure limestone with which these earths abound. If a small piece of limestone, no bigger than a pea, is allowed to remain in the clay, it will destroy any brick into which it finds its way. The carbonic acid is driven off by the heat of the kiln, and forces a vent through the side of tlie brick, leaving a cavity through which water finds its way, and the first sharp frost to which such a brick may be exposed generally suffices to destroy the face.

20. Gi'inding. — To remedy this serious evil, cast-iron rollers are now generally used throughout the midland districts for grinding the clay and crushing the pieces of limestone found in it, and their introduction has been attended with very beneficial results. The clays of the coal measures contain much ironstone, which requires to be crushed in the same manner.

In many yards the grinding of the clay is made to form part of the process of tempering, the routine being as follows : — clay-getting, weathering, turning over and

^se:.-

2i RUDIMENTS OF THE

■wheeling to mill, grinding, tempering, and moulding. In Staflbrdshire the clay is not only ground, but is also pugged in the process of tempering, as described in chap, iv, art. 38 ; the routine is then as follows : — clay-getting, grinding, weathering, turning over, pug- [^ ging, moulding.

At a well-mounted brickwork in Nottingham, belong- ing to Moses Wood, Esq., the clay used in making the best facing bricks is treated as follows : — it is first turned over and weathered by exposure to frost ; it is then again turned over, and the stones picked out by hand, after which it is ground between rollers set very close together, and then left in cellars to ripen for a year or more, before it is finally tempered for the use of the moulder. The bricks made from clay thus prepared are of first-rate quality, but the expense of the process is too great to allow of much profit to the manufacturer.

21. Washing. — The preparation of brick-earth in the neighbourhood of London is efi'ected by processes quite different from those just described. For marl or malm bricks, the earth is ground to a pulp in a wash-mill, and mixed with chalk previously grouud to the consistence of cream ; this pulp, or, as it is technically called, malm, is run off through a fine grating into pits pre- pared to receive it, and there left, until by evaporation and settlement, it becomes of sufiicient consistency to allow a man to walk upon it. It is then soiled, i.e. covered with siftings from domestic ashes, and left through the winter to mellow. At the commencement of the brickmaking season the whole is turned over, and the ashes thoroughly incorporated with the earth in the pugmill. In making common bricks, the whole of the earth is not washed, but the unwashed clay is

AKT OF MAKING BRICKS AND TILES. Si)

heaped up on a prepared floor, and a proportion of liquid malm poured over it, after wliicli it is soiled iu the same way as for making malms.

These processes are well calculated to produce sound, hard, and well-shaped bricks. The washing of the clay efiectually frees it from stones and hard lumps, whilst the mixing of the chalk and clay in a fluid state ensures the perfect homogeneousness of the mass, and enables the lime to combine with the silica of the clay, which would not be the case unless it were in a state of minute division.

22. There are very few earths suitable in their natural state for making cutters. They are therefore usually made of washed earth mixed up with a proportion of sand. Without the addition of sand the brick would not bear rubbing, and it would be very difficult to bring it to a smooth face.

23. It maybe here observed that sufficient attention is not generally paid to the preparation of brick-earth, as it too frequently happens that the clay is dug in the spring instead of the autumn, in which case the benefit to be derived from the winter frosts is quite lost. The use of rollers, to a certain extent, counterbalances this; but bricks made of clay that has been thoroughly weathered are sounder and less liable to warp in the kiln.

TEMPERING.

^ 24. The object of tempering is to bring the ptepared C brick earth into a homogeneous paste, for the use of ^ the moulder.

The old-fashioned way of tempering was to turn the clay over repeatedly with shovels, and to tread it over by horses or men, until it acquired the requisite plasti- city. This method is still practised in many country

2G RUDIMENTS OF THE

yards ; but where the demand for bricks is extensive,

mnplinipry iig ^jminlly prnploypfl, the clay being eithci

^^roMn^JbfitHeenjplIers or jugged in a pugmill. This latter process is also called grinding, and, therefore, in making inquiries respecting the practice of particular localities, the reader should be careful that he is not misled by the same name being applied to processes which arc essentially diflFerent.

When rollers are used in the preliminary processes, the labour of tempering is much reduced. Their use is, however, most generally confined to the process of tempering, which is then effected as follows : — The clay, which has been left in heaps through the winter to mellow, is turned over with wooden shovels (water being added as required), and wheeled to the mill, where it is crushed between the rollers, and falls on a floor Ijclow them, where it is again turned over, and is then ready for use.

When the clay is sufficiently mild and free from lime and ironstone as not to require crusJdng, tempering by spade labour and treading is generally adopted; but in the districts where rollers are used, the brick-earths are generally so indurated that a great proportion could not be rendered fit for use by the ordinary processes. The advantages and disadvantages of the use of rollers are considered at some length in chap. iii. art. 4.

25. In making bricks for railway works, which has been done lately to an almost incredible extent, con- tractors are generally little anxious as to the shape or appearance of the article turned out of the kiln, pro- vided it be sufficiently sound to pass the scrutiny of the inspector or resident engineer. As the whole process of railway brickmaking often occupies but a few weeks from the first turning over of the clay to the laying of

ART OF MAKING B^vV^LKS ANm TILES. 27

the bricks in the >york, the use of rollers in such cases is very desirable, as a partial substitute for weathering. On the line of the Nottingham and Grantham Railway several millions of bricks have been made as follows : — The clay is first turned over with the spade, and watered and trodden by men or boys, who, at the same time, pick out the stones. It is then wheeled to the mill and ground ; after which it is turned over a second time, and then passed at once to the moulding table.

26. Although in many country places, where the demand for bricks is very small, tempering is still per- formed by treading and spade labour, the pugmill is very extensively used near London, and in most places where the brick-earth is of mild quality, so as not to require crushing, and the demand for bricks sufficiently constant to make it worth while to erect machinery. The pugmill used near London is a wooden tub, in shape an inverted frustrum of a cone, with an upright revolving shaft passing through its centre, to which are keyed a number of knives, which, by their motion, cut and knead the clay, and force it gradually tlu'ough the mill, whence it issues in a thoroughly tempered state, fit for the use of the moulder. Some contend that the pug- mill is no improvement on the old system of tempering by manual labour; but, without entering into this ques- tion, there can be no doubt that it does its work very thoroughly, and its use prevents the chance of the tem- pering being imperfectly performed through the negli- gence of the temperers. In the London brickfields the process of tempering is conducted as follows : — The malm, or maimed brick-earth, as the case may be, ia turned over with the spade, and the soil* (ashes) dug

* Soil, i.e. ashes, must not be confountlcd with soil, vegetable mould, which is ia some places mixed with strong clay, to render it milder.

c 2

28 ^uDi,y^'^;Ts of the

into itj water being added as may be necessary. It is then barrowed to the pugmill, and being thrown in at the top, passes through the mill, and keeps continually issuing at a hole in the bottom. As the clay issues from the ejectment hole, it is cut into parallelopipedons by a labourer, and, if not wanted for immediate use, is piled up and covered with sacks to prevent it from becoming too dry.

In Staffordshire steam power is used for driving both rollers and pugmill, and the case of the latter is usually a hollow cast-iron cylinder.

MOULDING.

27. A brick-mould is a kind of box without top or bottom, and the process of moulding consists in dashing the tempered clay into the mould with sufficient force to make the clot completely fill it, after which the superfluous clay is stricken with a strike, and the newly- made brick is either turned out on a drying floor to harden, or on a board or pallet, on which it is wheeled to the hack-ground. The first mode of working is known as slop moulding, because the mould is dipped in water, from time to time, to prevent the clay from adhering to it. The second method may be distinguished as jt;«//e^ moulding; and in this process the mould is not wetted, but sanded. These distinctions, however, do not universally hold good, because in some places slop-moulded bricks are turned out on pallets.

28. These differences may, at first sight, appear trivial, but they affect the whole economy of a brick- work. In slop moulding the raw bricks are shifted by hand from the moulding table to the drying floor, from the drying floor to the hovel or drying shed, and from

ART OF MAKING BRICKS AND TILES. 29

the hovel to the kiln. It is therefore requisite that the works should be laid out so as to make the distance to which the bricks have to be carried the shortest pos- sible. Accordingly,* the kiln is placed in a central situation in a rectangular space, bounded on two or more sides by the hovel, and the working floors are formed round the outside of the latter.

In the process of slop moulding the newly-made brick is carried, mould and all, by the moulder^s boy to the flat, or drying floor, on which it is carefully deposited ; and whilst this is being done, the moulder makes a second brick in a second mould, the boy returning with the first mould by the time the second brick is being finished. As soon, therefore, as the floor becomes filled for a certain distance fi'om the moulding table, the latter must be removed to a vacant spot, or the distance to which the bricks must be carried would be too great to allow of the boy's returning in time with the empty mould.

29. In pallet moulding but one mould is used. Each brick, as it is moulded, is turned out on a pallet, and placed by a boy on a hack-barrow, which, when loaded, is wheeled away to the hack-ground, where the bricks are built up to dry in low walls called hacks. One moulder will keep two wheelers constantly employed, two barrows being always in work, whilst a third is being loaded at the moulding stool. When placed on the barrow, it is of little consequence (comparatively) whether the bricks have to be wheeled 5 yards or 50 ; and the distance from the moulding stool to the end of the hacks is sometimes considerable.

30. The moulding table is simply a rough table, made

* There are, of course, some exceptions; but, where practicable, the drying floors and hovel are placed close to the kilus.

30 RrDiMEXTs or the

in various ways in different parts of the country, but the essential differences are, that for slop moulding the rable is furnished uith a water trough, in which the moulds are dipped after each time of using; whilst in pallet moulding, for which the mould is usually sanded and not wetted, the water trough is omitted, and a page (see account of Brickmaking as practised in London) is added, on which the bricks are placed preparatory to their being shifted to the hack-barrow.

,31. Brick moulds are made in a variety of ways. Some are made of brass cast in four pieces and riveted together ; some are of sheet iron, cased with wood on the two longest sides ; and others again are made entirely of wood, and the edges only plated with iron. Drawings and detailed descriptions of each of these constructions are given in the subsequent chapters. lu using wooden moulds the slop-moulding process is almost necessary, as the brick would not leave the sides of the mould unless it were very wet. Iron moulds are sanded, but not wetted. Brass, or, as they are techni- cally called, copper moulds, require neither sanding nor wetting, do not rust, and are a great improvement on the common wooden mould formerly in general use. They, however, are expensive, and will not last long, as the edges become worn down so fast that the bricks made from the same mould at the beginning and end of a season are of a different thickness, and cannot be used together. This is a great defect, and a metal mould which will not rust nor wear is still a great desi- deratum. It is essential that the sides of the mould should be sufficiently stiff not to spring when the clay is dashed into it, and it is equally requisite that it should not be made too heavy, or the taking-off boy would not be able to carry it to the floor. A common

ART OF MAKING BRICKS AND TILES. 31

copper mould weiglis about 4 lbs., and, with the wet brick in it, about 12 lbs., and this weight should not be exceeded.

32. There is a great difference in the quantity of bricks turned out in a given time by the pallet moulding and by the slop moulding processes. In slop moulding 10,000 per week is a high average, whilst a London moulder wiU turn out 36,000 and upwards in the same period. This arises in a great measure from the cir- cumstance that in pallet moulding the moulder is assisted by a clot moulder, who prepares the clot for dashing into the mould ; whilst in slop moulding the whole operation is conducted by the moulder alone.

33. In some places the operation of moulding par- takes both of slop moulding and pallet moulding, the bricks being turned out on pallets and harrowed to the hack-ground, whilst the moulds are wetted as in the ordinary process of slop moulding.

34. The substitution of machinery for manual labour in the process of moulding has long been a favourite subject for the exercise of mechanical talent ; but

/ although a great number of inventions have been pa-

■y tented, there are very few of them that can be said to

' be thoroughly successful. The actual cost of moulding

-7 bears so small a proportion to the total cost of brick-

' making, that in small brickworks the employment of

machinery would effect no ultimate saving, and, there-

. fore, it is not to be expected that machinery will ever

( be generally introduced for brick moulding. But in

works situated near large towns, or in the execution of

large engineering works, the case is very different, and

a contractor who requires, say, 10,000,000 of bricks, to

be made in a limited time, for the construction of a

tunnel or a viaduct, can employ machinery with great

32 RUDIMENTS OF THE

advantage. A chapter on brickmaking macliines will be found in another part of this volume.

35. It has been much discussed by practical men, f whether bricks moulded under great pressure are better ' than those moulded in the ordinary way. They are of

L denser texture, harder, smoother, heavier, and stronger than common bricks. On the other hand, it is difficult to dry them, because the surfaces become over-dried '. and scale off before the evaporation from the centre is ( completed. Their smoothness lessens their adhesion to ) mortar ; and their weight increases the cost of carriage, ' and renders it impossible for a bricklayer to lay as many in a given time as those of the ordinary weight. On the whole, therefore, increased density may be con- sidered as a disadvantage, although, for some purposes, dense bricks are very valuable.

36. !Mr. Prosser, of Birmingham, has introduced a method of making bricks, tiles, and other articles by machinery, in which no drying is requisite, the clay being used in the state of a nearly dry powder. The clay from which floor-tiles and tesserae are made is first dried upon a slip-kiln,* as if for making pottery, then ground to a fine powder, and in that state subjected to heavy pressure t in strong metal moulds : by this means the clay is reduced to one-third of its original thickness, and retains sufficient moisture to give it cohesion. The articles thus made can be handled at once, and carried direct to the kiln. In some experiments tried for ascer- taining the resistance of bricks and tiles thus made to

• The sUp-hln is a stone trough bottomed with fire tiles, under which runs a furnace flue. It is used in the manufacture of potteiy for evapo- rating the excess of water in the slip, or liquid mixture of clay and ground flints, which is thus brought into the state of paste.

t It is a common but an erroneous notion, that articles made bv Mr. Prosser 's process are denser than similar articles made in the common wav : the reverse is the fact.

ART OF MAKING BRICKS AND TILES. 38

a crushing force, a 9-inch brick sustained a pressure of 90 tons without injury.

37. Mr, Prosser's method offers great advantages for the making of ornamental bricks for cornices, bas- reliefs, floor-tiles, tesselated pavements, &c. Screw presses are used to a considerable extent for pressing bricks when partially dry, to improve their shape and to give them a smooth face ; but we have in many in- stances found pressed bricks to scale on exposure to frost, and much prefer dressing the raw brick with a beater, as described in chap. iii. art. 34.

38. The great practical difficulty in making moulded bricks for ornamental work is the warping and twisting to which all clay ware is subject more or less in the process of burning. This difficulty is especially felt in making large articles, as wall copings, &c. In moulding goods of this kind it is usual to make perforations through the mass, to admit air to the inside, without which precaution it would be impossible to dry them thoroughly ; for, although the outside would become hard, the inside would remain moist, and, on being subjected to the heat of the kiln, the steam would crack and burst the whole.

The Brighton Viaduct, on the Lewes and Hastings Railway, has a massive white brick * dentil cornice, the bricks for which were made in Suffolk after several unsuccessful attempts to make bricks of still larger size. The thickness of the bricks first proposed presenting an insurmountable obstacle to their being properly dried, their dimensions were reduced, and large perforations were made in each brick to reduce its weight, and to enable it to be more thoroughly and uniformly dried ;

* Brick was preferred to stone on account of the expense of the lattei material.

c 3

31 RUDIMENTS OF mP.

and by adopting this plan the design was successfully carried into execution.

39. The usual form of a brick is a parallelopipedon, about 9 in. long, 4i in. broad, and 3 in. thick, the exact size varying with the contraction of the clay. The thickness need not bear any definite proportion to the length and breadth, but these last dimensions require nice adjustment, as the length should exceed twice the breadth by the thickness of a mortar joint.

40. Bricks are made of a variety of shapes for par- ticular purposes, as enumerated in art. 60, chap. iii. The manufacture of these articles is principally carried on in the country, the brickfields in the vicinity of the metro- polis supplying nothing but the common building brick.

41. A point of some little importance may be here ^>dverted, to, viz., is any advantage gained by forming a hollow in the bed of the brick to form a key for the mortar ? There are various opinions on this point ; but we think it may be laid down as a principle, that if it is useful on one side it will be still better on both, so as to form a double key for the mortar. In London, the brick mould is placed on a stock board, which is made to fit the bottom of the mould ; and the relative positions of the two being kept the same, no diihculty exists in forming a hollow on the bottom of the brick, this being effected by a kick fastened on the stock board. But this could not be done on the i/pper side, Mhich is stricken level. In slop moulding, the mould is simply laid on the moulding stool, or on a moulding board much larger than the mould, and both sides of the brick are flush witli the edges of the mould, no hollow being left, unless the moulder think fit to make one by scoring the brick with his fingers, which is sometimes done. When machii\ery is used in moulding, it is equally easy

ART OF MAKING BRICKS AND TILES.

35

to stamp the top aud the bottom of the brick ; and we have seeiij at the Butterly Ironworks, in Derbyshire, excellent machine-made bricks of this kind made in the neighbourhood.

42. Amongst the many inventions connected with brickmaking which have been from time to time brought before the public, ventilating bricks deserve attention, from the facilities they afford for warming and venti- lating buildings.

The annexed figures show the form of the bricks and the way in which they are used.

Fig- 1- Fig. 2.

Fig. 1 is a representation of a 9-in. wall, built witn the ventilating bricks, with one common brick used at the angle of each com'se.

Fig. 2 is a representation of a 14-in. wall; the half ventilating brick, being used alternately in the courses, forms a perfect and effectual boud.

Fig. 3 is an isometrical drawing showing the venti- lating spaces.

DRYING.

43. The operation of drying the green bricks requires great care aud attention, as much depends upon the

36 RUUlMEXrS OF TUB

P manner in -which thcv are got into the kiln. The great I point to be aimed at is to protect them against sun, 1 wind, rain, and frost, and to allow each brick to dry J uniformly from the face to the heart.

Slop-moulded bricks are usually dried on flats or drying floors, where they remain from one day to five or six, according to the state of the weather. "When spread out on the floor they are sprinkled with sand, which absorbs superfluous moisture, and renders them less liable to be cracked by the sun's rays. After remaining on the floors until suflSciently hard to handle without injury, they are built up into hacks under cover, where they remain from one to three weeks, until ready for the kiln. In wet weather they are spread out on the floor of the drying shed, and great care must then be taken to avoid drafts, which would cause the bricks to dry faster on one side than the other. To prevent this, boards set edgeways are placed all round the shed to check the currents of air.

The quantity of ground required for drying bricks in this manner is comparatively small, as they remain on the floors but a short time, and occupy little space when hacked in the hovels. The produce of a single moulding stool by the slop-moulding process seldom exceeds 10,000 per week, and the area occupied by each stool is, therefore, small in proportion. Half an acre for each kihi may be considered ample allowance for the working floor and hovel.

44. In places where brickmaking is conducted on a large scale, drying sheds are dispensed with, and the hacks are usually built in the open air, and protected from wet, frost, and excessive heat, by straw, reeds, matting, canvas screens, or tarpaulins ; all of which we have seen used in difierent places.

'C^

ART OF MAKING BRICKS AND TILES. 37

45. Bricks intended to be clamp burnt are not dried on flats, but are hacked at once on leaving the moulding stoolj and remain in the hacks much longer than bricks intended to be kilned. This is rendered necessary by the diff'erence between clamping and kilning. In the latter mode of burning, the heat can be regulated to great nicety, and if the green bricks, Avhen first placed in the kiln, be not thoroughly dried, a gentle heat is applied until this is effected. In clamping, however, the full heat is attained almost immediately, and, therefore, the bricks must be thoroughly dried, or they would fly to pieces. In the neighbourhood of London a good moulder, Avith his assistants, will turn out from 30,000 to 40,000 bricks per week, and the clamps contain from 60,000 to 120,000 bricks and upwards.

From these combined causes, the area occupied by each stool is greater than in making slop-moulded bricks. In Mr. Bennett^s brick-ground at Cowley, ten stools occupy twenty acres.

46. At the risk of wearying the patience of the reader, we recapitulate the leading points on which depends the difference of area required for each mould- ing stool in making : —

Slop-moulded brick?, Lacked under London pallet-moulded sand stocks, cover, and burnt in kilns. burnt in clamps.

Dried one day on flats ... 1st Hacked at once.

^, , » / J • u 1 ifv f Bricks loosely stacked in hacks.

Closely stacked m hacks 17 g ^^^^^^^ ^j j^ ^^^^ 2 l^,;,^^

courses high, placed close 2nd ^^ ^.^^ - fj_ ^ be- together under cover . . .) [ tween the hacks.

Remain in shed 10 to 16 days 3rd Remain in hacks 3 to 6 weeks.

Rate of production per stool, 1 ... f A gang will turn out 30,000 to

about 10,000 weekly . . .J \ 40,000 per week.

Kiln holds about 30,000 bricks, I [ Clamp contains 60,000 to

and may be fired once in 10 I 5th -^ 120,000 bricks, and bums

days J [ from 2 to 6 weeks.

47. It is scarcely necessary to observe that different

3S RUDIMENTS OF THE

clays require different treatment, according to their composition, some bricks bearing exposure to sun and rain without injury, whilst others require to be carefully covered up to keep them from cracking under similar circumstances. [See Appendix.] /* Superior qualities of bricks are generally dressed vriih a beater when half dry, to correct any twisting or \ warping which may have taken place during the first stage of drying.

BURNING.

48. Bricks are burnt in clamps and in kilns. The latter is the common method, the former being only employed in burning bricks made with ashes or coal- dust. It should be observed, however, that the name of clamp is applied also to a pile of bricks arranged for burning in the ordinary way, and covered with a temporary casing of burnt brick to retain the heat ; but this must not be confounded with close-clamping as practised in the neighbourhood of London.

49. The peculiarity of clamp burning is that each brick contains in itself the fuel necessary for its vitrifi- cation ; the breeze or cinders serving only to ignite the lower tiers of bricks, from which the heat gradually spreads over the whole of the clamp. No spaces are left between the bricks, which are closely stacked, that the heat to which they are exposed may be as uniform as possible. It is unnecessary here to go into the details of clamping, as they are very fully given in the account of London Brickmaking. [See also Ap- pendix.]

50. A kiln is a chamber in which the green briclca are loosely stacked, with spaces between them for the passage of the heat j and baked by fires placed either

ART OF MAKING BRICKS AND TILES. 39

m arched furnaces under the floor of the kiln^ or in fire holes formed in the side walls.

There are many ways of constructing kilns^ and scarcely any two are exactly alike ; but they may be divided into three classes : —

1st. The common rectangular kiln with fire-holes in the side walls. This is formed by building four walls enclosing a rectangular space, with a narrow doorway at each end, and narrow-arched openings in the side walls exactly opposite to each other. The bricks are introduced through the doorways, and loosely stacked with considerable art, the courses being crossed in a curious manner, so as to leave continuous openings from top to bottom of the pile to distribute the heat. In the lower part of the kiln narrow flues are left, about 8 in. wide and about 2 ft. or 3 ft. high, connecting the fire-holes in the side walls. The kilns having been filled, the doorways are bricked up and plastered with clay to prevent the ingress of cold air ; the top of the kiln is covered with old bricks, earth, or boards, to retain the heat, and the firing is carried on by burning coal in the fire-holes. A low shed is generally erected on each side of the kiln to protect the fuel and fireman from the weather, and to prevent the wind from urging the fires. The details of the management of a kiln are given in another place, and need not be here repeated. This kind of kiln is he simplest that can well be adopted, and is in use in Holland at the present day. It is the kiln in common use through the Midland districts.

2nd. The rectangular kiln with arched furnaces. This consists also of a rectangular chamber ; but difiers from the first in having two arched furnaces running under the floor the whole length of the kiln, the furnace

40 RUDIMENTS OF THE

doors being at one end. The floor of the kihi is formed like lattice-work, with numerous openings from the furnaces below, through which the heat ascends. The top of the kiln is covered by a moveable wooden roof, to retain the heat, and to protect the burning bricks from wind and rain. These kilns are used in the east of England.

3rd. The circular kiln or cupola. This is domed over at the top, whence its name is derived. The fire-holes are merely openings left in the thickness of the wall, and are protected from the wind by a wall built round tlic kiln at a sufficient distance to allow the fireman room to tend the fires. These cupolas are used in Staf- fordshire and the neighbourhood, and the heat employed in them is very great. Drawings of a cupola are given in chap, iv., with an account of the manner in which the firing is conducted, and therefore it is unnecessary to enter here upon any of these details.

51. The usual method of placing bricks in the kiln is to cross them, leaving spaces for the passage of the heat, but there are objections to this, as many bricks show a difl'erent colour, where they have been most exposed to the heat. Thus in many parts of the country, the bricks exhibit a diagonal stripe of a lighter tint than the body of the brick, which shows the portion that has been most exposed. In burning bricks that require to be of even colour, this is guarded against by placing them exactly on each other.

On first lighting a kiln the heat is got up gently, that the moisture in the bricks maybe gradually evaporated.

AVhen the bricks are thoroughly dried, which is known by the steam ceasing to rise, the fires are made fiercer, and the top of the kiln is covered up with boards, turf, old bricks, or soil, to retain the heat. As

ART OF MAKING BRICKS AND TILES, 41

the heat increases^ the mouths of the kiln are stopped to check the drafts and when the burning is completed, they are plastered over to exclude the air, and the fires are allowed to go out. After this the kiln is, or should be, allowed to cool very gradually, as the soundness of the bricks is much injm'ed by opening the kiln too soon.

Pit coal is the fuel commonly used^ and the quantity required is about half a ton per 1,000 bricks ; but much depends on the qiiality of the coal, the construction of the kiln, and the skill with which the bricks are stacked.

Wood is sometimes used as fuel in the preliminary stage of firing, but not to a gi'eat extent. In a letter received on the management of the Sufiblk kilns, the writer says, " The usual mode of firing bricks in Sufi'olk is in a kiln. The one near me, belonging to a friend of mine, is constructed to hold 40,000 ; it is about 20 ft. long and 15 ft. broad, and is built upon two arched furnaces that run through with openings to admit the heat up. The bricks are placed in the usual way for burning, by crossing so as to admit the heat equally through, when the whole mass becomes red hot : the first three or four days, wood is burnt in what is called the process of annealing ; with this they do not keep up a fierce fire. After this from 12 to 14 tons of coal are consumed in finishing the burning. Private individuals sometimes make and clamp 20,000 or 30,000 without a kiln ; then there is great waste, and the bricks are not so well burnt.

52. In the preceding pages we have briefly sketched the operations of brickmaking, and the principles on which they depend. In the following chapters the reader will find these operations described in detail, as practised in different parts of the country; it need

42 RUDIMENTS OF THE

hardly be said that the illustrations might be greatly extended, as there are scarcely two counties in England in which the processes are exactly similar, but this would lead us far beyond the limits of a Rudimentary Treatise, and enough is given to show the student the interest of the subject, and to enable him to think and examine for himself. If he be induced to do this from the perusal of these pages, the aim of this little volume will have been completely fulfilled.

n. TILES.

53. The manufacture of tiles is very similar to that of bricks, the principal differences arising from the thin- ness of the ware, which requires the clay to be purer and stronger, and renders it necessary to conduct the whole of the processes more carefully than in making bricks.

54. Tiles are of three classes, viz., paving tiles, roof- ing tiles, and drain tiles.

Paving tiles may be considered simply as thin bricks, and require no especial notice.

Roofing tiles are of tsvo kinds : pantiles, which are of a curved shape, and plaintiles, which are flat, the latter being often made of ornamental shapes so as to form elegant patterns when laid on a roof.

Pantiles are moulded flat, and afterwards bent into their required form on a mould. Plain tiles were formerly made with holes in them for the reception of the tile-pins, by which they were hung on the laths ; but the common method is now to turn down a couple of nibs at the head of the tile, which answer the same purpose.

Besides pantiles and plaintiles, hip, ridge, and

ART OF MAKING BRICKS AND TILES. 43

valley tiles, come under the denomination of roofing tiles ; these are moulded flat, and afterwards bent on a mould, as in making pantiles.

Draining tiles belong to the coarsest class of earthen- ware. They are of various shapes, and are made in various ways. Some are moulded flat, and afterwards bent round a wooden core to the proper shape. Others are made at once of a curved form, by forcing the clay through a mould by mechanical means. Tile-making machines are now almost universally superseding manual labour in this manufacture, and many machines of various degrees of merit have been patented during the last few years.

55. Besides the above articles, the business of a tilery includes the manufacture of tiles for malting floors, chimney-pots, tubular drains, and other articles of pottery requiring the lathe for their formation. We do not, however, propose now to enter upon the potter's art, which, indeed, would require an entire volume, but shall confine ourselves to the description of the manu- facture of roofing tiles as made in Staflbrdshire, and at the London tileries, adding a few words on the making of tesserae and ornamental tiles as practised by Messrs. Minton, of Stoke-upon-Trent.

56. In the country it is common to burn bricks* and tiles together, and as, in most places, the demand for bricks is not great, except in the immediate vicinity of large towns, -where the demand is more constant, the manufacturer generally only makes so many bricks as are required to fill up the kiln.

Where tliere is a great and constant demand for bricks and tiles, their manufacture is carried on sepa-

* In some places bricks and lime are burnt together.

4i RUUIMENTS OF THE

rately, and tiles are burnt in a large conical building, called a dome, which encloses a kiln -with arched fur- naces. There are many of these in the neighbourhood of London, and, as we have described them very fully in the chapter on London Tileries, we need say nothing further here on this subject.

57. The manufactui-e of draining tiles is one which daily assumes greater importance on account of the attention bestowed on agriculture, and the growing appreciation of the importance of thorough drainage. Any discussion on the best forms of draining tiles, ot the most advantageous methods of using them, would, however, be out of place in this volume. Neither need we say much on the practical details of the manufacture, as it is exceedingly simple, and as regards the prepara- tion of the clay, and the processes of drying and burning, is precisely similar to the other branches of tile-making. With regard to the process of moulding, there is little doubt but that hand moulding will soon be entirely superseded by machinery ; and the discussion of the merits of the numerous excellent tile-making machines now offered to the public, although of great interest to those engaged in the manufacture, would be unsuitcd to the pages of a rudimentary work, even were it practi- cable to give the engravings which would be necessary to enable the reader to understand their comparative advantages or defects.* A few words on the principal features of the manufacture of drain tiles are, however, required to enable the reader to appreciate its peculiar character.

58. Bricks, paving tiles, and roofing tiles, are little required, and seldom manufactured, except in the neigh-

• A few details will be found in the chapter on Brickmaking by Machinery.

ART OF MAKING BRICKS AND TILES. 45

bourhood of towns or of large villages^ where the demand is likely to be sufficiently constant to warrant the erection of kilns, drying sheds, and other appurtenances of a well-mounted brickwork. If a cottage is to be rebuilt, a barn tiled, or it may be once in twenty or thirty years a new farmsteading erected in a rural dis- trict, it is generally cheaper to incur the expense of carting a few thousand bricks or tiles than to erect the plant necessary for making these articles on the spot.

But with drain tiles the case is reversed. They are most wanted precisely in situations where a brick-yard would be an unprofitable speculation, viz., in the open country, and often in places where the cost of carriage from the nearest brick-yard would virtually amount to a prohibition in their use, if they cannot be made on the spot, and that at a cheap rate. What is wanted, therefore, is a good and cheap method of making drain tiles without much plant, and without erecting an expen- sive kiln, as the works will not be required after sufficient tiles have been made to supply the immediate neighbour- hood, and therefore it would not be worth while to incur the expense of permanent erections. The making drain tiles a home manufacture is, therefore, a subject which has much engaged the attention of agriculturists during the last few years, and it gives us great pleasure to be enabled to give engravings of a very simple and effective tile-kiln erected by Mr. Law Hodges, in his brick-yard, and described in the Journal of the Royal Agricultural Society, vol. v., part 2, from which publi- cation we have extracted so much as relates to the, description of this kiln, and the cost of making drain tiles in the manner recommended by him. [See Ap- pendix.]

59. We have ali'cady extended this sketch of the

46 RUDIMENTS OF THE

general principles and practice of brick and tile making beyond its proper limits^ and must therefore pass on to the practical illustrations of our subject.

The chapter '' On the Manufacture of Bricks and Tiles in Holland" is reprinted from the third volume of Weale's " Quarterly Papers on Engineering/' and will be read with interest on account of the great similarity of the English and Dutch processes.

The account of brickmaking, as practised at Not- tingham and the Midland counties, was written from personal examination of brickworks in the vicinity of Nottingham, and in the counties of Derby, Leicester, and Lincoln, and has been carefully revised by a gen- tleman long connected with one of the principal brick- works near Nottingham.

The paper " Ou Brickmaking, as practised in the Staffordshire Potteries/'^ was contributed to this volume by ;Mr. R. Prosser, of Birmingham, whose name is a sufficient guarantee for the value of the information therein contained. The details for this paper were col- lected by Mr. Prossei-'s assistant, Mr. John Turley, of Stoke ; and the valuable analyses of brick-earths were made for Mr. Prosser by ^Mr. F. C. Wrightson, of Birmingham, at a considerable expense.

The description of brickmaking in the vicinity of London has been drawn up with great care, and is the first illustrated accoimt that has yet appeared of the manufacture of clamp bricks. The drawings accom- panying this paper, and that on the London Tileries, arc from the pencil of ^Mr. B. P. Stockman.

Professional engagements preventing a personal exa- mination of the processes employed in brick and tile- making in the vicinity of the metropolis, !Mr. Stockman kindly undertook this task, and to his persevering

ART OF MAKING BRICKS AND TILES. 47

energy and talent we are indebted for a great mass of practical details embodied in these two chapters.

Lastly, in the Appendix are inserted various par- ticulars relative to brickmaking which could not have been introduced in any other part of the volume with- out interrupting the continuity of the text.

It should be noted that the various prices and esti- mates given in the following pages, refer to the time at which the descriptions were given. They are^ of course; subject to later modifications.

CHAPTER II.

ON THE MANUTACTUKE OF BRICKS AND TILES IN HOLLAND. By Hyde Clakke, C.E.

L — BRICKS. The Dutch make a most extensive use of bricks, of which they have several kinds. Not only are bricks used for ordinary building purposes, and for furnaces, but also in great quantities for foot pavements, towing- paths, streets, and high roads. It may be observed, that they have of late been used very effectively in this country for the pavement of railway stations. The paving bricks, or Dutch clinkers, are the hardest sort, and are principally manufactured at Moor, a smal vil- lage about two miles from Gouda, in South Holland. The brick-fields are on the banks of the river Yssel, from which the chief material is derived, being no other than the slime deposited by the river on its shores, and at the bottom. The slime of the Haarlem Meer is also extensively used for this purpose, as most travellers know. This is collected in boats, by men, with long

48 BUDIMEXTS OF THE

poles having a cutting circle of iron at the end, and a bag-net, with which they lug up the slime. The sand is also obtained by boatmen from the banks of the river Maes. It is of a fine texture, and grayish colour. The hard bricks are made with a mixture of this slime and sand, but in what proportions I am not informed. River sand is recognised as one of the best materials for bricks, and is used by the London brickmakers, who obtain it from the bottom of the Thames, near "Wool- wich, where it is raised into boats used for the purpose. For what are called in France, Flemish bricks, and which are manufactured in France, Flanders, and on the corresponding Belgian frontier, river sand is pre- ferred, and is obliged to be obtained from the Scheldt. At Ghent, and lower down, a considerable traffic is carried on in the supply of this material. The quantity used there is about one cubic foot of sand per cubic yard.

The slime and sand, being mixed, are well kneaded together with the feet, and particular attention is paid to this part of the process. The mixture is then depo- sited in heaps. The mode of moulding and drying is similar to that used elsewhere. Paving bricks are generally about 6 in. long, 4 in. broad, and If in. thick. Dutch clinks made in England are 6 in. long, 3 in. broad, and 1 in. thick.

The house bricks and the tiles are made for the most part at Utrecht, in the province of the same name, from brick earth found in the neighbourhood. House bricks are about 9^ in. long, 4^ in. wide, and nearly 2 in. thick.

IL — ERICK-KILyS.

The kilns are built of different sizes, but generally on the same plan. Sometimes they will take as many

ART OF MAKING BRICKS AND TILES. 49

as 1,200,000 bricks. A kiln for burning 400,000 bricks at once is represented in the " Memoirs of the Academy of Sciences of France/^ It is a square of about 33 ft. or 35 ft. long by 28 ft. or 30 ft. wide, closed in with four walls of brick, 6 ft. thick at the base, and which slope upwards outside to their extreme height, which is about 18 ft. Some slope also slightly inwards, but in a dif- ferent direction. DiflFerent plans are nevertheless adopted with regard to the form of the external Avails, the great object being, however, to concentrate the heat as much as possible. In the walls, holes are left for six flue-holes, and sometimes for eight or ten or twelve. In one of the walls, in the breadth of the kiln, an arched doorway is made, about 6 ft. wide and 12 ft. high, by which the bricks are brought into the kiln. The arrangements as to the doorway are also subject to variation. The interior of the kiln is paved with the bricks, so as to present a level base. The walls are laid with mortar of the same earth from which the bricks arc made, and with which they are also plastered in- side ; yet, notwithstanding the strength with Avliich they are built, the great power of the kiln fire sometimes cracks them. The kilns, I would observe, are not usually covered in, but some of those for baking building-bricks have roofs made of planks, and without tiles, to shelter them from the wind and rain. Others are provided with rush mats, which are changed according to the side on which the wind bloAvs. The matting also serves for protecting the bricks against the rain, Avhilst the kiln is being built up. A shed, or hangar, is put up on each side of the kiln, in order to contain the peat turf, or to shelter the fire-tender, and to preserve the fires against the cfi'ccts of wind. Such being the practice with regard to roofing, when the bricks are put into the

D

50 RUDIMENTS OF THE

kiloj a layer, or sometimes two layers, of burnt bricks is placed on the floor, laid lengthwise, about three- quarters of an inch from each other, and so as to slope a little from the parallel of the walls, that they may the better support the upper rows, which arc always laid parallel to the walls. This layer is covered with old rush mats, on which are arranged the dried bricks, which are laid without intervals between them. It is said that the mats serve to prevent the humidity of the soil from penetrating to the bricks while the kiln is beiug filled, which generally takes from about three weeks to a month. This row of burnt bricks is so placed as to leave channels or flues of communication with corresponding openings in the kiln walls. Six layers of dried bricks having been put down, the next three rows are made to jut over, so as to shut up the channels or flues. The layers are thus carried up to about forty-five in number, the last two being of burnt bricks, though in some kilns four layers of burnt bricks are used for closing in. The crevices are secured with brick earth or clay, on which sand is put ; the door of the kiln is then closed with one or two thicknesses of burnt brick, then an interval of about 10 in. or 12 in. filled in with sand, and this secured with walling, and by a wooden strut. The object of the sand is to prevent any of the heat from escaping through the crevices.

It is to be remarked that, in laying the bricks in the kiln, as they are laid down, a cloth is put over them and under the feet of the workmen, so as to prevent any of the sand which might fall oft', from getting down and blocking up the interval or interstice which natu- rally remains between each brick, and so interrupting the passage of the flame, and causing an unequal heat or combustion in the kiln.

The kiln being filled, a sufficient quantity of peat turf

ART OF MAKING BRICKS AND TILES. 51

is introduced into the flues, of wliicli one end is closed up with burnt bricks, and the turf is set fire to. The turf used is from Friesland, which is reckoned better than Holland turf, being lighter, less compact, and less earthy, composed of thicker roots and plants, burning quicker and with plenty of flame, and leaving no ash. The general time in Holland during which the supply of turf by the flues is kept up, is for about four-and- twenty hours, taking care at first to obtain a gradual heat, and supplying fresh turf about every two hours. The fireman, by practice, throws the turfs in through the small fire openings, and as far in as he judges necessary. TMien one side has thus been heated, the flue openings are closed, and the other ends opened for four-and-twenty hours, and supplied with fuel; and this alternate process is kept up for about three or four weeks, the time necessary to burn large bricks. In some kilns, however, the fire is kept up for five or six weeks, depending upon their size and the state of the weather. A fortnight or three weeks is, however, sometimes enough for the clinkers.

The burning having been concluded, about three weeks arc allowed for cooling. It generally happens that the mass of brick sinks in in some places, arising partly from the diminution of volume produced by burning, and partly from the melting of some of the bricks which have been exposed to too great heat.

The quolity of the bricks depends upon the degree of bm-ning to which they have been subjected. Those from about a third from the middle of the top of the kiln, or near the centre, are black, very sonorous, com- pact and well shaped, breaking with a vitrified fracture. These are generally employed for cellars, rescrvc;rs, and cisterns, and are most esteemed.

D 2

52 RUDIMLMS OF THE

III. — TILES.

The tiles manufactured in Holland are flat, hollow, S shaped, or \nth a square opening in the middle to let in a pane of glass, being much used for lighting lofts and garrets all over the Low Countries. They are cither red, grey, or blue, or glazed on one side only. The flat paving tiles are about 8^ in. square by 1 iu. thick; they are used principally for cisterns and for bakers' ovens. The clay for tiles, it is to be noted, is in all cases more carefully prepared than that for bricks, being groimd up wet in a pugmill or tub, with a shaft carrying half a dozen blades. By this means, roots, grass, kc, are got rid of. The clay comes out of the pugmill of the consistence of potters' clay, and is kept under a shed, where it is kneaded by women, with their hands, to the rough form of a tile, on a table dusted with sand. These pieces are carried off to the moulders, who are two in number, a rough moulder and a finisher. The tiles are then dried under sheds, and afterwards in the Sim. "With regard to the flat paving tiles, they are at first rough-moulded about an inch larger than the subsequent size, and a little thicker, and then laid out to dry under a shed, until such time as the thumb can hardly make an impression on them. They are then taken to a finishing-mouklcr, who, on a table quite level and slightly dusted with sand, lays one of the tiles, and strikes it twice or thrice with a rammer of wood larger than the tile, so as to compress it. He then takes a mould of wood, strengthened with iron and with iron cutting edges, and puts it on the tile which he cuts to the size. The mould is of course wetted each time it is used. The tiles are then regularly dried. In Switzer- and and Alsace an iron mould is used.

ART OF MAKING BRICKS AND TILES.

IV.— TILE-KILNS.

The tile-kiln is generally within a building, and about 16 ft. long (in ordinary dimension), 10 ft. wide, and 10 ft. high. The walls are from 4| ft. to 5 ft. thick, secured outside with great beams, and so secured to- gether as to form a square frame. Some of the largest of them are pierced with four flue-holes, as in brick- kilns ; but the flues are formed by a series of brick arches, about 2| ft. wide by 16 in. high. The opening of the flue-hole is about 10 in. by 8 or 9 in. high. On their upper surface, these series of arches form a kind of grating, on which the tiles are laid. The kiln is covered in at top with a brick arch, pierced with holes of difl'erent sizes. The kilns are charged from an open- ing which is constructed in one of the side walls, which opening is, of course, during the burning, blocked up and well secured. The fuel used is turf, as in the brick- kilns, and the fire is kept up for forty hours together, which is considered enough for the burning. Three days are then allowed for cooling, and they are after- wards taken out of the kiln . Those tiles which arc to be made of a greyish colour are thus treated. It having been ascertained that the tiles are burnt enough, and while still red hot, a quantity of small fagots of green alder with the leaves on is introduced into each flue. The flue-holes arc then well secured, and the holes in the roof each stopped with a paving tile, and the whole surface is covered with 4 in. or 5 in. of sand, on which a quantity of water is thi'OAvn, to prevent the smoke from escaping anywhere. It is this smoke which gives the grey colour to the tiles, both internally and externally. The kiln is then left closed for a week, when the sand is taken off the top, the door and roof-holes

51 RUDIMENTS OF TDE

are opened^ as also the flue-holes^ aud the charcoal produced by the fagots taken out. Forty-eight hours after^ the kiln is cool enough to allow of the tiles being taken out, and the kiln charged again. AVhenever any of the tiles are to be glazed, they are varnished after they are baked ; the glaze being put on, the tiles are put in a potter's oven till the composition begins to run. The glaze is generally made from what are called lead ashes, being lead melted and stirred with a ladle till it is reduced to ashes or dross, which is then sifted, and the refuse ground on a stone and resifted. This is mixed with pounded calcined flints. A glaze of manganese is also sometimes employed, which gives a smoke-brown colour. Iron filings produce black ; copper slag, gi'een ; smalt, blue. The tile being wetted, the composition is laid on from a sieve.

The manufacture of tiles, as already observed, is principally carried on near Utrecht, in the province of Holland, which, like most of the great cities of Hol- land, has facilities for the transportation of its produce by water communication all over the country.

Gouda is a great seat of the pottery and tobacco-pipe manufactures, of which formerly Holland had a virtual monopoly, with regard to foreign trade, exporting largely Delft ware, Dutch porcelain, tobacco-pipes, bricks, Flanders' bricks, painted tiles, and paving tiles. The manufacture of painted tiles, for the decoration of the old fireplaces, was very extensive; and an infinite variety of designs, principally on Scripture subjects, employed many humble artists. This, however, is almost of the past. The manufacture of tobacco-pipes was another great business, suitable to the consumption of tobacco by the Netherlandcrs. Gouda alone had, at one time, as many as 300 establishments for the pro-

ART OF MAKING BRICKS AND TILES. 55

duction of this article of trade. The manufacture of tobacco-pipes is still a large manufacture in England, much more considerable than is generally supposed ; while manufactures of bricks and porcelain constitute a staple means of employment for many thousands of our population

A great part of these descriptions, it -will be seen, strictly apply to our own practice, and are trite enough and trivial enough ; but in matters of this kind, there is nothing lost by being too minute, and it is always safe. In the present case, it is worth knowing these things, for the sake of knowing that there is no difference.

CHAPTER III

BEICKMAKING AS PRACTISED AT NOTTINGHAM.

1. The mode of making bricks at Nottingham and the neighbourhood presents several peculiarities, of which the principal are : —

1st. The use of rollers for crushing the brick-earth.

2nd. The use of copper moulds.

3rd. The hacking of the bricks under cover.

2. The use of copper moulds is not confined to the immediate neighbourhood of Nottingham, but has been for some years gradually extending to other districts, and will probably, sooner or later, become general throughout the country for the manufacture of superior qualities of bricks.

3. It may be proper here to say a few words on the object of grinding the clay, so generally practised throughout Staffordshire, Derbyshire, Nottinghamshire, and Lincolnshire, and probably in many other places.

Ob RUDIMENTS OF THE

1)1 mauy brickworks the earth used is not pure clay, but a very hard marl, which cannot be brought into a state of plasticity by the ordinary processes of weather- ing and tempering without bestowing upon it more time and labour than would be repaid by the value of the manufactured article. The expedient of grinding is, therefore, resorted to, which reduces the earth to any state of fineness required, according to the number of sets of rollers used, and the gauge to which they are worked, all hard lumps and pieces of limestone,* which would otheinvise have to be picked out by hand, being crushed to powder, so as to be comparatively harmless. 4. The advantages and disadvantages of the use of rollers may be thus briefly stated, —

1st. A great deal of valuable material is used which could not be made available for brickmaking by the ordinary processes. 2nd. The process of grinding, if properly con- ducted, greatly assists the operations of the temperer by bringing the earth into a fine state, quite free from hard lumps. On the other hand :

The facilities afforded by the use of rollers for working up everythiny that is not too hard to be crushed by them, induce many brickmakers to make bricks without proper regard to the nature of the material. A common practice is to work the rollers to a wide gauge, so that comparatively large pieces of limestone are suff'ered to pass through without being crushed by them. Where this has been the case, it need hardly be said that the bricks are worthless. They may appear soimd, and

* It may be necessary to explain, that all pebbles and hard stones must be picked out by hand before grinding ; where the brick earth used is much mixed with gravel, the only resource is the use of the waeh-milL

ART OF MAKING BRICKS AND TILES. 57

may have a tolerable face, but rain and frost soon destroy them, and, in situations where they are exposed to the weather, they will become completely perished in a very few years.

5. The following description of the mode of making bricks at Nottingham will apply pretty faithfully to the practice of the brick-yards for many miles round. It will, of course, be understood that in no two yards is the manufacture carried on in exactly the same way ; there being diflFerences in the designs of the kilns, the arrangement of the buildings, and other points of detail, which may be regulated by local circumstances, or which, from the absence of any guiding principle, may be left to chance ; the general features, however, are the same in all cases.

6. Brick-earth. — The brickmakers of Nottingham and its immediate vicinity derive their supplies of brick- earth from the strata of red marl overlying the red sandstone on which the town is built, and which in its turn rests on the coal-measures, which make their appearance at a short distance to the west of the town.

The banks of the river Trent present many good sections of these strata, as at the junction of the rivers Trent and Soar ; where they are pierced by the Red Hill tunnel, on the line of the Midland Railway ; and at Radcliff-on-Trent, where they form picturesque cliffs of a red colour covered with hanging wood j and they are exposed to view in many places in the immediate vicinity of Nottingham, as in the cutting for the old road over Ruddington Hill, in the Colwick cutting of the Nottingham and Lincoln Railway, and Goose Wong Road, leading to Mapperly Plains.

The marl abounds with loose and thin layers of skerry, or impure limestone, and in many places contains veins

D 3

58 UUDIMEXTS OF THE

of gypsum, or, a-5 it is called, plaster stone, which are extensively worked near Newark, aud other places, for the raauufactm*e of plaster of Paris.

The water from the wells dug iu these strata is strongly impregnated with lime.

7. The colour of the bricks made at Nottingham and in the neighbourhood is very various. For making red bricks the clay is selected with care, and particular beds only are used. For common bricks the earth is taken as it comes, and the colour is veiy irregular and unsatis- factory, varying from a duU red to a dirty straw colour. Some of the marl burns of a creamy white tint, and has been lately used with much success in making ornamental copings aud other white ware.

8. In the manufacture of common bricks no care is taken in the selection of the clay, and it is worked up as it comes to hand indiscriminately, the great object

'f the manufacturer being to clear his yard ; the same price being paid for all clay used, whatever its quality.

Stones and pebbles are picked out by hand, but the pieces of limestone are generally left to be crushed by the rollers, and much bad materitd is worked up iu this v.ay which could not be made use of if the tempering were effected by treading and spade labour only.

There are, however, many beds which are sufficiently free from limestone not to require grinding, and when these arc worked the rollers are not used.

9. For front bricks, and the superior qualities, the clay is selected with more or less care, receives more preparation previous to grinding, is gi'ound finer, and is sometimes left to mellow in cellars for a considerable time before using.

10. For making rubbers for gauged arches, the clay is carefully picked, aud run through a wash-mill into

ART or MAKING BRICKS AND TILES. 59

pits, where it remains until by evaporation and settle- ment it has attained a proper degree of consistency. The clay for this purpose is generally mixed with a cer- tain quantity of sand to diminish the labour of rubbing the bricks to gauge, the proportion varying according to the quality of the clay. The sand used for this purpose is the common rock sand, which burns of a red colour.

11. The clay immediately near the town of Notting- ham is not well suited for making roofing tiles, the ware produced from it being generally very porous. This statement, however, is not to be taken without exceptions, as there is plenty of suitable clay for the purpose within a few miles' distance.

12. The old houses in Nottingham are built with very thin bricks, much of the old brickwork gauging lOi in. to 4 courses in height, including mortar joints. These bricks are of a dark red colour, and were from works that have been long since abandoned. The bricks now made are much thicker, the walls of many new build- ings gauging 21 in. to 7 courses iu height, or about 13| in. to 4 courses in height, including mortar joints. The common bricks ai'e of a very uneven colour, which arises partly from the manner iu which they are set in the kiln, and partly from the want of care in selecting the clay, and the quantity of limestone ground up with it. From this circumstance the fronts of many of the new buildings have a mottled appearance, which is extremely unsightly.

GENERAL ARRANGEMENT OF A BRICKWORK.

13. The brick-yards from which the town of Not- tingham is at present supplied are situated on the slopes of a small vaDey along which runs the public

CO

RUDIMENTS OF THE

road firom Nottingham to Southwell, aud, being situ- ated on the sides of the hills, great facilities exist for draining the workings and for bringing the ground into cultiration again after the clav has been exhausted.

14. The proprietor of a brickwork usually rents the required land from the owner of the soil, at a price per acre, and in addition to the rent pars for aU clay dug, whatever its quality, at a set price per thousand bricks made and sold, exclusive of those used for the erection and repairs of the buildings and works.

ART OF MAKING BRICKS AND TILES. Gl

15. The arrangement of the several buiklings varies Tvith each yard more or less; but tlie prmciple on which they are laid out is the same in all cases, viz., to advance towards the kiln at each process, so as to avoid all unnecessary labour. This will be understood by inspection of fig. 1, which, it must be understood, is not an exact representation of a particular brickwork, but a diagram to explain the principle of arrangement usually followed. The pits from which the clay is dug are at the rear of the works, and at some little distance from them is placed the clay-mill, which, to save labour in wheeling the clay, is shifted from time to time as the workings recede from the kiln by the exhaustion of the clay. This is, however, not always done, as, where the mill has been fixed in a substantial manner, the saving in labour would not repay the cost of re-erection.

The hovel or drying shed generally forms two sides of a rectangular yard adjoining the public road, the kiln being placed as close to the hovel as practicable, and the working floors or flats in the rear of the latter. By this concentration of plan, the distance to Avliich the bricks have to be carried between the successive processes of moulding, drying, hacking and burning is reduced to a minimum, which is an important point to be attended to, as the raw bricks are shifted by hand and not harrowed.

As it is not always possible to obtain a supply of water at those parts of the works where it is wanted to be used, a water-cart* is kept at some yards for this purpose, the supply being taken from a pond into which the drainage of the works is conducted.

• The water-cart is seldom used, except where the water has to be fetched a considerable distance — indeed rarely, bat in times of drought. It is usually carried, in the yard, in buckets with yokes, as in the time of Pharaoh.

C2 RrDIMEXTS OF THE

The goods for sale arc stacked in the open part of the yard as near the public road as practicable.

16. Clay-Mill. — The machinery used in grinding the clay is very simple. The clay-mill consists of one or more pairs of cast-iron rollers, set very close together in a horizontal position, and driven by a horse who walks in a circular track, and, by means of the beam to which he is attached, puts in motion a horizontal bevelled dri^-ing-wheel placed at the centre of the horse track. A horizontal shaft connected at one end with one of the rollers by a universal joint, and having a bevelled pinion at the other end, communicates the motion of the driving-wheel to the rollers by spur-wheels keyed on their axles. The clay is tipped in a wooden hopper placed over the rollers, and passing slowly between the latter falls on a floor about 8 feet below them, where it is tempered for the moulder.

17. The common clay-mill has only one set of rollers, but the addition of a second set is a great improvement. In this case the bottom rollers arc placed almost in contact with each other, and should be faced in the lathe to make them perfectly true. If only one set be used this is a useless expense, as the gauge to which thev are worked is too wide for anv advantage to be derived from it.

18. Figures 2, 3, 4 represent a one-horse mill with a single pair of rollers 18 in. in diameter, and 30 in. long, manufactured by Messrs. Clayton and Shuttle- worth, of Lincoln, who kindly furnished the drawings from which the engrarings have been made. The detailed description of the several parts will be found iu art C9.

ART OF MAKING BRICKS AND TILES. Fig. 2

63

64

EE,

RrDIMENTS OF THE Fig. 3.

\^.

3

smrr'

I I

i

[

/

y

ART OF MAKING BRICKS AND TILES. 65

Fkj.4..

EkM'^M	\
,;/''	--
--S ^	-
'\^
'>	o~
1	lo-
/	-
.'-'	U (M
p**l	!-

This is a very good mill, of simple construction, and not expensive, the cost when ready for fixing (exclusive of foundations and brickwork) being .€35.

It cannot be too strongly insisted upon that the machinery should be boxed up close, so as to prevent stones or clay from clogging the wheels, as where this

66 RUDIMENTS OF THE

is not done the macliinery will unavoidably become deranged in a very short time.

19. In many yards, the horse-track is raised to the level of the top of the hopper, so that none of the machinery is exposed. A very good arrangement of this kind is shown in fig. o, of which a detailed descrip- tion is given in art. 69.

20. The quantity of work performed will of course vary greatly, accordiug to the distance between the rollers and the consequent fineness to which the clay is ground. One mill will grind sufficient clay to keep six moulders fully employed, and therefore there are very few yards in which the rollers are constantly in work.

21. The length of time during which a clay-mill will last in good working condition is chiefly regulated by the wear of the rollers. If the iron is of very imiform quality, and care be taken to pick out all the pebbles from the clay, a pair of rollers will last many years. The other parts of the machinery will last vriih care for an indefinite length of time.

22. JVash-mUL — The wash-mill is used only in the manufacture of arch bricks, and does not differ from that used in other places. The only one visited by the author consists of a circular trough, lined with brick- work, in which the clay is cut and stirred up with upright knives fastened to a horse-beam. From this trough, the slip runs through a grating into a brick tank, where it remains until by evaporation and settle- ment it becomes sufficiently consolidated for use.

23. The Pug-mill is not used in the Nottingham* brick-yards ; the tempering of the clay, after grinding, being effected by treading and spade labour. Instead of the clay being tempered directly after grinding, it is

* It i^, however, used in the neighbourhood.

ART OF MAKING BUICKS AND TILES.

67

08

RUDIMENTS OF THE

sometimes deposited to ripen iu damp cellars for a year or more. This is done for the best bricks only.

24. The Moulding Sand used is tlie common rock sand, which burns of a red colour. In making white bricks this is a great disadvantage, as it causes red streaks, which greatly injure their colour. The sand is only used to sprinkle upon the table to prevent the clay from adhering thereto, end therefore sand with a sharp grit is preferred.

25. The Moulding Table is shown in fig. G. It is

Fiff. 6.

ART OF MAKING BRICKS AND TILES. 69

furnislied with a sand-box^ wliicli is sometimes fixed to the table, as shown in the cut, and sometimes detached, and with a water-box, in which the moulder dips his hands every time he moulds a brick. In the operation of moulding, the moulder stands in front of the table, with the Avater-box immediately in front of him, the tempered clay at his right hand, and the sand-box at his left. A sloping plank is placed at one end of the table to enable the boy who brings the clay from the temperer to deposit it more conveniently on the table. The boy who takes oflF the newly-made bricks^ and brings back the empty mould, stands on the side of the table opposite the moulder, to the right of the water- box, in which he washes his hands after each journey, to prevent the clay from drying on them.

The cost of a moulding table varies according to the care with which it is made. Such a one as shown in the cut will cost about 20*., and will last, with occasional repairs, for several years. The part where the brick is moulded soon becomes worn, and has to be cased as shown in the cut. This casing extends over the part where the brick is taken off by the carrier boy ; but, as the wear is not uniform over this space, the casing is in two or more pieces, the part where the brick is moulded wearing much faster than the others, and requiring renewal sooner.

It is of importance that the drippings from the table should not fall on the drying floor, as they would render it slippery and unfit for use ; a rim is therefore placed at one end, and along a part of one side of the table, and the opposite side is furnished with a kind of apron and gutter, by means of which the slush is conducted to a tub placed under one corner of the table, but which ia not shown in the cut.

'0

RrDIMENTS OF THE

Fig.l.

26. Brick Moulds. — Until lately the moulds used Avere made of wood, but these have been almost entirely superseded by brass, or, as they are technically called, copper, moulds.

There are several diflferent ways in which these moulds are made. Some- times the brass work is merely an inside lining, screwed to a wooden mould; but the best construction appears to be that shown in fig. 7, in which the mould is of brass, cast in four pieces, and riveted together at the angles, the wood- work being in four distinct pieces and attached to the brass mould by the angle rivets. These moulds are costly, and formerly a pair of moulds cost .€2, but they may now be had for £1 5*. the pair.

It will be seen, by reference to the engraving, that the brass overlaps the woodwork all round the mould on each side, and these portions of the mould wear away very rapidly, so that the bricks made at the close of the season are considerably thinner than those made at its commencement. This renders it necessary to renew the projecting rims from time to time as they become worn down with use, and this will require to be done every season if the mould has been in constant use. It is an expensive operation, as the new rim has to be brazed on to the old part, and this must be done with great nicety, and so as to make a perfectly flush joint on the inside of the mould, or the latter would be rendered useless. The cost of plating a pair of moulds is nearly the same

ART OF MAKING BRICKS AND TILES. 71

as their original cost^ 20^. being charged for the opera- tion^ and therefore it would be preferable to use the moulds until they are quite worn out^ and then to replace them with new ones.

27. The use of copper moulds is confined to the making of building bricks_, and quarries for paving floors^ their weight and great cost preventing their employment for larger articles.

28. The mould has no bottom as in the London practice^ nor is it placed upon a raised moulding board as in Staffordshire ; but rests on the moulding table itself, the top and bottom beds of the brick being formed at two distinct operations with a little instrument called a plane.

29. The Plane, fig. 8^ is usually made 9 in. long by 3 in. broad, //O^^"^ with a handle at one end. Its use is to compress the clay in the mould, and to work over the top and bottom beds of the brick to give them an even surface.

The strike is not used at Nottingham.

30. The Flats, or working floors, are prepared with care, by levelling and rolling, so as to make them hard and even, and are laid out with a slight fall, so that no water may lodge on them. They are well sanded, and constant care is requisite to keep them free from weeds. Their usual width is about 10 yards. In unfavourable weather a single moulder will sometimes have as many as 7,000 bricks on the flats at once, for which an area of from 300 to 400 superficial yards will be required. This, however, is an extreme case, and in good drying weather a moulder does not require more than half that extent of floor, or even less than this.

72 RUDIMENTS OF THE

31. 77ie Hovel f or drying shed, in which the bricks arc hacked, is generally built in the roughest and cheapest manner possible, with open sides and a tiled roof, supported by wooden posts or brick piers; the width of the hovel is about 18 ft., or rather more than the length of a hack, but the eaves are made to project a couple of feet or so beyond this distance, in order to give additional shelter from the rain, for which reason, as well as for the sake of economy, the eaves are carried down so low as to make it necessary to stoop to enter the shed.

Some of the hovels have flues under the floor, the fire-places being placed in a pit sunk at one end of the hovel, and the chimney at the opposite end. These flues are made use of when the demand for bricks is so great that sufficient time cannot be allowed for dry- ing in the open air, and also during inclement seasons. The sides of the hovel are then walled up with loose brickwork to retain the heat. No specific rule can be given for the relative sizes of the hovel and the drying floor. The common practice appears to be to make them of the same length, which allows ample room, and enables the moulder to keep a portion of his shed always available as a drying floor when the weather is too wet to allow of the bricks being laid out on the flats. "When this is the ease the moulder protects the raw bricks from drafts, by surrounding them with a skirting, so to speak, of planks. This is a very neces- sary precaution, for the currents of air from different parts of the shed would cause the bricks to dry un- equally, and they would crack and become unsoimd. Matting is frequently hung up at the sides of the hovel for this purpose, and is also much used in some yards to prevent the finer clays, when tempered, from drying

ART OF MAKING BRICKS AND TILES.

73

too rapidly where cellars are not provided for that purpose.

32. The above description applies to the ordinary hovel, but the best front bricks are dried wholly under cover in a brick hovel inclosed by walls on all sides, and furnished with flues, by which the place is kept at a regular temperature. The expense, however, of conducting the whole of the drying under cover in this manner is too great to allow of its general adop- tion.

33. The claiyper, fig. 9, Fig. 9. is simply a piece of board 12 in. by 6 in. with a handle on one side. It is used to flatten the sur- faces of the bricks as they lie on the floors, and the bricks are also beaten with it during the process of hacking, to correct any warping which may have taken place in the first stage of drying.

34. Dressing Bench. — Fig. 10. Fig. 10. This is simply a stout bench, to which is fitted a plate of cast-iron, on which the best front bricks are rubbed or j^o- lishecl, to make them per- fectly true and even; the workman, at tlie same time, beating them with a wedge-shaped beater, tipped with iron, called a dresser, fig. 11. This operation toughens the brick, corrects any warping which may have taken place, and leaves the arrises very sharp.

£

74 RUDIMENTS OF THE

^'9- 11- 35. Machinery for

pressing Bricks. — In some yards screw presses are used for pressing front bricks, and with considerable success. It is, however, questionable whether they are as durable as those dressed by liana. In making machinery for this purpose the great desiderata are, 1st, to make the metal mould in which the brick is compressed so strong that it shall not spring on the application of the power; and, 2nd, that the piston shall exactly fit the mould : when, from bad workmanship or long use, this is not the case, the clay is forced between the piston and the mould for a short distance, leaving a slightly-raised edge all round the side of the brick.

3G. V\'e do not propose here to enter upon a com- parison of the respective merits of machine-pressed bricks and those dressed by hand. The operation of dressing on the bench requires an experienced work- man, whilst a common labourer can use a machine. For this reason machine-pressed bricks can be pro- duced much cheaper than those dressed by hand, and there is little inducement to employ the latter process.

37. Kiln. — The kilns vaiy considerably as regards their dimensions and constructive details, but they are all built on the same principle.

Tlie kiln shown in figs. 12, 13, 14, 15, 16, and 17, is a good one, though rather weak at the angles, and will convey an idea of the general construction. (See chap, ix.j page 210.1^

AKT OF MAKING BRICKS AND TILES.

75

Fig. 12.

It consists of four npriglit walls, inclosing a rectangu- lar chamber. The floor is sunk about 4 ft. below the general surface of the ground, and is not paved. The doorways for setting and drawing the kiln are merely narrow openings at the ends of the kiln, raised a step above the ground, and about 5 ft. from the floor. The fire-holes are arched openings opposite each other on the sides of the kiln, lined with fire bricks, which require to be renewed from time to time, generally every season. The width of these holes is reduced to the required space .e2

76

RUDIMENTS OF THE

by temporary piers of brickwork, so as to leave a narrow opening about 8 in. wide and about 3 ft. hio-h. This will be understood by reference to fig. 12, in which

Fig. 13.

r^'H"

W

Fig. 14.

- 1' .0 At

-^-^.

:^l^

ART OF MAKING BRICKS AND TILLS.

//

Fig. 15.

Fig. 16.

^3^

Fig. 17.

the dark shading shows the fire-brick lining, and the unshaded parts the temporary piers.

On each side of the kihi a pit is sunk to the level of the floor, and covered with a lean-to roof, which protects the fuel and the fire-man from the weather, and prevents the wind from setting against the fires. The avails of the kiln are about 3 ft. thick, and are built of old bricks, rubble stone, and the refuse of the yard. No mortar is used, as the use of lime would destroy the brickwork,

78 RUDIMENTS OF THE

under the intense heat to which the walls are exposed. The bricks are therefore set in loam or fire-clay, if it can be readily procured. The fire-bricks for lining the fire-holes are sometimes brought from Ilkeston, where excellent fire-clay is worked, but it is most common to make them at the yards with such clay as can be got in the neighbourhood, which answers pretty well. This clay is brought from the neighbouring collieries, and is obtained when sinking shafts ; there is no fire-clay at any of the Nottingham yards.

38. Instead of being built with walls of parallel thickness, resting on arches, as in the example just described, some kilns are built with walls of great thickness at bottom, and diminishing by set-ofis until, near the top of the kiln, they are comparatively thin. Many kilns also are provided with massive buttresses at the angles, with the intention of counteracting the tendency which the walls have to lift themselves with the heat.

Very great care is requisite in drying a newly-built kiln, or the walls will be cracked at the first firing, and the thicker the walls the greater the care necessary.

39. So long as the brickwork is sufficiently thick to retain the heat, no purpose is attained by increasing the strength of the walls, unless they are made so massive that they are unaffected by the heat externally, and heavy enough to counteract the Vijting cause by the expansion of the sides exposed to the fire. In the one case the walls expand bodily with the heat, forming large and dangerous cracks ; in the other, separation takes place between the inside and outside of the walls, from the expansion of the parts most exposed to the heat, and the kiln soon requires relining.

40. The kiln shown in figs. 12 to 17 is an example

ART OF MAKING BRICKS AND TILES. 79

Fig. IS.

of the mode of building with -walls of the same thick- ness top and bottom ; that shown in fig. 18 is one of a more massive construction^ and has buttresses at the angles. The upper part of this kiln is formed by build- ing, in a temporary manner, a thin parapet roimd the inside of the top of the walls, about a couple of feet in height. This expedient is often resorted to for the sake of increasing the capacity of a kiln at a small expense.

41. Some of the kilns are provided with a Hight of steps by which access is obtained to the top, in others ladders are used for this purpose. Many of the kilns have also a kind of light fence round the top, made of rough poles. This serves as a protection from falling, and as a scaffold to which screens may be hung in windy Aveather to keep the wind from setting on the top of the kiln. This fence is shown in fig. 2. The outside staircase is shown in figs. 1, 13, and 16.

42. The sizes of the kilns vary considerably. A kihi such as that shown in figs. 12 to 17, 20 ft. long, 10 wide, and 12 ft. high, will, with the addition of a parapet^ burn 25,000 bricks at once, and wiW requii'e rather more than that number of bricks for its erection. The cost of such a kiln would be from £'30 to £50, the value of the materials being almost nominal.

The capacity of a kiln may be roughly calculated on the assumption that ten bricks require a cubic foot of space in the kiln, but much, of course, will del end on

80 RUDIMENTS OF THB

the nature of the clay and the amount of shrinkage before bui*niug.

43. A ^ell-built kiln will last for many years with occasional repairs.

PROCESS or BRICKMAKING.

44. Clay digging. — The clay or marl is^ or should be, dug in the autumn, and collected in large heaps at the bottom of the slopes, to be mellowed by the ■sriuter frosts. These heaps are shown in fig. 1.

The cost of this operation varies from 1*. to \s. 9d. per 1,000 bricks, according to the labour of getting the clay, and the distance to which it has to be wheeled.

45. Tempering. — In the spring the clay is turned over by spade labour, being at the same time well watered and trodden. The pebbles and large lumps of lime- stone are picked out by hand with more or less care. The prepared clay is then wheeled to the mill, and tipped into the hopper. Sometimes the clay, after being ground, is at once tempered for use on the floor beneath the rollers ; but for the best bricks, as before stated, it is allowed to remain in cellars to ripen for a year or more.

46. The temperer is generally paid by the moulder, who contracts for tempering, moulding, and hacking at a price per 1,000. The cost of tempering for common bricks is about \s. Sd., exclusive of the cost of horsing the mill, which is borne by the proprietor of the yard.

One temperer will keep one moulding-table constantly supplied, and will also assist the moulder in getting up his bricks from the floor.

47. Moulding. — A sufficient quantity of clay hanng been prepared on the tempering floor, one of the moulder's boys takes up as large a lump as he can

ART OF MAKING BRICKS AND TILES. 81

conveniently carry^ ancl^ placing it on his head, walks with it to the moulding table, and walking up the sloping plank, deposits it at the end of the table, to the right hand of the moulder at b, fig. 6.

The moulder having sprinkled some dry sand over the part of the table marked D, takes from the heap of tempered clay a piece sufficient to make a brick, and kneads this clot with his hands on the sanded part of the table, so as to bring it approximately into shape. He then raises the clot in the air, and dashes it with some force into the mould, striking off the superfluous clay with his fingers. He then dips his hands into the water-box, and, with very wet hands, works over the face of the brick, so as to force the clay perfectly into the mould in every part. He next takes the plane and passes it backwards and forwards with considerable pressure, until the face of the brick is flush with the edges of the mould, and then, reversing the mould, planes the underside in the same way. The brick being moulded, the moulder slides it on the wet table to his left hand side, where it is taken off by a second boy, who carries it, mould and all, to an unoccupied part of the floor, where he turns it out carefully on one of its sides, and returns with the empty mould. Meanwhile the moulder has made another brick in a second mould, which is now ready to be taken off, and this process is repeated until the distance to an unoccupied part of the floor is too great to allow of the boys returning in time, and the table is then shifted to another part of tlic floor.

48. Drying. — After the bricks have remained for a few hours in the position in which they were first placed on the floors, they are turned on their edges by a boy, who turns up two at once, one with each hand. They

£ 3

82 RUDIMENTS OF TUE

remain in this position a few hours longer, and are then laid flat on the opposite side to that on wliieh they were first placed. Careful moulders sprinkle sand over the wet bricks as they lie on the floor, which absorbs the superabundant moisture, and renders them less liable to crack ; but this is not always done.

Tlie new bricks sometimes also undergo a slight dressing with the clapper, to take off any roughness at the edges, and to correct any alteration of form which may have taken place on turning them out of the mould, and in some cases they are scraped with a small iron scraper, to remove any dirt that may adhere to them.

After lying flat a few hours longer, they arc carried by the boys, three at a time, to the hovel, where the moulder builds them into hacks 50 bricks long and 1 !• courses high, each hack containing 700 bricks. As the bricks are hacked they are hatted with the clapper, to correct any warping which may have taken place whilst lying on the floors. The bricks remain in the hovel without being again shifted, until they are ready for burning.

'19. The time allowed for drying varies with the weather, the size of the kiln, and the demand for bricks. Some brickmakers get the bricks out of the kiln within a fortnight of their leaving the moulds, but this haste is very prejudicial to the soundness of the bricks, and, as a general rule, three weeks is the least time that should be allowed for drying.

The time that the raw bricks lie on the flats depends Bolcly on the weather. In good drying weather the bricks are made one day and hacked the next; but at other times several days may elapse before they are fit for liacking.

50. It is not very easy to separate the cost of hacking

ART OF MAKING BRICKS AND TILES. 83

from that of moulding, as both operations are per- formed by the moulder. The price for moulding, in- cluding tempering and hacking, is from 5^. per 1,000, and upwards J 5s. 3d. is a common price. Where the clay is ground the moulder pays for feeding the mill, but not for horsing it, this expense being borne by the proprietor of the yard.

51. The above description refers to the ordinary mode of proceeding, but for facing-bricks additional processes are employed. Pressed bricks, as their name implies, are prepared by putting the raw bricks one at a time, when nearly dry, into a metal mould, in which they are forcibly compressed by the action of a powerful lever which forces up the piston forming the bottom of the mould. This gives a very beautiful face to the brick, and leaves the arrises very sharp, but bricks so prepared require longer time for drying and judicious management in the kiln, otherwise they will be un- sound, and when exposed to the weather soon become perished.

52. Polished bricks, as they are called, arc rubbed upon a bench plated with iron, to make their surfaces perfectly even, and are also dressed with a dresser, as before described. This process is only gone through with the very best bricks, and its cost is such that it is not employed to any very great extent.

53. The contraction of the clay in drying is very slight, and no perceptible diminution of size takes place in burning if the bricks have been previously thoroughly dried.

The brick moulds are made of different sizes at dif- ferent yards, their proportions having been altered from time to time, so as to increase the depths of the moulds at the expense of the other dimensions.

84 RUDIMENTS OF THE

When the thickness of a piece of brickwork is mea- sui'ed by the number of bricks, as in house building, and not by feet and inches, as in building the piers of bridges and other solid works, the number of bricks required for the execution of a rod of brickwork is considerably reduced by a very trifling addition to the thickness of the bricks, and this is always an induce- ment to purchasers to prefer the yards where the deepest moulds are used.

The largest common bricks now made measure, when burnt, 9^ in. lonjr, 4f in. wide, and 3yV ^^- thick, or thereabouts ; the size of the moulds being 91 in. long by 4^1^ in. wide, and 3 ^ in. deep. These bricks weigh about 7 lbs. 15 oz. when burnt.

The best red facing-bricks made at Mr. Wood's yard, in the Carlton Road, measure, when burnt, 9^ in. long, 4| in. wide, and 2|^ in. thick. The moulds for these bricks are 10 in. long, 4^ in. wide, and 3^ in. deep.

54. A good moulder, if solely occupied in moulding, will turn out 2,000 bricks in a day, between G a.m. and G P.M. ; but as nearly one-third of the moulder's time is taken up with hacking, the average day's work is not more than about 1,300 per day, or between 7,000 and 8,000 weekly.

55. Burning. — The setting of the kiln is an opera- tion on which much depends, and requires to be done by an experienced hand, as there is a great deal of art in arranging the bricks in a proper maimer, so as to allow the heat to be diffused equally through the kiln, and to afford a proper draught, so as to obtain the greatest amount of steady heat Midi the smallest ex- penditure of fuel.

The lower part of the kiln is filled with common bricks, narrow openings being left, as shown by the

ART OF MAKING BRICKS AND TILES. 85

dotted lines in fig. 12^ forming flues connecting the opposite fire-holes^ the tops of these flues heiug formed by oversetting the bricks on each side till they meet. These flues are of the same height as the fire-holes.

The best bricks* are placed in the middle of the kiln, and above these again are placed common bricks up to the top. The bricks are not placed close together, but a space is left all round each brick to allow of the pas- sage of the heat round it ; the bricks in the successive courses being crossed either slantwise, or at right angles to each other. When a brick rests partly on others, and is partly exposed to the fire, the exposed part will commonly be found of a lighter red than those to which the fire has had no access, and this is one great cause of the mottled colour of the Nottingham bricks. When, therefore, it is wished to produce bricks of a uniform red tint, great care is taken to keep the faces and ends of the bricks in close contact, crossing them every few courses only.

The kiln being topped, the doorways are built up Avith refuse brick and plastered over with clay, to prevent the admission of currents of cold air, and the fires being lighted, the heat is got up gradually, care being taken not to urge the fires, until all the steam is driven ofi" from the bricks, and the actual bui'ning begins. "When the fire has attained its full heat, the fire-holes arc partially stopped with clay, and the top of the kiln is covered over with earth, turfs, or boards, to check the draught, and a steady uniform heat is kept up until the completion of the burning, which generally occupies three days and three nights from the first lighting of

• If tiles be burnt at the same time, which is frequently the case, as they cannot be burnt alone without great waste, they take the sain« position in the kila as dresied bricks.

86 RUDIMENTS OF THE

tlic fires ; at the expiration of which time the fire-holes are completely stopped, and the fires put out ; after the fires have been extinguished, the kiln should be allowed to cool very gradually, as the soundness of the bricks is much deteriorated by the kiln being opened too soon j this, however, is a point not sufficiently attended to.

56. The fuel employed is coal,* the quantity! used being about half a ton per 1,000 bricks, the exact amount depending on the quality of the fuel and the judicious setting of the kiln. The town of Nottingham being situated on the very edge of the Nottinghamshire coal-field, the cost of firing is very low, and excellent coal can be laid down at the yards at from 8s. Gd. per ton upwards. The small coal or slack frequently used in the early stage of burning does not cost more than 5s. to 6s. per ton.

57. The colour and soundness of the bricks vary according to their position in the kiln and the intensity of the heat to which they have been exposed. Those nearest the fire become partially vitrified, and of a blackish tint. Those w^hich have been more favourably placed burn of various tints according to the nature of the clay, from red to straw colour and white, and when struck together riugw^ith a clear metallic sound. Those which are underburnt are tender, of a pale red colour, and give a dull sound when struck together.

58. The cost of setting and drawing the kiln is gene- rally reckoned at I*. 6d. per 1,000, this including stacking the bricks in the yard, or placing them in the carts of the purchasers. If, however, they are

* Soft coal is preferred.

t In some great yards a deal of coal is wasted on the top of the kiln. As the heat has always an upward tendency, this lias very little effect on tlie bricks, and a great deal of fuel is wasted in smoke and flame.

ART OF MAKING BRICKS AND TILES. 87

not for immediate sale, an additional 6d. is charged for loading the carts.

59. The labour in firing is reckoned at Is. per 1;000.

60. At "Nottingham, and at the yards in the neigh- bourhood, many varieties of brick are manufactured; as cant, or splayed bricks, for plinths ; Tveathered and throated copings of several sizes ; round copings ; bricks with quarter-round ends ; wedge-shaped bricks for culverts ; compass, or curved bricks for lining shafts and wells, and also paving, roofing, and draining tiles of all descriptions. It is unnecessary to enter into any details on the manufacture of these articles, as they offer no particular points of interest. It may, however, be worth while to mention that the use of copper moulds is confined to the manufacture of those articles which are of a convenient size, and for which there is a large demand ; the moulds for cant bricks, compass bricks, and other fancy articles for which there is only a limited demand, being made of wood.

COST OF MANUFACTURE.

61. Land, and Brick-earth. — The proprietor of a brickwork usually rents the necessary land at a price per acre, and in addition pays for all clay removed at a set price, whatever its quality.

As the brick-earth is exhausted, or the workings reach an inconvenient depth, the ground is levelled and again thrown into cultivation. This is of course done at the earliest period possible ; and in some cases the rental of the land is nearly made up by the profit dc' rived from cultivating the site of the exhausted work iiigs, so that it is impossible to give an accurate estimate

88 RUDIMENTS OF THE

of the proportion which the rental of the land bears to the total cost of manufacture^ as it must vary widely in each particular case. This remark does not hold good with regard to the brick-earthy which is paid for at the rate of 8^. per cubic yard, or 2s. per 1,000 bricks, a thousand bricks requiring about 3 cubic yards of clay.

It must be remembered that, as above stated, this price is paid for all clay removed, whether suitable or not for brickmaking. For common bricks the earth is taken as it comes, good and bad being ground up to- gether ; the cost of grinding being less than the loss wliich would result from the rejection of the inferior earths, which are often so hard, and contain so much skerry in pieces of all sizes from that of a walnut to that of a man's head, that they could not be worked up by the ordinary process of tempering by treading and spade labour only. For front bricks and the best qualities, the clay is carefully picked, and the cost is propor- tionately increased thereby.

Ko estimate can be given for the amount of land required for making a given number of bricks, as it depends on the situation of the yard and the depth to which the workings can be carried.

62, Buildings and Maclthieiy. — From the circum- stance that in existing yards the buildings have been erected at different times without any very systematic plan, it is not very easy to ascertain what are the best relative sizes of Avorking floors, hovels and kilns, or what extent of building and plant are required for working a yard to the greatest advantage. Unless the manufacture be conducted on a very large scale, the griuding-mill will, in most cases, be often unemployed ; aud the wash-mill being used only in the manufacture of arch brii^ks, it is only in the immediate neighbour-

ART OF MAKING BRICKS AND TILES. 89

hood of a large town that a retui'ii for the cost of its erection can be hoped for. It -will always be found an advantage to have an excess of shed-room rather than the contrary.

G3. The following rough estimate will give an idea of the buildings and machinery required for mounting a new yard^ to produce from -iOjOOO to 50^000 per week : —

1 clay -mill.

120 yards lineal of hovel^ 6 yards wide.

1^200 yards superficial of working floor.

This extent of hovel and floor will be sufiicient for the operations of six moulders ; and^ taking the work of each moulder to average throughout the season 1^300 per diem^ the week's work of the six moulders would produce 46; 800 per week^ or in round numbers 140^000 every three weeks.

This rate of production would render necessary two kilnSj each to burn Bo^OOO^ and these kilns would be kept in constant activity, each kiln bemg fired twice every three weeks.

64. For a yard in which it is proposed to make all kinds of brick ware additional buildings will be required, as: —

Cellars for ripening the ground clay ; A tempering shed, for tempering under cover ; One or more drying-houses, provided with furnaces and flues ;

A wash-mill for running the clay for making rubbers.

Besides the above erections, there will be required in all yards stabling to a greater or less extent ; a cottage for the under-taker of the yard ; and sheds and out- buildings for keeping tools, carts, and implements.

90 RUi)IMEXTS OF THE

65. Tools. — The tools required by each moulder are : —

A pair of brass moulds ;

A moulding table, and appurtenances complete ;

A plane ;

A clapper.

In addition to these implements a variety of other articles are required, as shovels, picks, barrows, planks, sand baskets, sieves, &c., which are kept in store by the proprietor of the yard, and supplied to the men as required.

G6. Labour. — The proprietor of the yard finds all tools and implements, sand, and coals, and horses the mills. The general management of the yard is con- ducted by an under-taker, who superintends the yard and contracts with the proprietor for all the labour required in the actual manufacture, at a price per 1,000 on the tale of bricks delivered from the kiln, the imder-taker bearing all loss from frost, wet, or other causes.

The under-taker sublets the moulding to a moulder, who contracts with him at a price per 1,000 to mould and hack the bricks ready for setting in the kiln ; the moulder employing two boys to assist him in moulding and hacking, and also a tcmperer, who tempers the ciay for him, and assists in getting up the bricks from the floor. The first turning over of the clay is per- formed by labourers, under the direction of the under- taker, who, with the assistance of a few boys and labourers, sets and draws the kilns himself, and attends to the burning.

67. The actual selling price of bricks is regulated more by the demand and the amount of competition

ART OF MAKING BRICKS AND TILES. 91

than by the cost of their production. Good building bricks^ made in copper moulds, may be had in Notting- ham at 2os. per 1,000 ; but a fair selling price may be considered as 28^. per 1,000, which may be thus subdivided : —

Clay digging per 1,000

Turning over and watering clay and feeding mill „

Grinding „

Tempering for moulder „

Moulding, drying and hacking ... „

Setting and drawing kiln .... „

Burning ,,

Total cost of labour ... „

Coal, half a ton, at 8s „

Dutv, OS. lOd. per 1,000, with 5 per cent, added „

Clay

Rent, tools, machinery, and profit ... „

Selling price at yard . . . ,,

This may be considered as the lowest price which ^Till afford any profit to the proprietor of the yard, when proper allowance is made for depreciation in buildings and machinery, tools, repairs, and other contingencies.

68. The relative value of the different qualities of

brick may be thus stated : —

£ s. d. Common bricks (the clay not picked) . . per 1,000 18 0 Front bricks (made in copper moulds, the clay

picked) „ 1 13 0

Polished bricks (made in copper moulds, the

earth selected with care, and the bricks

dicssed on a bcnrh) ,, 3 0 0

£	s.	d.
0	1	6
0	0	8
0	0	6
0	0	4
0	4	0
0	1	6
0	1	0
0	9	6
0	4	0
0	6	H
0	2	0
0	6	4i
1	8	0

92 RUDIMENTS OF THE

69. Repere.vce to the Illustrations accompanying

THE FOREGOING ACCOUNT OF BrICKMAKING AS PRAC- TISED IN Nottingham.

Fig. I. General view of a brickwork, showing the arrangement of the works.

A. The face of the workings.

B B. Heaps of brick-earth, dug in the autumn, to be worked up the

following season, after being mellowed by the winter frosts. c. The clay-mill. D D. The working floors, generally made about 9 or 10 yards wide.

E. The hovel. This hovel is flued, — the door at the end of the hovel next the road is the entrance to the furnace pit ; the chimney into which the flues are conducted is shown at the opposite end. In some drying houses the flues arc made to return nearly to the furnaces before they are led into the chimney, so that the latter is close to the former.

F. The kiln. This form of kiln is a weak one, and is liable to be split from top to bottom by the expansion of the walls, from the intense heat to which they are exposed. The reader will observe the steps and the wooden fence roimd the top of the walls, men- tioned in article 41.

G. Goods for sale.

This 'illustration is not an exact representation of any particular brick- work, but has been made up from the details of several yards, to show the principle on which they are laid out ; which is, to save all unnecessary carriage of either brick-earth or bricks, from the time of first turning over the clay to the stacking of the finished bricks in the sale yard.

Figs. 2, 3, and 4. Clay-mill, with a single pair of rollers 18 in. in diameter, and 32 in. long, as manufactured by Messrs. Clayton and Shuttleworth, of Lincoln. The letters of reference are the same in each figure.

a. Horse beam, 12 feet long, from centre of horse track to centre of driving wheel.

b. Bevelled driving wheel.

c. Pinion.

d. Driving shaft, 1^ in. diameter.

e. Universal joint. ff. Spur wheels.

g g". Cast-iron rollers 18 in. diameter and 32 in. long. The roller marked ^ is longer than the other, hanng a flange round each end by which the roller g is kept in its proper position. The roller marked (f is coimected by the universal joint e with the driving shaft d.

h. Wooden hopper.

J I. Cast-iron standards to support the hopper.

k h. Axles of rollers.

ART OP MAKING BRICKS AND TILES. 93

/ L Bearings for the axles k h. These bearings are made to slide on the bottom plate m, in order that the gauge of the rollers may be adjusted at pleasure. m. Bottom plate, on which the bearings rest. n. Strengthening bar.

0 0. Adjusting screws, by which the rollers can be set to any gauge, according to the degree of fineness to which the clay is required to be ground. p. End beam of fiaming. q q. Sides of framing. 7-, Balance weight to horse beam. The rollers in this mill are not faced in the lathe, but they are cast upright in loam moulds, which insures great accuracy in casting, and renders turning imnecessary, where only one set of rollers is employed. The aiTangement of the rollers, when two or more sets are employed, is shown in chap, iv., figs. 1, 2, and 3, which shows the construction of the clay-mills used in Stafibrdsihire,

The temporary floor on which the clay falls after passing between the rollers is formed about 8 feet below them, and is inclosed on three sides with brick walls which support the wooden framework of the machinery. The clay is prevented from adhering to the surfaces of the rollers by strong knives fixed on their under sides.

Fig. 5 is a diagram showing an improved arrangement of the ordinaiy clay-mill, in which the horse track is raised to the level of the top of the hopper, the whole of the machinery under the hopper being completely boxed up, so that no dirt or stones can lodge on the wheels. The driving wheel is placed in a circular pit lined with brickwork to keep up the horse track to the required height. Fig. 6. Isometrical view of a moulding table.

A. Sloping plank, placed at one end of the table to enable the moulder's boy to deposit the clay on the table.

B. End of the table where the tempered clay is deposited.

c. Sand box. This is not always fixed to the table. In many cases it is a detached box, on three legs, placed close to the moulding table.

D. The part of the table on which the clot is moulded.

E. The place where the clot is put into the mould.

F. The water-box, in which the moulder dips his hands each time he moulds a brick.

0. A slip of wood on which the plane rests in order to raise it from the table, that the moulder may take it up the more readily.

H. The part of the table at which the brick is taken off. This part of the table is alw.iys very wet, and the slush runs off into

1. Gutter, to cany off the drippings from the table into a tub placed beneath it, but which is not shown in the drawing. If the water were allowed to run down on the working floor, the latter would soon become wet and sUpperr, and unfit for receiving the bricks.

Fig. 7. Copper brick mould.

This kind of mould is cast in four pieces and riveted together, the sides projecting half an inch beyond the ends. Each casting haa a flange at top and bottom, forming a rim half an inch wide all round the top and bottom of Cbe mould. These rims become

04) RUDIMENTS OF THE

gradually worn down by the friction of the plane and the action of the moulding sand, and require replating from time to time. The expense of replating with brass has induced a trial of iron rims, but they have not been found to answer. The outside of the mould is cased with wood, secured to the brass by the rivets. To give a hold to the latter, each pair is passed through a piece of sheet copper, as shown in the cut.

The moulds for making quarries are somewhat different, two of tho sides only being cased with wood, whilst the others arc stiffened by strengthening ribs cast on the sides of the mould. Fig. 8. The plane. Fig. 9. The clapper.

Fig. 10. Bench on which the best bricks are polished and dressed with a dresser, as described in art. 34. Fig. 11. The dresser.

Figs. 12, 13, 14, 15, 16, and 17. Plans, sections and elevations of a kiln.

Fig. 12. Plan at level of floor, showing the firing sheds and fire-holes. The latter, in this example, are arched over, and are built of con- siderable width, which is afterwards reduced by temporary piers of brickwork. In many kilns, however, the fire-holes are made at once of the requisite width, and finished at top by oversetting the bricks on each side till they meet, instead of being arched over. The fire-brick lining to the fire-holes is indicated in the plan by a tint darker than that of the rest of the walls. The temporary piers of brickwork are shown in outline only. These are pulled do^m whenever the fire-brick lining requires to be renewed. The floor of the kiln is not paved.

Fig. 13. Plan, showing the roofs of the firing sheds (b b), and the stejjs (a) leading to the top of the kiln.

Fig. 14. Cross section of kiln, taken through the firing sheds, and showing the construction of the fire-holes.

Fig. 15. Longitudinal section, taken through the doorways at the ends of the kiln, and showing the appearance of the fire-holes in the inside.

Fig. 16. End elevation of kiln, showing the doorway and the ends of the firing sheds, as well as the steps leading to the top of the kiln.

Fig. 1 7. Side elevation, with the firing shed removed, in order to show the fire-holes. Fig. 18. Perspective view of a kiln. This kiln is built very differently from that shown in the previous figures, the walls being very massive at the bottom, and diminishing in thickness as they ascend. Tho angles are strengthened by buttresses. The doorways do not reach to the top of the walls, and are arched over, so that the latter form a continuous terrace all round the top of the kiln, on which a thin parapet is built up in a temporary manner, to increase its capacity.

ART OF MAKING BRICKS AND TILES. 90

CHAPTER IV.

BRICIvMAKING AS PRACTISED IN THE STAFFORD- SHIRE POTTERIES. By R. Prosseb, C.E.

1. Bricks. — There are made in this neighbourhood the following sorts of bricks for building, viz., red, blue, and drabj and also a blue brick used as a paviour for footways, which brick is called a dust brick, from the circumstance of coal dust being used when it is moulded. When fired it has a smooth and somewhat glossy sur- face, and being very durable is extensively used as a paviour.

2. The drab brick is used to a limited extent for building, but more generally as a fire-brick by potters and iron-masters ; it is, however, inferior to the Stour- bridge brick, the latter being used where intense heat is generated.

3. Tiles. — There is a variety of other articles made in the brick-yards of this locality, as, roofing tiles in several varieties, tubular drain tiles from 3 in. to 16 in. meter, and generally 18 in. long; also floor tiles or t ^uarries both red and blue, the latter resembling the blue brick.

4. Clay. — The blue colour is obtained from the same clay that fires red by additional heat being generated when blue is required, at a cost of half a ton more coal, and two hours more time allowed per oven. The clays or marls are selected for the purposes to which they are best adapted, and an extensive supply of the best quality for red is procured at Cobshurst, about two miles south of Longton (which marl is used to make the red orna-

96 RUDIMENTS OF THE

mental and encaustic tiles, now so much admired, and which are extensively made by Messrs. !Minton and Co., of Stoke-upon-Trent). Marls and clays suitable for brickmaking are plentiful, and of several varieties, in this neighbourhood, but the most extensive bed of red marl runs in an almost unbroken line through this country from south to north, and generally west of the great coal-field, and is worked with the same results at Stooi-bridge, Tipton, Hanford, Basford, Tunstall, and other places. A reference to a map of the country will show the peculiarity of this long bed of stratified marls.

5. In the pottery district there are about ten distinct sorts or strata. The following names are given to the seven sorts most used ; and their position with relation to the earth's surface is shown by the order of their names here given.

Top red marl, dun coloured, top yellow (rotten red, not used), mingled, bottom yellow, brown, and bottom

grey.

Seven of these marls vary but slightly in their chemical composition, and, when used, three sorts at least are generally mixed together. (For an Analysis of the above-named marls, sec Table 1, art. 37.)

In this locality there is a very favourable combination of circumstances for the manufacture of ornamental bricks for architectural decorations; and Mcre archi- tects to give the subject their attention, and such bricks free from duty, much might be done.

6. The following description of the process and cost of brick and tile-making will apply, first, to the make of bricks, &c., upon the property of the manufacturer ; and, secondly, to the make of tiles^ &c., at a yard which is rented.

ART OF MAKING BRICKS AND TILES. 97

PIRST EXAMPLE. — BRICKMAKINQ.

7. Buildings and Plant. — This yard, "with the ground opened for work, has an area of about 6 acres, and has the following buildings and machinery upon it, viz. : —

A 5-horse power steam engine ; A pug-mill ;

A set of horizontal rollers ; Six drying-houses ;

(Three pairs to the set, placed over And nine ovens, each other).

The drying-houses measure 40 yards in length, by 8^ yards in width, and have two flues under the floor through their entire length.

At times they fire these nine ovens in one week ; and if used exclusively for bricks, each oven sould be fired five times in a fortnight. Besides bricks, the following goods are made at this yard : — pipe tiles from 3 in. to 16 in. diameter, roof and ridge tiles, quarries, dust bricks, &c.

8. Rate of Production. — Provided the make were confined to bricks, with these conveniences they would make 100,000 weekly during the usual brick season, which at the present selling price, £1 8s. per 1,000, gives a weekly produce value ^6140, which quantity would pay in duty £27 lis. 3^., the duty being 6s. l^d. per 1,000, with 10 per cent, off": this leaves for cost of production and profit £112 85. 9d.

9. Tempering. — The marls used at this yard answer to the description previously given, 'i'heir average con- traction when mixed is 1 in 10 ; that is, a 10-iu. mould gives a 9-in. brick when fired, although some of the varieties used separately contract 1 in G. The marls are dug and wheeled two runs for Aid. to 7d. per cube yard, the price depending upon the difficulty of digging. The marl is then placed in a hopper over the topmost

f

98 RUDIMENTS OP THE

rollers, and passing successively through the three pairs, is deposited on a floor about 8 ft. below the hopper. The marl is then wheeled away, and some three or more sorts mixed together with a proper quantity of water, by spade labour (for the quantity of water in the marl when dug, see Analysis, Table 1, art. 37). The mixed marls, if wanted for tiles or dust bricks, are now passed through the pug-mill ; but if required for ordinary bricks, the ground marls are mixed with marls that have been weathered but not ground. Lastly, the marl is tempered by spade labour until the proper degree of plasticity is obtained.

10. Moulding. — The bricks are moulded by what is called the slop -moulding process at the rate of 3,000 per day.* The price paid for tempering and moulding is. -is. 6d. per 1,000. The process is as follows : the temperer wheels the prepared marl in a barrow up a plank, and empties it upon the moulding table. The moulder having sprinkled sand upon the moulding board, and upon that part of the table where the clot is moulded, takes as much clay as will fill the mould, and by a quick roll and a tap gives the clot an approxi- mate form Xa) the movdd ; he then lifts up this lump of clay about 12 in. high, and with force throws it into the mould, pressing it down with both hands to fill all the cavities, and strikes oflF the surplus with a wooden striker, which he throws into a small water-box in front of him after each time of using. f An attendant boy, who has previously dipped a moidd in a water-trough by the side of the table, places it on the table ready for the moulder, and carrying away the moulded brick

•In the neighbourhood of Noltingham.uhere the bricks are not Etrkken, but planed, the rate of production is only 2,000 per r5aj. — tc» t See chap, iii., art. 47.

ART OF MAKING BRICKS AND TILES. 99

in the mouldy carefully empties it on its flat side on the floor ; these operations are repeated until the floor is filled, when the moulding-table is removed to a second floor.

11. Drying. — The floors are of difierent sizes ; a con- venient size is 25 yards in length by 6 yards in breadth, upon which they will lay 3,000 bricks. Here they are allowed to dry until sufficiently hard to handle and place in hacks, the length of time depending upon the weather. In quick drying weather they vrill remain half a day as deposited from the mould, and half a day tui'ned upon edge, and afterward they are placed up in hacks, where they remain until placed in the oven.

12. An ordinary blue brick weighs, wet from the mould, 12 lbs. 4oz. ; when fired it weighs 8 lbs, 1 oz., having lost by evaporation in drying and burning 4 lbs. 3 oz., or 3i per cent, of its original weight.

The specific gravity of an ordinary blue brick in the wet state from the mould is . , . 2,171 In the dry state, ready for the kiln . . 2,075 And when burned, the specific gravity is . 1,861 The Table on the next page shows the amount of evaporation during the process of drying.

The total loss of weight in drying and burning is as follows : —

196 ounces, the weight of a brick wet from the mould. 46 „ „ lost by drying, or 23^ per cent.

150 „ „ dry ready for the kiln.

21 „ ,, lost in burning, or 14 per cent.

129 „ „ of an ordinary blue brick.

13. Burning. — The oven is of a circular form, with a F 2

100

BUDIMEXTS OF THE

	x		1
z	— ? X
« •	•- «- .1.
e ^	O S oi C
		c «
c "^
	(N •= 5 —	••■
g =	>-_« — «	£ <~
Si	o " « ""	c =>
c a	s -- - 2 f tC >^ "ttD	II
— "	>, .S" jj .^
•• o	a B •c s
U-*	"H o o o
	o ^ ^ ^
^1	c .5 .= .=	■|^
M	^ -«• ra» -*»	"^ ei
	t~ o o e«	c
o	74 ^>	o
•^	*->-'— N . >-
•Sm^fUk		"i s
Tpwnaa^taq	'?'*-f?»'^-?-*rj	c =
tnoqai i«ua;ni
		o
'gitJuiio	>-»r>- -^-i-* -<>--*-. *■ »i -■ i-» ^	5 >._.
nj^ilSrajijOBWi
		_ o — S 2 5 "" o 2
	-<:«— ^ -o-3-»-o—
Is	6 ^ r i3 2 S S i? o S
^	f5	•«T
:&	o	.5 —
e o s
a	<;:•<;.<	Cm ""■	t;
H	j t^ — rtt^t^ — r:t-t^	^ "^	.Hf
	I ^~ ^"	5 g	'3
	~*
	"3 — ^	o
		.= t£
	eo - - : ^ - - - o	ti. =	'u
OB	«>
	B
H	& -. r : : ; : : r	'	^^
	-5

spherical top, and will contain 8,000 bricks, which are PD placed as to allow a space between the sides of each for the action of heat, and an equal diffusion thereof, ^hen the oven is full, the clamm'ms or doorway is made up, and the fires kindled and kept burning 3G hours for red, and 38 hours for blue bricks, consuming 3^ tons of coak for the former, and 4 tons for the latter. The

ART OF MAKING BRICKS AND TILES.

101

firing, and drawing follows : labour 12s.

an oven ol , and coals

expense of setting, 8,000 bricks is as £1 13*. M.

14. Cost of Manufacture. — The details of tlie cost of manufacture are as follows : —

Clay getting . . _ . . . .per 1,000

Tempering and moulding ....

Setting oven, firing and drawing

Coals, 4 tons at 8s. Ad., divided amongst 8,000

Duty, 05. 10(/., with 5 per cent, added

Eent, machinery, clay, contingencies, and profit

Present seUing price for ordinary blue bricks

d. 6 9 6 2

114

1 8 0

15. Rental. — Brick-yards with mines of marls are set with the following appendages, viz. : 1 oven, moulding or drying-house, and pug-mill, with a breadth of brick floor and marl bank sufficient to work one oven for £30 per annum ; if two ovens are worked in the take, they are set at £2o each.

102

RUDIMENTS OF THE

DESCRIPTION OF ILLUSTRATIONS.

IG. Fi(js. Ij 2, 3, Machine, with three pairs of Rollers,

for grinding Marl.

Fig. 1. Side elevation.

Fig. 2. Front elevation, with the gearing removed.

Fig. 3. Elevation of gearing, No. 1 being the drivicg wheel.

'or

^

^v\\mr'^A\\\^m\: iTiiiiJiiii'ii^piiB

r

ART OF MAKING BRICKS AND TILES. 103

17. Fig. 4. Isometrical View of a Moulding Table.

A. Sand basket. b. Detached water-box. c. Moulding board D. Water-box. e. Clay knife.

In the process of moulding the moulder takes in his hand, from the basket, a portion of sand, and dusts upon that part of the table where he rolls the clay into the form necessary to mould ; also upon the moulding board. The water-box or trough, b, is used by the boy to wash the mould in, and is lower than the table, so as to be convenient for that purpose. The water-box, d, is level with the table, and is used to throw the strike in after each time of using.

18. Fig, 5. Isometrical View of a Brick Mould.

N.B. The mould is made of oak, the edges plated with iron.

104

RUDIMENTS OF THE

19. Bgs. 6, 7, 8, and 9. The Oven or Cupola

Fig. 6. Plan taken at top of fire-holes at level a b, Fig. 9.

'mA.

3 i' 1 O

Fig. 7. Plan, looking down on top of oven.

ART OF MAKING BRICKS AND TILES. 105

Fig. 8. Elevation.

Fig. 9. Section, on line c d, Fig. 6.

SECOND EXAMPLE. — TILE MAKING.

20. At Basford there is an extensive hill of good marls from which eight brick-yards are supplied (working four- teen ovens), some of which have been in work for forty years. The makers are subject to the rental stated in art. 15. The leading article made at these yards is roofing

F 3

106 RUDIMENTS OF THE

tiles ; besides which are also made some quarries, dust- bricks; drain tiles, and just so many common bricks as are necessary for the manufacture of tiles, it being necessary, in order to set the oven properly, to burn 2,000 bricks with every oven of roof tiles, as will be hereafter ex- plained. The process of tile making here is as follows : —

21. Weathering a7id Tempering. — The marl is dug and spread upon slopes of this hill (which has a south- east aspect) to weather; the length of time depends upon the quality of the air : a hot dry summer's day will do good service, and three or four such days would enable the makers to collect a thin surface in a work- able condition. Frosty weather, provided it be dry, is preferred ; wet, and alternations of wet and dry, retard the process of what is termed weathering. During ? hot dry season marl can be dug, weathered, and mad& in one month, and this is frequently done. At the yards here referred to, the workers collect their marls, so weathered, at the foot of these slopes, and mix them with a quantity of water. That to be used for tiles is placed in the pug-mill, and about 1 cube yard per hour is ground by one horse ; and that used for common bricks is not ground, but simply mixed and tempered.

The pug-mill consists of a wooden tub slightly tapered, the largest end being uppermost ; it is circular and about G ft. high and 3 ft. diameter at the top or largest end, in which a cast-iron spindle revolves, carrying a series of flat steel arms, arranged so as to form by rotation a spiral or worm-like motion upon the clay, which is thereby pressed from a larger to a less diameter of the tub in which the clay is confined, and ultimately comes oozing out of an aperture at the bottom : this operation kneads the clay, and more com- pletely mixes it, giving it great cohesive power. This

ART OF MAKING BRICKS AND TILES. 107

clay or prepared marl is now ready to make roof tiles, dust bricks^ quarries, &c., and is wheeled away to the stock kept under cover for that purpose. The tiles, and all articles in the making of which coal-dust is used, are made in a building called by brickmakers the hovel or drying house : but they prefer placing their tiles when first moulded in the open air, weather permitting. The moulding of roofing tiles varies from that of bricks before described, principally in the clay being stiffer, and coal dust being thrown in the mould each time it is filled.

22. Moulding. — The mould is 12 in. by 7| in. and ^ in. thick, made of oak plated with iron. The moulder at his bench takes up a lump of clay, and works it by hand into an oblong square, somewhat less than the mould, say 11 in. by 7 in. or thereabout ; the mould is placed upon the bench, and fine coal-dust thrown into it ; the man then takes up the lump of clay in the right position for the mould, and throws it into it with con- siderable force ; then, with a brass wire strained upon a wooden bow, cuts off the surplus clay level with the mould, removes the lump, and finishes moulding the clay left in the mould by adding a little clay if it be wanted, and smooths it over with a wooden tool. By his side upon the bench he has two thin boards about the size of the moulded tile, their surfaces are dusted over with coal-dust ; upon one of these he places the moulded tile, without the mould, the half circular pro- jections extending beyond the board; and so he repeats the process of moulding at the rate of from 1,300 to 1,500 per day, adding more clay to his lump about every six tiles moulded, and in quantity about as much as the six tiles moulded.

23. Drying, — The attendant boy carries away two

108 RUDIMENTS OF THE

tiles at each time to the floor ; he takes up one on the boards and by the thick part of the hand presses up the two projections at right angles with the face of the tile, and then places board and tile on his head, and takes up a second and operates upon this in like manner, as he walks to the floor, where he lays the two tiles, carrying the boards back to the moulding bench ; and so he repeats his operations.

The tiles remain on this floor, out of doors in fine weather, about four hours ; they are then collected and placed close together, the nib end changed alternately to allow of their resting close and square ; in this state they are walled up in a dry but not hot situation, and so remain for a day or two : this is said to toughen them.

24. The Set. — The next process is to give them a curved form, sometimes termed the set, which is done on a three-legged stool, called a horse, the top of Avhich is a little larger than the tile, and is curved one way to about a 10 feet radius. With the horse is used a wooden block, curved to correspond with the surface of the horse. These implements are used as follows : six tiles are taken as last placed and put on this horse ; the man lifts up the wooden block and gives them three sharp blows with it ; they are then carried away and placed in an ingeniously built wall to complete the drying process (the wall built with the tiles to be dried), after which they are carried to the oven, twelve at each time, in a peculiar manner, with the edges of the tiles against the breast of the carrier.

25. Quarries and dust bricks are moulded in like manner from stiff" clay, coal-dust being used to facilitate the articles leaving the mould.

26. Drain Tiles. — Pipe drain tiles are made as fol.

ART OF MAKING BRICKS AND TILES. 109

lows : tlie clay is first moulded to the lengtli^ width, and thickness required, and then wrapped round a drum, the edges closed together by hand, the drum or mandril turned round, and the pipe tile shaped by the operator's hand, assisted in some cases by a wooden tool : this is the mode of making pipe tiles from 3 in. to 16 in. in diameter, whether cylindrical, tapered, or egg-shaped.

The usual length is 18 in., and the diameter from 3 in. to 9 in. They are sold at Id. per in. bore ; that is, a pipe 3 in. in diameter and 18 in. long, would cost at the yard 3d. ; and a pipe 9 in. in diameter and 18 in. long, 9d. This price applies to cylindrical pipes without sockets.

27. Tile Machines. — One of Ainslie's machines has been introduced into this neighbourhood^ upon the estate of the Duke of Sutherland, for making small tubular drain tiles, which makes two pipes 1^ in. in diameter at the same time. The prepared clay is forced through two dods to form the tubes, which are cut into lengths by wires affixed to the machine, and when partially dry are rolled straight by hand upon a flat surface, and then set up in racks to finish the drying process.

28. Firing. — Firing the articles enumerated in the previous description requires much more care than firing bricks, and as roof tiles are the thinnest and require most care, the largest sized pipe tiles excepted, we shall describe firing an oven of such tiles.

On the bottom of the oven are first placed 2,000 bricks, as shown in fig. 13, and upon these are placed 7,000 tiles, forming a square, the spaces between the tiles and the curved side of the oven being filled up with bricks, as shown in fig. 14. The tiler are placed

110 RUDIMENTS OF THE

edgewisGj in parcels of twelve, changing their direction each parcel of twelve. The nibs on the tiles space them off from each other, and support them in the vertical position ; from this description, and a reference to the illustrations, it will appear, that the goods placed in the oven are in each case so placed as to allow the diffusion of heat between them ; and as the uniformity of heat is the desideratum in firing blue bricks and tiles, the circular oven is found to answer better than any other at present in use.

It is necessary to have a wall round the outside of the oven, about 6 ft. high, and at a distance therefrom to allow the fireman space to attend his fires conve- niently ; this wall is dry built generally with imperfect bricks, and its use is to avoid one fire being urged more than another by the set of the wind, which duty it performs tolerably well.

The oven being set, the clammins (doorway) is made up with bricks daubed over with street sweepings as a loam ; then the fires are kindled, and are kept slowly bui'ning for the first 5 hours, after which they are pro- gressively increased for the next 33, making 38 hours for hard fired blue tiles or bricks; four tons of coal being consumed in the firing. The heat is determined by the sight of the fireman directed to the mouths and top outlet of the oven. When the heat is obtained, and before the fires bum hollow, the mouths arc stopped up with ashes to prevent the currents of cold air passing through the oven, which is then suffered to cool gradu- ally. An oven is usually fired once a week, but may be fired three times in a fortnight. After firing, twenty- four hours should be allowed for cooling before an oven is opened to take out the tiles.

29. The following table shows the selling price per

ART OF MAKING BRICKS AND TILES.

Ill

IjOOOj and cost per superficial yard^ of quarries^ dust bricks, and roof tiles : —

Site.	i.ooo- 1 000 i . y*"^"^ ' ' 1 m pence.	Thickness. Description.
6 in. sq. 7 „ 9 » 9X4i 10 8X7 „	35s. 27-89 yards. 46s. 37-80 „ 80s. 62-50 „ 40s. ' 31-25 „ 25s. 1 58-33 „ 1	15-00 14-59 15-36 14-33 5-14	I 1 inch Quarries. 2 „ Dust bricks. 1 „ Roof tUes.

DESCRIPTION OF ILLUSTRATIONS.

30. Fiy. 10. Isometrkal Vieiv of a Bench for moulding Tiles,

A. Coal-dust box, 14 in. by 8 in.

B. Moulding board, 14 in. by 10 in. c. The bow.

31. Fiy. 11. Elevation, showing the Manner in which the Tiles are placed during the last Drying.

d d, laths, two to each course.

112

RUDIMENTS OF THE

32. Fig. 12. Tile Block and Horse.

a. The block. b. The horse.

Tiles,

33. Fig, 13. Plan of Oven, as seen when eight courses of Bricks are placed edgewise.

The eight rows of twelve bricks in each, as seen in plan, cover a space left in continuation of flues from the eight fire-holes. The bricks in the fust seven courses are so placed as to leave a flue of an average width of 4 inches. The dotted lines show the position of the fire-holes.

ART OF MAKING BRICKS AND TILES.

113

Si. Fiq. 1^- Plan of Oven, as seen when the first course of Tiles are placed upon the Bricks, as seen in Bg. 13.

The tiles are placed in bungs of twelve, and laid alternately cross and lengthwise, the nib spaces them off, and supports them in a vertical position. Each side of the square is made up with bricks, as shown on the plan.

35. The manufacture of bricks^ &c., for building and paving purposes^ in a systematic mannerj in suitable premises with improved conveniences^ so that the opera- tives may be employed the whole of the year instead of a portion of it as noAV, is a subject deserving the atten- tion of the capitalist and inventor. Improvements in the quality and conveniences of this manufacture are intimately connected -with the moral, intellectual, and physical condition of society, as may be seen by a visit to any ordinary brickyard, and a reference to the evidence before the Sanitary Commission. "Where ex- tensive supplies of marls or clay are found, suitable works might be erected for such manufacture, could a

114 nUDIMENTS OF THE

cheap and ready mode of transportation be commanded, so as to carry bricks, See, a distance of 60 to 100 miles without materially increasing their price.

36. Assuming the -sveight of bricks to be 3^ tons per 1,000, the present railway charges for the carriage of bricks, viz. 2(1. per ton per mile, if under 40 miles, and l|rf. per mile if more than 40 miles, would add to their cost as follows : —

£ s. d.

If carried under 40 miles . . .00 7 per 1,000 per mile.

Or for a distance of 39 miles . .12 9

And if carried above 40 miles . .00 6 per 1,000 per mile.

Or for a distance of 60 miles . .110 7

Therefore a carriage of 60 miles at the lowest railway rate more than doubles the value of a common brick compared with the price at the yard. The high rate of charge for carriage, and the duty, which amounts to nearly 22 per cent, of the selling price at the yard, constitute obstacles to the improvement of the brick manufacture, and the bettering of tlie coudition of the operatives employed therein. The recent improvements in connection with domestic comfort and health, and the encouragement offered to architectural improve- ments in the houses for artisans, may probably awaken an interest in this department of industry, and place even brickmaking in the position its importance deserves, if not demands.

ART OF MAKING BRICKS AND TILES.

115

6

S'3

-■3 33

;S»

-wg B— jgnq iqSn	oc la 00 •* CO «0 Tt -o 1 W 1 rt 1 1 ^
•aniq oiiiq jou iipi pa« 'paj sujnq -^uaox-uodn -a^ojS oioJJ -^810	1	60-02 24-26 9-14 1-60 Trace. 1-40 3-89	CO
•aniq poo3 sujnq ,'» POB '£ 's 'i -sojj •s.iBlo JO 3aTi;xiH	1	ic r< — 5^	PI ci
	■<* — r» o — O ■'I" 00 O Ca 1 CO tS <JI 1 O	CO o o
•qsippaa anjq stunq '[aBoi paiSmji	i^ L2 — r-. o — ?) -i" 1 Tl , , ,00	00
•aniq qsrppw suJnq	00 -o n I- t^ '^ lb lb 00 1 -^ 1 1 I o
•aniq pooS samq 't-WoipajnoioDnna	(N	64-32 20-33 10-8(3 Trace. 6-60	T-l O
•aniq snjnq qoiqii 'ia«ni paa	-	69-87 16-79 8-88 Trace. 4-26	o 00
	'3 >. "3 a < o u o E 3	a \Z '•X.	1 <	1 'eroxide of iron, with a little protoxide Trofoxide of iron, with a little peroxide Linio	"1 '. • 5c'5 • 1 i^ • 3lJI	1 !

116

RUDIMENTS OF THE

o

	t^				X				s 1
oc		•>*	5	«	o				H
			CO
	t^		w		•>*				o
	ac				t»				o
t-	c^	—	|5)	o	o		*	■<»	f;
	~		o		'"		2		M
	X				■*		Eh		ts
vc		-	•	l-H		B	n
			to c				i		IN
			'5				5
	c^		a		00				n
^	n	^	•a	^	00			0*	n
	-r		u		00				t^
	CS		J5				i		M
			s o
	^^				o		B		•ft
	^^		"o		Tf		5 c o		O
■^	c	^-.	o	n	00		00	n
			^			OD	u
rt	-9	cs	a o o	f	00	s Xi i 3	OD O s Cm o CO	«e	n n
						s	c o
	X		•a		r~	3			00
Ci		K	o O	o	S4	•« o	1	»^	lb
	*"					e
			♦*			^^	o.
	X	O	1 c	00	3 o ■i	•	B e i o	•ft	6 •o
			,		.	.
			^«
			o	.			K«		B
							c		U
			"2				■fc	^	"3
		•■^	Eh				O	u	^•^
		a		o			f		3
		I	c CO e				02 1		CO CI J
		.2		.2			•J	.2
		<	1 C5	<	s Cm			B <	O a
	^	o	•■-■^	o	o			O	eS
	"u				o				t)
	C3		n	u ^				e a ;2;	a _3
	'3	"c	<	E	o
c	X	2	E-i	a 525				<

ART OF MAKING BRICKS AND TILES. 117

No. 5, Table 1, contains 42"84 per cent, silicic acid; this requires^ theoretically, 47*60 of alumina, or its chemical equivalent in other bases, to form a fusible compound ; it therefore contains only 3'31 per cent, excess of base. This is insufficient to prevent its fusion — a much larger excess would. No. 1 contains 2259 of base, which requires 25 "1 of silicic acid, therefore 69'87 — 25*10 = 44*77 the excess of silicic acid, or uncombined silica in the clay, rendering it infusible.

Analysis of Coal, called Norton Coal, used in the potteries for burning pottery and bricks : —

Carbon 81 08

Hydrogen 5'04

Oxygen 10'55

Sulphur 0-36

Nitrogen Trace.

Ash 2-97

10000

A.NALYSIS of a porous substance which floats in water. It is a piece of a vitrified fort from Connel Ferry, near Dunstaffnage Castle, Scotland : —

Alumina and peroxide of iron 28"45'\

Silica 67-85

Lime 0-32

Manganese .... Trace. Water . . , . 1-88

98-50 ;

This specimen has the appear- ance of pumice-stone. It is only very slightly fusible even in the very highest temperature of the blow-pipe.

BRICKMAKING ON THE SOUTH STAFFORDSHIRE RAILWAY.

38. The following additional particulars respecting brickmaking in Staffordshire were sent to the author of this volume by Mr. J. L. Brown, of Farewell, near Lichfield, and arc given in his own words : —

118 RUDIMENTS OP THE

*' The brickyard I visited is on the highway from Lichfield to Walsall^ at a place called Walsall Wood ; it is -worked by ^Ir. George Brown, of the Sand Hills, near that place. Mr. B. has another brickyard in the neighbourhood, more extensive than the one I visited, and from these brickyards have been supplied all the bricks used for building the bridges, -viaducts, cattle- arches, culverts, &c., &c., on the South Staftbrdshire Junction Railway.

^' The brickyard I visited has six kilns or cupolas, and three large moulding and drying-sheds for use in the winter season, each 40 yards long by 8 yards wide, having fire-places at one end, and traversed by flues, longitudinally, to a chimney at the other end.

" The material used is not a clay, but a friable kind of marl. The first stratum under the surface soil is about 4 ft, thick, very compact in body, and requires the pick to get it ; it is of a purplish hue. This is suc- ceeded by a stratum, 3 ft. thick, of bright yellow -looking marl, equally intermixed with marl, of a bright scarlet colour, and afterwards, down to the depth of 20 ft., the purple-coloured marl comes in again.

" The earth in its raw state is dra-vni up an inclined plane on a common railway truck, by a steam-engine of 20-horse power, and at the top of the incline it tips itself into a hopper placed over the cast-iron rollers, between which the marl passes and comes down an inclined board, after being ground quite small. It is afterwards wheeled into heaps and tempered, and is then wheeled up an inclined plane of earth to the engine- house, where it is passed through vertical cylinders of cast iron, in the centres of -which are revolving pistons armed with flanges, like the screw propeller of a steam vessel, which grind the tempered clay and force it

ART OF MAKING BRICKS AND TILES. 119

tlirougli holes in the bottoms of the cylinders to chambers beneath them, whence it is -wheeled to the moulders.

" They make red and blue bricks of the same marl, prepared in each case by rolliog and grinding. To make the blue bricks, they keep the fires very much sharper and hotter, which changes their colour, and seems to run or fuse the material more, giving them at the same time a shining appearance. They make very Pew red bricks.

" The price of the best bricks at the kiln is 30^. per 1,000; common bricks, 2os. per 1,000. Plain-tiles for roofing, 285. to 32*. per 1,000. They also make chimney-pots, pipes for the conveyance of water, splayed bricks, coping bricks, and bricks to any model."

CHAPTER V.

BEICOIAKING IN THE VICINITY OF LONDON.

1. For facility of reference, we propose to divide the subject under three heads, as follows : —

1st. Materials and Plant. 2nd. Process of Manufacture. 3rd. Cost of Manufacture.

1. MATERIALS AND PLANT.

2. Brick-earth. — The brickmakers in the vicinity of London at present derive their principal supplies of brick-earth from the alluvial deposits lying above the London clay, the blue clay not being used for brick- making at the present day. The general character of

120 RUDIMENTS OF THE

the brick-earth may be described as being a gravelly loam, passing by fine gradations into either a strong clay or into marl, or, as it is technically called, malm, an earth containing a considerable quantity of chalk in fine particles. "We may, therefore, for the purpose of descrip- tion, class the several qualities of brick-earth under three heads, as follows :* strong clay, loam, and malm.

3. 1st. Stronff Clay. — This is generally sufficiently free from stones to be used without washing, and the bricks made from it are hard and sound, but are liable to crack and contract very considerably in drying, and become warped and misshapen in burning. These de- fects are in a great measure removed by mixing the earth with chalk, reduced to the consistency of cream, as will be presently described, which greatly diminishes the contraction of the clay, and improves the colour of the brick.

4. 2nd. Loam. — The loams are often so full of gravel that it is impossible to free them from stones, except by passing the earth through the wash-mill. The quantity of sand present in these earths renders them less liable to shrink and warp than the strong clays ; but, on the other hand, the texture of tlie earth is so loose and in. coherent, that a mixture of chalk is necessary to bind the mass together, and to take up the excess of fusing silica in the process of burning.

5. 3rd. Malm. — This is an earth suitable for making bricks, without any addition, but there is very little now to be had, and for making the best qualities of bricks (or, as they are called, malms) an artificial malm is made,

* It may be obscn-cd that this classification is such as wouKl be best understood by the generality of readers, but would not be comprehended by most brickmakers, who class these three qualities of brick-earths as strong clay, mild clay, and malm. When the clays are strong, they are said, in brickmakers' language, to hc/vul.

ART OF MAKING BRICKS AND TILES. 121

by mixing together chalk and clay, previously reduced to pulp in wash-mills. This pulp is run off into shallow pits, where it remains until, by evaporation and settle- ment, it has become of sufficient consistency for subse- quent operations. This process is adopted for the best qualities of bricks only, as the expense of it is very con- siderable ; and, for the commoner sorts, all that is done is, to mix with the loam or clay a sufficient quantity of malm to make it suitable for brickmaking : the quan- tity of malm required for this purpose varies, of course, according to the quality of the earth.

6. It -will be readily understood, from the above remarks, that the mode of preparing the clay differs greatly in different yards. The brick-earth (according to its quality) being used —

1st. Without either washing or maiming.

2nd. It may be maimed, i.e., covered with artificial malm.

3rd, and lastly. The bricks may be made entirely of malm.

The second process is the most common, and we pro- pose, therefore, in the following pages, to describe the successive operations of brickmaking as practised at those works where the loamy character of the earth renders the maiming indispensable. This will enable the reader to understand the first and third methods of treating the brick-earth without any farther description.

7. The object of adding chalk to the clay is twofold. In the first place it acts mechanically, in diminishing the contraction of the raw brick before burning ; and in the second place it acts chemically, as a flux during the burning, combining with the silica of the clay, so that a well-burnt London brick may be described as a silicate of lime and alumina, and, therefore, differs

o

122 RUDIMENTS OF THE

greatly from an ordinary red kiln-burnt brick made of pure clay, ■without lime or alkaline matter, the silica and alumina of the brick-earth being, in the latter case, merely in mechanical and not chemical combination.

8. Soil. — The process of maiming is not the only peculiarity of London brickmaking. Instead of the bricks being burnt in close kilns, as is the practice in most country yards, " clamping" is universally resorted to ; and to render this effective, it is considered neces- sary that the fuel should be mLxed up with the brick- earth, so that each brick forms, as it were, a fire ball, and becomes thoroughly burnt throughout, instead of being merely baked, as is the case in kiln burning. The fuel used in clamp burning is domestic ashes, or, as they are technically called, breeze. The ashes are collected in large heaps, and sifted ; the siftiugs, which are called soil, being mixed with the brick-earth, and thoroughly incorporated with it in the processes of soiling and "tempering," whilst the cinders, or " breeze," are used as fuel. A small quantity of coal and wood is also made use of in lighting the clamp.

The soil, or sifted ashes, materially assists in pre- venting the contraction of the raw bricks whilst drying, and the sulphur contained therein appears to assist in colouring the bricks when burnt.

9. Sa7id. — The moulding sand is brought, at a con- siderable expense, from the bed of the river Thames, near Woolwich. It is spread out to dry in the sun in thin layers, which are repeatedly raked over, so as to expose every particle in succession to the sun's rays, that the whole may be perfectly dry when brought to the moulding stool. The moulding sand serves many useful purposes. It assists in preventing the contrac- tion of the clay, and gives a more durable surface to the bricks. It is indispensable to the moulder for pre-

ART OF MAKING BRICKS AND TILES. 123

venting the bricks from sticking to his mould. It also prevents the bricks from sticking together on the hacks, and from breaking up into cracks and flaws when cool- ing, after being burnt. Lastly, the salt in the river sand becomes decomposed in the burning, and assists in fluxing the brick-earth, and in giving the bricks their grey colour. Common sand burns of a red tint, and would injure the colour of the London bricks.

10. General Arrangement of a Brickwork. — This will be readily understood by reference to fig. 1. The brick- earth is turned over to receive the malm as near as possible to the clay pits. The clay and chalk mills are placed close together in some convenient position, so as to interfere with the works as little as can be helped, and the malm is conveyed from them to the heap of brick- earth, by means of troughs or shoots supported on tressels.

Close to the brick-earth, and immediately behind the moulding stool is placed the pug-mill, and in front of the moulding stool is the hack ground, which should, if possible, be laid out with a gentle fall towards the clamps, which is placed at its furthest extremity. These arrangements are of course much modified by the circumstances of the locality.

11. The Chalk and Clay Mills. — These washing- mills are placed close together on a large double mound, sufiiciently elevated to allow the malm to run down freely to the brick-earth. The chalk-mill is a circular trough lined with brickwork, in which the chalk is ground by the action of two heavy wheels with spiked tires, made to revolve by either one or two horses. The trough is supplied with water by a pump, the lever of which is worked by the machinery of the clay-mill, and as the chalk becomes ground into pulp it passes, by

G 2

124

RUDIMENTS OF THE

Fig.l.

K

ART OP MAKING BRICKS AND TILES. 125

means of a shoot, into the clay-mill. The clay-mill is also a circular trough, lined with brickwork, but much larger than that of the chalk-mill ; and in this trough the clay is mixed with the pulp from the chalk-mill, and is cut and stirred by knives and harrows put in motion by two horses, until the whole mass is reduced to the consistency of cream, when it passes off through a brass grating into the troughs or shoots, and is conducted to the brick earth which has been heaped up to receive it. The machinery of the washing-mills is very fully de- lineated in figs. 2 to 10, and is described in detail in arts. 53 and 54.

12. The Pug-mill. — The pug-mill used in brick- raaking is a conical tub, with its larger end uppermost, in the centre of which is a revolving vertical shaft of iron, to which are attached horizontal knives, inclined so that the clay is slowly forced downwards by their motion. The top and bottom knives are called force knives, and their use is merely to force the earth through the mill, and out at the ejectment hole ; all the other knives are furnished with cross knives, which assist in cutting the clay, and breaking up any hard lamps that may not have been broken up by the pre%4ous wintering and turning over. In order to feed the mill, an inclined barrow-run is laid up to it, to enable the wheeler to tip the clay in at the top.

The construction of the pug-mill is shown in figs. 1 1 and 12.

13. TJie Cuckhold, fig. 13, is an instrument for cutting off lumps of the tempered clay for the use of the moulder, as it is ejected from the pug-mill, and requires no particular description.

14. The Moulding Stool. — The moulding stool is quite different from that used in most parts of the

126

RUDIMENTS OF THK

J^i^. 2 and 3.

country. It has a rim at each cncl^ to keep the moulding sand from falling off, and is provided with a stock-board, which forms the bottom of the brick mould, and with a

ART OF MAKING BRICKS AXD TILES. 127

J^js. i and 5.

y/rr

page, which is formed with two rods of f iron, nailed down at each end to the wooden rails on which they rest. The use of the page is to slide the raw bricks more readily from the moulder to the place from whence thev are taken and put upon the hack barrow by the " taking-off " boy. The moulder, when at work, stands

J 28

RUDIMENTS OF THE

I'lg. 6.

J.

near the middle of the stool, with the page on his left hand, and his assistant, the clot-moulder, on his right.

ART OF MAKING BRICKS AND TILES.

129

Fig. 6.

The moulding sand for the nse of the moulder and clot- raoulder is placed in separate heaps at the opposite ends

G 3

130

RUDIMENTS OF THE

Fig. 7.

^

ART OF MAKING BRICKS AND TILES. 13]

Fig. 8.

^iiH

hi

!e

10

Figs. 9 and 10.

of the stool, and the tempered clay nearly opposite to the moulder. There is no water-box, but a tub is placed

132

RUDIMENTS OF THE

jpig. 11.

on the stool, into which the strike is thrown when not in use. The pallets are placed at one end of the page,

ART OF MAKING BRICKS AND TILES.

133

Fig. 12.

134

RUDIMENTS OF THE

Fig, 13.

and close to the moulder's left hand. These particulars will be fully understood by reference to fig. 13, and to the detailed description in art. 56.

ART OF MAKING BRICKS AND TILES

135

15. The Brick Mould is made of sheet iroUj iu four pieces, riveted together at the angles, aud strengthened with wood at the sides only. The bottom of the mould is detached, and forms what is called the Stock-board. See fig. 14.

Fig. 14.

f2

IN^

16. The Stock-board is a piece of wood plated with iron round the upper edge, and made to fit the mould

loG RUDIMENTS OF THE

accurately, but easily. At each corner an iron pin is driven into the moulding stool, and on these pins the bottom of the mould rests, the thickness of the brick being regulated by the distance to ^vhich the pins are driven below the top of the stock -board. The hollow in the bed of the brick is produced by a rectangular piece of wood, called a kick, of the size and shape of the hollow required, which is fastened on the upper side of the stock-board.

17. The Strike is a smooth piece of wood, about 10 in. long by 1^ in. wide and \ in. thick, and is used to remove the superfluous clay in the process of moulding.

The Pallets are pieces of board § in. thick, and of the exact width of the mould, but about f in. longer. Three sets of pallets, twenty-six in each set, arc re- quired for each moulder at work.

18. The Hack Barrow, figs. 15 and 16, is of a pecu- liar construction. It consists of a light frame, sup- porting a flat top of lattice work, on which the bricks are placed in two parallel rows, thirteen in each row. Three barrows are required for each moulder.

19. The Hack Ground occupies the space between the moulding stool and the clamp. It should be well drained, and it is desirable that it should be on a slight fall towards the clamp, as this lessens the labour of wheeling. The foundations of the hacks are slightly raised. It is of importance that the barrow-runs be- tween the hacks should be perfectly even, as any jolting of the hack barrow would injure the shape of the raw bricks, which, when first turned out of the mould, are very soft. The hacks are placed 11 ft. apart, measured from centre to centre, their length varying according to the shape of the ground. It is very difiicult to say

ART OF MAKING BRICKS AND TILES.

137

£ig. 15.

T- '

what extent of hack ground should be allotted to each moulding stool, as this varies greatly in diflFerent yards. In round numbers, the quantity of land required for a brickwork may be stated at from 1 ^ to 2 acres for each

138

RUDIMENTS OV THE

Fig. 16.

moulding stool, but tins includes tlic whole of the land required for the several purposes.

II.— PROCESS OF MANUFACTURE.

20. Clay Digging. — The first turning over of the hrick-earth should take place in the autumn, in order that it mav have the benefit of the winter firosts before

ART OF MAKING BRICKS AND TiLES. 139

being used. The vegetable mould and top soil having been wheeled to spoils the brick-earth is turned up three or four spits deep, and laid on a level floor, prepared for the purpose, and banked round to prevent the escape of the malm in the process of maiming.

21. The quantity of clay required per 1,000 bricks is variable, of strong clay more being required than of milder qualities.

It is generally calculated that an acre 1 ft. deep, or about 1,600 cubic yards of clay, will make 1,000,000 bricks, but strong clays will require from 182 to 200 cubic yards per 100,000 bricks. For practical purposes the quantity may be thus approximately stated : —

Strong clay 2 cubic yards per 1,000 bricks. Mild clay If cubic yard per 1,000 bricks.

22. Maiming. — It has been before explained that the best bricks only are made entirely of malm, but that the process of maiming is resorted to for other descriptions of bricks, where the quality of the clay renders it unfit for brickmaking without this addition. It Avill, therefore, be readily understood that the quantity of malm mixed with the clay in the ordinary process of brickmaking varies very considerably, so that it is impossible to say, a priori, what quantity of malm should be used, as this must be left to the judgment of the brickmaker in each particular case, according to the quality of the earth.

To keep the washing-mills in full work are required —

To the chalk-mill, 2 diggers and 1 wheeler. To the clay-mill, 4 diggers and 2 wheelers.

The chalk-mill is worked sometimes with one, and sometimes with two horses. The clay-mill always re- quires two horses. No drivers are required.

140 nUDIMENTS OF THE

The average work of the washing-mills, working 10 hours a day, may be taken at about 12 cubic yards of malm,* or sufficient for making 6,000 malm bricks.

The process of maiming scarcely requires description. Water having been pumped into the troughs, chalk is ■wheeled to the chalk-mill, and clay to the clay-mill, and the horses being driven round, the chalk is crushed and ground by the wheels, and runs through the outlet into the clay-mill, where both chalk and clay get well mixed by the harrows, the liquid malm flowing out through the brass grating to the shoots, by which it is conducted to the brick-earth. As the heap becomes covered the shoots are shifted, so that the malm shall be equally distributed over every part of the heap.

When a sufficient quantity of malm has been run oflp, it. is left to settle for a month or more, until it has become sufficiently consolidated to bear a man walking over it. As the solid portion of the malm settles, the water is drained off from time to time, and when the mass is sufficiently firm, the soiling is proceeded with.

23. Soiling. — The proportion of ashes depends very much on the quality of the earth, but may be stated approximately at about 35 chaldrons for every 100,000 bricks. The soil is laid on the top of the maimed earth, the thickness of the layer depending on that of the heap, about 3 in. of ashes being allowed for every spit of earth.

The soiling concludes the preparation of the brick- earth, which is allowed to remain undisturbed until the

* At a manufactory of artificial hydraulic lime at Meudon, near Paris, the clialk and clay arc ground together in a washing-mill, of the same, construction as those used in England, and worked by two horses. The quantity of malm produced is about Ij cubic ^ard per hour. — See Vicat on Cements.

ART OF MAKING BRICKS AND TILES, ] dl

moulding season, -whicli generally commences in April, The first process of the actual manufacture is —

'14.'. Tempering. — The heap, prepared as above, is turned over by spade labour, and the ashes thoroughly incorporated with it, wate?' being added to bring the mass to a proper consistency. The tempered clay is then wheeled to the pug-mill, which, as before stated, is placed close to the clay heap, and immediately behind the moulding-stool.

25. Pugying. — The tempered clay being thrown in at the top of the mill, gradually passes through it, and in so doing becomes so thoroughly kneaded as to be of a uniform colour, the ashes being equally distributed through the mass. The quantity of clay ground is about 1^ cubic yard per hour, so that a horse working 10 hours per diem will grind 12^ cubic yards of clay, or sufficient to make 6,250 bricks.

If the moulding process does not proceed as fast as the pugging, so that the clay will not be immediately used, the clay, as it comes out at the bottom of the mill, is removed with the cuckhold, and covered with sacks, to keep it from becoming too dry for use,

26, Moulding. — Before commencing moulding, the moulding-stool is provided with two heaps of dry sand, a tub of water, in whicli to place the strike, a stock- board and brick-mould, and three sets of pallets. Everything being in readiness, and a supply of tern- pered clay having been placed on the stool by the feeder, whose business it is to carry the tempered clay from the pug-mill to the moulding-stool, the clot-moulder, who is generally a woman, sprinkles the stool with dry sand, and taking a clod, or clot, from the heap of tempered clay, dexterously kneads and moulds it roughly into tlie shjxpe of a brick, and passes it to the moulder on her

142 BUUIMENIS Of Tirz

left hand. The moulder, having sprinkled sand on the stock-board, and dashed the mould into the sand-heap on his left hand, places the mould on the stock-board, and dashes the clot into it with force, pressing it with his fingers, so as to force the clay into the angles of the mould. He then, with the strike, which has been well wetted in the water-tub, removes the superfluous clay, which he throws back to the clot-moulder to be remoulded. The mould is then lifted oflf the stock- board, and placed by the moulder against one of the pallets, which he catches dexterously with his fingers, and, turning out the raw brick upon it, slides it along the page to the taking-oflf boy, and, lifting up the empty mould, dashes it into the sand, and replaces it on the stock-board, preparatory to moulding a second brick ; when he has moulded one set of bricks, he scrapes away the sand which has adhered to the mould during the operation with the strike, and then proceeds with the next set. A moulder and clot-moulder, with the assistance of a feeder, a taking-off boy, and two men to wheel and hack the bricks, will make about 5,000 bricks between 6 a.m. and 6 p.m. ; but this quantity is often exceeded.*

27. Hacking. — The raw brick is removed from the page by the taking-off boy and placed on the hack barrow, and when the latter is loaded, dry sand is sprinkled over the bricks, and they are carefully wheeled away to the hack ground. Having arrived at that part of the ground where the hack is to be com- menced, the man takes a spare pallet and pkccs it on

* Sec the following : — " Brickmaking. On Wednesday last. Job. Bash, at Peterskre, Cumberland, performed the feat of making 1 ,000 bricks in •n boar ; 100 in fire minutes ; and 26 in one minate." — Carlisle JoumdU (This is not a solitary instance.)

ART OF MAKING BRICKS AND TILES 143

one of the bricks, which he carries between the two pallets to the ground, and sets it up carefully edgeways, taking care in removing the pallets not to injure the shape of the soft brick. One of the pallets is replaced on the barrow, and with the other another brick is removed ; and the process is repeated till the twenty-six bricks have been placed on the ground, when the empty barrow is wheeled back to the moulding stool. In the meantime another barrow has been loaded, and is ready for wheeling to the hack ground. Three hack barrows are required, so that one of them is constantly being unloaded upon the hack ground, another loading at the moulding stool, and the third being wheeled to or from the hack ground. Thus two men are necessarily em- ployed in the operations of wheeling and hacking. The hacks are set up two bricks in width, the bricks being placed slantwise, and not at right angles, to the length of the hack. After the bottom row of one hack is com- pleted, a second hack is commenced, to give the bricks time to harden before a second course is laid on them ; and when the second course is commenced, the bricks must be placed fairly on each other, or they will be marked, which injures their appearance. The hacks are carried up in this way until they are 8 bricks high, when they are left for a few days to harden. To protect the new bricks from frost, wet, or intense heat, straw or reeds are provided and laid alongside the hack; and with these the bricks are carefully covered up at night, and at such other times as the weather may render necessary. When half dry, they are scintled,'^- that is, set farther apart, to allow the wind to pass freely between them, and they receive no further atten- tion until sufficiently dry for burning. The time

• Literally, scattered.

144 RUDIMENTS OF THE

required for drying varies from tlii'ce to six weeks, according to the weather. =»=

28. C/o/«;;i»^.— Figures 17, 18, 19, 20, and 21. The process of clamping requires great skill, and its prac- tical details are little understood, except by the ■work- men engaged in this part of the manufacture. Scarcely any two clamps are built exactly alike, the differences in the methods employed arising from the greater skill or carelessness of the workmen, and local circumstances, such as the situation of the clamp, and the abundance or scarcity of burnt bricks in the yard with which to form the foundation and the outside casing. We pro- pose, therefore, first to describe the method of building a clamp, according to the most approved system, and then to explain the principal variations practised in different yards.

29. A clamp consists of a number of walls or necks, 3 bricks thick, about 60 bricks long, and 24 to 30 bricks high, in an inclined position on each side of an upright or double battering waU in the centre of the clamp, the upright being of the same length and height as the necks, but diminishing from 6 bricks thick at bottom to 3 bricks thick at top. The sides and top of the

• Mr. n. Chamberlain, in a paper read before the Society of Arts, IV. 515, speaks of the great importance of drj-ing bricks : — " The dning of bricks ready for burning is a matter of great importance, and requires more attention than it generally receives. From hand-made bricks we have to evaporate some 25 per cent, of water before it is safe to burn Ihem. In a work requiring the make of 20,000 bricks per day, we have to evaporate more than 20 tons of water every 24 houi-s. Hand-made bricks 1092 in drying about one-fourth of their weight, and in drying and burning aboui ur.e-tliird. The average of machine bricks — those made of the stiff plastic ciay-do not lose more than half the above amount from evaporation, and arc, therefore, of mutit ^;:rcatcr specific gravity than hand-made ones." The artificial drying of bricks over flues can of course only be carried on where coal is cheap. Mr. Beart has contrived a steam chamber, where steam made to circilate in pipes is the source of heat for drying tl)e bricks.

ART OF MAKING BRICKS AND TILES.

115

Fq. ll

146

RUDIMENTS OF THE

Fig. la

ART OF MAKING BRICKS AND TILES.

147

Fig. 20.

rn

7/ / // //>///// r-n-rn-T

3

I I I I I r

r I I I I rfn I i\i I I

T-r)-n-T^

i

^

TT^T^^

TTT I I 1) ) I I I I I

THE l/y£-//OL£ (cj

148

RUDIMENTS OF THE

Fig. 21.

I

ART OF MAKING BRICKS AND TILES. 149

clamp arc cased with burnt brick. The fuel used in burning the laid bricks consists of cinders (breeze, as before described), which are distributed in layers between the courses of bricks, the strata of breeze being thickest at the bottom. To light the clami^, live holes or flues, 7 in. wide and 9 in, high, are left in the centre of the upright, and at every 7th or neck. These live holes extend through the whole thickness of the clamp, and are filled with faggots, which, being lighted from the outside, soon ignite the adjacent breeze. As soon a^ the clamp is fairly lighted, the mouths of the live holes are stopped, and the clamp burns until the whole of the breeze is consumed, which takes from three to six weeks. This description will give the reader a general idea of the arrangement of a clamp ; and we will now describe in detail the manner of building one, premising that the term close bolting signifies stacking bricks so that they shall be perfectly close to each other ; and that scintling means stacking bricks with spaces be- tween them.

30. Foundation. — The ground is first carefully drained and levelled, and made perfectly firm and hard. The exact position of the clamp having been fixed, the ground is formed with a flat invert whose chord is equal to the width of the intended clamp. The object of this is to give a lift to each side of the clamp, which prevents the bricks from falling outwards as the breeze becomes consumed. The ground being prepared, the upright is commenced. But, previous to building, the clamp barrow-roads or tramways of sheet-iron are laid down between the hacks, and extended to the clamp ground, to give an easy motioi. to the barrows ; as, from the kind of barrows used in clamping, tlie bricks being piled on each other several courses high, and the

]30 KUDIMENTS OF TIIi:

wheeling carried on with considerable vclocitr, they are apt to upset.

31 . Upright. — The upright is commenced by building two 9 inch battering walls about 45 ft. apart, of burnt bricks laid on edge, which are termed close bolts, the length of each wall being equal to the thickness of the upright, which at the bottom is 6 bricks thick, or about 4 ft. 6 in. (their height is IG courses, or about 6 ft.). Between these bolts a line is stretched, by which the upright is built true. The ground between the bolts is paved with burnt bricks laid on edge, to exclude the moisture of the ground. Upon this paving are laid two courses of burnt bricks with spaces between them, termed scintles. In the bottom course of scintUs the bricks are laid diagonally about 2 in. apart. The second course consists of bm-nt bricks on edge, laid across the lower one, in lines parallel to the ends of the clamp, and also 2 in. apart. In laying these two courses of scintles, a live hole is left about 7 in. wide, the whole length of the upright ; and, on the completion of the second course, the live hole is fiUed up with faggots, and the whole surface covered over with breeze, which is swept or scraped into the spaces left between the bricks. On this surface is placed the first couree of raw bricks, laid on edge and quite close, beginning over the live- hole. Over this first course of raw bricks is laid a stratum of breeze 7 in. thick, the depth being increased, at the ends of the uprights, to 9 or 10 inches, by inserting three or four bricks on edge among the breeze. The object of this is to give an extra lift to the ends. The first course of bricks, it should be observed, is laid all headers. Over the first layer of breeze is laid a second course of raw bricks on edge, all stretchers. This is covered with 4 in. of breeze, and at each end arc inserted

ART OF MAKING BRICKS AND TILES. 15 1

two or three bricks to increase the lift still more ; huL this time they are laid flat^ not edgeways. Upon the 4 in. layer of breeze is laid a heading course of raw bricks laid close, and on this 2 in. of breeze, without any extra lift at the end. To this succeed stretching and heading courses of raw bricks on edge, laid, close up to the top of the clamp, a layer of breeze, not more than | in. thick, being placed on the top of each course, except on the top course, which has 3 in. of breeze. The top of the up- right is finished by a close bolt of burnt bricks. The upright is built with an equal batter on each side, its width diminishing from six bricks lengthways at the base to three bricks lengthways at the top. In order that the upright should be perfectly firm, it is necessary that the bricks should be well tied in at the angles j and, in order to obtain the proper width, the bricks are placed in a variety of positions, so that no very regular bond is preserved, as it is of more consequence to keep the batter uniform.

The close bolts first commenced, and which form the outer casing of the clamp, are not built close to the raw bricks, there being a small space left between the clamp and the close bolting, which is filhd up with breeze. The close bolts, however, are built with a greater batter than the ends of the upright, so that they just touch the latter at the 16th course, above which the clamp is built without any external casing. "When, however, the up- right is topped, and whilst the top close bolting is going on, the casing is continued up to the top of the clamp. This upper casing is called the bestowing, and consists of five or six courses of burnt brick laid flat, forming a casing 4| in. or half a brick thick ; and above the 6th course the bricks are laid on edge, forming a still thinner casing only 3 in. thick. When the weather is

152 KUDIMENTS OF THE

bad, and during the latter part of the brickmaking season, a little extra bestowing is given beyond what is here described. The great art in clamping consists in the proper construction of the upright, as the stability of the clamp depends entirely upon it.

32. Necks. — The remainder of the clamp consists of a number of neck? or "svaUs leaning against the upright. They are built in p'"ecisely the same way as the upright, as regards invert, close bolts, paving, scintling, breeze, and end lifts. But there is this essential difference, viz., that they sive parallel walls, built in alternate courses of headers and stretchers laid on edge, each heading course in one neck being opposite to a stretching course in the next neck, and vice versa. The thickness of each neck is made up of three bricks lengthways in the heading courses, and ten bricks edgeways in the stretching courses. The necks are close bolted at top, and be- stowed in the same manner as the upright. When the last necks have been built, the ends of the clamp are close bolted, and bestowed in the same way as the sides, and this operation completes the clamp.

33. Firing. — The number of necks on each side of the upright may be extended to eight or nine, without an additional live hole; but if this limit be exceeded, additional live holes are required, according to the judgment of the brickmaker or the demand for bricks; the live holes are placed seven, eight, or nine necks apart. It is not necessary that the additional live holes should pass under the centres of the necks, and it is more convenient to form each live hole so that the face of the last-built neck shall form one of its sides.

In the close bolting surrounding the clamp, two bricks are left out opposite the end of each live hole, and to each of these openings a fire is applied made of coals,

ART OF MAKING BRICKS AND TILES. 153

and wood heaped up in a brick fire-place built round the opening, and known by the name of a devil-stove. The fire is kept up for about a day, until the faggots in the live hole are thoroughly ignited, and as soon as this is found to be the case, the fire is removed, and the mouth of the live hole stopped with bricks, and plastered over with clay. In firing a large clamp with many live holes, it should be begun at one end only, the live holes being fired in succession, one after the other.

The bricks at the outside of the clamp are under- burnt ; they are called burnovers, and are laid aside for reburning in the next clamp that may be built. The bricks near the live holes are generally partially melted and run together in masses called clinkers or burrs. The bricks which are not fully burnt are called place bricks, and are sold at a low price, being unfit for outside work, or situations where they will be subjected to much pressure. The clinkers are sold by the cart- load, for rockwork in gardens and similar purposes.

34. The quantity of breeze required varies much with c'Ae quality of the earth. The usual proportions for every 100,000 bricks are about 35 chaldrons of the sifted ashes, mixed with the brick-earth, and about 12 chal- drons of the cinders or breeze to light the clamp.

The quantity of fuel to the live holes it is difiicult to calculate; about lOs. may be taken as the average cost of coals and wood for every 100,000 bricks.

35. If the proportion of breeze be too small, the bricks will be undcrburned, and will be tender and of a pale colour. If too much fuel be used, there is danger of the bricks fusing and running into a blackish slag. No rules can be laid down for avoiding these errors, as the management of the breeze must depend upon the quality of the earth, and can only be learnt from

II <J

154 BUDIMEXTS OF THE

experience, some brick-earths being much mere fusible than others.

36. The time of burning varies considerably. If ex- pedition is requisite, the flues are placed near together, and the burning may be completed in a fortnight or three •weeks; but, if time is no object, the flues are further apart, and the clamp is allowed to bum off" more slowly.

37. Another system of clamping is to begin at one end and to follow with the necks iu one direction only. This is done when the clamp ground is partly occupied by the hacks, so as to render it impossible to commence at the centre. AVhen this system is adopted, the clamp- ing begins with the erection of an end-wall, termed the upright and outside, which is made to batter very con- siderably on the outside, but of which the inside face is vertical. As regards dimensions and modes of building, the outside and upright is built in the same way as the ordinary upright, but it has, of course, no live hole under it, the first live hole being provided in the centre of the 2nd or 3rd neck. In the style of clamping the necks are all upright. The live holes are placed at every 8th or 9th neck, as in the usual system.

38. We now proceed to describe the principal varia- tions in the methods of clamping practised in different brick-yards.

Paving. — The practice with regard to the paving of burnt bricks is very variable. Some clampers omit it altogether; others pave only where clamping for the first time on a new clamp ground.

Scintks. — "U'hen burnt bricks run short, as in build- ing the first clamp on a new ground, the second course is laid with raw bricks. This, however, is a very objeC' tionable pr?ctice.

AllT OF MAKING BRICKS AND TILES. 155

Live Holes. — The live holes are sometimes close- bolted at the sides^ to prevent the breeze from the scintles falling into them. This^ howe\^er, is not often done, and its utility is questionable.

Breeze. — Some clampers put the 7 in. stratum of breeze on the top of the scintles^ instead of placing it over the 1st course of raw bricks; very frequently the breeze is dispensed ■with after the 2 in. stratum, with the exception of the top layer. All clampers, however, agree as to the necessity of having the 7 in., 4 in., and 2 in. layers.

39. The several descriptions of bricks made for the Londoujgjoarket, and their relative prices, as given in the Builders' and Contractors' Price Book, for 1868 are as under, viz. : —

Price per 1,000.

.£ s. d.

Malm cutters 5 5 0

„ seconds . . . . . 3 12 0

„ paviours . , . . . . 3 2 0

„ pickings 3 2 0

„ stocks 2 7 0

„ roughs 1 18 0

„ place 1 10 0

Comraon stocks 2 2 0

„ roughs 1 16 0

„ place 18 0

Red stocks 2 5 0

„ rubbers 3 4 0

Paving bricks 2 10 0

Dutch clinkers 2 5 0

The prices of the various kinds of fire-bricks will be found at page 18.

The bricks commonly sold are known by the follow- ing terms : —

Cutters. — These are the softest, and are used for gauged arches and other rubbed work.

Malms. — These are the best building bricks, and are only used in the best descriptions of brickwork j coloui yellow.

156 RUDIMENTS OF THE ^

Seconds. — These are sorted from the best qualities, and are much used for the fronts of buildings of a superior class.

Paviours. — These are excellent building bricks, being sound, hard, well shaped, and of good colour. They must not be confounded with paving bricks, ha^-ing nothing in common with them but their name.

Pickings. — These are good bricks, but soft, and inferior to the best paviours.

Rough Paviours. — These are the roughest pickings from the panours.

Washed Stocks. — These are the bricks commonly used for ordinary brickwork, and are the worst description of malms.

Grey Stocks. — These are good bricks, but of irregidar colour, and are not suited for face work.

Rough Stocks. — These are, as their name implies, very rough as regards shape and colour, and not suited for good work, although hard and sound.

Grizzles. — These arc somewhat tender, and only fit for inside work.

Place Bricks. — These are only fit for common purposes, and should not be used for permanent erections.

Shuffs. — These are unsound and shuffy — that is, full of shakes.

Burrs or Clinkers. — These arc only used for making artificial rockwork for cascades or gardens, &c.

Bats. — These are merely refuse.

It may be here observed, that at the brickworks round Loudon the bricks made are usually in the form of regular parallelopipcdons, 9 in. long, 4^ in. wide, and 3 in. thick. If in the execution of apiece of brickwork, bricks of other shapes are required, it was formerly the practice, and still sometimes is, for the bricklayer to cut

ART OF MAKING BRICKS AND TILES. 157

the ordinary bricks to the required shape. This practice^ so destructive to sound bond and good work, cannot be too strongly reprehended;* especially now that the manufacture is free from the trammels of the excise there can be no excuse for not making bricks of a great variety of shapes for various purposes.

40. Brickmaking'".t Cheshunt. — In the " Illustrations of Arts and Manufactures," by Mr. Arthur Aikin, is a valuable paper on pottery and brickmaking, the perusal of which is strongly recommended to the reader. The following notice is there given of the Cheshunt bricks : — '' At Cheshunt, in Hertfordshire, is a bed of malm earth of the finest quality, no less than 35 ft. in depth ; from this are made the best smUl kiln-burnt bricks, called paviers." Not having an opportunity of personally examining the Cheshunt works, the author requested Mr. B. P. Stockman to do so, and, in reply, received the foUoAving communication, from which it appears that kiln burning has been now disused for some time at Cheshunt ; clamping being now generally adopted : —

" There are no bricks now made near London of natural malm ; the once well-known bed at Grays in Essex has been exhausted some years. No one can inform me of any bed of natural malm except that at Cheshunt, and I was told, previous to my going there, that I should not find the works conducted as I had been led to expect from your letter.

" There are only two brickmakers at Cheshunt, and, from going over their works, I am able to vouch for the accuracy of the following particulars.

* The brick columns, wliosc failure caused the frightful accident which OCCun-ed in January, a.d. 1848, during the erection of the new buildings at the Euston Station of the North Western Eaihvay, were built in thia way. The additional cost of bricks made expressly lor the work, of such forms as would have bonded properly together without any cutting, would have been very trifling.

158 nUDIMENTS OF THE

" There is a bed of natural malm, and a bed close to it of ordinary brick-earth, which also contains malm. When they make malms, -which they ■\vere not doing at the time of my visit, they do not use the natural malm earth by itself, but wash and mix chalk with it, and I am told that they never have made malms without adding chalk to the natural earth, although the propor- tion is small compared to that required for the other bed from which they also make malms. The earth is soiled with ashes precisely in the same way as in the London works, and turned over and pugged in the same kind of pug-mill. The bricks are hacked and clamped, as in London, and there are none burnt in kilns, nor have been for many years. There are no kilns on the ground, and no kiln burning of any description, though in former years there used to be kilns for bricks and tiles, and also for glazed ware.

" The bricks made at Cheshunt are very superior to the London bricks ; in fact, the stock made there is really a kind of malm brick, and the malms themselves, as you may suppose, are perfection. I examined the brick-earth from both pits, and saw the several processes of moulding, hacking, scintiing, and clamping going on. The names of the different qualities are the same as in London ; but, as regards quality, some of the common descriptions are equal to the London malms, and I believe the shuffs would be sold for malms in London."

41. Brickmaking is carried on to a great extent all round the metropolis, but the principal brick-fields are situated north of the Thames.

ART OF MAKING BRICKS A\D TILES. 159

III. COST OF MANUFACTURE.*

42. We propose to consider the cost of manufacture under three heads^ viz.: —

1. Materials and fuel.

2. Machinery and tools.

3. Labour.

I. MATERIALS A^D FUEL.

43. Clay. — The cost of brick-earth must depend ver/ much on the circumstances of the locality^ but it ii> usually considered to be worth 2^. 6d. per 1,000 bricks, exclusive of getting.

41. Chalk. — The cost of chalk is trifling where the works have the advantage of water carriage, as it can be brought to the canal wharfs round London at 2s. lOd. per ton. To this must be added the cartage, which, in some cases, must be a serious expense.

45. Sa7id. — The above remarks apply to the mould- ing sand ; which is brought from the bed of the Thames, near Woolwich, in barges to the canal wharfs at 2s. per ton, a ton being about 1;^ cubic yard. To this must be added cartage, and labour in drying the sand to make it fit for use.

It is difiicult to say what quantity of sand is used per 1,000 bricks, but the cost may be taken approximately at from 6d. to 8^. per 1,000 bricks.

46. Breeze. — The quantity of breeze required varies according to circumstances ; the proportion may be taken to range from 12 to 20 chaldrons per 100,000 bricks. The cost of breeze may be taken at about 10^.

* The estimates under this head must be considered as belonging to the date of the first edition of this work (1850), but later prices will be found at page 162.

160 RUDIMENTS OF THE

per chaldron. It may here be mcntioued, that in London stringent regulations are in force to prevent householders from making use of their domestic ashes^ which are collected by parties who contract with the parish authorities for this privilege.

In the Midland Counties the domestic ashes are generally used for manure^ the ashes being thrown into the cesspoolsj an aiTangement which would not be per- mitted in the metropolis. This mode of disposing of the domestic ashes completely prevents the use of breeze in the manufacture of bricks in the district where it is practised.

47. Soil. — The cost of soiling cannot be very accu- rately ascertained. The quantity of soil required de- pends much on the quality of the brick-earth; 35 chaldrons per 100.000 bricks may be considered a fair average. The cost per chaldron may be taken at 85. to 9s. To this must be added the cost of harrowing to the clay heap, say 10s. to 125. per 100^000 bricks.

48. Coals and Wood. — The quantity of faggots re- quired will depend on the number of live holes. This item of expense is very trifling, say \0s. per 100,000 for faggots and coals to light the clamp.

49. Water. — The water required for the washing- mills is pumped into the troughs as before described, and as shown in the drawings of the washing-mills, fig. 7. That which is used in tempering the clay is brought in buckets from the nearest pond on the works. In some yards the supply is drawn from wells by the contrivance known in the East as a shadoof, and in use at the present day in Germany, and throughout Russia. This simple contrivance is described at page 3 of Mr. Glynn's " Rudimentary Treatise on the Construction of Cranes and Machinerv," and the reader is there-

ART OF RIAKINO BRICKS AND TILES. 161

fore referred to the description and "svood-cut there given.

It may, however, be worth while to remark, that there is scarcely any difference between the ancient shadoof used in Egypt in the time of the Israelitish bondage and that in common use at Stoke Newington, and other places near London, in our own time.

It is impossible to make any calculation as to the proportionate cost of the necessary supply of water to a brickfield, as it forms a portion of the cost of tempering, and cannot be separated from it.

II. MACHINERY AND TOOLS.

50. The average cost of the machinery and tools re- quired in a London brickfield is about as follows : —

Chalk and clay mills, together . Pug-mill .......

Cuckhold .......

For each moulder arc required —

1 moulding stool, complete, at

1 mould „

3 sets of pallets, 26 in each set

3 bearing-ofF barrows .

In addition to the above are required, a few plauks, shovels, barrows, buckets, sieves, and other articles, the aggregate cost of which it is impossible to estimate.

No buildings are required for the actual manufacture.

It is, however, usual for the foreman, or '''moulder,^' to live at the field. Stabling may be required or not; according to circumstances and locality.

	£	«.	d.
£00 to	70	0	0
	10	0	0
5s. to	0	6	0
	0	14	0
	0	10	6
at 3s.	0	9	0
at 12s.	1	16	0

iG2

KUDIMEXTS OF TllK

III. LABOUR.

51. The cost of labour, &c., may be taken as follows : —

rer

1,000 bricks. £ s. d.

Rent of field

Ashes ....

Removing top moulJ

Dijrging earth

Soiling and turning cartli

Clialk and expense of washii

Moulding

Horse grinding earth

Sand

Straw and hurdles

Setting

Bolting, sorting, fee.

Loading

Implements, &c. .

Superintendence .

Interest on capital

. Royalty

Bad debts

Preparing hacks, obtuining water, making coals and wood in burning, materials building sand-houses ....

1 8 0 6

for

0 0 6

1 0 0

This is the actual cost for every thousand bricks be- fore they leave the field ; and in order to secure a fail profit, I. e., about 20 per cent., the stock bricks must be sold at £1 85. per 1,000; while the place bricks -will sell at from 15*. to £1, the grizzles and rough bricks at from 19*. to £1 Zs., and the shuff's at from 85. to 10«. per 1,000.

BRICKMAKTN'G AT THE COPENOAGEN TUN^^:L, ON THE GREAT NORTHERN RAILWAY.

After the above description of the ordinary practice of London brickmakers was written, ^lessrs. Pearce and Smith, the contractors for the Copenhagen Tunnel,

ART OF MAKING UUICKS AND TILES. 163

ou tlie line of the Great Northern Railway, commenced brickmaking on a large scale at the tunnel-works ; and as the mode of manufacture practised by them was new at the time in London, a short notice of it may Le interesting: —

The clay is neither Aveathered nor tempered, but as soon as dug is wheeled up an incline to the grinding- mill, which consists of a single pair of cast-iron rollers, driven by a steam-engine. The clay is mixed with a certain proportion of sifted ashes, and, passing between the rollers, falls into a shed, whence it is, without further preparation, wheeled to the moulders.

The moulds are of wood, and the process employed is that known as slop-moulding.

The moulding and drying processes are both carried ou in drying houses, with flues under the floors.

The bricks, as soon as moulded, are carried one by one to the floors, where they remain until dry, when, without being hacked, they are wheeled to the kilns.

The kilns are of the construction commonly used in the Midland Counties, but have no sheds at the sides to shelter the fires. The fuel used is coal.

The bricks thus mode are of an irregular reddish brown colour, and of fair average quality.

On first commencing operations, Messrs. Pearce and Smith made a large quantity of bricks without any admixture of ashes, sand only being added to diminish the contraction of the clay. These bricks burnt of a clear red colour, and were mostly very hard, but proved brittle, and were apt to become cracked in burning.

Amongst other novelties adopted, may be mentioned the use of saw-dust in lieu of sand,* the latter material

♦ It may be necessary, perhaps, to remind the reader that sand is used lov many purposes besides that of sanding the brick-mould.

164 KUDIMEXTS OF THE

being very costly, ^Thilst the former is supplied on the works from a saw-mill worked by a steam-engine, which at the same time drives the mortar-mill, and works the lifts at two of the tunnel shafts.

RErEBENCE TO ILLUSTRATIONS ACCOMPANYING THE FORE- GOING Account of BRiciMAKixo ix the vicinity of London.

52. — Fig. 1. General Plan of a Brickworl:. (Scale 40 ft. to an inch.)

A. The chalk-mill.

B. The clav washing-mill. c The pump.

D. The shoot to the brick-earth.

i;. The brick-earth turned over in readiness to receive the malm. r. The pug-mill. G. The moulding RtooL H. The hack ground. K.K.. Clamps.

53. The Chalh-miU.

Figs. 2 and 3. Section and Plan. (Scale 10 ft. to an inch.) a.a. Grinding-whccls. b. Inlet from pump.' e. Outlet to clav washing-mill. Details. (Scale 5 ft. to an inch.) Fig. 4. Grinding-wheel.

Fig. 5. Mode of connecting the axle-tree of the grinding-wheels will: the centre shaft.

The mill consists of a circular trough lined with brick- work, and furnished with a pair of heavy wheels with spiked tires, which, being drawn round by horses, crush and grind the chalk until it is reduced to a pulp. The wheels arc shown in detail in fig. 4. It is necessar}' that they should accommodate themselves to the level of the chalk in the trough, and to effect this, the framing

ART or MAKING BRICKS AND TILES. 165

of which the axle-tree forms a part is secured to the centre shaft by a staple^ as shown in fig. 5, which allows the whole of the timbering to rise or fall, as may be requisite. The centre shaft is a bar of iron, steadied by being built up in a mass of brickwork. The yoke beams are kept at the proper height, and their weight supported by common light chaise wheels, about 2 ft. 6 in. diameter, which run on the outside of the horse track. The mill represented in these engravings is mounted for two horses ; many mills, however, have but one.

5-1. The Clay-washing Mill.

Figs. 6 and 7. Plan and elevation. (Scale 10 ft. to an inch.)

a. The inlet from the chalk-mill.

b. The outlet to the shoot. ex. The harrows.

d.d. The cutters. e. The pump.

Details, (Scale \\ in. to 5 ft.) Fig. 8. The cutters.

Fig. 9. The outlet to the shoot, and the strainer. Fig. 10. The strainer.

The mill consists of a circular trough of larger dimen- sions than that of the chalk-mill, also lined with brick- work, and furnished with a two-horse gin, to which are attached knives and harrGws, which, in their passage round the trough, cut up the clay and incorporate it with the pulp from the chalk-mill. The framing of the gin is very simple, and requires no description. The knives, or cutters, are placed in two sets, four in each. They are fixed in an upright position, and steadied to their work by chains, and by being bolted together with bolts passing through tubular distance pieces, as shown ki fig. 8. The knives cut the clay and clear the way for the harrows, which are similar to those ujsed for agricultural purposes, and arc merely suspended by

166 RUDIMENTS OF THE

chains from the timber framing. The piimp is worked by the horizontal wheel f, fig. 7, which is provided with friction rollers on its rim, for the purpose of lifting the lever g, which raises the lever of the pump by means of the spindle h. The outlet to the shoots is simply a square trunk made of 2 in. plank. It is furnished with a brass grating, or strainer, shown in fig. 10. The bars are | in. wide, and ^ in. apart, so that even small stones will not pass through. This grating is fixed in grooves, so that it can be lifted out of its place by the handles, when required.

55. The Pug-mill.

Fig. 1 1 . Elevation. (Scale 4 ft. to an inch.)

a. The yoke arm.

b. The opening for the ejectment of the earth when ground.

c. The brick-earth surrounding the mill, on whitJi is an

inclined barrow road to the top of the mill. Fig. 12, Section. (Scale 2 ft. to an inch.)

a.a. Force knives. These are not provided with cfuss knives, their purpose being merely to force the ei»rth downwards and out at the ejectment hole.

56. — Fig. 13. Isometrical View of the Moulding Stool. (Scale 4 ft. to an inch.)

a. The lump of ground earth from the pug-mill.

b. The moulder's sand.

e. The clot-moulder's gand.

d. The bottom of the mould, termed the ttock-loard.

e. The water-tub.

/. The pape, which is formed of two rods of gths of an inch round or square iron, nailed down at each end to the wooden rails or sleepers on which they rest. The use of the page is to slide the new bricks, with their pallets, away from the moulder with facility.

p. The pallets in their proper position for use.

k. A newly-made brick just slidden from the moalder, and rcadjr for the taking-off boy,

k. The moulder's place.

m. The clot-moulder's place.

«. The taking-off boy's place.

g. The cuckhold, a concave shovel used for catting off the ground- earth as it is ejected from the pug-mill.

ART OF MAKING BRICKS AND TILES. 167

7o. — Fig. 14. Isometrical View of the Brick Mould, with its detached bottom or Stock-board. (Scale 2 in, to a foot.)

a.a,a. The iron pegs on which the mould rests daring the opera- tion of moulding. They are driven into the stool in the positions shown in the drawing ; their height from the stool regulates the thickness of the brick. The mould is lined throughout with sheet-iron, which is turned over the edges of the mould at the top and bottom.

58.— Fig. 15. The Hack ^arroz^;— loaded. (Scale 2 ft. to an inch.) Fig. 16. The hack Harrow— unloaded. (Scale 2 ft. to an inch.)

59. The Clamp.

Fig. 17. Transverse section (parallel to necks). (Scale 10 ft. to an inch.)

Fig. 18. Longitudinal ditto ditto ditto.

a. The upright. b.h. Close bolts.

c. Live hole.

d. Bestowing.

Details. (Scale 2 ft. to an inch.) Fig. 19. Plan of the lower course of scintles. Fig. 20. Plan of the upper course of scintles. . The live hole.

It should be understood that the directions of the scintles,

as well as that of the paving below it, are changed for every

neck, so as to conrespond with the upper work, as shown in

the figures.

Fig. 21. Detail of the end of the upright, showing the paving, the

ecintling, the live hole, and the 7 in., 4 in., and 2 in. courses of breeze.

CHAPTER VI.

LONDON TILEKIES.

1. The general term^ " Tile Manufacture," is so com- prehensive, that it would be impossible, within the limits of a little volume like the present, to give anything like a complete account of the manufacture of the different

J 68 RUDIMENTS OF TUE

articles made at a large tilery ; we only pro^jose, there- fore^ in the present chapter, to give a succinct account of the manufacture of pantiles, as carried on at the London tileries, which will serve to give the reader a general idea of the nature of the processes employed in tile-making. It must, however, be borne in mind, that although the principle of proceeding is the same in each case, there are no two articles made exactly in the same way, the moulding and subsequent processes being carried on in a different manner, and with different tools and implements, for every description of article.

The manufacture of plain tiles and drain tiles has already been described in Chap. IV., to which the reader is referred, as also to the supplementary chapter at page 220.

2. The following is a list of the principal articles made at the London tileries : —

Oven tiles. Kiln bricks.

10-in. paving tiles. Fire bricks.

Foot ditto. Paving bricks.

Plain tiles. Circulars (for setting coppers.&c.)

Pantiles. Ck)lumn bricks (for forming co-

Ridge tiles. lumns).

Hip tiles. Chimney-pots.

Drain tiles. Garden-pots.

Drain pipes. And anytbing required To order.

For all these articles (excepting fire bricks) the same clay is employed (mixed, for the making of paving tiles, oven tiles,* kiln bricks, paving bricks, circular bricks, and column bricks, with a certain quantity of loam), and they are all burnt in the same kiln, the fire bricks included ; but each different article presents some pecu- liarity in the processes intervening between the tem- pering and the burning, having its separate moulding. ♦ For oven tiles the stufT must be of superior quality.

ART OF MAKING BRICKS AND TILES,

169

Fig. 1.

st©ol, frames^ strike, &c., and being stacked and dried differently. The details of these differences, however (even would our limits allow us to describe them), would scarcely be suited to the pages of a rudimentary work intended for popular reading.

170

BUDIMENT3 OF THE

Figs. 2 and 3.

^rr

BUILDINGS AND PLANT.

3. Pugmill. — The pug-mill used in tile making for pugging, or, as it is termed, grinding the elay, differs considerably from that used in brick-making. The tub, instead of being conical, is made to taper at both endsj

ART OF MAKING BRICKS AND TILES. 171

Fig. 5.

^^^^^^^^^^^p=^^r5lj^^^^^^5^

1

15

itT

and the ejectment hole is at the bottom instead of in the front, as in the brick pug-mill.

The knives, also, are made in a superior manner. 1 3

172

RUDIMENTS OF THE

Fig. 9.

iff

The mill is provided vith foree knives -without cross knives at top and bottom. See figures 1, 2, and 3.

The pug-mill is placed under cover in a shed called the grinding shed.

ART OF MAKING UUICKS AND TILES. 173

Fig. 6.

4. The Sling, fig. 4, is simply a piece of thin wire Tvitli two liandles, used for cutting the clay.

5. Moulding Shed. — Tiles are made uuder cover in sheds about 7 yards wide, the length of the shed de- pending on the number of moulding tables, the area allotted to each table being about 7 yards in length by 4 yards in breadth.

The moulding tables are placed against one side of

174

RUDIMENTS OF TKJ

Fiy. 10.

the shed, and the remainder of the area is oecupied by the blocks or drying-shelves ; every shelf being formed with three 1 in. planks placed edge to edge, and sepa- rated from each other by bricks placed edgewise at the end of the planks, as well as at intermediate points, each block containing about 1-i shelves, and thus measuring 12 ft. long by 2 ft. 8 in. wide, and about 7 ft. high. A passage way, 3 ft. wide, is left round the blocks, to give free access to every part of them.

These details will be understood by reference to fig. 5.

6. The Pantile Table, or moulding table, is shown in

ART OF MAKING BRICKS AND TILES.

175

Fig. 11.

Fig. 12.

Fig. 13.

Fig. 15.

fig. 6. It is furnished with a trug or trough, in which the moulder dips his hands when moulding, and with a block and stock-board, on which the tile mould is placed in the operation of moulding.

7. The Block and Stock-board is shown in fig. 7. The two form one piece, which rests on the moulding table, and is firmly keyed to it by means of a tenon on

176

RUDIMENTS OF THE Fig. 13.

^FT

thte under side of the block passing through a mortice in the table. Four pegs, driven into the table at the corners of the block and stock-board, serve as a support for the mould and regulate the thickness of the tile, f in. being the thickness of a pantile.

ART OF MAKING BRICKS AND TILES. 177

Fig. 14.

?fr

8. The Tile Mould is sliown in fig. 8, and requires no particular description.

9. The Foil, fig. 9, is merely a round roller of a particular size, as sliown by the scale, and is used for striking a smooth surface to the tile.

10. The Washincj-off Table, fig. 10, is a stand with

I 3

178

RUDIMENTS OF THE

t'ig'<. 17 and 18.

\

py -^ ^^^^^ . V

fP in

-36 7- ^v->

J—L

bof:

a water trougli and a frame ealled the JVashing-oif Frame, see fig. 11, on wbicli, when moulded, the tile 'is

AUT OF MAKING BRICKS AND TILES.

]7&

Fig. 19.

10

20

30

40

M '1 I 1 I I I 1 1-

^fi

washed into a curved form. The washing-off table is placed at the left hand end of the pantile table, and near the block.

BUDIMENTS Of THE

2:)

40

SO.

11. TTie SpJayer, fig. 12, is an instrument on which the tile is removed from the washing-off frame to the block.

12. The Thicacking Frame, fig. 13; is a frame on

ART OF MAKING BRICKS AND TILES.

181

Fig. 21.

182

RUDIMENTS OV THE

Fiff.22.

^i^M^M%^ -MM^^.;^^^^^.^c^:.^i^

ART or MAKING BRICKS AND TILES. 183

wliicli the tilcj when half dry, is thwacked or beaten with a ihwacker (lig. 15), to correet any warping which may have taken place whilst drying in the block.

When thwacking those tiles taken from the bottom of the block, the thwacking frame is placed upon the Thwacking Stool, fig. 13 ; but when the tiles to be thwacked are at the top of the block, the thwacking frame is placed upon the Thwacking Horse, fig. 14, which brings it conveniently to their level.

The Thvjacking Knife, fig. 16, is used for trimming the wing of the pantile immediately after thwacking.

13. The Tile Kiln, figs. 17, 18, 19, 20, 21, and 22, consists of a kiln Avith arched furnaces, enclosed in a conical building called a dome. The arrangement of die whole building Avill be clearly understood by refer- ence to the figures, and to the detailed description at the end of this chapter.

PROCESS OF MANUFACTURE.

14. Clay-getting and Weathering. — The clay used for making tiles is purer and stronger than that used for making bricks, and consequently requires more care in its treatment.

When the clay is too strong, it is mixed with sand before passing it through the pug-mill, but this is not often required.

The weaMicring of the clay is performed by spreading it out in thin layers, about 2 in. thick, during the winter, and each layer is allowed to receive the benefit of at least one night's frost before the succeeding layer is placed over it. Sometimes the clay is spread out in the summer to be scorched by the sun, which effects the flreathcriug equally well. The greater the heat, or

184; RUDIMENTS OF THE

the sharper the frost, the thicker may be the layers, but 4 in. is the maximum thickness.

The object of the process of weathering is, to open the pores of the clay, and to separate the particles, that it may absorb water more readily in the subsequent process of mellowing.

The clay thus weathered is thrown into pits, where it is covered with water, and left for a considerable time to mellow, or ripen.

15. Tempering. — The process of tempering is per- formed simply by passing the clay through the pug-mill. If the clay be very foul, that is, full of stones, it is sluny before using, and passed a second time through the mill. For chimney-pots and similar articles, the clay is slung either once or twice, and pugged, or, as it is called, ground, twice or thrice, according to the nature of the clay, and the purpose to which it is to be applied.

16. Slinging. — The operation of slinging is as fol- lows : as the clay issues from the ejectment hole of the pug-mill, it is cut into lengths of about 2 ft., with a sling. These lumps are taken by the slingers and cut up into slices, not exceeding j in. in thickness, during which operation most of the stones fall out, and those which remain are picked out by hand. The clay thus freed from stones is once more ground, and is then ready for the moulder.

(N.B. In some parts of England the clay is freed from stones by sifting, and the tempering is performed by treading ; this part of the work being done by boys, who tread in a spiral track, so as to subject each portion of the mass to a uniform amount of kneading.)

17. Moulding. — The clay, as it issues from the mill, is cut into lumps, called pieces, which arc stacked on a rough bench in the grisding shed. A labourer cuts

ART OF MAKING BKICKS AND TILES. 185

these lumps in half, each half being called a half-piece, and wheels these half-pieces one by one to the pantile table.

A rough-moulder, generally a boy, takes the half- piece and squares it up, that is, beats it up into a slab near the shape of the mould, and about 4 in. thick, from which he cuts off a thin slice, the size of a tile, and passes it to the moulder.

The moulder, having sanded his stock-board, and placed his mould on the four pegs which regulate the thickness of the tile, takes the slice of clay from the rough-moulder, and puts it into the mould. He then, with very wet hands, smooths the surface, cutting off the superfluous clay with his hands, in long pieces, called strippings, which are thrown to a corner of the table. This done, he strikes the surface level with the roll; and turning the tile out of the mould on the washing-off frame, with very wet hands washes it into a curved shape. He then strikes it smartly with the splayer, and turns it over on that implement, on which he conveys it to the block, where he deposits the tile with the convex side uppermost, and, the splayer being withdrawn, the tile is left to dry. The button end of the tile is placed inside the block.

18. Thwacking. — The tiles remain in the block until they are half dry, when they are taken out one by one, placed on the thwacking frams, and beaten with the thwacker to perfect their shape.

The wing of each tile is then trimmed with the thwacking knife, and the tiles replaced in the block, still with the convex side uppermost; but this time the button end is placed outside. The tiles then remain in the block until ready for kilning.

It should be observed that the tiles flatten slightly

18G RUDIMENTS OF THE

whilst ill the block, aud for this reason the washing-off frame is made a little more convex than the thwacking frame, which corresponds to the permanent form of the tile.

19. Kilning. — In setting the kiln, a course of vitrified bricks is laid at the bottom, herring-bone fashion, the bricks being placed \h in. apart. On this foundation the tiles are stacked as closely as they will lie, in an upright position, one course above another. As the body of the kiln is filled, the hatchways are bricked up with old bricl:s, and when the kiln is topped, the)' are plastered over with loam or clay. The top is then covered with one course of unburnt tiles, placed flat, and lastlv, upon these a course of old pantiles is loosely laid.*

The fires are lighted on Monday morning, and are not put out until Satiu'day evening, whatever the articles in the kiln.

The fuel used is coal, and the quantity consumed at each burning about eight tons. This, however, varies with the kind of articles to be burnt, — hollow goods, as chimney-pots, garden-pots, kc, requiring less than more solid articles. Foot tiles, oven ditto, and 10-in. ditto, are stacked in the kiln the same way as paving bricks. The covering on the top of the kiln varies in thickness, according to the sort of goods to be fired.

COST OF MANUFACTURE.*

20. From the manufacture of tiles being carried on under cover, the establishment of a large tile-work involves a considerable amount of capital. The kiln

• The estimates here given refer to the First Edition, except where otherwise stated.

ART OF MAKIXG BRICKS AND TILES. 187

used in London is very costly^ such a one as we have shown in figs. 17 to 22 costing in its erection no less than £2,000.

The cost of making pantiles is about as follows, per

1,000 :—

£ s. d.

Clay — this is usnally included in the rent, but, if pur- cliased separately, may be taken at 2^. 6rf. per yard cube — 2^ yards cube make 1,000 pantiles .

Weathering clay

Mellowing ditto, and grinding once _ • • • •

Add for horsing the pug-mill . ■ . . .

If slung and ground a second time, add ....

Moulding, including all labour in fetching clay from mill, moulding, washing, blocking, thwacking, and blocking second time

Setting and drawing kiln

Burning

Cost of making ....

Rent, repairs, breakage, contingencies, and profit .

Selling price per 1,000 . . .3100

21. The following are the ordinary prices, in 1862, for a variety of articles, which will give an idea of the comparative amount of labour bestowed upon them : —

0	5	n
0	5	0
0	2	0
0	1	6
0	2	0
0	10	0
0	3	Q-
0	15	0
2	4	U
1	5	104

Plain tiles

Patent tiles

Pan, hip, or ridge tiles

Ornamental plain tiles

Paving tiles, 9 in.

10 „

12 „ Mathematical tiles, red . „ white

Oven tiles

per 1,000

each

£	s.	d.
2	4	0
3	6	0
3	5	0
3	4	0
9	0	0
12	0	0
14	10	0
3	0	0
3	10	0
0	0	9

22. The above sketch of the manufacture of pantiles will g've the reader a general idea of the processes used in tile-makiug, but every article presents some pecu- liarity of manufacture. Plain tiles are dried on flats, called Flace Grounds. Hip and ridge tiles are washed

188 RUDIMENTS OF THE

and thwacked in a similar manner to pantiles. Drain tiles are only washed. Pa\'ing tiles and oven tiles are stricken with a flat strike instead of the roll, and are not washed, but they are thwacked and dressed with a knife.

23. Description of Illustrations.

Figs. 1, 2, and 3. The pug-mill. The png mill used in tilc-making is different from that used in brick- makinr], as will readily be seen from the figures. Fig. 1. Eleration of pug-milL (Scale \ in. to the foot.) Fig. 2. Details of the knives. (Scale ^ in. to the foot.)

These knives are made in a superior manner to those of the brick pug-mills, both as regards strength and fitting. The mill is provided with force knives at top and bottom, which have no cross knives attached to them. Fig. 3. Cross section of the tub. (Scale \ in. to the foot.) a. The ejectment hole, which is at the bottom of the tub, and not at the side, as in the brick pug-mill. Fig. 4. The sling, or wire knife, used for cutting the clay into lengths as it issues from the pug-mill, and also for freeing the clay from stones (slinging).

Fig. 5. The tile shed, shown in plan and section. (Scale 10 ft. to the inch.)

a.a.a. The blocks, which consist of a series of shelves, on which the tiles are placed to dry. Each shelf is formed of three 11-inch planks. The shelves arc 4J in. apart, and are spaced off from each other by bricks laid edgewise, at the end of the block, and also midway between these points. b.h.b. The moulding tables. Fig. 6. The pantile table, used for moulding pantiles. (Scale | in. to the foot.)

a. The half-piece squared up.

b. The block and stock-board. e. The trug or trough.

d. The moulder's sand.

e. The stripping?.

/. A hole in the table for sweepings to drop through. g.g.ff. The pegs on which the mould is placed. There are four of these pegs ; viz., one at each comer of the block and stock-board ; and the distance to which they are driven below the top of the Etock-boiird, determines the thickness of the tile.' Fig. 7. The block and stock-board. (Scale 1 in. to the f(X)t.)

c. A tenon, which drops into a mortice in the table.

d. A mortice in r, by which the block and stock-board is keyed tightly to the table.

Fig. 8. The pantile mould. (Scale 1 in. to the foot) Fig. 9. The roll. (Scale 1 in. to the foot.)

ART OF MAKING BRICKS AND TILES. 189

Fig. 10. The washing-off table. (Scale ^ in. to the foot.) a. The washing-off trug. }. The washing-off frame. Fig. 11. The washing-off frame. (Scale 1 in. to the foot.) Fig. 12. The splayer. (Scale 1 in. to the foot.) Fig. 13. The thwacking frame placed on the thwacking stool. (Scale 1 in. to the foot.)

Fig. 14. The thwacking horse, on which the thwacking frame Is placed for thwacking those tiles at the top of the blocks. (Scale ^ in. to the foot.) a. Tiie table on which the thwacking frame is placed. d. The place where the thwacker stands to thwack. c.c. Two wheels to facilitate the moving of the horse from place to place when required. Fig. 15. The thwacker. (Scale 1 in. to the foot.) Fig. 16. The thwacking knife. (Scale 1 in. to the foot.) This is simply an iron blade, with a piece cut out exactly to the intended profile of the wing of the pantile, which is trimmed with it immediately after thwacking.

Figs. 17 to 22. The tile kiln. (N.B. The whole of the furnace and body of the kiln is constructed of fire brick.) Fig. 17. Plan of the kiln, taken through the body. (Scale 20 feet to the inch.) k.h. The hatchways. Fig. 18. Plan of the basement, to the same scale, showing the entrance to the vaults.

Fig. 19.* Section through the centre of the kiln, in the direction of the line a b, fig. 18. (Same scale.)

Fig. 20. Section through the centre of the kiln, in the direction of the line c d. (Same scale.)

Fig. 21. Transverse section of the furnaces. (Scale \ in. to the foot.) The section marked a is taken through the throat of the furnace, on the line marked x ij, in fig. 22.

Fig. 22. Longitudinal section of the furnaces. (Same scale.) The arrows ia each of the above figures show the direction of the flues.

CHAPTER VII.

ON THE MANUFACTUKE OF ENCAUSTIC TILES.

1. The highly-decorative pavements of the mediaeval ages, principally to be found in our old ecclesiastical structures, which often shared the fate of many beautiful

* This cut and the following are not quite accurate, the sides of the dome not being straight, as shown in the engraving, but slightly convex.

190 BUDIMEXTS OP THE

details of architectural ornament, by being made to give way to -what rustic cliurcbwardens, and others of equal taste and discemmentj deemed improvements — after attracting the attention of the antiquary for centuries, have at length excited some interest amongst the prac- tical minds of these our stirring business times. About thirty years since a patent was obtained by Mr. S. "Wright, of the Staffordshire Potteries, for the revival of this interesting branch of art, for such it may be truly called. As might have been expected, many difficulties beset the patentee, and for some years nothing was pro- duced equal to the old specimens. But still a beginning was made that promised success when skill and capital, and a determination to succeed, should be brought to bear upon the subject. And these were not long want- ing, as the patent ultimately passed into the hands of a gentleman undeterred by difficulties or previous failures, and who expressed his intention to make encaustic tiles, such as would secure the public approbation, even if each one cost him a guinea! This is the spirit that has achieved such surprising results in our manufactures generally, within a comparatively brief period ; and no wonder that in this, as in most other instances, success has been the satisfactory result. TVe need scarcely say that the gentleman referred to is !Mr. Herbert Minton, who, with untiring industry, collected the best speci- mens of old tiles that could be found in this country, and by a succession of experiments overcame the obstacles that had retarded the success of the undertaking.

2. The chief of these obstacles was, to discover clays of different colours that could be made to amalgamate in such a way as to contract or shrink equally during the processes of drying and firing; and until this was effected, a perfect tile of several colours could not be produced,

ART OF MAKING BRICKS ANP TILES. 191

sundry unsightly cracks appearing on the inlaid parts of the surface. It will be unnecessary to speak of the present state of perfection to which these beautiful tiles have been brought^ further than to observe that they are yearly becoming more appreciated^ both on the score of durability and ornament; and there can scarcely be a doubt thatj very soon^ no ecclesiastical building, having any pretensions to architectui'al superiority, will be con- sidered to be complete in its decorations without them. By way of information, we may add, that not only copies of old tiles are manufactured, but every variety of design suitable for the character of the building they are intended for are supplied. Indeed, almost any pattern can be produced with facility; and we have seen some of the arms of our nobility and gentry so finely executed, that the uninitiated might be pardoned for mistaking these inlaid clays for the highly-finished and elaborate work of the pencil. In many instances they have been adopted as a substitute for oil- cloth in the halls and passages of the mansions of our nobility, being considered far more beautiful, and, from their durability, more economical also, in the long run.

3. We will now take a peep into the interior of Messrs. Minton and Co.^s manufactory.* We must first notice, that the clays of which the tiles are composed are ob- tained in the immediate neighbourhood — the ordinary marl producing a good buff colour when fired j another kind a warm red ; black is produced by staining with manganese; blue with cobalt, &c. W'th the native clays there is a slight admixtui'e of Cornwall stone and clay, and flint from Kent, &c. The whole are subjected to a variety of washings and purifications — the clay in-

• Further details will be fouud ia " Tomlinsoa's Cjclopjedia "— article, Pottery and Porcelain.

193 RUDIMENTS OF THE

tended for tlie surface^ especially — and passed througli fine lawn sieves in a liquid, or ''slip'' state, as it is technically termed. In this state it is conveyed to the slip-kiln, or rather pumped on it, and boiled, until it is in a plastic state, and fit for use.

4. After the modeller has done his part, the pattern is cast in plaster in relief, and is then placed in a metal frame of the size required ; but it should be stated that to produce the ordinary 6-in. square tile, it is modelled 6f in., to allow for shrinkage or contraction, which takes place during drying and firing. The maker then com- mences his operations. A piece of the fine clay for the surface is flattened out to about a quarter of an inch thick, somewhat after the manner of preparing a pie crust, and this is thrown upon, and pressed upon, the plaster pattern, and receives, of course, a correct indenta- tion, or outline of the design. The metal frame containing the plaster mould is divided horizontally, and after the surface is put in, the upper part of the frame is screwed on, and the maker fills up with clay of a somewhat coarser description, to form the tile of the requisite thickness. The tile is then put under a screw-press to impart the proper degree of solidity.

5. As far as we have gone, the tile is but of one colour; next comes the task of giving the difi'erent colours required. Suppose a tile be required of three colours — red, blue, and buff. "SVe will say the surface piece already put in is of abuff colour. The maker provides himself with vessels of a suitable kind, containing — the one the blue, the other the red colour, in a " slip" state, and these he pours into those parts of the indented surface that the drawing or finished tile before him tells him to be correct. These slips cover the surface entirely, and \hexe is now not the slightest appearance of any pattern

ART OF MAKING BRICKS AND TILES. 193

or design. After remaining in this state for three days, until the water has evaporated for the most part^ the process of scraping or planing the surface commences, which is an operation requiring care, though easily effected by experienced hands. The pattern then makes its appearance, but the colours are scarcely distinguish- able the one from the other.

6. The tile is then finished as far as the maker is concerned ; and, after remaining in the drying house from 14 to 21 days, according to circumstances, is con- veyed to the oven, where it is exposed to an intense degree of heat for about 60 hours. After being drawn from the oven, the tile is finished, except it be that the parties ordering wish the surface glazed, a rapid and easy process, the dipper merely placing tbe surface in a tub of glaze.

7. Plain self-coloured tiles, such as black, red, choco- late, buff, &c., and also tesserae, are made of the same material as the encaustic, only that it is dried longer in the kiln, passed through rollers to reduce it to a powder, and is then finely sifted. Presses of great power, made under Prosser's patent, make these tiles. The powdered clay is swept into a recess of the proper size, the screw descends, and, by its immense power, presses the powder into a solid tile, ready for drying and firing. One man can, with ease, make about 500 per day.

8. Tessera. — The tesserae made by Messrs. Minton, under Mr. Prosser's patent, are now extensively used for mosaic pavements, for which they are admirably adapted. A few words will suffice to explain the nature of the improvements effected in this branch of art by the introduction ot the new material.

The mosaic pavements made by the Romans were formed of small pieces of stone or marble of various

K

194 RUDIMENTS OF THB

colours, bedded one by one in a layer of cement, each (if the pieces being levelled with the others as the work l>roceeded, and on the completion of the work the un- avoidable inequalities of surface were corrected by rubbing the whole to a plciue surface.

This mode of proceeding was attended with many defects. The irregular shapes of the tesserae caused the cement joints to be of a thickness that greatly in- jured the effect of the design, whilst the piecemeal way in which the work was laid rendered it very difficult to produce a level surface.

It is not our purpose here to detail the several at- tempts that have been made during the last few years, with various degrees of success, to produce mosaic pave- ments, by the use of clay tesserae, coloured cements, &c. ; but it will readily be understood that the principal difficulties to be overcome in the use of solid tesserje arc those aiising from irregularity in the shape and size of the several pieces, as well as the great labour and expense attending the laying of such pavements piece by piece.

These difficulties have been entirely overcome by the use of the patent tesserae, which, being made in steel dies, by the process above described, are perfectly uni- form in size, and fit closely together, with an almost imperceptible joint.

The mode in which the tesserae are used is precisely the reverse of the Roman process, and is as follows : — a coloured design of the intended mosaic having been drawn to scale, after the fashion of a Berlin wool pattern, the pattern is set out full size on a cement floor, perfectly smooth and level, and on this floor the tesserae are placed close together, the workmen being guided in the arrangement of the colours by the small drawing.

ART OP MAKING BRICKS AND TILES. 195

The pieces are then joined together by a layer of cement applied to the upper surface, and in this way they are formed into slabs of convenient size, which, when hard, are ready for use, and can be laid with as much ease as ordinary flagstones. It will at once be under- stood, that the side of the slabs which is next the floor during the process of manufactui'e forms the upper side of the flnished pavement, the pattern appearing reversed during its formation.

CHAPTER VIII.

ON THE MANUFACTUEE OF BRICKS AND DRAIN PIPES BY MACHINERY.

Ii is the general opinion that brickmaking by ma- chinery is not economical in small work, since the cost of moulding bears so small a proportion to the total cost. In large engineering works, however, where a contractor requires many millions of bricks in a limited time, for the construction of a tunnel or viaduct, the use of machinery may be desirable. In this chapter we do not, of course, pretend to give descriptions of the various patented and other machines connected with the manu- facture of bricks and tiles. Our object, in a work of this kind, being to deal with the principles of the art rather than with a multiplicity of minute details. "We may, however, in order to show the great vitality of the trade, quote a few titles of inventions, &c., belonging to the years 18G1 and 1862. The patent list displays the strong tendency to invention for making bricks, &c., by machinery. Thus, we have —

K 2

196 RUDIMENTS OF THE

Wimball's pateut for making bricks^ tiles, and drain pipes.

^Morrell and Charnley's apparatus for making bricks^ tiles, and other articles from plastic materials.

Green and Wright's machinery for the manufacture of plain and ornamental bricks, slabs, tiles, and quarries.

Basford's patent for constructing brick -M-alls, and ornamenting the materials to be used for the same.

Effertz' machinery for making bricks, tiles, &c.

Grimshaw's patent for compressing brick-eai'th and other materials.

^lorris and Radford's pateut for the manufacture of fire bricks, blocks, kc.

Poole's patent for making ornamental bricks, tiles, &c.

Newton's machine for making bricks.

Sharp and Balmer's apparatus for the manufacture and drying of bricks.

GrimshaVs patent apparatus^ used in drying, pul- verising, and compressing clay.

Piatt and Richardson's apparatus for making bricks.

Foster's method of rendering bricks impervious to damp.

Smith's patent apparatus for the manufacture of bricks, tiles, S:c.

The following description of Oatcs's brickmaking machine is from Tomlinson's " Cyclopsedia of Useful Arts, &c." It was described by ':Mr. J. E. Clift, of Birmingham, at a meeting of the Institution of Me- chanical Engineers, in November, 1859, and the descrip- tion is printed in the ''Proceedings" of that body, and is illustrated by four engraved plates, from which Mr. Tomlinson has compiled the illustrative figure. "NVc do not give this machine as the best, since there are many other well-known machines of merit in use ; but we

ART OF MAKING BRICKS AND TILES. 197

offer it as an example of the meclianical means adopted in tins class of inventions.

The present brickmaking machines at work are divided by Mr. Clift into two classes, viz., those that operate on the clay in a moist and plastic state, and those for -which the material requires to be dried and ground previous to being moulded. In the former class, the plastic column of clay, having been formed into a continuous length by the operation of a screw, pugging blades, or rollers, is divided into bricks by means of wires moved across, either while the clay is at rest or while in motion, by the wires being moved obliquely at an angle to compensate for the speed at which the clay travels. This wire-cutting requires the clay to be soft, so that the bricks are but little harder than those made by hand, and require a similar drying before being placed in the kiln ; and aV this renders the expense of manu- facture about the same as for hand-made bricks. In the second class of machines, tlie bricks are compressed in a dry state in the mould ; but the processes for drying the clay, and reducing it to a uniform powder, add to the cost of manufacture.

JNIr. Gates has got rid of both objections, viz., the difficulty respecting the previous preparation of the clay, and the subsequent drying of the bricks. In his machine the clay is used of such a degree of dryness as to allow of its being mixed up and macerated, and compressed into bricks by a single continuous action, the clay being formed into a continuous column and compressed into the moulds by the action of a revolving vertical screw. The clay requires, in general, no previous preparation beyond that given by the ordinary crushing rollers, and, in some cases, may be put into the machine direct from the pit, unless it contain stones, when it is passed through

198

RUDtMENTS OF THF

a pair of rollers. Figs. 2 and 3, when joined at the parts indicated by the dotted lines^ form a longitudinal section of the machine, and fig. 1 is a plau of the screw.

Fig. I.

The cast-iron clay cylinder A is expanded at the upper part to form a hopper, into which the clay is supplied, and the lower cylindrical portion is about the same in

ART OF MAKING BRICKS AND TILES. Fig.d.

199

diameter as the length of the brick mould F, at the bottom of the pressing chamber B. The vertical screw C is placed in the axis of the cylinder, and carried by

200 RUDIMENTS OF THE

two bearings in the upper frame D ; this screw is parallel at the lower part^ the blade nearly filling the parallel portion of the clay cylinder, and is tapered conically at the upper part to nearly double the diameter. "When the clay is thrown loosely into the hopper it is divided and directed towards the centre by the curved arm E revolving with the screw shaft, and drawn down by the tapered portion of the screw into the parallel part of the clay cylinder in sufficient quantity to keep this part of the cylinder constantly charged. The clay is then forced downwards by the parallel portion of the screw into the pressing chamber B_, and into the brick mould F, which consists of a parallel block equal in thickness to a brick, and sliding between fixed plates above and below, and containing two moulds, F and G, corresponding in length and breadth to the bricks to be made. The mould-block F is made to slide with a reci- procating motion by means of the revolving cam H, which acts upon two rollers in the frame I, connected to the mould-block by a rod sliding through fixed eyes; and the two brick moulds are thus placed alternately under the opening of the pressing chamber B to receive a charge of clay, the mould-block remaining stationary in each position during one quarter of the revolution of the cam H. "When the brick mould F is withdrawn from under the pressing chamber, the brick is dis- charged from the mould by the descent of the piston K, which is of the same dimensions as the brick mould ; the piston is pressed down by the lever M, worked by the cam X, when the brick mould stops at the end of its stroke, and is drawn up again before the return motion of the mould begins. A second piston L acts in the same manner upon the second brick mould G, and the discharged bricks arc received upon endless bands

ART OF MAKING BRICKS AND TILES. 201

O, by wliich they are broiiglit successively to the fron^ of the machine, when they are removed hy boys to the barrows used for conveying them to the kihis to be burnt. The solid block that divides the two brick moulds F and G is slightly Avider than the discharge opening at the bottom of the pressing chamber B, having an over-lap, so that the making of one brick is terminated before that of the next begins, in order to ensure com- pleteness in the moulding. During the instant wheij this plauk is passing the opening at the bottom of the pressing chamber, the discharge of the clay is stopped, and it becomes necessary to provide some means eithei of relieving the pressure during that period, or of stop- ping the motion of the pressing screw. Accordingly the pressure is relieved by an ingenious contrivance, forming in effect a safety-valve, which prevents the pressure in the chamber from increasing wdien the brick mould is shut off, and also serves to maintain a uniform pressure during the formation of the brick, so as to en- sure each mould being thoroughly and equally filled with clay; this is effected by an escape-pipe P, similar in form to the brick mould, but extending horizontally from the side of the pressing chamber, and is open at +hc outer extremity. The regular action of the screwy forces the clay into the escape-pipe, as far as its outer extremity, forming a parallel bar of clay in the pipe. The resistance caused by the friction of this bar in sliding through the pipe is then the measure of the amount of pressure in the machine ; and this pressure cannot be exceeded in the machine, for the instant that the brick mould is full, the further supply of clay, fed into the pressing chamber by the continuous motion of the screw, escapes laterally, by pushing outwards the column of clay in the escape-pipe. The uniform pres-

K 3

202 RUDIMENTS OF THE

sure of every brick in the mould up to this fixed limit is ensured by the escape-pipe not beginning to act until that limit of pressure is reached. Its action is similar to that of a safety-valve, and the amount of pressure under which the bricks are made is directly regulated by adjusting the length of the escape-pipe. The latter discharges a continuous bar of solid clay, advancing by intermittent steps of j to ^ in. in length, each time that the brick mould is shut oflF and changed. The projecting piece of clay from the end of the escape-pipe is broken off from time to time, and thrown back into the hopper of the machine.

The upper side of the solid block separating the two moulds F and G is faced with steel : and the upper face of the brick is smoothed bv beiug sheared oflp bv the edge of the opening in the pressing chamber ; the under face of the brick is smoothed by being planed by a steel bar R, fixed along the edge of the under plate, and having a groove in it for discharging the shaving of clay taken oflf the brick.

The screw shaft is driven by bevil gear from the shaft S, which is driven by a strap from the engine, the speed being adjusted according to the quality of the clay or the Avear of the screw. The screw is driven at about thirty revolutions per minute, when at full speed, or one brick for each revolution of the screw. The machine completes 12,000 bricks per day, or an average of twenty per minute. The clay, as already stated, can be taken dii'cct from the pit, passed through crushing rollers, and then fed straight iuto the moulding machine. Indeed, tlie clay within a quarter of an hour after being brought from the pit may be seen stacked in kilns, and in a few days burnt ready for use. The amount of power required for driving the machine, and the wear

ART OF MAKING BRICKS AND TILES. 203

of the screw, vary according to the material worked. With a calcareous marl about twelve horse-power was found sufficient. AVhen the material is very siliceous the cast-iron screws wear out quickly. Gun-metal has been found much more durable than iron for the screw and mould-block.

In burning bricks that contain much alumina, and consequently retain a good deal of moisture, it is found advisable to stack the bricks in the kiln in lifts of from fifteen to twenty courses each. As soon as the bottom lift has been stacked, small fires are lighted to drive off the steam from the bricks, which might otherwise soften those stacked above ; the middle lift is then stacked and similarly dried, and then the top lift; after which the full fires are lighted.

The crushing strength of these bricks made in the machines at Oldbury is said to be double that of the hand-made blue bricks of the neighbourhood, being an average of 150 tons compared with 76 tons, or 8,024 lbs. per square inch compared with 4,203 lbs. The trans- verse strength, with 7 in. length between the bearings, was found to be, for hand-made bricks, 2,350 lbs., for machine-made bricks, 3,085 lbs., and for the same, hard burnt, 4,320 lbs.

One of the advantages of this machine is, that clay containing a good deal of stone, which could scarcely be worked for hand-made bricks, can be used. Th.< brick-earth at Cobham is very unfavourable for brick- making, it being so weak and friable that hand-made bricks made fi'om it were crushed by a moderate pres- sure; when made by the machine, however, serviceable bricks were turned out. A material containing 84 per cent, of silica has been made by this machine into bricks. The bricks had not any hollow or frog in the

204 RUDIMENTS OF THE

upper space for holding the mortar, but arraugementt were being made for producing it.

The extent to which bricks absorb water is im- portant, since dry houses cannot be built with bricks that are very absorbent. A brick of 9 lbs. weight will absorb about 1 lb. of water, and it is stated that the bricks made by this machine absorb less.

The cost of Oates's machine is from £150 to £200, exclusive of the engine for driving it. The cost of brick- making varies according to the price of coal in diflferent localities ; but there is very little variation in the price of the unburnt bricks made by the machine, the differ- ence arising chiefly from the varying amount of royalty charged on the clay in the pit, which varies from 1*. to 2s. 6d. per 1,000. A machine at Cobham, employed by ^lessrs. Peto and Betts, produced 200,000 bricks in a fortnight of eleven days, but the average number per week, of five and a half days, was considered to be 80,000, or at the rate of twenty-four bricks per minute. The contract for the bricks in and out of the kilns, exclusive of the cost of the coals, was first taken at 5*. 9d. per 1,000 bricks ; which was afterwards raised to 65. 9d., owing to the distance of the clay from the machine. To this had to be added 6d. per 1,000 royalty, and the wages of the engine-driver at Gd. per 1,000, raising the expenses to 7s. 9d. per 1,000 bricks. The quantity of coals required for burning the bricks, and for the engine driving, might safely be taken at ^ ton per 1,000 ; and the price of coal at that place being 25*. per ton, the total cost of making the bricks by the ma- chine amounted to 20^. per 1,000, including the burning.

The following particulars respecting drain-pipe mak- ing machines, and hollow bricks, ai'e also from Mi. Tomlinson's " Cyclopaedia.^'

ART or MAKING BRICKS AND TILES.

205

The large and increasing demand for draining tiles and pipes has led to great economy in their manufac- ture. Some are moulded flat^ and afterwards bent round a wooden core to the proper shape : others are made at once of a curved form by forcing the clay through a dod or mould, fig. 4, by mechanical pressure. The action will be readily under- stood from fig. 5, which repre- sents a section of a strong iron cylinder, containing a quantity of clay in the act of being pressed down Avith enormous force by a solid piston or plunger. The clay, as it escapes through the dod, is evidently moulded into the form of the pipe (also shown in section), which is cut ofi:' in lengths, by means of a wire, and these, after a preliminary drying, ^'9- S-

are ready for firing. By using dods of different sizes, pipes of various magnitudes arc formed.

Fig. 6 is an elevation of a drain-pipe making machine, which we have copied from ]\Ir. Green's Avorks at Lambeth. The cylinder contains a second cylinder, capable of holding a given weight of clay, adapted to the moulding of a certain number of pipes at one charge. Thus, one box-full will furnish five 9-in. pipes, six 6-in. pipes, seven 4-in. pipes, and so on. By the action of the rack the piston forces the clay through the dod or die upon a table, so balanced by Aveights that the lengthening pipe is sufficient by its weight to force doAvn the table, and when a certain ^engtli of pipe

206

RUDIMEXTS OF THE

is formed, the boy stops the machine by shifting the strap "vrhich drives the rack-screw from the fast to the loose pullevj and then cuts off the length of pipe with

Fig. 0.

a wire, removes the pipe so formed, raises up the table, sets the machine in action, and receives a pipe upon the

ART OF MAKING BRICKS AND TILES. 207

table as before. When all the clay is thus forced out of the cylinder^ the action of the rack is reversed, whereby the plunger is drawn up out of the cylinder. The cylinder, which moves on a kind of hinge, is then tilted on one side to receive its charge of clay, and being restored to its vertical position, the action proceeds as before. By an ingenious contrivance, the fork which shifts the strap from the fast to the loose pulley, is weighted in such a manner that, when the boy raises his foot from a treadle, the strap is at once moved on to the loose pulley, and vice versa, thus giving the attendant a third hand, and diminishing the chances of danger from the strap. Mr. Green has a machine worked by a screw, in which the process is continuous. These pipes are washed with glaze before the firing, as will be explained hereafter.

^ yV means of a tile machine, the holloiv bricks are formed, which are so much recommended by the " So- ciety for Improving the Condition of the Labouring Classes,'^ and introduced by them in the construction of dwelling-houses for the poor. The idea of tubular bricks is not new, for such articles were used by the Romans in large vaultings, where lightness of construc- tion was required, and they are said to be in common use in Tunis at the present time. The size of the bricks is 12 in, long, and three courses rise 1 ft. in height. Nine hollow bricks will do as much walling as sixteen of the common sort, with only a slight increase in weight. In passing through the tile machine, or in the process of drying, the bricks can be splayed at the ends for gables, or marked for closures, and broken off as required in use, or they may be perforated for the purpose of venti- lation. If nicked with a sharp-pointed hammer, they will break off at any desired line ; and the angles may

208

RUDIMENTS OF THE

be taken off with a trowel as in the common brick. The bricks for the quoins and jambs may be made solid or perforated, and with perpendicular holes, either cir- cular, square, or octagonal : those in the quoins may be so arranged as to serve for ventilating shafts. The hollow bricks, from their mode of manufacture, are more compressed than common bricks, require less drying, and are better burned with less fuel .

The following figures represent some of the forms of hollow bricks in common use. a, fig. 7, is an extei'nal brick, llf in. long, which with the quoin brick e, and the jamb brick b, are sufficient for building 9-iu. walls, e is 10^ in. long, with one splayed corner for forming external angles, reveals, and jambs of doors and windows, either square or splayed. The internal jamb and chimney brick, b, is 8| in. long; c is an

Fig.

internal brick, adapted to any thickness of wall beyond 9 in. : d is for 5|-in. partitions, or internal walls, and arch bricks, and is used for floor and roof arches of 7 to 10 ft. span. / is used for the same purpose, with

ART OF MAKING BRICKS AND TILES.

209

a webb to give extra strength, and to adapt them for using on edges in partitions, 3f in. thick to rise in 6-in. courses.

Fig. 8 represents a specimen of hollow brick work in 6-in. courses, with square rebated joints for extra strength. These bricks are adapted to the lining of flint or concrete walls. Fig. 9 is a section illustrative of the construction adopted in H. E,. H. Prince A.lbert's model houses. The span of the arches is increased over the living rooms to 10 ft. 4 in., with a proportionate addition to their rise. The external springers are of cast-iron, connected by wrought-iron tie rods. It is stated that there is an advantage of 29 per cent. in favour of the patent bonded hollow bricks over ordi-

Flff.8.

nary bricks, in addition to a considerable diminution in the cost of carriage or transport, and of 25 per cent, on the mortar and the labour.

210 RUriMENTS OI TUB

CHAPTEB IX.

ADDITIONAL KEMAEKS ON THE MAXTFACTTRE OF BRICKS BY MACHIXEEY.

It is proposed here to supplement the previous chapter, written by Professor Tomlinson in 1863, by giving full descriptions of some of the most remarkable, or most used, of the very many brickmaking machines now before the public. The trade in producing brick machinery itself has come to be a very large one, in which great intelligence, energy, and capital have been invested, and from which have emanated an immense number of inventions, chiefly the subjects of patents. The results have naturally been much rivalry and com- petition, so that, perhaps, there is no one of the trains of machinery for making brick, which has had a success enough to make it worth notice, which has not been ex- posed to partial advocacy, and to equally interested and frequently more mijust depreciation.

It would be highly out of place that "an outline" such as this volume can alone pretend to, within its limits, should undertake to appraise the relative merits or demerits of the various machines we are about to notice — the rather, as we are imable to treat the whole sub- ject in the exhaustive manner that alone would justify 8uch criticism. The following notices, therefore, must be viewed as merely collecting before the reader, with sufficient illustrations, a few of the more prominent brick and tile machines, or those most in use in Great

ART OF MAKING BRICKS ,VND TILES. 211

Britain, sufficient to serve as an index to those specially interested, whereby more complete information may be obtained through the respective makers or otherwise.

As has been sufficiently shown in the preceding parts of this volume, the natural clays from which bricks are to be made, though they may occasionally be found in a state capable of being at once made into brick, must most usually be subjected, after having been dug out, to more or less disintegration, grinding, and mixing into perfect plasticity, before being em- ployed. For these purposes, the screen sometimes being used beforehand, the crushing rollers and the pug-mill are employed. Other methods of pro- ducing perfect freedom from adventitious matter and perfect plasticity are occasionally employed, when special qualities of extra fine bricks are sought for, but with those we need not trouble the reader here.

The above machines are employed in combination, i.e., as parts of one compoimd machine, as produced by some makers, separately as turned out by others. The clay-mill, with crushing rollers working on edge in a circular pan, is also in use. Brick machinery itsell*, since the invention of Prosser, many years since, is divisible into two great classes, wet and dry clay ma- chines, i.e., machines which form the brick, by moderate pressure in moulds, from ah'eady tempered and plastic clay, and those which, under a far more severe com- pression, mould the bricks from clay perfectly commi- nuted, but either dry, or at most only very slightly moistened. One of the most salient advantages of the dry method is, that it produces a denser brick, and one that shrinks less both in drying and in baking than do those made wet ; and that a certain amount, though not a very great one, of the labour and cost of the

212

RCDliLENTS OF THE

pelimmary preparation of the clay is saved. The disadvantages, or some of them, are, that miless the clay in the dry or merely damp state be scrupulously well prepared, and unless a degree of pressure be employed which demands a good deal of power, the brick may be deficient in tenacity and in uniform solidity, or even in perfect fairness of face. On the other hand, with certain clays, and pressures beyond a given point, bricks are thus produced, which, though dense and resistant, have so ?/;«porous a surface as hardly to take bond with either cement or mortar. Fig. 1 represents Whitehead's Improved Clay Crush-

ing and Grinding Roller Mill, consisting of two pairs of large iron rollers, fitted in a massive cast-iron frame. The dimensions of the top rollers (which revolve at equal speed) are 2 ft. 6 in. long by 1 ft. 8 in. diameter. The lower pair (running as two to one, fur more thoroughly incorporating the clay) are 2 ft. 6 in. long by 1 ft. 6 in.

ART OF MAKING BRICKS AND TILES.

213

diameter. The above mill is constructed for the pur- pose of reducing rough strong clays or hard marls not disintegrable by water, into a state to be rendered plastic by future operations in the pug-mill, of which two dif-

Fiff.2.

feront examples are given in figs. 2 and 3 by the same maker.

Fig. 2 is a large and powerfid pug-mill. The cylinder is one strong loam casting made perfectly true ; it is erected upon a massive iron basement, and provided with two cast mouth-pieces for the discharge of the pugged clay, one situate on each side at bottom. These mouth-pieces may have sliding doors fitted, to increase or diminish the area of the orifice, so as to cause the clay to be more or less finely groimd. This is valuable in admitting the adaptation of the mill to the pressing out of large and small pipes, &c.

This mill makes about three revolutions per minute, Vjrorked by the power of one horse, The cylinder is 24 in.

214

RUDIMENTS OF THE

diameter inside, and 54 in. liigli ; the total height to top of vertical shaft is 87 in.

Fig. 3 represents TVhitehead's Perforated Pug-mill. The advantage of this mill is, that during the opera- tion of pugging the clay is forced out through the

'm^- iiii

perforations at the sides in the plastic state, leaving behind the stones, which are carried, by means of the internal arrangement of the knives on the vertical shaft, through an aperture at the bottom ; thus combining the process of pugging and screening in one op<»ration.

We entertain some doubts of the advantages of this machine, however ingenious ; for screening as a pre- liminary operation should, whenever practicable, never be omitted.

Fig. 4 shows a very good form of nearly portable

ART OF MAKING BRICKS AND TILES,

215

clay-milL Mills in this fonn may be used for grinding wet or plastic clay, but are more suitable for indurated dry clays, wbich are to be used with, one or other of the dry-clay brick machines. The pan, as is evident from

the figure, revolves, and the runners are carried round by it, being free to move within a certain range verti- cally. The pan is provided with curved blades, so fixed as to keep the stuff constantly beneath the runners.

We now come to the composite machines, in which crushing rollers and horizontal pug-mill are combined, as in fig. 5.

For very hard clays, such as fire-clays for fire-brick, two or even more pairs of crushing rollers may be needed above each other, those closest set being at bottom.

216 A"RT or MAKING BRICKS AND TILES.

The rollers are driven at different speeds, so as to produce a rub as well as a mere squeeze between the sur-

lig. 6,

faces, and so better disintegrate the clay. The rollers are usually made about 20 in. diameter, and about 3 ft. long. They are fed by hand, through a hopper at top.

Haying thus described the machinery generally in use for the pre}mrat\on of the clay, whether plastic or dry, we proceed to illustrate a few of the brickmaking machines themselves, commencing with those for operat- ing on moist or plastic clays.

Fig. 6 represents a large machine as constructed by Whitehead, of Preston, in which the rough clay thrown in between the rollers at top is ground, and then passes

218

RLDIMENTS OF THE

at once into the vertical pug-mill, and is thence expressed in two continuous prisms of the size in section of a brick

Fxg.l.

on flat, and which are at intervals cut transversely into bricks by the wires of the frames, seen in the front of the drawing. These are moved by hand.

Fig. 8 represents another form of machine, in which the clay, already tempered, is drawn in and con- tinuously expressed by a pair of rollers, the prism being cut asunder into bricks by the radial wires forming the arms of the wheel C, which is moved auto- matically.

An extremely simply-contrived and most efficient French machine of this class was exhibited in 1862 in the French department. It was an invention of M. Jardin, and manufactured by Cazenave & Co., Paris. At work in the Exhibition, it made at the rate of twelve thousand per day of ten hours, with only the attendance of two men. The division of the prism of clay was effected by wires attached to a wheel moved by

ART OF MAKING BRICKS AND TILES,

219

the macliine, but differently arranged from that of fiff. 8.

^^ '.'

The followmg machine belongs to this same class. It is Clayton and Co.'s second-sized horizontal brick

l2

ART OF MAKING BRICKS AXD TILES.

221

machine, which combines the crushing rollers, pug- mill, and brick-forming in one machine.

These machines are largely run upon, and have been employed extensively by our great contractors, and upon many public works — facts which give the best assurance that they answer well.

One of these machines weighs about 3^ tons, and of this second size, with about 8 or 10 horse power, will turn out from 75,000 to 90,000 bricks per week.

We now come to another class of machines working

Fig. 10.

with plastic clay, though capable of employing clay nearly dry, or at least very stiffly tempered. The machine shown in fig. 10 consists of a vertical pug-mill, into the upper part of which the clay is fed, and in which it imdergocs tempering and mixing, and, on

222 RUDIMENTS OF THE

reaching tte bottom of the mill, is pressed into the moulds, of the form and size of brick required, which are arranged in the form of a circular revolving table. As this table revolves, the piston-rods of the moulds ascend an inclined spiral plane, and so gradually lift the bricks out of the moiilds, whence they are taken from the machine by a boy, and placed on an endless band which carries the bricks direct to the "waller." The speed of the several parts is so arranged, that the operations of pugging, moulding, and delivery proceed simultane- ously in due order, the whole being easily driven by a steam engine of about 6-horse power, which, at the ordinary rate of working, will make 12,000 bricks per day ; or with 8-horse power from 15,000 to 18,000. In consequence of the great pressure to which the clay is subjected in the moulds, the bricks produced by this machine may be made from stiffer clay, so that less H-ater has to be evaporated in the drying, thus saving much of the time required for hand-made bricks, and n voiding the risk of loss from bad weather.

One poiut of importance to remark as respects this last class of machines, compared with the previous one, is this — wire-cut bricks are smooth and perfect in form, provided the clay be not only perfectly plastic, but per- fectly uniform and free from adventitious particles. If, however, the plastic clay contains gravelly par- ticles, or be of such a quality that it is necessary to mix it with ashes or '•' breeze," then the section made by the passage of the wire drags out and after it more or less of these solid particles, and the faces of section are rough and uneven ; in such cases resort is best had tD those machines of pressure only.

In the following brick-pressing machine also, for plastic clay, the moulded bricks are delivered by the

AUT OF MAKING BRICKS AND TILES. 223

mactine directly on to tlie horizontal belt that carries them away ; so that the labour of attendance is nearly limited to feeding the tempered clay into the top hopper. We are not aware to what extent as yet this ingenious machine has been employed.

Figs. 11, 12, 13, and 14 illustrate a brick-pressing machine recently patented by Mr. W. Longley, of Leeds. The invention relates to an arrangement of brick- moulding machinery, whereby bricks are produced from "wet" clay, having great solidity, with a smooth ex- terior, and containing a less amount of moisture than those produced by hand, or by machinery at present in use.

Fig 11 is a side elevation of the machine ; fig. 12 is a partial end elevation, showing in longitudinal section the cylinder which carries the moulds, and presents them successively to a conical hopper to be fed with clay ; fig. 13 is a cross section of the mould-cylinder, showing its connection with the hopper ; and fig. 14 shows the means used for locking the cylinder, so as to keep the moulds stationary while being filled and discharged.

A A is the main framing of the machine, upon which is mounted in suitable bearings a horizontal cylinder B. This cylinder is cast with open ends, and it is fitted near the middle of its length with a series of four moulds, C C, arranged radially around it. These moulds are formed by recesses cut through the periphery of a projecting band a a, that surrounds the cylinder, having their ends closed by the rings b h (bolted to the cylin- der) : a series of close chambers, D D, are formed in a similar manner between the moulds for receiving steam for heating the latter. Immediately above this con- centric projection of the cylinder B, and in close prox- imity thereto, is situate the hopper E, in which a screw

ART OF MAKING BRICKS AND TILES. 225

is mounted for forcing down the clay into the moulds as they arc presented to the former. Fitted into the moulds are plungers, F, the stems of "which project through the inner periphery of the cylinder B, and are intended for discharging the bricks from the moulds ; the inner periphery of the cylinder B is also pierced to receive the ends of a cruciform arrangement of steam pipes, G (fig. 18), for supplying steam from a central pipe running in the direction of the axis of the cylin- der to the chambers D ; an intermittent axial motion is given to the cylinder, for the purpose of bringing the moulds severally imder the hopper to be filled, and subsequently under the action of a plunger the clay thus filled into the mould presented to it is compressed therein. "When this is efiected, and the cam in its revolution has passed out of action, the weighted crank lever draws back the plunger N out of the mould. An- other movement of the cylinder B now takes place, and the compressed brick is brought down to the position for being discharged on to an endless apron 0. This is efiected by the stem of the plunger, F, of the mould, being pressed upon at its rear end by the rocking lever H. This rocking lever is mounted on a bent bracket arm attached to the main framing, and it is provided with a roller, which bears upon a rocking cam having a stud pin on the framing for its fulcrum. This rocking cam is jointed to a rod, which connects it with a rocking arm, pendent from a bracket on the framing. The arm carries a roller which bears against a cam on the cam shaft ; the revolution therefore of the cam shaft gives a reciprocating motion to the cam H, thus causing it to rock the lever H, and depress the plunger that has been brought beneath its inner end. This depression of the plunger efiects the discharge of the brick, which

l3

226 TltT)DJEXTS OF THE

is facilitated by the heating of the moulds through the admission of steam as before explained. To prevent the adherence of the clay to the compressing plunger, that is made hollow, and steam is convered into it by an arrangement of jointed steam pipes, as shown at fig. 1 1 . The discharged brick is received on to an endless apron, 0, which receives motion from the spur wheel on the cylinder B, gearing into a spur wheel on the axle of one of the carrying rollers of the apron. The cylinder B is also furnished with a ring, in the periphery of which are four notches, corresponding with the moulds. These notches (see fig, 14) are for the purpose of receiving the taper end of a locking bar P, which, when it is desired temporarily to lock the cylinder (as at the moment of filling, pressing, and discharging the moulds), is thrust forward by a cam on the cam shaft pressing upon a roller, mounted on the end of the locking bar, which slides in guides provided to receive it. The release of the cylinder is efiected by throwing back the locking bar by means of a weighted crank arm, as in the case of the compressing plunger.

This machine (fig. 15), the subject of a patent, is made by Whitehead, of Preston ; it works upon tem- pered clay also. The merits claimed for it consist in simplicity of construction and eflUcient performance. The junk of clay or brick may be previously moulded as for other pressing machines, but with this machine it is not absolutely necessary to previously mould the lump, if only sufficient clay be supplied to make a brick, and be simply placed in front of the piston ; it then is forced into the mould or die (of which there are four on a revolving shaft) of the desired size, and any superfluous bulk of the clay is cut ofi", thus making all the bricks

ART OF MAKING BRICKS AND TILES.

227

perfectly true and of uniform dimensions. During the return of the piston the box of dies or moulds revolves one-fourth of the way round, thus bringing another empty mould, which has already been oiled and cleaned by a self-acting lubricator, directly opposite the piston,

Fig. 15.

to receive the next brick. In the meantime, a self- acting push-plate forces the brick, already pressed, out of the die upon a self-acting table prepared for carry- ing it away.

The following well-arranged machine belongs to the class which can operate upon either plastic or dry clay, but which is, in our opinion, best adapted to the former. The makers and patentees, Messrs. Bradley and Craven, of Wakefield, have had a large experience in machinery of this sort.

Simplicity of parts and strength are the main cha- racteristics of this machine.

If the material be coarse or strong, it must be crushed

228

RrDiHEirrs of the

before being passed into the hopper, into which it may be delivered either with or without water.

Two moulds receive the charge of clay at once. ^Vhile these are being filled, the two that had been

Fig. 16.

just before filled are being subjected to a considerable pressure, and the two bricks that had just previously to that been so pressed are in process of delivery, out of the moulds and on to a flat belt which takes them away.

For the production of smooth, well-squared facing bricks this machine works extremely well.

We now arrive at the last class, namely, of ma- chines intended specially to operate upon dry clay, or nearly dry clay.

Amongst these we may notice the patent machine of Hersey and Walsh, which has been recommended by a

ART OF MAKING BRICKS AND TILES. 229

competent authority — Mr. Humphrey Chamberlain, Consulting Pottery Engineer, formerly of Kempsey, near Worcester.

This machine is stated to have been an American invention, which attracted attention from the simplicity of its movements and the enormous power it was capa- ble of exerting with a small amount of friction. It was found working successfully in the United States, and arrangements made for its introduction in this coxmtry. It produces an excellent article, and works satisfactorily here also.

Some few alterations had to be made to adapt it to English-sized bricks, as American bricks are little more than one-third the cubical contents of the English. The weight of these machines is about 25 tons, which is necessary to withstand the enormous pressure they are capable of exerting. They are made with any number of moulds from 2 to 8. "With 6 moulds, and driven by a 6-horse engine, to deliver 24 bricks per minute, one machine is capable of giving 330 tons pressure on the 6 bricks ; and if worked by a more powerful engine, the pressure can be increased, only limited by the strength of the machine. As few clays require more than 20 or 30 tons on a brick, from 4 to 5 horse power is ample. The motions of this machine are performed by a pair of cam wheels, the pressure being communicated by a pair of rollers running on the cams, with the mould pistons fixed on the shaft between them. The moidds are raised and lowered by the same cams. The bricks are delivered and the moulds re-fed with dry clay from the hopper by a feeder worked by friction. The ma- chine, after pressing 6 bricks, delivers them on a board ready for removal, so that they go dii-ect to the kilns without being handled or injured. The whole machine

230

RUDIMENTS OF THE

is fixed on one bed-plate, and is made of such strength as not to be likely to get out of order.

The following machine will afibrd a sufficiently clear notion of the construction, or at least the general prin- ciples of construction, of the great majority of dry- clay brick-machines which have been brought into successful action.

Fig. 17 represents the di-y-clay brickmaking ma-

nj. 17.

chine, of which Messrs. Bradley and Craven, of "Wake- field, are the inventors and patentees.

One of the disadvantages or difficulties of making per- fectly sound and solid bricks from completely dry clay, however finely pulverised, is that the air lodged in the interstices of the clay dust is sometimes not easily and completely expelled by a single compression, but lodges in one or more irregular cavities into which it has col- lected, and so leaves the brick hollow. One of the main objects of this machine is to obviate that evil,

AKT OF MAKING BRICKS AND TILES. 231

which is proposed being accomplished by its possessing the power of relieving each brick from pressure, and again applying it, so as gradually to force out the air, and finally consolidate the brick, and that to an extent that a single pressure, though greater, and hence exerting a greater strain on the machine, might not accomplish.

The patentees state : " By this machine two or three distinct pressures can be given to each brick. If two pressures (that is, upward and downward) are sufficient to produce a good article from the clay, then the ma- chine makes two bricks at a stroke, or for every revolu- tion one brick by each eccentric. If the clay is of such a character that the whole of the air cannot be expelled, or the dust sufiiciently condensed to make a perfect brick by two pressures, then a third is given by carry- ing the brick round under the second eccentric. With most clays two pressures will be found sufficient. It is only necessary to test a little of the clay to be worked so that the machine may be adjusted to mould and press from any kind of earth equally good bricks. The only change for giving three pressures is, to adjust the machine to run faster, and change the inclined plane for giving the upward or first pressure, and delivering the bricks. The action of the machine is easily imderstood. The clay being delivered by an elevator from the crushing rollers into the hopjDcr of the machine in motion, the tappet wheel turns the mould table the length of one mould. This action delivers two empty moulds under the hoppers to receive clay, delivers two bricks to the attendant, and gives a powerful upward pressure to the clay received in the moulds that have just left the hoppers. The table is then for a moment stationary, while the two eccentrics give

232 RUDIJIENTS OF TKR

the final strain on two bricks. When the eccentric pistons are clear of the moulds the tappet again turns the table one brick's length, and the same action is renewed. During the time the eccentrics are giving pressure, the table is held firmly by a stop, which if then released."

The last of this class which we shall notice is the dry-clay machine of Wilson, of Campbellfield Brick- works, Glasgow, which was exhibited in action at the Exhibition of 1862.

The peculiarity of working of this machine is, that the dry and pulverised clay prepared for being made into brick is carried along automatically to the hopper, and, just before being delivered into it, is subjected to being blown upon by the waste steam discharged from the non-condensing engine which drives the machine. The result is a slight condensation of steam on and in tive pores of the clay, and a slight Karming of the clay itself. From this arises a much-increased tendency to rapid and perfect agglutination in the clay when sub- mitted to pressure in this state, between wet and dry, and a much readier expulsion of the air involved in the mass. There is not the slightest doubt of the great advantage derived from this very simple mode of treating the dry clay prior to compression.

There are several contrivances in Mr. Wilson's ma- chine, as to details, also of value, especially one by which the maximum pressure possible is so regu- lated that the destruction of the machine is guarded against.

One great improvement yet remains to be made to render perfect dry-clay brickmaking machines, namely, to adapt to them the same method that was employed by Mr. Brockedon, in his patent for compressing dry

ART or MAKING BRICKS AND TILES.

233

powder of plumbago into a dense and solid block to be sawed into pencils, namely, the operatiJig the compres- sion in a vacuum, so that the air involved between the particles of dry clay (or dust, if quite dry) being thus extracted, the mechanical pressure is free to act fully and solely in producing condensation and agglutination of the clay particles.

Any one of the brick machines of the first class, down to fig. 8, inclusive, may, by a suitable alteration of the discharging dies and receiving tables, be made to express and form perforated bricks, moulded bricks, drain or other pipes, or tiles of any sort, as in Fig. 7.

"We shall therefore confine our illustrations of tile- making machinery, specially so designed, to two exam- ples, viz., to fig. 18, the large drain-pipe machine of

Fig. 18.

Page and Co., of Bedford, which forces out a con- tinuous hollow cylinder from the plastic clay (as at A, fig. 19), and fig. 19.

234

RUDIMEXTS OF THE

The macliine by "Whitehead, of Preston, for pressing one end of the cylinder so cut off to a given length, as

at A, into the socket form, as at B, fig. 10, so that the

lengths shall go together with spigot and faucet joints.

Dies of Tarious forms, prepared to adapt to any of

the brick or tile machinery, are supplied by the makers,

ART OF MAKING BRICKS AND TILES. 235

by w'hicli almost any form (solid or hollow, tubular or multitubular, i.e., perforated like "perforated brick"), that can be produced by the advance of a given section parallel to itself, may be formed. The figures in Fig 7 show a few of the more usually employed sections — those at the right being drain-pipes, those in the middle for building purposes, and the left-hand ones for roof- ing use.

In addition to the machines for brick and tile making, which we have thus pretty copiously illustrated, there are other machines almost innumerable for making special forms in plastic or in dry clay, referable to the great family of bricks and tiles. A great tribe of these machines, to which our space forbids our making any allusion, is employed in Great Britain and abroad in the manufacture of encaustic, or inlaid, or intaglio tiles for flooring and other architectiu'al purposes. Those who desire still more complete or enlarged infor- mation on the subject of this class of machinery shoidd consult the Practical Mechanic's Journal Record of the Exhibition of 1862, Mr. D. K. Clarke's "Exhibited Machinery of 1862," the Reports of the Juries of Exhibition, 1862, and the volimie of Abridgments of Patents, relating to drain tiles and pipes, bricks, tiles, and pottery, issued by the Patent Office, extending from 1619 to 1861. There have been many patents since that date, and many descriptions of machines of more or less value are also to be found scattered through the British and foreign mechanical journals, in encyclop?edia articles, &c. Though not important for those employ- ing brick machinery at home, it may be desirable, for the information of British colonists, that we should in- dicate the form of portable high-pressure steam engine most usually employed for actuating such. It is that

236 RUDIMENTS OF Tire

shown in fig. 20, being one of this class of engines manufactured by Cla3rton and Shuttle worth. When bricks, &c., are required for a special contract or some private work presenting but a terminable demand, such

Fi^. 20.

portable engines are the best and cheapest in ever^ way ; but, for a great and permanent brickmakiug establishment, engines upon fixed bed-plates or foimda- tions are to be preferred.

In concluding these notices of the apparatus of the mechanical brick and tile maker, we must not omit to call the reader's attention to probably the greatest im- provement that has ever been made in the constructioD

ART OF MAKING BRICKS AND TILES.

237

of kilns, for at once drying and burning brick, viz., the patent brick-kiln of Hoffmann. This kiln is, in fact, an admirable adaptation to brick

FUj. 21.

drying and burning of Siemens's regenerative principle of furnace, as will be apparent from the following

Tig. 22.

account, abridged chiefly from a paper by Professor James Thomson, of Belfast. Fig. 21 is a half-plan on top of the kiln, the other being a horizontal section at

238

RrDIMESTS OF THE

the level of the flues, leading into the central chimney- stalk, as seen in the vertical section, fig. 23. Fig. 22 is a diagram of the whole to a reduced scale, which is

referred to in illustrating the description of the mode of working of the kiln.

The accompanying engravings illustrate this remark- able form of kiln, invented by M. Hoffinann, of Berlin, but patented in England by Mr. H. Chamberlain, who supplies designs ibr their construction, &c. Some sixty of these kilns are already at work on the Continent and in Great Britain. The furnace or oven consists of a circular channel, 0, of any section, which receives the objects to be fired, introduced through doors in the outside wall ; the fuel is fed in by apertures formed in the top of the arch. Flues lead from the bed of the

ART OF MAKING BRICKS AND TILES. 239

furnace to the smoke-chamber R, whicli surroimds the base of the central chimney, the commimication with which can be cut off when required by means of cast-iron bell-shaped covers. An intercepting damper can be lowered or placed in grooves built into the walls of the furnace immediately behind each flue, so as to separate it at any distinct or equidistant compartment. The fuel passes through apertures which are constructed in the arch, and falls through channels formed by the objects to be burnt to a chamber in the bed of the furnace, from which a certain number of small flues radiate to produce a free current from fire to fire. In practice it is found barter to divide the kiln into twelve chambers, to which there are twelve entries or doorways, and the same number of flues communicating with the smoke-chamber, and just as many openings in the arch for the reception of the large intercepting dampers — thus the furpace can be divided at any one of the twelve parts. For clearer distinction, these compartments may be numbered, as in fig. 22, from 1 to 12, of which two, ISTos. 12 and 1, we will suppose are separated by the intercepting damper. The objects to be burned may be bricks or tiles, &c. Suppose the fire in full operation — the doors leading to the compartments 1 and 2 being open, No. 1 for filling it with fresh goods, and No. 2 for taking out those already burnt. The chambers Nos. 3, 4, 5, and 6, which arc all filled with burned goods, are gradually cooling by the air entering through the doors of Nos. 1 and 2, and as it passes on through warmer and at last glowing ware, it will result that the kiln fires are supplied with atmospheric air almost as hot as the furnace itself. In chamber No. 7 the fire is burn- ing, and when its contents have reached the desired

240 RUDIMENTS OF THE

temperature, No. 8 will have arrired at such a degree from the absorption of the waste heat, that the fuel introduced from the top is instantly inflamed.

The compartments Nos. 9, 10, 11, and 12, will be dried ofi", and heated one after another by the waste heat which passes through and expends itself on the contents of these chambers, and on its arrival in No. 12, meeting with the obstruction of the large damper, it is conducted by the small flue to the chimney, with its temperature again so lowered that it will only just support the draught. No. 1 being now filled again, the damper between 12 and 1 is lifted and lowered be- tween 1 and 2. The bell damper above the mouth of the flue No. 12 is lowered, and that of No. 1 lifted. The doorway of No. 12 is then closed, and that of the compartment No. 3 opened, the contents of which wiU be sufficiently cooled to be taken out, while No. 2, which is empty, can be fiUed again.

On the 5th of January, 1864, Professor J. Thomson, of Belfast, read a paper on the manufacture of bricks, before the Chemico- Agricultural Society of Ulster, in which he referred at considerable length to the Hofl&nann oven. The foUonNnng is an abstract of his paper : — Having explained the chief methods in use for working the clay and forming it into bricks ready for the kiln, he then turned attention to the great loss of heat which occurs in the ordinary modes of burning bricks in com- mon kilns. This loss is twofold. First, during the burning of the bricks the air which has passed through the fuel, or among the heated bricks, and the smoke, including the gaseous products generally, passes away from the kiln to waste at a very high temperature, even at a red heat, during a considerable part of the process. Secondly, when the bricks are raised to the high tern-

ART OF MAKING BRICKS AND TILES. 241

peratnre I'equired to burn them, and render them pei-^ manently hard, the great store of heat which they contain is entirely thrown to waste while they are left to cool. In this new kiln a remarkable economy of fuel is effected, by saving the twofold loss of heat uli'eady mentioned : first, it saves the heat of the gaseous products of combustion and imconsimied air passing through and away from the burning bricks, by applying this heat effectively in drying the new fresh bricks about to be burnt, and raisiiig them up to an incandescent temperatui'e, so that oiliy a very slight addition of-heat ffbm ignited fuel directly is required to complete their burning; and, secondly, it saves the heat of the cooling bi'icks, after their having been sufficiently fired, by appl^^ing it all again in warming the air which goes forwaM io supply the fires; so that the fuel is bufnt with air already at nearly an incan- descent temperature, instead of requiring, as usual, to heat the air for its own combustion. Professor Thom- son explained, as an example, the large kiln which Mr. Moore was then constructing at his brick- works at IIayfieldPark,in the neighbourhood of Belfast. Thekiln, as will be seen, is built in the form of a large arched passage, like a railway tunnel, bending round in going forward on the ground till it closes with itself to form a great circular ring-chamber, within which the burning of the bricks is carried on. This ring-chamber maybe of any convenient dimensions, 160 ft. diameter being a suitable size. Round its circumference there are twenty-four entrance doorways, admitting of being closed with temporarily-built bricks and clay, so as to retain the heat and exclude all entrance of air by the doorways so built up. The great ring- chamber may now be conceived as consisting of twenty-foui* compartments

M

242 RUDIMENTS OF THE

or spaces, with one of these doorways to each. In the centre of the ring a high chimney is erected, and from each of the twenty-four compartments of the annular chamber an underground flue leads into the chimney. There are, then, twenty-four of these flues converging towards the centre like the spokes of a wheel, and each flue has a valve, by which its communication with the chimney can be cut off. Arrangements are made by which a partition like a damper can be let down at plea- sure, or otherwise placed, so as to cut off all communi- cation between any of the twenty-four compartments of the ring- kiln and the next one. Let us now suppose the working of the kiln to have been already fairly esta- blished ; for, after being once kindled, the fire is never extinguished, but the burning of new bricks and the removal of the finished produce are carried on by a con- tinuous and regular process from day to day. Two adjacent compartments have this day their entrance doors open, all the rest being perfectly closed. By the arrangement of the valves in the flues, and the large partition, the air which gets admittance alone by the two open doors has to go round the whole circuit of the ring-kiln in order to be drawn into the chimney. From one of the two open compartments men are taking out the finished and cooled bricks, and in the other one they are building up newly-formed uubumt bricks which are not yet quite dry. The air, entering by these two compartments, passes first among bricks almost cold and takes up their heat, and then goes forward to warmer bricks, and then to hotter and hotter, always carrying the heat of the cooling bricks forward with it till it reaches the part of the ring diametrically opposite to the two open and cold compartments. At this place it gets a final accession

ART OF MAKING BRICKS AND TILES. 243

of heat ftom the burning of a very small quantity of small coal, which is dropped in among the bricks from time to time by numerous small openings furnished with air-tight movable lids. Thus at this part of the kiln there is generated the full intensity of heat which is required for the burning of the bricks. The hot air, including the products of combustion, which, for brevity, we may call the smoke, though it is really perfectly gaseous and free from sooty particles, then passes for- ward to the bricks, which, by its continuous current, are being heated ; and it passes on among them from hot bricks to those which are less and less hot, heating them as it goes, and then passes on to those which are still damp, drying them as it goes ; and then it passes to the chimney, in a state almost cold, and saturated with the moisture, in the form of steam or vapour, which it has taken from the damp bricks. On the following day to that on which the operations just described have been going on, the partition is shifted forwards by the space of one compartment, and a corresponding change is made as to the flue which is to communicate with the chimney, and as to the pair of compartments open for the admission of air and for the removal of finished cold bricks, and the building in of fresh damp bricks ; and so the air, including the products of combustion, at the end of its circuit in the annular chamber, just before passing ofi" to the chimney, now passes among the fresh bricks which were described as built in on the yesterday of this new day. The place where the small-coal fuel is thrown in is also advanced roimd the circle by the stage of one compartment ; and so now the whole process goes on just as it did yesterday. The fire thus makes a complete circuit of the annvJar chamber in twenty-four working days. The whole

M 2

244 VRT OF MAKING BRICKS AND TILES.

process may be left dormant on Sundays, merely by this closing of all apertures for the admission of the current of air. The same kind of kiln, with the same process of working, is applicable in the burning of lime ; and both for the brick-burning and the lime-burning, the saving of fuel, relatively to what is consiimed by the ordinary methods, is such as to appear at first sight almost incredible.

The Hoffimann or Chamberlain kiln is not so easily applicable to burning lime as it is to brick, nor will it answer without considerable modification for burning

o

thin and light tiles or pottery. There must be mass enough in the goods to be fired to afibrd the requisite magazine of absorbed heat to be afterwards used up, and the draught must not be impeded as by the breaking down of limestone when burnt into lime.

Those kilns are not necessarily made circular. They are, indeed, now more usually rectangular, with or without rounded ends, in plan. 'V\T?en originally writing the preceding, the author of this chapter had not himself seen those kilns at work, and hence quoted from others as to their properties, &c. He has since, however, had occasion, professionally, to make himself fully acquainted with their construction and perform- ance, and can indorse fully all that has been stated, and, indeed, might say much more in their com- mendation.

Many structural improvements and simplifications have latterly been made in those kilns ; but as the patentee, Mr. H. Chamberlain, as a Pottery Engineer, is professionally engaged in providing designs for those who employ these kilns, it would not be fair that the writer shoiild here enter into further details.

APPENDIX 1.

The following pajier was read by Mr. Tomlinsoii at a meeting of the Geologists' Association, ou February 3, 1862 : —

On the Plasticity and Odouk of Clay.

It is a happy result of Bacon's method of inquiry that science is not required to explain the causes of things, but to state the laws of phenomena. Nevertheless, while these laws are obscure, and facts are scattered, theory may often do good service by collecting and marshalling them : for, as our great master of induction well observes, "Facts are the soldiers, but theory is the general." And again, " Truth is more easily evolved from error than from confusion." That is, a bad theory is better than none at all, for it serves to collect and arrange the facts, and thus makes them more easy to handle.

In these remarks must be found my excuse to-night for endeavour- ing to bind together some of the facts respecting a property of a very common substance ; namely, the Plasticity of Clay.

The more I consider this property the more wonderful and inex- plicable does it appear. Take a mass of dry clay ; it cracks easily, and crumbles readily : add to it a certain proportion of water, and it becomes jtlasiic — it obeys the will of the artist or the artizan, who can, out of this yielding mass, create new forms, or perpetuate old ones. Drive off the water at a red heat, and plasticity is for ever lost ; rigiditi/ takes its place : the clay is no longer clay, but some- thing else. It may be reduced to powder, and ground up with water; but no art or science can again confer upon it its plasticity.

All this is very wonderful. There is another fact that is equally .-0 : if we combine the constituents of clay in the proportions indi- cated by the analysis of some pure type of that substance, we fail to produce plasticity. I have on the table specimens of Dorset clay3 dry and crumbling ; the same wet and plastic ; and the same in the forma of casts of fossils, which have been passed through the- five,

246 APPENDIX.

and have exchanged plasticity for rigidity. Tiiey are, in fact, in the form of biscuit.

With respect to the temperature at which clay becomes rigid, we have no accurate information. It is much lower than is generally supposed, as will appear from the following experiment : — I pounded and sifted some dry Dorset clay, and exposed it to a sand-bath heat in three portions varying from about 300° to 600°. Specimens were taken out from time to time, and rubbed up with water, but they did not lose their plasticity. Some clay was put into a test tube with a small quantity of mercury, and heated until the mercury began to boil. At this temperature (viz. 650°) the clay did not cease to be plastic. The flame of a spirit-lamp was applied, and the tube was heated below redness ; after which the clay, on being mixed with water, showed no sign of plasticity.

In experiments of this kind, the first action of the heat is to drive off the hygrometric water. The clay then becomes dry, but is not chemically changed ; it does not cease to be plastic. On continuing to raise the temperature, the chemically combined water is separated, and the clay undergoes a molecular change, which prevents it from taking up water again, except mechanically. With the loss of this chemically combined water, clay ceases to be plastic.

It was, I believe, first noticed by Brongniart,* that we cannot pro- duce plasticity by the synthesis of clay. The fire clay of Stourbridge, for example, is a hydrated silicate of alumina, represented by the for- mula Alo O3, 2 Si O2 + 2 Aq. If we mix one atom of the sesqui- oxide of alumina with 2 atoms of silica and 2 of water, we get a compound which cannot be called clay, since it is wanting in plasticity.

It is quite easy to obtain either alumina or silica in the gelatinous state ; but we cannot obtain them in the plastic state.

Clay is almost the only substance in the mineral kingdom that pos- sesses plasticity. In loam, if the sand be in large proportion, and in marl, if calcareous matters abound, so as to deprive either material of plasticity, it ceases to be clay. There are also certain silicates of alumina which are not plastic ; such as bole, lithomarge, and fuUers'- earth. Bole consists chiefly of a hydrated bisilicate of alumina, in which a portion of the alumina is replaced by sesquioxide of iron. Lithomarge also contains iron, and is sometimes so compact as to be used for slate-pencils. FuUers'-earth contains lime, magnesia, and iron, in addition to its principal ingredients.

■ '■ Tiai'4 Jes Arts C^ramiques." Parij, 18M. Vol. 1. p. 83.

APPENDIX. 247

There is probably no substance so indeterminate in its composition as clay. Regarding it, as Lyell does,* as " nothing more than mud derived from the decomposition of wearing down of rocks," it must necessarily contain a variety of substances ; such as oxide of iron, lime, magnesia, potash, silica, bitumen, fragments of uudecomposed rock, &c. These substances impair the plasticity of the clay, and impress upon it certain characters which are of more importance to the manufacturer than to the chemist, or the geologist. Bronguiartf enumerates, and gives the analyses of no fewer than 167 clays and 28 kaolins, all of which are in use in the arts in different parts of the world. They probably all differ in plasticity, but they all possess it ; and at a high temperature exchange it for rigidity. A rough method of measuring the plasticity of different clays is to note the length to which a cylinder of each can be drawn out in a vertical direction without breaking. In such a comparison, the clays must, of course, be worked equally fine, and contain the same proportion of water.

It is commonly stated that the ingredient that confers plasticity on clay is its alumina ; and yet, strange to say, pure alumina alone whether gelatinous, or after having been dried and ground up with water for a long time, never gives a plastic paste. Indeed, nothing can be conceived less plastic than gelatinous alumina, as may be seen from the specimens on the table. We may drive off most of the water from this gelatinous hydrate, but it will not become plastic. Or we may form clay by mingling solutions of the silicate of alumina and the aluminate of potash. You see they are perfectly fluid. I apply the heat of a spirit-lamp, and we get an opalescent gelatinous mass, but still no plasticity. We have, indeed, formed a gelatinous clay.

We cannot say that the gelatinous state of alumina is the cause of plasticity in clay ; for silica may be made as gelatinous as alumina, and silica is certainly not the cause of plasticity. It may be that the strong affinity of alumina for water (retaining a portion of it even when near a red heat) may be the cause of this property — ^just as turpentine renders wax plastic; and water and gluten confer the same property on starch.

We have seen that clay ceases to be plastic when its chemically combined water has been driven off. Still, however, water cannot be said to be the cause of plasticity, as a general property, since we have, in melted glass, a more perfect example of plasticity even than

» "Manual of Elementary Geology" (1855), p. 11. i *' Des Arts C^ramiques," Atlas of Plates.

•248 APPENDIX.

in clay ; and few substances are more plastic than sealing-wax at a certain temperature.

A clear idea of plasticity, and of some of the other mechanical properties of matter, may probably be gained by considering them as variations of the forces of cohesion and adhesion, and by bringing these, in their turn, under Newton's great law of attraction, which, whether exerted between atoms or masses, is directly as the mass, and inversely as the squares of the distances.

Now, if we suppose the distances between the molecules of matter to be 1-millionth or billionth, or 2, 3, i, 5, 6, &c., millionths or bil- lionths of an inch asunder, the intensity of their attractions will be 1, ^^th, -g^th, iV^h, &c., or, to represent it in a tabular form : —

Distances 1 2 3 4 5 6 7 8 9 10, &c.

Intensities of attraction 1 i i iV -rs -sV "iV "CT -gV tdij. &c- Suppose the molecules to be of the same density, but at different distances apart, as represented in the upper line. At the distance of 1-millioath of an inch we get an intensity of attraction represented by 1. At 2-milliouths of an inch the force of attraction is only one- fourth. Now, the idea is this, that the mechanical properties of matter, — such as porosity, tenacity, hardness, brittleness, plasticity, elasticity, &c., depend upon variations in the attractive force of the molecules according to the distances apart of such molecules. Thus, if the molecules of clay require to be 5-millionths of an inch apart iu order to produce plasticity, the intensity of attraction between them will be represented by ^Vth ; but if such clay be passed through the fire, and the molecules, in consequence of the escape of water, be brought nearer together, and rigidly fixed at 4-millionths of an inch asunder, the force of attraction will then be iVth.

Now, the method of arranging the particles of clay at that precise distance that shall impart plasticity, is one of Nature's secrets that we have not yet succeeded in penetrating. It may be that the circum- stances under which clay is formed and deposited, or the time that has elapsed since its formation, or the pressure of the superposed layers, may have so arranged the particles as to enable them to become plastic when the proper proportion of water is added. It may be that a certain state of disintegration is required on the part of the alumina and the silica, so that their proximate elements shall be neither too fine nor too coarse ; or it may be that the silica, in combining with the alumina, separates the atoms of the latter to pre- cisely those dis*anccs required for the development cf the property ;

APPENDIX. 249

or, lastly, the presence of a small portion of animal or other organic matter in clay may have something to do with this remarkable pro- perty.

An extensive series of experiments, by Delesse,* show the presence of animal matter in quartz and various rocks, where its presence had not previously been suspected ; and this may have as important an effect in modifying the properties of a mineral as the presence of minute portions of bodies, formerly entered as impurities, has in producing pseudo morphous crystals.

Still, the question recurs, "VYhy is not a clay artificially formed from pure materials plastic ? The answer is, that we do not know all the conditions of plasticity. We do know the conditions under which some mechanical properties exist — such as the hardness of steel, the brittleness of unannealed glass — and can confer or remove such pro- perties at pleasure. Eut with respect to plasticity, we can only confer a factitious property of this kind on mineral substances by taking advantage of another property which it somewhat resembles, namely, viscosity or viscidity. Viscosity differs in plasticity in this, that the viscous body does not retain the form impressed upon it when the force is removed, as a plastic body does. The materials of the old soft porcelain of Sevres had no plasticity ; but this property was con- ferred by means of soft soap and parchment size.f

TYithout speculating further on the nature of plasticity, I may remark that in the ancient pliilosopliy the word was one of power. Derived from the Greek -KXaocuv, or -KXarrnv, " to form," or " to create," it not only included the arts of modelling in clay, but also sculpture and painting, and, by a refinement of language, poetry and music. Plato and Aristotle even supposed that a plastic virtue resided in the earth, or did so originally, by virtue of which it put; forth plants, «S:c. ; and that animals and men were but effects of this plastic power. They did not suppose the world to have been made with labour and difficulty, as an architect builds a house ; but that a certain "efficient nature" {natura effectrix) inherent and residing in matter itself, disposed and tempered it, and from it constructed the

* " De I'azote et des matiferes organiqnes dans I'ecorce terrestre."— jlnn<i7« dei iiines, xviii., 1860.

t Brongniart (" Des Arts Cferamiqiies ") says that the old porcelames tendret were formed of 22 per cent, of fused nitre, 60 of Fontainebleau sand, 7-2 of salt, 36 of alum, 8*6 of soda, and 3-6 of gypsum. These materials were fritted and ground, and 75 parts taken, to which were added white chalk 17 parts, marl 8. This mixture was ground, sifted very fine, and made up Into a paste with l-8th soft soap and size, or, at « later period, with gum tragacautb.

M3

250 APPENDIX.

whole world. Aristotle distinctly recognises mind as the principal and directing cause, and nuiura as a subservient or executive instru- ment. Even in later times men have contended for the existence of a plastic nature, or incorporeal substance endowed with a vegetative life ; but not with sensation or thought, penetrating the whole uni- verse, and producing those phenomena of matter which could not be solved by mechanical laws. The learned Cudworth supports this view,* and the discussions into which it led him and other metaphy- sicians form a curious chapter in the history of the human mind. In England we do not now retain the term pbsiici/y, except as a phy- sical property of matter ; f but in Germany it has still an extensive Cgurative meaning. The word plastisch still means bild^nd or schopferitch (i.e. " creative") ; and it is still applied not only to sculp- ture, but adso to painting, poetry, and music. A German well under- stands the expression " plastische Gedsmken," or " plastic thoughts."

Before concluding, I would refer to another property of clay, which seems to me as wonderful as its plasticity ; namely, its odour when breathed on, or when a shower of rain first begins to wet a dry clayey aoil. This odour b commonly referred to alumina, and yet, strange to say, pure alumina gives off no odour when breathed on or wetted. The fact is, the peculiar odour referred to belongs only to impure clavs, and chiefly to those that contain oxide of iron. This was pointed out by Brongniart as far back as ]816,J who also remarked that minerals which do not contain alumina, such as pulverised chal- cedony, possess this remarkable property.

I have found that a pure kaolin, ground up in a mortar with a small quantity of water, emits a slight odour, which, however, becomes much more sensible if a little sesquioxide of iron be added.

Smooth quartz pebbles when rubbed together give an electric spark, and a fetid odour. It is commonly supposed that sea-side pebbles aJonc i>osses5 this property ; but the odour belongs equally to those found among gravel overlying the chalk, and in ploughed lands where the surface is exposed to all the vicissitudes of the weather. It is quite possible that the odour of these pebbles may hereafter be traced to the presence of oi^nic matter ; but I cannot resist the reproduction here of a suggestive hint given me by my friend Professor Bloxam,

• See " The True Intellectn»l System of the Universe," by RAlph Cadworth, D.D., 167*. A reprint hM been pnblUhed by Tege, in which see Vol. I.. P. 22S, el «f. i Dr. Johnic>n dtfioeiptarfie as " having the power to give form. J " DictionnaJre del Sciences >'atttrelles," art. ArgiU.

APPENDIX. 251

who is reminded by the spark aud odour from these pebbles of the presence of ozone.

What, again, is the cause of the odour in the narrow parts of stone buildings, not of new buildings alone, but of old ones, as in the stair- cases of old cathedrals ?

I do not attempt to reply to these questions. It requires some amount of knowledge and experience to put them — but how much more to answer them !

On Drying Bricks. ^Extracted pom Noble s ''Professional Practice of ArcJiitects" p. 143.) " The observations by Richard Neve, above a century since, upon itock bricks, will illustrate tlie subject : ' When the hack is as high as they think fit, they cover them with straw till they are dry enough to burn, ' &e., &c. He proceeds : ' A brickmaker being sent to Rum- ford, in Essex, went to work unadvisedly, aud laid them abroad in a place to dry ; but the sun, about ten o'clock, began to shine very hot, and the whole quantity of bricks burst to pieces, so that he was forced to go to work again : and then, before the sun shone too hot, he thatched or covered them over with straw till the next morning, when removing it, they did very well when set on the hack ; and when burnt, were curious red bricks, which would ring when hit with any hard thing.' "

On the use of Coal Dust in making Clamp Bricks.

{Extracted from Noble's " Professional Practice of Architects" p. 153.)

" Natives should be employed {in making bricks in Wales) in the manufacture, in preference to London hands, as the former use coal dust in preparing the earth, and not breeze (ashes), as about London ; and provided an undue portion of coal is used, a whole clamp would be destroyed, of which there was an instance at Lampeter (Cardigan- shire). An Islington brickmaker was sent to Wales, and as he was too conceited to make inquiries, or to receive information, set light to a clamp he had prepared with coal, being 70,700 ; and in a very short time the whole kiln was in one general blaze. The man being alarmed, took to his heels, and, unlike Lot's wife, he turned not back, neither looked behind him. Even from the heights leading to Landovery the rejlectioii was quite enough for him ; nor did he stop

252 APPENDIX.

till he reached London, being, as he said, ' afeared' tbey xvould catch him and put him in prison ! "

Bkicksiaking at Great Gkimsbt, Likcolnsuibe.

Large quantities of bricks have been made during the last few years at Great Grimsby, for the Dock Company, from the Humber silt. These bricks are remarkable for their colour, which varies in the same brick from dark purple to dirty white, passing through various shades of blue, red, and yellow, in the space ol two or three inches. The silt, when first dug out of the bed of the Humber, is of a dark blue colour, which soon, from exposure to the air, changes to a brown.

The bricks made for the Dock Company were burnt in close clamps — fired with layers of small coal, but without coal-dust or ashes being mixed with the clay as in London brickmaking. With the first clamps there was much waste, the quantity of fuel being excessive, and the bricks were cracked and made brittle in conse- quence ; but the experience obtained by the first trials has led to the production of a sound well-burnt brick, with, however, the peculiar colour above mentioned.

Considerable quantities of bricks have been lately made for sale at Great Grimsby, and burnt in clamps with Hues, as in kiln burning, which method appears to be attended with less waste than close clamping.

The slack or small coal used for fuel may cost from 25. G(/. to \s. per 1,000 bricks. The cost of clay getting, tempering, moulding, and drying, is about S*. G(/. per 1,000. The moulds used are of wood, plated with iron. The process employed is that known as slop-moulding.

Kilns as well as clamps arc used in this part of Lincolnshire, their construction being similar to that of the kilns in general use in the Midland Counties.

BaiCKilAKIXG IN SUFPOLK.

Two kinds of bricks are made in Suffolk, viz., reds and whites. The latter are much esteemed for their shape and colour, and large quan- tities arc annually sent to Loudon, for facing buildings of a superior

class.

APPENDIX. 253

Clay. — The supplies of brick-earth are chiefly derived from the plasvio clays lyiug above the chalk, although the blue clay is occasion- ally used.

The clays in most parts are too strong to be used as they rise, and have consequently to be mixed with a white loam or a milder earth. Tempering. — The clay is turned over in February and March, and in some parts of Suffolk it is passed through the wash-mill, but this is not generally the case.

Tempering is generally performed by spade labour, but the pug-mill is sometimes used, although not commonly, for white bricks ; it is, however, used for all oilier white ware. Moulding. — The brick mould is of wood, shod with iron ; the dimen- sions vary slightly according to the nature of the clay, but are usually as follows : 9|ths long by 4yf ths wide and 2>\ deep. There is no hollow formed in the bottom of the brick for the mortar joint. Brass moulds are unknown.

Sea sand is used in the process of moulding, for sanding the mould and the table.

The strike is used for taking off the superfluous clay from the mould. The use of the plane is not known. Dri/ing. — The bricks are not dried on flats as in the Midland Coun- ties, but are taken directly from the moulding stool to the hacks. Sheds are used in some yards, and drying houses with flued floors are used in winter for pantiles and kiln tiles, but not for bricks.

The length of a hack is about 70 yards, and each moulder will keep four hacks going.

The time required for drying in the hacks of course varies according to the weather, but may be stated on an average at about eighteen days for red bricks. White bricks dry somewhat quicker.

The contraction of the clay in drying amounts to about | in. in the length of a brick, and, if properly burnt, the shrinkage iu the kiln is imperceptible.

The weight of a brick, when first moulded, is about 8 lbs. ;

when dried, about 7 lbs. ; and when burnt, about 6 lbs. ; but

much depends upon the nature of the earth.

Bvrning.—The construction of the kiln is quite difi'erent from that of

the kilns used in other parts of England, having two arched

254 APPENDIX.

furnaces runninjr its whole length underneath the floor, which ij formed of a kind of lattice work, througli the openings of which the heat ascends from the furnaces below.

The cost of erecting a kiln to burn 50,000 whites is about £1 -15. A kiln to burn 35,000 reds costs about £100.

The bricks are commonly set in the kiln in bolts two bricks long by ten on ; but some brickmakers prefer to cross them in the alternate courses, in order to admit the heat more freely.

The fuel used is coal, and the quantity consumed is about half a ton per 1,000 for white, and 7 cwt. per 1,000 for red, bricks.

The iime of burning is about GO hours for white, and 40 hours for red, bricks ; white bricks requiring a greater heat than the red ones to bring them to their proper colour. The coal costs from 15s. to 16*. per ton.

Cost of Manufacture* The selling prices vary from £1 10*. to £2 per 1,000 for reds, and Trom £2 2«. to £3 per 1,000 for whites.

Of red bricks two qualities only are distinguished, viz., out- side and inside ; of white, four qualities are distinguished, viz., best, 2nd, 3rd, and murrays. The price of the ordinary red brick is about £1 lO*. per 1,000, uud the cost may be thus divided :—

Clay digging, per 1,000 ....

Tempering, ditto

Moulding, ditto

Drying, ditto

Barrowing from hacks and setting kiln ditto

Burning, ditto

Drawing kiln, ditto .

Stacking, ditto

Cost of labour per 1,000 £0 12 2

Coals, about , 0 6 0

Duty 0 6 U

Rent, tools, contingencies, and profit . .058^

£	s.	d.
0	2	6
0	1	0
0	5	0
0	0	f)
0	1	0
0	1	3
0	0	8
0	0	3

Selling price at the yard, about £1 10 0 These ostimates l^long to the date of the First £<liUoa of this work.

APPENDIX. 255

White bricks are made in many parts of England, but the Suffolk whites have the pre-eminence over all others.

The white bricks made near Lincoln are remarkable for swelling when laid in work, which causes them to throw off the mortar joints, and renders it impossible to make use of them in good work.

The clay from which these bricks are made extends from the VVitham northwards as far as the Humber, and, so far as we are aware, possesses the same property throughout this distance, the bricks made from it at various points between the Witham and the Humber having the common defect of swelling after burning. A curious specimen of this may be seen in a large chimney at Saxilby, which has a complete twist, from the irregular swelling of the brick- work.

The peculiar property of swelling after burning is not confined to the Lincolnshire white clay. The author was informed some years ago, by Mr. Vignoles, C.E., that some of the bricks made on the ^lidland Counties Line of Railway, between Rugby and Derby, had the same defect.

For the above particulars respecting the Lincolnshire white bricks we arc indebted to Mr. William Kirk, of Sleaford.

On the Making and Buening of Dbain Tiles.

Extracts from a communication by Mr. Law Hodges, published in the Journal of the Royal Agricultural Society of England, Vol. V. Part II. :—

" Reflecting on these obstacles to universal drainage, where required, I conferred with Mr. John Hatcher (brick and tile maker and potter, Benenden, Kent), on the possibility of erecting a kiln of common clay that would be effectual for burning these tiles, and of cheap construction— and the result was the building one in my brickyard in July last, and the constant use of it until the wet weather at the commencement of this winter compelled its discon- tinuance, but not until it had burnt nearly 80,000 excellent tiles ; and in the ensuing spring it will be again in regular use.

" I shall now proceed to take in order the six points enumerated under the 9th head of the Prize Essays for lSi5, as printed in th* last volume of the Royal Agricultural Society's Journal, viz. : —

2j6 ArrtNDix.

•■ ]i)(. Mode of vrorkinj^ clav according to its qaaiitj.

" iad. Machine for making tiles.

" 3rd. Sheds for drying tiles.

" 4th. Construction of kilns.

" 5th. Cost of forming the esfablishmcn*.

" Cth. Cost of tiles when ready for sale.

" 1st Point. Working the clay.

" All clay intended for •working next season must be dug in the winter, and the earlier the better, so as to expose it as much as pos- sible to frost and snow. Care must be taken, if there are small stones in it, to dig it in small pits, and cast out the stones as much as possible, and also to well mix the top and bottom of the bed of clay together. It is almost impossible to give minute directions as to mixing clay with loam, or with marl when necessary, for the better working it afterwards, as the difference of the clays in purity and tenacity is such as to require distinct management in this respect in various localities ; but all the clay dug for tile-making will require to be wheeled to the place where the pug-mill is to work it ; it must be there well turned and mixed in the spring, and properly wetted, and finally spatted down and smoothed by the spade, and the whole heap well covered with litter to keep it moist and fit for use through the ensuing season of tile-making.

" 2nd Point. Machine for making tiles.

" For the reasons already alluded to, I prefer Hatcher's machine- Its simplicity of construction, and the small amount of hand labour required to work it, would alone recommend it ; for one man and three boys will turn out nearly 11,000 pipe tiles of 1 in. bore in a day of ten hours, and so in proportion for pipes of a larger diameter ; but it has the great advantage of being movable, and those who work it draw it along the shed in which the tiles are deposited for drying, previously to their being burnt : thus each tile is handled only once, for it is taken off the machine by the little boys who stand on each side, and at once placed in the rows on either side of the drying shed, thus rendering the use of shelves in the sheds wholly unnecessary, for the tiles soon acquire a solidity to bear row upon row of tiles, till they reach the roof of the sheds on either side; and they dry without warping or losing their shape in any way.

"The price of this machine is £25, and it may be proper to add, that the machine makes the very best roofing tiles that can be made, and at less than half the price of those made by hand, as well as

APPENDIX. 257

hvjing much ligbter, and closer, and straighter, in consequence of the pressure through the die.

" It is necessary, in order to ensure the due mixing of the clay, as well as to form it into the exact shape to fill the cylinders of the machine, to have a pug-mill, Messrs. Cottam and Hallen make these also, and charge £10 for them. This mill must be worked by a horse ; in general one day's work at the mill will furnish rather more prepared clay than the machine will turn into tiles in two days

" 3rd Point. Sheds for drying.

"The sheds necessary for this system of tUe-making wUl be of a temporary kind : strong hurdles pitched firmly in the ground in two parallel straight lines, 7 ft. apart, will form the sides of the sheds, and the roof will be formed also of hurdles placed endways and tied together at the top, as well as to the upper slit of the hurdle, with strong tarred twine, forming the ridge of the roof exactly over the middle of the shed. They must then be lightly thatched with straw or heath, and the sharpness of this roof will effectually protect the tiles from rain. Two of these sheds, each 110 ft. long, will keep one of the kilns hereafter described in fuU work.

" N.B. — These sheds should be so buQt as to have one end close to the pug-mill and the clay-heap, only leaving just room for the horse to work the mill, and the other end near the kiln. Attention to this matter saves future labour, and therefore money.

" 4th Point. Construction of kilns.

" The form of the clay kiln is circular, 11 ft. in diameter, and 7 ft. high. It is wholly built of damp earth, rammed firmly together, and plastered inside and out with loam. The earth to form the walls ■s dug out round the base, leaving a circular trench about 4 ft. wide and as many deep, into which the fire-holes of the kiln open. If wood be the fuel used, three fire-holes are sufficient ; if coal, four will be needed. About 1,200 common bricks are wanted to build these fire-holes and flues ; if coal is used, rather fewer bricks will be wanted, but then some iron bars are necessary — six bars to each fire- bole.

"The earthen walls are 4 ft. thick at the floor of the kiln, are 7 ft. high, and tapering to the thickness of 2 ft. at the top ; this will determine the slope of the exterior face of the kiln. The inside of the wall is carried up perpendicularly, and the loam plastering inside becomes, after the first burning, like a brick wall. The kiln may be safelj erected in March, or whenever the danger of injury

258

AITLNDIX.

F'kj. 2. I'ian of Top of Kiliu

APPENDIX.

25«

Fig. 3.

Trom frost is over. After the summer use of it, it must be protected by faggots or litter against the wet and the frost of winter. " A kiln of these dimensions will contain —

47,000 1-in. bore pipe tiles. 32,500 \\ 20,000 If 12,000 2i

and the last-mentioned size will hold the same number of the inch pipes inside of them, making therefore 2i,000 of both sizes. In good

26C

^

weather this kiln can be filled, burnt, and discharged once every fort- night ; and fifteen kilns maj be obtained in a good season, producing —

705,000 1-iu. pipe tiles. Or isr.oOO H „ „ Or 300,000 If „ „

and so on in proportion for other sizes.

" N.B. — If a kiln of larger diameter be built, there must be more fire-holes, and additional shed room.

APPENDIX. 261

" 5th Point. Cost of forming the establishment.

The price chared by Messrs. CotUm and Hallen for the machine,

with its complement of dies, ;» £25

Price of pug-mill 10

Cost of erecting kiln 5

Cost of sheds, straw 10

60

(The latter item presumes that the farmer has hurdles of his own.)

" 6th Point. Cost of tiles when ready for sale.

" As this must necessarily vary with the cost of the fuel, rate of wages, easy or difficult clay for working, or other local peculiarities, 1 can only give the cost of tiles as I have ascertained it here accord- ing to our charges for fuel, wages, &c., &c. Our clay is strong, and has a mixture of stones in it, but the machine is adapted for working any clay when properly prepared.

" It requires 2 tons 5 cwt. of good coals to bum the above kiln full of tiles. Coals are charged here at £1 8*. per ton, or 1,000 brush faggots will effect the same purpose, and cost the same money ; of course some clays require more burning than others ; the stronger the clay the less fuel required.

" The cost of making, the sale prices, and number of each sort that a waggon with four horses will carry, are as follows : —

Cost. Sale Price. Waggon

*. d. s. holds —

l-in. pipe tiles 4 9 per 1,000 12

li „ 6 0 „ 14

1} „ 8 0 „ 16

2} „ 10 0

, 20

2} „ 12 0 „ 2t

Elliptical tiles

Boles

n-

8,000 7,C00 5,000 3,500 3,000

2,000

" AU these tiles exceed a foot in length when burnt.

" The cost price alone of making draining tiles will be the charge to every person making his oicn tiles for his otcn use. If he sell them, a higher price must, of course, be demanded to allow for some profit, for credit more or less long, for bad debts, goods unsold, &c. &c. ; but he who makes his own saves all expense of carriage, and, as his outlay will not exceed £50, the interest on that sum is too trifling to be regarded, and he has no additional rent to pay; and after he has made as many tiles as he wants, his machine and pug-mill will be as good AS ever, with reasonable care, and will fetch their value "

APPENDIX II.

The Sciekce op BsicKscAKiyG.

It has been said by the author of this volume, in his preface, *.hat the science of brickmaking has yet to be formed and written.

This is no doubt in one sense true, though it must be remarked that, inasmuch as the art of the brickmaker is to be viewed iu its chemical and physical relations as only the humblest branch of that of the potter or porcelain manufacturer, the saymg so is not to dis- credit the vast and wide-spread importance of exact knowledge to the brickmaker, nor of the value of his universally-diffused and indis- pensable art.

The manufacture of pottery, in all its branches, having been the subject of lengthened and important scientific labours at the hands of successive able men of science, amongst whom are Reaumur, Bottcher, Brongniart, Malaguti, and Salvetat, as well as of the tentative and technological labours of innumerable manufacturers, amongst whom Cookworthy, Chaffers, Wall, Wedgwood, Minton, and others stand pre-eminent, in England alone, it cannot be said that pottery in general is devoid of a formed and established science, though very much remains to be discovered over its wide domain of theory and practice. This being so, and very much of the science of the porcelain manufactory being directly applicable and available in the brick-field (if indeed the brickmaker himself possess the requisite foundation in general scientific education, especially in chemistry and physics), it is only true in one sense that no science of brickmaking yet exists, namely, in the sense that the knowledge we already possess of the science of the ceramic arts has not yet been systematised and applied in a special manner to the brickmaker's art. To attempt to supply this want in the present little volume is impossible. Three such volumes would scarcely afford sufficient space to treat of the science of brickmaking in a systematic and complete manner.

APPENDIX. 263

SI ill it seems undesirable that in an elementary outline of this art so little should have been given in the original text, even as a sketch, of some salient points which such science presents. We shall attempt iliis, however incompletely.

The brickmaker deals with natural clays only, the constitution of which, when more or less ascertained in respect to his object, he may modify by the addition of other mineral bodies, such as sand, ashes, &c., or by the mechanical extraction of naturally-mixed matter, as sand, pebbles, pyrites, &c., and whose physical qualities he may alter by mechanical means— grinding, "slip-washing," Sec.

The choice of a clay that shall answer well for the brickmaker's use cannot be made before trial, by any amount of examination, unless we also possess a chemical analysis of the natural material. Aided by that, it is quite possible upon tempering a ball of the clay, observ- ing its plasticity and body, and then wetting further a little bit, and rubbing it between the thumb and the forefinger, to tell with a great degree of certainty whether it will make good brick or not ; either alone or, as is almost always the case, mixed (and so altered) either with more sand or more tough clay, and occasionally with coarsely- ground coal, or breeze, or ashes, &c.

Clays are essentially chemical compounds, and this is true, whether they be or be not always mere mud from disintegrated rocks, as some geologists have probably erroneously supposed. They are in fact true hydrates, and have the general constitution (S 0 + Al, O3) + H O ± R 0 ; tiie last or accidental base or bases being usually cal- cium, magnesium, manganese, or iron, or more than one of these ; and they may be divided into four great classes. Pure aluminous clays and pure magnesian clays, both hydrated : these are rare, the latter especially so— when indurated, constituting meerschaum ; and we may pass them without further notice here. They belong, not to the brickmaker, but to the porcelain-maker.

More widely spread for our use, we Iiave the ferruginous clays, which have generally this combination (Si 0 + (Al., Os -f Fe« 0 ) ± Fe 0 -f N 0 + K 0) + H 0 ; and the calcareous clays (Si 0 + (AU O3 + Fe., O3) + (Ca 0 -f C 0, + lilg 0 + C 0,) ± Fe + N 0 + K 0) + H 0. Either of these may be mixed with more or less siliceous sand, and when this is in considerable proportion the clay is a loam.

At a red heat they lose most of their combined water, losing more nr less hygroscopic water at 212°; and at a bright yellow or white

264 APPENDIX.

heat, or rather below it, they bake into pottery or brick. And while many of the clays rich in alumina, silica, and iron do not fuse, or but very slowly, at the melting-point of cast-iron, most of the cal- careous clays melt at or below this temperature, or at least agglu- tinate, assuming the vitreous texture if rhe heat be long contina^.

The following table contains the analysb of ten natural clays, which gives a pretty clear notion of their usual range of constitu- tion : — No. 1 is a fuller's earth, analysed by Dr. Thomas Thomson. No. 2. A sandy clay, known as the " ball-clay " of the Potteries,

and used for salt-glazed ware ; analysed by Cowper. No. 3. An ash-white pipe-clay. No. 4. A grey-blue clay. No. 5. A red-brown Glasgow clay.

No. 6. A yellow midland counties clay, used for brick and for Kockinghaii pottery.

(Ail these analysed by Cowper, Phil. iJag. xxii. p. 435.) No. 7. A marly English clay ; analysed, with the following, by

Berthier. No. 8. A marl from Yitry, Department of Mama ; used in Paris

foundries. No. 9. A German clay {Loeu of the Rhine), used at Bonn; analysed

by Kjenulf. No. 10. A loam, analysed by 'Jr. Ure.

APPENDIX.

265

1	«							'~~	^~'~~^~~~
o	-o o	o	^^				^
	O C-l	oc		o				o
6	M ^	c-		-o				o
i^	CO .^	c
	r^ r^ CI to •* ^	i->		c-l
a	C> C5 O -7	O (M	'^'		CO
o*	a: C3 O o o ■*	■^		CO
^	lO		(M
	-— . —	'
Qt5	o		-		o		^	~	o
	o		^"Z		'-"^		O '"	o
o	OO		i		CO		C'	~t	■rr<
A	c<		•^					"
	,— -—	^
»•'	o c		c=		o		G		o
6	X y		"?		C-l		• c
CI c		a		ifl		li		A
CO —		CO						'^
^	t^ oc	o		O		c		o
	9 ^	^c		O		CO		CO
6	K) t^ O		u	•		CO		o
'O c^
to	■* «:	«		^		■*		-*<
T« <>J			c>		i^	> •~*
6	o -•	^		^	•		t^		o
A	^ c:								1
■»	00 -*	c:		^			'f		1^
CO o	c-		o
d	o i	_		r_	•		t ^		CO
*A				■^
ri	o o o	O		t^	cc
o o -^	O ,		!>l		o
d	CO i-	o	ii		• G		CI
/5	O CO
c^	en oc	^		o	c^			-*<
	o c:	oi:		2 :	c
1	CO i	6		^			li
O CM			"*^
	o o	cc		c			G
	o c	c		o ,		C		*
1	4< i	Tf		if)	•		C^		•
-«< CO
										u
										z>
										C
flD
d										o
5										M
										+
6				O						o
				4	-	+			o	o
		] o	o	O	O	o	O	a	"r;
^m	o				o	"" o	X	^

2G6 ArPEXDix.

Most of these clays, as found in nature, contain some organic matters and pebbles of foreign bodies. Unless these are of hard pyrites or limestone, they are unimportant. Flinty pebbles can generally be crushed in the clay-mill, or taken out by the screen or sieve.

Clays should, if possible, be delivered into the brick-yard in their moist natural state; for when they have been permitted to dry up under a scorching sun or drying wind, they shrink and harden greatly, and the labour of mixing into good brick "stuff" is greater, and the plastic mixture not as free and nice as before.

Whether a natural clay contains much or little «a?icZ naturally is not important. Every clay requires more or less grinding and mix- ing; and when sand in a separate form is at hand, it is easiest and best mixed in such proportions as we may require in the pug- mill. Clays naturally very rich in lime or in the alkalies (derived from felspar) are the worst, and in fact a clay that contains more than about 5 per cent, of lime, at the utmost, is scarcely fitted for good brickmaking.

If the lime be in the state of carbonate, it is so much the worse; and if it exist in the state of ditfused limestone or chiUk-pehhles, it is worst of all ; for these burn into caustic lime in the brick-kiln, and then as in after-time the brick absorbs moisture and carbonic acid, the contained nodules of lime "slack," and swell in their places, and so burst the brick to pieces. This is oue of the most prevalent evils of the ill-made bricks which are almost universal in Ireland, arising from the wide diffusion of limestone gravel in that country, and the total neglect of grinding or efficient sifting of the clay.

Iron pyrites also is a not uncommon accidental product present in clays, and unless separated, durable, to say nothing of well-coloured, brick can never be made of the clay. The pyrites in the kiln is but partially decomposed: oxide of iron and basic sulphides of iron remain. When at an after-period these are exposed to air and moisture, which are absorbed to all depths in brick, oxidation takes place, sulphate of iron, and frequently also sulphates of lime or alums (sulphates with double bases), are formed, and, crystallising within the mass of the brick, split it to pieces.

Common salt is nearly always present in minute quantity in clays; but when these are taken from the sea-shore, or without or beneath tiie sea-washes, or from localities in and about the salt-formations (trias), liicy freq\iently, though in all other respects excellent clays, are unfit for burning into good brick. Chloride of sodium is not only a

APPENDIX. 267

powerful flux when mixed even in very small proportion in clays, but possesses tlie property of being volatilized by the heat of the brick- kiln, and in that condition it carries with it, in a volatile state, various metallic compounds, as those of iron, which exist in nearly all clays, and also act as fluxes. The result is that bricks made of such clays tend to fuse, to warp, twist, and agglutinate together upon the surfaces long before they have been exposed to a sufficient or sufii- ciently prolonged heat to burn them to the core into good hard brick. " Place bricks " can be made of such clay, but nothing more ; and these are always bad, because never afterwards free from hygrometric moisture.

Much carbonaceous matter naturally mixed in clays is also in certain states objectionable, for when not burnt completely and in the kiln, which is sometimes with the denser clays difficult, the bricks are of a different colour in the interior and exterior, and will not bear cutting for face-work, without spoiling the appearance of the brick- work. But, worse than this, such bricks when wetted in the wall occasionally pass out soluble compounds like those absorbed from soot by the bricks of the flue, and, like those (when used again in new workj, discolour plastering or stucco-work.

The normal constituents of brick clays, then, may be said to be oxides of the earthy metals, and of a few others, hydrated or not, with silicic acid, and with small amounts of the alkalies, potash and soda, also present, together with several other chemical elements occasionally, but uncertainly, present in minute proportions, with which we need not concern ourselves. Silicic acid, the (jreat electro-nega- tive element of clays when combined with the oxides of the eartliy bases, singly or in combination, and exposed to high temperatures in certain proportions, forms glass or enamel (i.e., opaque glasses). Alumina, though in a less degree, also plays the part of acid towards the earthy bases, though itself a base with respect to silicic acid. As regards the oxides of the earthy metals, alumina, lime, magnesia, &c., these, in accordance with the general law of chemistry, that bodies in the same range combine, oxides with oxides, &c., also combine at high temperatures. The most powerful bases, such as the alkalies or oxides of potassium and of sodium, and the oxides of iron, combine more readily with silicic acid than do the earthy oxides. These combinations usually take the form of glass at once, the chief characteristic of which is the vitreous fracture. When such glasses are formed with oxides of earthy bases also present, they may assume wystaiiine or porcellaneous textures when cooled.

CG8 APPENDIX.

Porcelain, earthenware, and hard brick (such as the Staffordshire or Flintshire blue bricks) coniist in substance of such compound glasses, diffuied throughout their substance uniformly, and binding together the finely-diffused particles of the excess of earthy oxides which are present, or binding together fragmentary bits of uniformly- diffused silicic acid (sand, ground flint, &c.). The degree of fusi- bility, or of partial fusibility (agglutination), of any hard-baked brick depends, then, not only upon the chemical nature of the constituents of the clay, but upon the proportions in which these are present.

The laws, so far as they have been ascertained, upon which depends the induration or agglutination by heat of silicic and earthy compounds, with or without other metallic oxides present, have been elicited from innumerable experiments made by ceramic chemists upon very varied compounds. The phenomena are complex, and in great part as yet in results only empirical. "We must refer for these to the works of Kirwan (" ^Mineralogy"), who made very many experiments upon known combinations of earths when exposed to heat — which have not in England attracted the attention they deserved — of Achard, Brongniart, Berthier, Lampadius, and various systematic chemical writers. Silica, alumina, lime, magnesia, are all infusible, per te, at the highest temperature of the porcelain furnace or brick-kiln.

Silicic acid combined with any one earth is less fusible than when combined with two or more — a proof that not only the silicic acid combines with each earth, but ihat these in its presence combine with each other. Binary compounds of silicic acid and of earths, or of earths with earths, are most usually infusible except at still higher temperatures. Compounds of silicic acid with alumina are less fuiible than with lime, and these less so than with the alkalies.

With oxides of iron, silicic acid forms fusible compounds in certain proportions. Magnesia, present in large proportions with either of the other earths, produces a very difficultly-fusible compound. Where the silicic acid constitutes the largest proportion of the mass, it is much more fusible, the bases being iwo others combined, with or without alkalies ; but if the silicic be in great excess (as in Dinas fire-brick), or if one or other of the earthy bases be in great excess, more especially alumina or magnesia, the mass is infusible in the kiln.

All difficultly-fusible and pulverulent oxides, as when obtained by precipitation or by levigation, when exposed for some time to a high temperature, Wcome hard in grain, i.e., indurated more or less, and

APPENDIX. 269

frequently compacted. This is true eveu of some pure earths, such as alumina aud magnesia, and of nearly all the oxides of the com- mon metals. Compound oxides, when so exposed to heat, become still more indurated and compact, though presenting no traces of agglutination or of fusion. Thus alumina and sesquioxide of iron become compact. This induration, which is probably rather a change in the state of molecular aggregation than a chemical combination, but which may be both, is much concerned in the production oi certain qualities of brick ; for example, the fine, soft, scarlet cutting brick — that which was so much employed for fine facing-brick in the reign of William III., down to George II. — presents no sign of agglutination; its constituents have merely become partially indurated and compacted by the fire. The same is true of many of tlic light- coloured bricks now in use.

Two sets of forces, then, are, or may be, in play in the burning of brick — chemical, and physical or molecular — and must be held in view by the scientific brickmaker. To the latter belongs the con- traction that takes place in the process of firing of all porcelain aud brick. This is greatest with those which contain most alumina, aud with any given specimen, is great not only in proportion to the eleva- tion of tlie temperature to which it is exposed, but with the duration of the time of exposure. It is least in compounds in which the silicic acid predominates ; and if these pass partially from the ci'ystalline to the vitreous state of aggregation in the firing, the specific gravity is reduced, and the increase of volume may more than equal the contrac- tion. This is said to be the case with Dinas fire-brick, which, when liighly heated in furnaces built of it, is said to expand.

Were brick constituted of silicic acid and pure clays only, it would be perfectly white. Bricks, like porcelain, owe their oolour to admixed metallic oxides — iron in various states of oxidation, from prot. oxide to sesquioxide, or true chemical combinations of those with each other, or with the earths themselves, and present in the most varied proportions, give the wliole range of colouring to bricks, from the liglitest tawny yellow, through full yellow, orange, and to the rich scarlet of red facing-brick, almost as bright as red-lead. Where the proportion of oxide of iron present is very large, and it com- bines with silicic acid to form silicates of iron in or on the brick, its colour may be dark purple or nearly black, as is the Staffordshire blue brick ; and when a small quantity of oxide of manganese is present also, the colour is still darkened, and may become quite black.

N 3

270 ArrENDix.

For light- coloured bricks ilie clays must be almost free from iron, and the latter must not be peroiidised, if possible, in the burning.

For tbe production of fine red brick, on the contrary, the clajs must be pure, silicic acid not present in excess, oxide of iron present in abundant proportion, and be fully peroxidised, but must not be fused into a silicate of peroxide of iron, which is fatal then both to the texture and colour.

With a given constitution of brick clay, the final colour of the burnt brick depends upon a large number of conditions in the pro- cess of firing, but mainly upon two — viz., what proportion of air be admitted to the combustion of the fuel in the kiln — i.e., whether the brick be finally burnt with an oxidising or a deoxidising fiame ; and whether or not, or in what proportion, steam or water be present in the brick, or be brought in the state of vapour in contact with it, when at elevated temperatures.

Upon an exact knowledge of the effects producible by the play of these conditions (chiefly) upon the brick in burning rests the power of the brickmaker to vary or maintain with certainty the good colour of his ware, or to effect any desirable changes of colour of which his material may be susceptible.

From this very incomplete sketch it will be seen that brickmaking is one of the chemico-mechanical arts. Being so, we ne«d scarcely say that the foundation of all accurate and predictive knowledge of it must be based upon a sound knowledge of chemistry, and of the laws of physics, and of heat especially, which is but a branch of the latter.

KOTES. CoLorRED Bricks.

Quite a new branch of trade remains to be opened in the manufac- ture of coloured and intagUo bricks, so treated upon the one face- side only, for both external and internal decorative building.

"What may be done in this way may be seen in the Romanesque domes of the interior covering of the great centre hall of the museum building of Trmity College, Dublin, erected, a few years iince, by Messrs. Deane and Woodward, architects, in which ordinary bricks arc enamelled in brilliant glazed coloms, arranged in desigiis, upon the exposed face only.

The German architects are generally in advance of us in (he art

APPENDIX. 271

of ornamental polyclircme brickwork, avoiding those hideous discords of colour that so otFend the eye in many of our London buildings. See especially for this "Les Constructions en Briques, par Louis Degen, Ingenieur de la Commission Speciale d' Architecture de la Ville de Munich," published in ]S65, at Paris. It is marvellous how much beauty the German brick architects contrive to extract out of tlie judiciously-arranged patterns producible from mere common brick, combined with delicate and beautiful harmonies of tint and colour.

Infusoeial Siliceous Matebiais, p. 22.

The bricks with which the arching of the floor of the Museum at Berlin was built, were made from tl\is infusorial siliceous and micro- scopically porous material, mixed with a certain proportion of clay " slip." Many of the floor arches of the Pinnacotheca, however, ■were constructed of hollow bricks, in the form of frustra of cones, like flower-pots without bottoms, laid into place with plaster or cement.

Materials exist in Southern Italy in abundance, as also in many other places, from which brick of considerable strength and of great lightness might be readily and cheaply made, viz., either from certain varieties of volcanic tufa or from pumice-stone detritus. Of the former there are suitable beds close to Naples, and elsewhere ; of the latter, inexhaustible supplies exist in the islands of Lipari, Ischia, and the Ponza Isles, from which it might be brought wuth facility.

Plasticity and Odour of Clay, p. 210.

It is certainly not a general fact that no chemically pure preci- pitates are cliaracterised by pla-^ticity. Precipitated carbonate of hme and white-lead are iu^tances to the contrary ; but nearly all precipitates (especially when rapidly made), though to the eye amorplious, are in fact crystalline, as Stokes long ago proved micro- scopically {Ditllin Phil. Mag.) \ and crystalUsed bodies are often not plastic.

Water Chemically Combined on Mechanically Present, p. 212.

Water mechanically present is one thing, but water chemically combined is another. Hydrate of alumina, in wliich the water plays the part of base, is a different body chemically from the alumina dehydrated and separated from its base by heat. The former may

272 APPENDIX.

possess plasticity, the latter not, simply because the former has the power to retain, intimately diffused throughout its divided mass water in mechanical mixture, while the latter has not. This diffused water seems to be the real cause of the plasticity of clay and of all plastic precipitates ; the mmute, solid, and rigid particles slip over each other, as it were upon liquid rollers, just as two plates of glass or metal slip over each other when a film of water is iutcrposed.

INDEX,

Ainslie's tile machine, 109. Alumina, use of, in brick-earth, 14.

Blue brlck-i, 21.

Breeze detcribed, 19 n, ; use of, by London brickmakers, 122; quan- tity required for 100,000 bricks, 153.

Brick buildings, list of early, 4.

Brick-earth, composition of, 14 ; pre- paration of, 12.

Brick-kilns, Dutch, described, 48.

Brick-kilns, Hoffmann's, described, 237—244.

Brickmaking, introduction into Eng- land by the Eomans, 4 ; perfection of, in time of Henn' VIU., 4 ; the science of, 262—270.

Brickmaking machines described — Oates's, 197 ; Whitehead's, 216 ; Clayton's, 219 ; dry-clay machines — Bradley and Craven's, 230; "Wilson's, 232.

Brick-mould described, 28.

Brick-pressing machines described — Longley's,223 ; Whitehead's, 226 ; Bradley and Craven's, 227 ; Her- sev and Walsh's, 228.

Bricks, coloured, 21, 270.

Bricks, lirst use of, 1 ; early use of, by the Dutch, 3 ; application of, by the Dutch, 47 ; Roman use of, 3 ; repeal of the duties on, 8 ; schedule of duties on, 7 ; strength of bricks, 9; comparison of the strength of hand and machine- made bricks, 11 ; use as a build- ing material after the fire of Lon- don, 5.

Bricks, manufacture of, 12; various modes of manufacturing described, 9; colour of, 20 ; influence of the chemical composition of clay on

the colour of bricks, 20 ; variation

in the weight of, 10 ; drying, 251 ;

usual form of, 34 ; warping of, 33 ;

weekly produce of a London yard,

37 ; annual manufacture of, in

Great Britain, 8. Bricks, manufacture of, by machi-

nerj-, 195 ; list of patents for, 196 ;

macliines described, 197 ; strength

of machine-made bricks, 203. Bricks, Egyptian, 2 ; two classes of,

19 ; with hollow beds, 34 ; for

railway work, 26. Burning, process of, 38.

Chalk, use of, in brickmaking, 18, 121.

Cheshunt, brickmaking at, 157.

Clamp-burning described, 38.

Clay, analysis of, 12, 115, 265 ; com- position of, 13 ; properties of, 245 ; cannot be produced artificially, 246; its plasticity, 248—271"; odour of, 250 ; digging, 22 ; pro- cess of preparing, 24 ; tables of colour, order of fusibilitv, ic, 116.

Clay, dry, machines for working, 230,

Clay, machines for preparing, 212— 215 ; clay crushing and grinding mill, 212 ; pug-mill, 27, 2l3 ; per- forated pug-mill, 214 ; portable clay-mill, 215 ; composite machines for crushing and tempering, 215.

Clayton's horizontal brick machine, 219.

Coal, analysis of, 117.

Coal-dust, use of, for making clamp bricks, 251.

Compound for brick-earth, 14.

Copper moulds, method of using, SO

Cupola, 40.

Cutters, 19.

274

INDEX.

Dense bricks, disadvantages of, 3 J.

Dinas fire-bricks, 16 ; manufacture of, 16.

Drain-pipes, machine for the manu- facture of, 205 ; manufacture of, by machinery, 195.

Drain-tiles, manufacture of, 43 ; making and burning, 255 ; cost of, 201 ; machine for making, 256 ; cost of, 256 ; sheds for drying, 257 ; working the clay, 221.

Drying, process of, described, 35.

Dutch, their early use of bricks, 3.

Dutch bricks, size of, 43.

Dutch method of burning bricks described, 50.

Dutch tile kilns described, 53; me- thod of filling the kilns, 53, 49 ; fuel used for, 43.

Dutch tiles, method of making, 52 ; method of glazing, 54 ; mode of burning, 53.

Encaustic tiles, manufacture of, 1S9 ; colours, production of, 191 ; colouring the tiles, 192 ; glazing, 1;'3 ; moulding, 192 ; plain tiles, 193 ; slip described, 192.

Fire-bricks, 15 ; value of, 18. Fire-clays, composition of, 15 ; where

found, 17. Floating bricks, 21. Fuel for brickburning, 41. Fusible earllis, 19.

Cn'nding described, 23.

Holland, manufacture of bricks and

tiles in, 47. Hollow bricks, form of, 207 ; method

of asing, illustrated, 209 ; machine

made, 207 ; Roman use of, 207 ;

use of, in Tunis, 207.

Kiln described, 38 ; circular, 40 ; burning described, 39, 40.

Lincolnshire, brickmaking in, 252 ; cost of production, 252.

Tx)am«, 14.

lyondon-made bricks, superiority of, 19.

London, brickmaking in, 119 ; pro- cess, 138 ; cost, 1-39 ; arrangement of a brickwork, 123 ; cost of ma- terials, 1.59; breeze, 155; cost of breeze, 159; brick-earth, 119;

cost of chalk, 159 ; chalk mill, 164 ; cLiuip described, 144; clamp- ing, 144; foundations of the clamp, 149 ; upright of ditto, 150 ; paving, 154; necks, 152; clay described, 120 ; cost of the clay, 159 ; digging the clay, 138 ; quantity of clay required for 1,000 bricks, 139 ; clay washing mill, 165 ; use of chuck- hold, 125 ; process of firing, 152 ; cost of fuel, 1-59 ; hacking de- scribed, 142; hack barrow, 136; hack ground, 136 ; cost of labour, 162 ; cost of machinery, 161 ; pro- cess of maiming, 139 ; malm, 120; hand method of preparing malm, 120; chalk miU described, 123,164; clay mill, 123 ; brick mould, 135 ; moulding, 141 ; moulding-stool, 125 ; pallets, 136 ; pug-mill, 123 ; pugging, 141 ; cost of sand, 159 ; scintles, 154 ; scintling, 143, 149 ; process of soiling, 140 ; use of soil, 122 ; cost of soil, 159 ; use of stock- board, 135 ; use of the strike, 136 ; tempering described, 141 ; cost *t tools, 161 ; cost of water, 159 ; cost of wood, 159 ; illustrations of London brickmaking, 164.

London brickm.iking : bats, 156 ; place bricks, 156 ; burnovers, 153 ; burrs, 156; clinkers, 153; cutters, 155 ; grizzeles, 156 ; malms, 155 ; paviours, 156 ; pickings, 156 ; second?, 156 ; shufTs, 156 ; grey stocks, 156 ; rough stocks, 156.

London tile making described, 167 ; block board described, 175 ; build- ings, 170; cby getting, 183; kiln, 1S3; kilning, 186; illustrations to, described, 1S6 ; moulding, 184 ; moulding-shed, 173 ; pantile table, 174; place grounds, 167; plant, 170; roll described, 177; sling, description of, 1 70 ; slinging, 184 ; splayer, 180; tempering, 184; thwacker, 183; thwacking, 185; thwacking frame, 180; thwacking knife, 183; thwacking stool, 183; washing-off frame, 178 ; wash- ing-off table, 177 ; wealliering, 183.

Marls, 14.

.Minton's encaustic tile manufactory

described, 191. >roulding, process of, 28. Moulding table, 29. •

INDEX.

275

Norton coal, analysis of, 117.

Nottingham, brickmaking at, 55 ; process of, 80 ; illastrations of, described, 92 ; batting, 82 ; cost of buildings, 88; burning described, 84 ; colour, 58 ; brick-earth, 57 ; cost of ditto, 87 ; brick-moulds, 70 ; bricks, number made per day, 84 ; size of bricks, 84; brick-yard, general arrangements, 59; clapper described, 73 ; clay digging, 80 ; clay mill described, 62 ; dressing- bench, 73 ; dressing described, 82 ; dr}-ing process, 81 ; fiats described, 71; fuel for the kilns, 86 ; hovel described, 61, 72 ; kiln, 75 ; setting the kiln, 84 ; cost of setting and drawing kiln, 86 ; cost of labour, 90 ; cost of land, 87 ; machinery for pressing bricks, 74; cost of machinery, 88; cost of manufacture, 87 ; moulding de- scribed, SO ; moulding sand, 68 ; moulding table, 68 ; plane de- scribed, 71; polished bricks, 83; pressed bricks, 83 ; tempering de- scribed, 07, 80 ; cost of tools, 90 ; wash mill described, 66.

Oates's brickmaking machines, 196 ;

cost of, 204 ; rate of production,

204. Ornamental brickwork, examples of,

6.

I'allet moulding described, 29. Paving tiles, 42. Pressed bricks, defects of, 33. Prosser's method of making bricks,

32. Pug-mill described, 27.

Red bricks, 21.

Refractory clays, composition of, 15.

Roofing tiles, 42.

Sand, object of using, li:2.

.'^ilica, use of, in brickmaking, 14.

Slip kiln, 32 n.

Slop moulding described, 28.

Soil, term described, 27 ».

Staffordshire brickmaking described, 95, 97 ; buildings described, 97 ; burning, 99; clay, described, 95; cost of manufacture, 101 ; drying, 99 ; firing, 109 ; illustrations, 102; moulding, 98, 103; oven

described, 100 ; plant described, 97 ; rate of production, 97 ; rental, 101 ; specific gravity of the bricks, when raw, dried, and burned, 99 ; tempering, 97 ; weight of the bricks, 99 ; arrangements of yard, 118.

Staffordshire tile making, 105 ; class of tiles made, 95 ; drain tiles, 108 ; drying, 107 ; manner of drying. 111; firing, 113; illustra- tions to, described. 111 ; machines for making, 108 ; moulding, 107 ; moulding bench described. 111; pug-mill described, 106 ; setting described, 108; tempering, 106; weathering, 106.

Stourbridge clay, 151,

Striking tlie clay, 28.

Suffolk, brickmaking in, 252; burn- ing, 253 ; clay, 253 ; drying, 253 ; cost of manufacture, 254 ; mould- ing, 253 ; cost of plant, 254 ; tem- pering, 253.

Table of analysis of different kinds of clay, 13 n. ; of analysis of Norton coal, 117; of analysis of Staffordshire clays, 115; of the colour of Staffordshire clays, 116 ; of the cost of 1,000 bricks, London make, 162 ; of the cost of London- made pantiles per 1,000, 187; of the cost and profit on 1,000 Not- tingham-made bricks, 91 ; of the cost and selling price of Stafford quarries, dust bricks, and roof tiles. 111 ; of the fusibilitv of Staffordshire clays, 116; of the price of fire-bricks of various manufactures, 18 ; showing the proportion of bases contained in Staffordshire clays, ]16; of llie relative value of different quilities of bricks Nottingham make, 91 ; of the selling price of London- made tiles, 187; of space required for each moulding-stool by eitlicr process, 37 ; of loss of weiglit in drying and burning, 99; of the strength of hand and machine- made bricks, 11. Taxes upon bricks, 6; repeal of the,

8. Tempering, 25 ; process described,

I 27.

] Terra-cotta, early use of, 5.

I TessMse, Clinton's, 193 ; Roman

276

INDEX.

process described, lOS , modern process described, 194.

Tile-burning, 44, 255.

Tile-kilns, construction of, 183, 189, 257 ; in Holland, C3.

Tile-making in England, 42 ; in Holland, 52 ; in Staffordshire, 105 ; in London, 167.

Tile-making machines, Ainslie's, 109; Hatcher's, 256; Page's,233; White- head's, 2'M.

Tile-moulding, 184.

Tileries, London, 167 ; Staffordshire, 105.

Tiles, encaustic, manufacture of, 189.

Tiles, manufacture of, 42 ; schedule of duties on, 7 ; cost of manufac- ture, 186 ; manufacture of, in Holland, 52.

Tower of Babel, btirot bricks used in building, 1.

I'nsoiling, 22.

Utrecht, principal seat of tile mw.u- facture in Holland, 54.

Ventilating bricks, 35.

Washing described, 24. Weathering, process of. 22. White bricks, 21. Whitehead's brickmaking machine,

216 ; brick-pressing machine, 226 ;

clay crushing and grinding mill,

212 ; perforated pug-mill, 214 ;

tile-making machine, 234. Wilson's drj-cla\' brick machine,

232. Wooden moulds, method of usiag,

30. *

Yellow bricks, 21.

THE END.

LONUO.-. : ll.l.N'lLD DV J. 6. VIUILK .\.\U CO., LIMITLU, CllV UOAU.

THE

PRACTICAL BRICK AND TILE BOOK

PART II. TEE RUDIMENTS OF

PRACTICAL BRICKLAYING

By ADAM HAMMOND

THE BUDIMEXTS OF

PRACTICAL BRICKLAYING

m SIX SECTIONS :

GENERAL PRINCIPLES OF BRICKLAYING ; ARCH DRAWING,

crrnxG, and setting; different kinds of

POINTING ; PAVING, TILING, MATERIALS ; SLATING, AND

PLASTERING; PRACTICAL GEOMETRY

MENSURATION, etc.

By ADA]\I HAMMOXD

ILLUSTRATED WITE SIXTY-EIGHT WOODCUTS

SIXTH EDITION. CAREFFLLY REVISED, TTITH ADDITIONS

gpio^Jj

LONDON

CROSBY LOCKWOOD AND CO.

7, STATIONERS' HALL COURT, LUDGATE HILL 1887

PREFACE.

The object of this little work is to assist young beginners and others who, though in the trade many years, have not had the opportunity of seeing so much of the higher branches of practice as they might desire. I also trust it will not be thought unworthy the notice of the more skilful mechanic.

The language I have used is as simple as the subject would allow, and the terms used are those well understood in the trade ; for it is to be regretted that the greater number of books upon " building construction " are written in such terms that it is very difficult for the majority of working men to understand their meaning without continually referring to a technical dictionary.

In speaking of foundations, I have said nothing of those which are formed in soft situations, upon piles, or woodwork of any description ; for in such cases the bricklayer has nothing to do with the work until the foundation is made.

VI PREFACE.

I have no hesitation in saying tlie methods here employed in drawing and cutting arches, also in mixing the materials and executing the difFerent sorts of pointing, are practically the best, and those generally adopted by the most experienced workmen.

For the sake of those who have not had an opportunity of learning Geometry and Mensura- tion, such problems are given as are generally required in bricklaying.

The tables, and also the quantities of materials, have been carefully calculated ; and during the eighteen years I have been in practice I have proved them correct.

Adam Hammond.

NOTE TO FIFTH EDITION.

The author views with satisfaction the extensive sale of this little work, and also the favour with which it is generally received, having already run through four editions since its publication.

The present edition has undergone a thorough revision, and various additions and corrections, thought necessary for the improvement and utility of the work, have been made throughout.

A. II.

London, August, 1884.

co:n'tents.

SECTION I.

GENERAL PRINCIPLES OP BRICKLAYING.

pag:i

Foundations 1

Concrete and Concreting 3

Drains ...... .... 4

Footings 4

Bonding —

Old English 5

Flemish Bond G

Broken Bond 8

Herringhone Bonding ...... 8

Douhle Herringhone Bonding 10

Garden-wall Bond . . . . . .10

Damp Courses 11

Air Bricks , ..11

Wood and Iron Bonding 11

Joints .... 12

Window Sills 13

Ruhhle "Work 14

Brick and Stone combined 15

Limes, Cements, &c. —

Blue Lias Lime 16

Dorking and Hailing Limes 16

Chalk Lime 17

vni	CONTENTS.
	TAOt
Limes, Cements, Sec,
Cements .	17
Portland Cement				17
AVood Bricks .				18
Frost				19
Toothings				19
Thick and Thin Joints-	-their Evils .			19
Profiles .	.			. 20
Trammels				. 21

SECTION II.

DEAWTXG, CUTTING, AND SETTING ARCHES.

Plain Arches 23

Ased Arches 24

Gauge-work ......... 25

Various Arches used in the Building Trades —

The Semi-circular 26

The Segment 26

The Camher . . 26

The Gothic 26

The Elliptic Gothic 27

The Scmi-ellip.«e 27

Drawing Arches —

The Semi-circular 29

The Segment 31

The Camber Arch 32

The Gothic 35

The Reduced or Modified Gothic .... 36

The Ellipse Gothic 37

The Semi-ellipMs 39

The Wheel Arch, or Bull's Eye .... 41

Moulding ......... 42

Setting 44

Axed Work 46

CONTENTS.

IX

SECTION III. DfFFERENT KINDS OF POINTING.

PAOK

Stock Work with the "White Joint 47

Yellow Stopping ........ 48

White Putty . 48

Eed Brickwork .51

Red Stopping . . ...... 61

AVhite Brickwork 62

Black Putty 62

Kcd Putty 53

Old Brickwork 53

Flat-joint Pointing 54

SECTION IV.

PAVING, TILING, USE OF 5IATERIALS, Etc.

Paving —

Brick Paving Plain Pa\'ing Tile Paving

Tiling- Roofing Tiles Plain Tiling

Scaffolding

Relieving Arches

Bakera' 0\ens .

Smoky Chimneys— their Causes, &c

To proporlion Windows to Rooms

Materials— their Use, &c.— Memoranda and

showing the Quantities of Materials required for various Kinds of Work— their Weight, &c.

.	55
.	55
o .	5G
	57
	58
	60
	Dl
	62
»	63
	64

T

'ables,

Go

X CONTENTS.

SECTION Y.

SLATER AXD PLASTERER'S WORK.

Slater- Description of Slater's Work ....

Gauge, " Lap " Margin, &c

Table of Sizes and Gauges of Roofing Slates

Slater's Scaffold

Plasterer —

Plasterer's Work

Lime and Hair, or Coarse Stutf .

Fine Stuff, or Putty ....

The Operations of Plastering ...

Bough Stucco ....

Laid Work ...

Cement Floors

Plaster and Welsh Lime Floors

Memoranda of Materials and Quantities required for different Kinds of Plastering

Artificial Stone

Distempering of Ceilings, Walls, &c.

70 71 73 74

74 75 75 77 79 79 SO 80

81

82 S3

SECTION YI.

PRACTICAL GEOMETRY AND MENSURATION.

Geometry ......... 84

Problem I. — From a given point in a straight line to

erect a perpendicular . . .87

When the point is at the end of the

line 88

,, II. — Fpon a given right line to describe an

equilateral triangle . . . . 8S

COXTEM'S. XI

PAGS

Problem III. — To describe a triangle, having tlie length of

the three sides given .... 89 „ rV. — To find the centre of a given circle . . 89 ,. V. — To describe a regular pentagon upon a

given line 89

„ VI. — To describe a regular hexagon upon a

given line 90

Table of Polygons showing an easy Method of di-awiug any Polygon, from Five to Twelve Sides, the Length of the Side or Diameter of circumscribing Circle being

given 90

Description of the above Table, with Examples . . 91 Problem VII. — To describe an eUipsis, ha\-ing the

longest diameter given ... 92 Another method of describing an ellipse 93 „ VIII. — To describe a circle about any triangle . 93 ., IX. — To inscribe a circle within a triangle . 94

.. X. — In a given circle to inscribe a square . 94

■ I XI. — In a given circle, to inscribe any regular

polygon ; or, to divide the circumfer- ence of a given circle into any number

of equal parts 94

„ XTI. — To draw a straight line equal to any

given arc of a circle .... 95 „ XIII. — To make a square equal in area to a

given circle . . , . . 95

A FEW RE5IARKS ON MEXSIJEATION OF BRICKLAYEES" WOEK.

Duodecimals . 96

Decimal Fractions .97

Subtraction of Decimals .99

Multiplication of DecimiUs .99

Division of Decimals 100

Uow Brickwork is measured — with Examples . . .101

To find the Contents of Chimneys and Chimney Shafts . loa

XU CONTENTS.

PACB

103 105 105 106 106 106

Cfaimiiej Shafts in the Form of a Circle .

When the Shaft is in the Form of a Bcgular Polygon

Table for measuring PolygoHS .....

Vaulting ..... . .

Groins .....

Bakers' Ovens .... ...

A Table of Brickwork, showing an Cds y Method of flnding the Quantity of l?eet and Bricks contained in any Nimiber of Supeificial Feet, from 1 foot to 10.000 Feet, by Addition only ... ... 106

Explanation of Table . . . 107

Mensuration of G-auge-work . . .114

Old and new Bricks stacked in Bollfi .114

Short and useful Table .... .114

Tiling and Slating ... .114

Paving 11.5

Plastering ll.5

THE RUDIMENTS

or

PKACTICAL BEICKLAYING.

SECTION I.

GENEEAX PRIXCIPLES OF BRICKLAYING.

The Business of a Bricklayer not only consists in the execution of all kinds of brickwork, but it also includes rough stonework or "walling," paving, and tiling, both plain and ornamental ; and (in many parts of the country) slating and plastering is united with the above-nam«i|^ business. The bricklayer also superintends all excavations and concreting for ordinary building purposes.

In preparing for the erection of most buildings the first things required are the plans, elevations, sections, &c., and upon these too much care cannot be bestowed so that the foreman may get them thoroughly impressed upon his mind, for by so doing very many mistakes will be prevented.

FOUNDATIOXS.

The ground should be set out from a given line, such as the face-line of the building, and wood stakes driven into the ground on which to

7

Z BRICKLAYING.

strain the different lines. Great care is required in squaring out the foundation trenches so that the brickwork (when built) shall stand in the centre of them, and not all on one side of the trench and none on the other, which is but too frequently the case, for the greatest care is usually taken when the icaU line is drawn.

The sides of the trenches ought to be upright, so that there is not a less area for the concrete at the bottom than at the top : for upon this depends the strength of the superstructure.

Should the ground be ** an incline plane,'^ or unlevcl, it is much better to bench the ground carefully out — that is, cut out the bottom of the trench in horizontal steps.* The concrete will then be of a more uniform thicknes?, and the settlement of the building will be more regular, as nearly all buildings are built with materials that will settle little or much, and it does not so much matter as long as the settlement is perfectly regular, but the evil effects are seen when it is greater in one part than in another, and, in con- crete as well as brickwork, the greater the thick- ness the more will be the settlement.

It is usual to drive stakes in the bottom of the

trenches to show the level of concrete ; but

perhaps it would be better, if possible, to drive

these stakes in the sides of the trenches, leaving

just enough projecting out to level them with,

for very often by shooting the concrete into the

• Taking care that each step shall be 3, 6, 9, or 12 inches above the next lower one if the work above is to be built 4 couTBee to the foot.

GENERAL PRINCIPLES OF BRICKLAYING. 6

trench the stakes are knocked further into the ground and the concrete levelled to them, thereby causing a great deal of trouble when the brick- work is begun.

Concrete.

The " limes " generally used for concreting in this country are obtained from Dorking in Surrey, and Rochester in Kent,* besides other places where the grey limestone is to be obtained.

This lime is ground and mixed with ballast while in a powdered state ; it is then wetted and turned over twice, to mix them well together ; this is then wheeled in barrows to an elevated position and thrown into the trenches, and after- wards levelled to receive the brickwork. This kind of concrete is mixed in the proportions of one part of lime to six or seven parts of gravel. Although this kind of concrete is very much used in and about London, it is considered a very- imperfect method, although economical as regards the labour : it proves most expensive in the material, for if the work was properly executed it would not require nearly so much of the latter.

The method of concreting which is thought by most engiueers to be the best is, to reduce the lime to the state of a thick paste, and tlien it is made into a soft mortar by mixing about an equal quantity of sand with it before it is mixed with the gravel ; and instead of shooting it down from a height and leaving it to settle by itself, it

• This ia open to local circumstances.

«2

4 BRICKLAYING.

ought to be wheeled in upon a level and beaten with a rammer ; for it is thought by being thrown from a height the materials separate, and by so doing some parts get more lime than they ought to have, while others get but very little.

Of course this kind of artificial foundations is not required where there is a natural one, such as a bed of rock, hard gravel, or anything that is thought sound enough to sustain the weight of the building.

Drains.

As soon as the concreting is completed, all levels should be taken for the drains, &c., so that the brickwork is not cut about afterwards ; and if the pipes are very large it would be better to leave out the brickwork so that they may be fixed after the work has had time to settle. And if a small arch of brick is turned over each of these pipes, it will be found very convenient should they want repairing or cleaning at any time.

Footings.

In all buildings of any importance it is usual to build a certain number of courses as footings (as shown in Fig. 1) to give the walls a greater bearing ; and where the building is principally constructed with piers, such as a great many warehouses, &c., inverted arches are turned for the purpose of distributing the weight over the

	1
	1
	1 1
	1
III 1
1 1 1 J

GENERAL PKINCirLES OF BRICKLAYING. 5

whole length of the foundation, as shown in Fisr. 2. Sometimes these are formed in the

Fig. 2.

footing courses, but generally upon the top of the

footings.

Bonding.

The next thing of importance is the bonding of the brickwork, of which a great deal may be said, for this is a very important part of brick- laying.

Old English is that which is used in nearly all buildings where strength is the principal object, as it is the strongest of any, on account of the greater quantity of " headers " used, and also because there are less broken bricks required to fill in with.

But the appearance is not considered so neat as Flemish bond.

Figs. 3 and 4 show two successive courses of Old English bond : in all cases the inside headers and stretchers should be opposite those of the same names on the outside {i.e. a is opposite b, Fig. 3). If this rule is strictly adhered to, there will always be correct quarter bond throughout the whole thickness of the wall.

Very often but little attention is paid to

6 BRICKLAYING.

the middle of the \call, so long as the faces are

		1
	1							1
	1	1
	,

I I I 1

ri?. 3.

lip. 4.

kept right, although it is of quite as much importance.

Figs. 5 and 6 show the bonding of the face and

iig. 6.

1 iL-. 6.

end of what is called an 18-inch, or two-brick wall, in Old English bond.

Flemish Bond (Fig. 7) is very much used for house building, owing to ita neater appearance. But very often the inside of the house is Old English ; and when the walls are built in this manner, the heading bricks of the Fle- mish work are halved (" bats," as they are more generally called) every second course ; and by so

TV

I I

_LJ_

Rfr-.

GENERAL PRINCIPLES OF BRICKLAYING. 7

doing the inside of the wall gets a half-brick tie into the face -work.

In Flemish bond the headers and stretchers are laid in turns in each course, as shown in Fig. 7.

In all cases where quoins are to be got up at different parts of the building, gauge-rods should be used after the work has been levelled, and a nail or something of the kind knocked into the work at the level of which it is intended to gauge from.

If this is not done, different bricklayers will raise their work some more and some less than the others, thereby causing the work to get out of level.

If it be possible every man ought to be kept on his own work ; then he is more likely to take an interest in that particular part. But if they are not, when one man goes on to another's work there is often a great deal of fault-finding, and if the work is wrong it is simply impossible to 15 nd out who it was that did it.

Architects are generally under the impression that the bricks used in and about London are something under 9 inches in length, 4^ inches wide, and 2^ inches thick ; the thickness may be about right, but the other dimensions are decidedly wrong. This causes a great deal of trouble to the bricklayer when working to plans ; because he is asked to build a wall (for instance) eighteen inches thick, the regular bond of a two-brick wall, which is impossible to do without cutting the

8 BRICKLAYING.

bricks, as they are from nine inches to n>ne inches and a quarter in length, and never less than the former.

Again, as regards the width of the brick, if it were 4j inches, it would be impossible to build, say, a 9-uich wall, giving it the proper waU-joint,* without sailing the stretching course over ; which, of course, is against all rule.

This is the reason (the bricks being only A\ inches wide) that bricklayers have to cut so many three-quarters, or long bats, in face- work, to keep the cross-joints' quarter-bond on the stretcLers.

Broken Bond. — A great deal of this might be done away with if the plans were got out to suit the bricks more than they usually are ; for very often we see pairs between openings sixteen, twenty, and thirty inches in length, without the least regard to what the bricks will work ; thereby causing a great quantity of brick to be wasted, more labour, and then the work is nothing near so strong as if the work had been arranged so that the bricks would work without cutting them.

It is very necessary, when laying the first course on the footings, that all doorways, windows, and other openings, should be measured, and the bond properly set out, so that there is no diffi- culty when the work is up, ready to receive them, and the perpends t are kept throughout the height of the building.

Herringbone Bonding, as shown in Fig. 7a, is

• Three-eighths of an inch between the bricks, t The cross joints in a perpendicular line.

GENERAL PRINCIPLES OF BRICKLAYING,

9

greatly used for cores of arches and other places where something different to the regular plain work is required in the shape of ornamentation. But it has but very little tie with the inside work. This work should be begun and continued with

the set square of 45 degrees ; and if the bricks are all of one length, the joints will all cut straight with one another, showing so many oblique lines at an angle of 45 degrees with the horizontal from where the herringbone started; that is, place the set square upon the base-line A B, Fig. 7 A, in such a manner that the right angle of the square shall be uppermost and the longest side upon the line, and as it is drawn along from a to b, or from b to a (if the work is right), it will cut in a line with the joints c d, E F, &c., and as the work proceeds it will be necessary to either hold up a levelled straight- edge and work the square upon it, or otherwise draw a line perfectly level, and so hold the square to it.

But to do this kind of work properly, it is

really necessary that every hick sJwuId be of one

length, that is, what three courses of bricks will

measure upright when laid temporarily with joints

b3

1 0 BRICKLAYING.

the same thickness as those required for the herringboning. If the joints are to be small very often the bricks will have to be cut short, and this gives it a better appearance than having thick joints, and, beside, it is much stronger work if it is well grouted in at the back. But in all cases let the grout be of the same kind as the work is built with.

Fig. 8 represents another style of herringbone. This is called " Double Herringbone" on account

of two bricks being worked instead of one, as shown in Fig. 7a. The working of this is much the ^ame aa Fig. 7a, but perhaps a little more difficult in the arrangement of the bricks ; nevertheless the joints must cut one with another just the same as the " perpends " of plain brickwork. If the bricks are cut to 8| inches in length the work will show a neat joint, and there will be less trouble in keeping the work right. But it is very frequently done without any care being taken to get the bricks to suit the work, or to keep them in their proper places while laying them.

Garden Wall Bond, as it is generally called, is that which is in practice usually when build- ing 9-inch walling, which requires to be faced on both sides ; and as the headers cause an un- sightly appearance if worked through too often, on account of their different lengths, it is

GENERAL PRINCIPLES OF BRICKLAYING. 11

usual to work three " stretchers " between two ** headers," instead of one, as in Flemish bond.

Damp Courses.

As soon as the work is above ground it ought to receive a course of something to prevent the damp from rising up into the walls, and for this purpose asphalte is often used to cover the walls. But where this is difficult to be obtained a clouhle course oj slates bedded in Portland cement will generally answer the same purpose ; but they must be so bonded, that no two joints shall be over each other to allow the dampness to rise between them.

Air Bricks.

"Where the ground-floors of the building are to be laid with boards, air bricks should be built in the face of the walls, and a passage left through, so that the air can freely circulate under the floors, and by leaving two or three bricks out in difierent places of the inside or parting walls to any part of the building where required.

Wood and Iron Bonding.

In addition to the regular bonding of brickwork, as before described, a further security is sometimes provided in the form of bond timber ; that is, long lengths of wood cut to the form of a 4|-inch course of bricks, and so laid throughout the length of the walls to answer as a longitudinal tie, and also to keep the pairs between openings steady until the work is thoroughly set.

12 BRICKLAYING.

But of late years this has been superseded to a great extent by hoop-iron, both on account of the wood shrinking when it gets dry and so causing the work to settle, also, in case of fire, to have material in the building as little inflam- mable as possible.

The hoop-iron is laid at different stages throughout the whole building. This is sometimes tarred and drawn through sand, to protect the iron from contact with the mortar ; but it is more frequently laid between courses of bricks, and built with Portland cement, without being tarred.

Joints.

It is very necessary that all joints should be kept of one thickness ; for if one piece of brick- work is raised with thick bricks and another with thin (as it often is when two sorts of bricks are used — one for outside and the other for inside) the work done with the thickest joints will settle more than the other, thereby causing the wall to overhang or batter : this is the case with mortar joints. Cement acts in the reverse manner, on account of its sxcelling properties ; therefore in both cases it is considered very unsound work.

Portland cement having this stceUing property, it is well adapted for underpinning old walls, where the ground has been taken out for cellars, &c., below the foundations ; but slate ought not to be driven into the joint between the old and new work for the purpose of wedging it tight, for the cement will not take hold of the slate

GENERAL PRINCIPLES OF BRICKLAYING. 13

to any great extent; besides, if the joint is well filled up with cement, it will expand sufficiently to wedge itself perfectly tight.

Window Sills.

Where these are of stone, it is much better to leave the brickwork out at the reveals just large enough so that the sill can be fixed after the brickwork is up and settled ; if not, the weight of the brickwork upon each end of it will very likely break the sill, owing to the greater settle- ment of the work between the windows (where there are the greater number of mortar joints) than there is directly underneath the sill.

Bricks ought to be well wetted in summer time, 80 as to exclude the air which fills up the pores ; but be careful that they are not wet if there is any likelihood of frost, as it takes fast hold of work that is damp, not only causing the joints to burst out, but sometimes greatly disturbing the bricks.

All walls ought to be thoroughly "flushed" up every successive course with soft mortar or cement, as the case may be. This is sometimes preferred to " grout," because the latter, being so much thinner, will naturally shrink more when setting ; so, if there is the proper wall-joint, there is little doubt but what the mortar- flushing makes the soundest work. There is a common but very evil practice in many places of building walls with mortar and afteruards grouting them in tcith Port- land cement mixed with sand. Where this is the case, the weight of the building must be con-

14 BRICKLAYING.

Bidered as standing upon the grout alone, for it is well known " that cement swells and mortar shrinks;" therefore, whenever the cement grout runs under the bricks, it will surely lift them off the mortar bed ; and, instead of strengthening the work, it has a great tendency to weaken it. Great care should be taken, in building walls of any considerable length, that the line is kept perfectly straight from end to end ; because if the line is drawn tight one course and another loose, there will be " brick and brick " in some places, and a thick joint in others, which gives the work a very bad appearance. In fact the line ought to be " loohed through " every course.

Rubble "Work.

In many parts of England rubble work is done to a great extent with flint and other stones ; and in such cases it is usual to have brick quoins, and these are generally " ashlarcd," as shown in Fig. 9. In London this name is applied to stone- facing.

Although flint-stones are not so well adapted for works requiring great strength as bricks, still they answer very well for what they are generally used, that is, cottage and wall-building, &c., but it is not advisable to use sea stones for house-building, on account of the salt clinging to them causing the walls to turn damp in wet weather.

Fig. 9.

No flint-stones ought to be used in wet weather,

GENERAL PRINCIPLES OF BRICKLAYING. ]5

or if they are at all wet ; for this is the cause of many a wall falling to the ground.

Brick and Stone Combined,

When the building is composed of brick and stone, which it yery often is, the bricklayer and mason ought to be careful to get their work arranged to suit each other, as brickwork cannot be built to the specified thickness without a very great deal of extra labour and waste of material. For instance, a wall supposed to be built 2 feet 3 inches in thickness very often cannot be worked under 2 feet 3f inches because the bricks are full 9 inches long, and a wall never ought to be built without allowing room for the mortar to go be- tween each brick in the middle of the wall.

And so by the stonemason cutting and work- ing the stone that has to pass through the wall three-quarters of an inch longer, it would save the cutting of each course of bricks from begin- ning to end of the wall.

And if this is not thought of in the founda- tions, it will very likely cause a vast amount of trouble when the work is further advanced. Again, in arch work, &c., where drawing is re- quired, and stone and brick are to be used, it is best for both mason and bricklayer to work to one drawing ; for it is possible for two separate drawings to be difierent, so causing confusion when fixing the work ; and it very often happens when anything is set out wrong through the oversight, carelessness, or ignorance of the fore-

16 BRICKLAYING.

man, the blame is directly thrown on to the workman for the purpose of clearing himself. But this is a cowardly way of doing business, and cannot be too much condemned.

Limes, Cements, etc.

Of limes, blue lias is reckoned the best in this country, because it is equally adapted for work below water-level or for moist situations as for dry ones. But it is not generally used for ordi- nary building purposes, principally on account of its taking but a very small proportion of sand before its setting properties are weakened ; so it is thought best only to use little more sand than lime in the mixing.

This lime must not be made into mortar a long time before it is required as other limes often are, or else it will get so hard that it will be of very little use for the purpose of laying bricks.

This lime will take less water than the other limes usualty do ; and it ought to be slacked several hours before it is made into mortar, as some parts will take much longer than others.

The principal supplies of lias limestone are obtained from Aberthaw, near Cardiff, in "Wales ; Barrow, near Mount Sorrel, in Leicestershire ; and "Watchet.

Dorldng and HaUinrj Limes. — These may be considered the principal limes used in and about London for making mortar, owing to their taking a greater quantity of sand than any other before their setting properties are weakened, the usual proportions being three or four parts of

GENERAL PRINCIPLES OF BRICKLAYING. 17

sand to one of lime. But it must be remembered that very often it is not the quantity but the quality of sand that destroys the lime ; for the cleaner and sharper the sand, the better the mortar will be.

These limes are obtained from Dorking in Surrey; and between Rochester and Maidstone in Kent.

Chalk Lime is seldom used in London for out- side work, because it sets so slowly, and in damp places never sets at alL But it is used to a great extent for plastering the inside of houses, &c., where there is no dampness ; and, although it is not used in London for outside work, it is very much used in many parts of the country, where it is very cheap, and better limes are not so easily obtained.

Cements. — The cements used by the builder are of various kinds ; such as Portland and Roman for external, and Keen^s and Martinis for internal, decorations.

Portland Cement is considered the best for general use, owing to its fine setting properties and its cheapness ; for it takes a greater quantity of sand than any other before it is much weakened. This is made in different parts of the coimtry, principall^'^ from the cement-stone found in the Ijondon clay at Harwich in Essex, and the Isle of Sheppey in Kent ; and will take two or three parts of sand to one of cement for ordinary purposes.

But whenever it is required to set directly oi for water-work, it is best to use it in its pure

18 BRICKLAYING,

state. For although sand docs not prevent its setting very hard after a few days, it stops its setting directly.

All sands used for making up lime and cement into mortar should be as free from clay or dirt as possible, and the sharper the better. If this is ne- glected, the best limes or cements are soon ruined.

Owing to the great demand for Portland cement, a great many manufacturers have been induced to bring out an artificial kind, and this is as much used as that made from the cement- stone. The greater part of this is made with clay obtained from the sides of the River Medway in Kent, mixed with a definite proportion of chalk •from the pits in the same district, and so manu- factured as to produce a cement nearly equal to the original.

Roman cement, although possessing many good qualities, is greatly inferior to Portland, and therefore is but little used by the builder.

Keen's and Martin's cements are in appearance a great deal like plaster of Paris, but they set much slower, thereby giving the workman more time to add finish to his work before it gets hard. They are almost always used for work which re- quires a hard and beautiful finish. But in no case should they be used for outside work, or in any place where they are exposed to the action of water, as they are like all pure limes, partly soluble in water.

"Wood Bricks. "Wherever woodwork is to be fixed to the walls

GENERAL PRINCIPLES OF BRICKLAYING. 19

(such as door and window frames, angle beads, skirting boards, &c.) wood bricks, or, rather, wood joints, should be used — that is, pieces of board the length and width of a brick, and about three-eighths of an inch thick, should be laid between two courses of bricks instead of the mortar joint. These will be found far better than having wood bricks the fall size of the ordinary brick, because the latter generally shrink, and so become loose. When the inside is to be matched-lined instead of plastered, it is best to lay a joint of this sort throughout the length of the wall inside. If these are laid about three feet apart from floor to ceiling, there will be no plug- ging afterwards in fixing the matchboards.

Frost.

If the brickwork is carried on in frosty weather, all walls must be carefully covered up with weatherboards, straw, or something that will pro- tect them ; if not, the frost will penetrate into the work, and greatly destroy the strength of all that which is damp.

If Portland cement is mixed with mortal the fi'ost does not take hold of it so much as it does if mortar alone.

Toothings.

"When necessary to carry one part of the build- ing up without the other, the walls where they join ought to be "racked" back, if possible; if not, they ought to be toothed, as shown in Fig. 10, so as to avoid as much as possible upright toothings from bottom to top of the wall.

1 1	1 k
	1
1	1 1 .
	1
: 1	1 1
	1
■ 1 1 1 1 1 1
.1 1 1
■ i 1' 1 1 1 1
1 1 1
( 1 1 1 1 1
1 1 1

20 bricklaying.

Thick and Thin Joints.

So much has been said by different writers about tJdck joints, that it is quite unnecessary for me to say that they are a very great evil, as they cause settlements. But perhaps a little ought to be said about very thin ones, for it is well known that the bricks made in most yards are not all of one thickness ; and it is possible to buy a quantity of bricks all made Fig. 10. {j^ Qj^(, yard, and to find two or

three different sizes — some as much as a quarter of an inch thicker than others. Therefore, when these thick bricks are laid, it is found impossible to keep down to the gauge to which the thin ones are laid with a joint of the same thickness.

The result is, the bricklayer does not spread out a bed to receive the brick, as he usually does, but he "butters" it — that is, he draws a little mortar, as fine as he can get, upon the front and back edges of the brick, and then lays it, leaving an air-passage imdcr every one. This is almost as bad as thick joints, for it is evidently not bedded at all. This is very bad work, but the bricklayer cannot be blamed for it.

Profiles.

In building retaining walls, either upright or battering, or, in fact, any kind of work that is to be racked back to receive additional work, it is often

GENERAI, PRINCIPLES OF BBICKLAYING. 2]

found convenient to erect profiles upright or batter- ing, as the case may be, with the face of the wall, and gauo^ed accordino: to the srau o^e of the work from bottom to top — and so strain the line to it ; by this means the work is kept right both on the face and bed.

These profiles answer very well for setting arches when they are required in advance of the other work ; for they can be easily set up at each end, and the line for the face of the arches drawn to them, and afterwards drawn perfectly level over the crown of the arches, to level up the brickwork between them — and in tJm case it will answer the purpose of both level and plumb-rule.

Trammels.

Where work is to be cut to receive inverted arches, such as the bottom half of a wheel arch, and also cores to receive any other arches, it is much best to fix trammels. These are fixed to the centre, and struck with the same radius as the arch. For the wheel arch, when it passes throughout the thickness of the wall, it is usual to fix an upright piece of wood on each side of the wall, and pass a bar of either wood or iron from one to the other ; this will answer as a centre for the trammel to swing round upon, either on one side of the wall or the other.

All joints in good face- work ought to be struck as full as possible without projecting beyond the face of the wall, and as straight as the bricks will allow.

22 BKICKLAYING,

^^SECTION 11.

DRA\rrS'G, CTTTIXG, AKD SETTING AECHES.

It is very necessary, in speaking of arches, that the reader should thoroughly understand what an arch really is. It must not be supposed that any kind of building material which has been used to cover an opening is necessarily an arch simply because it is made to form a curve, for in many cases we see a block of stone cut out in the form of an arch, and placed over doorways, windows, &c. ; but in the centre or crown, where the proper arch is the strongest, the stone being thinnest is the weakest, and being liable to break at any time, causes the work above to give way.

An arch that is perfectly equal may be con- sidered as a slightly elastic curved beam, and, when loaded, every part is in a state of com- pression. The arch that the bricklayer has to deal with is a quantity of bricks so arranged that they may, by their pressure one upon another, not only support their own weight, but transmit any weight that may be placed on them to the abutments.

Therefore all bricks should be of such a shape that they should "bed " with a perfectly equal bed- joint, one against the other, and at the same time carry an equal curve, or fit the centre upon which the arch is turned, throughout the whole span.

And by each joint cutting in a line to the point or centre from which the arch is struck,

|. DRAWING, CUTTING, AND SETTING ARCHES. 23

eaeli brick will be in tbe form of a wedge ; these are often called " Youssoirs," and the thickest or uppermost part of them the " mi^0t»s," and the ■ small, or that part which is fixed upon the centre, the "intrados," or sofl&t of the arch.

These few remarks will serve to clear the mind of the reader as to what the general principles of an arch are.

The higher calculations connected with the designing of arches, and rules to find the weight with which each course of voussoirs should be loaded to bring the arch into perfect equilibrium, would be out of place here, as this little work is intended for the working bricklayer, and he is very seldom fortunate enough to be able to enter into calculations of this kind, although they would be of great service to him.

Plain Arches.

All arches turned without the bricks being cut or shaped in any way may be classed under this head ; and these are in general use for railway- bridges, tunnels, vaultings, and all work where strength is essential, and appearance no particular object.

In building arches of this description, in order to avoid the thick joints that would appear at the extrados if the bricks were laid with the end upon the centre — as they are not wedge-shaped, but of one thickness throughout the length — it is usual to build them in rings the thickness of half a brick, or brick on edge, so that each ring is

24 BRICKLAYING. ^

separate, having no connection with the others beyond the cohesion of the mortar in the collar- joints between them, except a heading-course occasionally, wheneTcr the joints of two rings happen to coincide : sometimes this is objected to.

It is very necessary that each ring should be pro- perly bonded throughout the length of the arch, and also that the joints should be of a regular thickness. For if the soffit-ring is built with a thick bed-joint, and the second ring with a thin one, the thick joints will shrink most, thereby causing an unsightly fracture between the two, and so deprive the arch of the strength of the bottom rinw.

Mortar made with good lime is considered by many better than cement for this kind of work, for very often cement sets before the work is complete, and any little accident in striking the centres, or from any other cause, is very liable to break the arch.

Let it be here understood that no kind of arch ought to be turned without the centre has folding wedges, so as to drop it, when the arch is finished, as easily as possible, and without shaking the arch.

These wedges ought to be drawn a little a day or two before the centres are really struck, so as to give the arch its " bearincj."

Axed Arches.

These are used very much in the present day, on account of their taking less labour, as it is thought. But it is an inferior sort of work at the best, and often costs as much as gauge-work by the time it is fi^nished.

UUAVVING, CUrriNG, AND SE'lTING ARCHES. 25

The bricks of these are simply axed down to a given size, and nothing but the soffits are rubbed ; and this is done after they are brought to the required bevel with the hammer boaster and scotch ; they are then set in cement, with a joint about three-sixteenths of an inch in thickness, and afterwards pointed.

Gauge Work.

This consists of all kinds of work that is cut and brought down to a given gauge upon the rubbing- stone ; such as all kinds of arches, mouldings for external cornices, architraves to doorways and windows, eaves, &c., and is considered the most important branch of the trade.

For this purpose a shed should be built to protect the bricks that are to be cut from the wet, and also large enough for the workmen to erect their benches and chopping-blocks to suit their own convenience. They then require the rubbing- stone and a bedding-block. The former ought to be in the form of a circle, and not exceeding 14 inches in diameter ; for if it is, it will be very likely to rub out of level on the face, that is, either hollow or cambering ; and even with this size it will be found necessary to turn it round in its bed about once a day when in use, for if the stone is unlevel the bricks will assuredly be the same, making very bad work.

The bedding-block is square and of a perfectly smooth surface. It is used for the purpose of scribing and fitting the bricks to the moulds, and c

26 BRICKLAYING.

is usually made to the size of one course of the arch, if double-faced ; if not, about 14 by 18 inches.

Various Arches tsed in the Building Trade.

It is necessary that the bricklayer should thoroughly understand the names of all arches used in the building trade, and also what is meant by these names. The following are the principal arches used in building construction : —

The Scmi'Circular, as shown in Fig. 11.

The Segment, which is the part of a circle only, as Fi^. 12.

Rg. 11. Fig. 12.

The Camber (Fig. 13). — This arch is a very small

part of a circle, as it is generally reckoned to rise

only one-eighth of an inch to the foot ; so if the

span of the arch is four feet,

V ~7 the crown or centre of the

Rff. 13.

soffit will only be half an inch above the springing line, and the top ought not to be more than a quarter of an inch above a straight line drawn from the top of each skewback ; then, by the slight settlement of the arch when taking its " bearing," this line w ill have the appearance of being perfectly straight.

The Gothic Arch (Fig. 14) is ver}- much used at the present day, both as shown in this figure.

DRAWING, CUTTING, AND SETTING ARCHES. 27

and also with a greater or less rise above the springing line, as Figs. 15 and 16.

The Elliptic Gothic (Fig. 17), which is simply an ellipse with a Gothic head.

Tig. 17.

Fig. 18 represents a Semi-ellipse, or half- oval.

There are many other arches in use in other branches of the building trade ; such as the horseshoe (Fig. 19), the 0 G (Fig. 20). But it

Fig. 18. Fig. 19. Fig. 20.

is very seldom the bricklayer has the building of any but those that have been mentioned.

We have thus far only had the forms of different

arches. The next thing of importance to the

workman is the methods of striking them out, and

taking off the moulds and bevels for cutting them.

c2

28

BRICKLAYING.

Drawing Arches.

As it is out of reason for the builder to pay the workman for tis time while he is jiiactising on the work, it will be found necessary that he should learn the diflferent ways of striking out those things that he will require, either at his homo, or at some other equally convenient place. And for this purpose he will require a drawing-board. Sixteen inches square will be large enough for this purpose; but should a larger one be required, it would be better to get one 2 ft. 6 in. by 1 ft. 10 in. This will take an imperial sheet of drawing-paper. Also, a T square and set square, lead pencils, a pair of com- passes with pen and pencil, and a piece of india rubber to clean out any false lines. And as it is always best in these kinds of drawings to work to a scale, the 2-ft. rule will answer this purpose.

Should the reader wish to practise drawing other forms of the arch, he will require moreand better instruments. It is necessary, in almost -g every kind of arch, to draw the horizontal and perpen- dicular lines at right angles with one another. If the reader knows how to do this, he will find it his principal guide to drawing the arch.

Fig 21.

So, from the points a and u, Fig. 21, '»'\t|U any

DRAWING, CUTTING, AND SETTING ARCHES. 29

radius greater than half the given line A b de- scribe two arcs intersecting each other at o and s; then the line joining o s will be in the centre of A B and at riorht ano^les with it. But with the T square and drawing-board this is unuecessar}', as he is simply guided by the square when fixed first to the side, and then to the bottom of the board.

In showinw the methods of drawing: arches and taking ofi" the moulds, it will not be necessary to speak oi plain arches, as the bricks are not cut for them, therefore it will be best to deal with them as gauged.

The Semi -circular (Fig. 22). — In drawing this arch, it is oidy necessary to place one point of the

Fig. 22.

compass at the centre o, and with the radius d b describe the half-circle which will answer lor the sofiit ; then with the same centre describe a greater half-circle, according to the depth of the arch required.

Divide the outer ring with the compas.s into as

30 BRICKLAYING.

many parts as there are required courses in the arch, taking care to see how thick the bricks will work first, so that no more is wasted in the cutting than necessary. Then from the centre o draw the lines to each of the divisions marked on the outside half-circle as shown. This will be the size and shape of the mould for cutting each course of the face of the arch. And a parallel mould, the width of the stnall end of the face mould, will do for the cutting of the soffit of the brick, after allowing for the joint in each case (this ought to be about one-tenth of an inch thick), and is best done by working a little nearer the small end of the mould, which will be easily seen in the workinor. The bevel for cutting the soffit is taken by placing the stock of the bevel to the line a, and setting the blade to the line repre- senting the soffit of the first course of the arch at D.

This is the only bevel required (if a X bevel is used) as the tops are cut to this bevel fitted on the brick the reverse way.

Fig. 23 is another kind of semicircular arch with a Gothic head. To draw the outside portion of this arch it is necessary to draw the line or chord A B, bisect it at d, draw a line with the eetsquare from d, at right angles with a b, to any point c, and upon this line the centre is taken to describe the outside curve of the arch, according to the haunch required; and the inner ring must be divided in the same manner as the outer ring of Fig. 22 ; but the bevels for the tops must be

DRAWING, CUTTING, AND SETTING ARCHES 31

taken separately. In all other respects it is the same as Fig. 22.

A

Fig. 23.

The Segment (Fig. 24) may be worked in the

snrae way as the semicircle, the only difference being in taking the centre to strike it with

32 BRICKLAYING.

This is taken in the perpendicular line below the springing level, with radius according to the rise required as shown at d, and this is the point to which all lines must be drawn, both to get the skewback and also the size of the course. The bevel for cutting the skewback is taken by placing the stock paritllel with the springing line a b, and setting the blade of the bevel to the skewback line D E.

We now come to the Camber Arch, which is perhaps one of the most difficult to draw and cut. To draw this arch, supposing the opening to be 4 feet in the clear, would require an arch with only half an inch rise above the springing line at the crown, as it would take a very long radius to strike an arch having so small a rise in the ordinary way of striking a segment of a circle; it is necessary, therefore, to resort to other means.

To do this it is best, in the first place, to get the horizontal and perpendicular lines, and measure out the width of the opening equal on each side of the upright line, then take the rise as shown at a. Fig. 25, and drive three nails into the board upon which it is intended to strike the arch, at the three separate points b, a, c ; this done, get a piece of |-inch board as long a* the opening is wide, in the form of a very flat triangle, as shown in Fig. 26, takinj? care the rise of the triangle is just half that re- quired for the arch. Place the end b. Fig. 26, to the nail at b. Fig. 25, a to a, and c to c, keeping it tight against a c with the left hand ;

DRAWING, CUTTING, AND SETTING ARCHES. 33

then with the right hand fix the pencil firmly against a, the centre of the trammel, and gently draw the curve with the right hand, as the trammel is drawn from a to c with the left. If care is taken to keep the pencil hard against the centre a of the trammel, and that part of the

£

N"-

Fis- 25.

trammel against the two nails as it is drawn from A to c, it will describe very correctly that half of

Fig. 26.

the camber's soffit. Then by repeating the operation the reverse way, by drawing the trammel with the left hand from a to b, while with the right hand and pencil that half is de- scribed in like manner, this will complete the regular curve of the camber arch. Then with

34 BRICKLAYING.

c, as centre, and c b, as radius, cut the perpen- dicular in D ; this is the point to which the lines are drawn to get the proper skewbaek.

It is then necessary to measure the bricks to see how they will work. If 3 inches, set oflF I3 inches on each side of the centre line e d, and draw lines to the point d, as shown : this will give the shape of the moulds of which there ought to be three, a quarter of an inch thick, and about 18 inches in length. If the arch is to be 1 foot in depth, and in proportion if more or less, then mark them all at about 3 inches from the narrow end.

Fix one of these upon the centre line, as shown at a, so the line above mentioned shall be exactly at the soffit-line of the arch, and then trace the other two alternately towards the skew- back, keeping each line on the moulds to the soffit-curve each time.

If the last mould does not meet the skewbaek exactly, it must be raised or dropped down until it does; then mark each course, and the joint must then be allowed as before stated.

The bevels must be taken for each course, and marked on the mould ready for working ; one bevel will answer for soffit, cross-Joint, and top of each course, if it is reversed for the two last named. But perhaps it would be best to leave the tops and cut them when setting the arch, for very often mistakes are made in taking the length of the courses with the template. The bond of the camber arch is the same as the quoin of a

DRAWING, CUTTING, AND SETTING ARCHES. 35

common wall of Flemish bond, only the arch is level and the quoin is upright, always remem- bering to work from the soffit, as shown by the two courses at c, Fig. 25.

The Gothic Arch (Fig. 26) is much easier to construct than the camber, owing to its having a shorter radius.

Set out the extent of the arch at a b on the horizontal line, then with a for centre, and the distance a b for radius, describe the arc c b ; then with AE as radius and with the same centre describe

Fig. 26a.

the inner arc d e — this forms one side of the arch ; then with b as centre, and same radii used for the first half, describe the second.

Divide the outer curve into courses according to the size of the bricks, and draw the lines to the point A as shown, taking care in dividing out the courses that half a course shall be on each side of the perpendicular line at c, to answer for key- brick. The bevel once set will answer for the

36

bRICKl-AYING.

whoJe of this arch, the same as the st mi -circular. There are diflerent ways of forming the key of this arch, but the one shown is considered the best. Sometimes the Gothic arch is cut as repre- sented in Fig. 27, but it is very seldcm, c

Fig. 27.

account of the extra work in soffiting the bn'cks, for in this case each course must be cut to a sepa- rate bevel. But the lines for each course are drawn to the centre o, instead of the opposite springing, as Fig. 26.

A Beduced or Modified Goihic. — To draw this arch it is necessary to draw the chords a b and b c, Fig. 28, from the springing to the crown ; bisect A B and B c at D and h ; and from these points of bisection draw the lines to the points o o with the setsquare. And upon these lines the points are taken to strike the arch according to the rise required above the chord. The outer ares are then divided into courses and lines dr<iwn to the points o for the size of the mould, if the arch is to be cut in the same way as Fig. 26. But if i'

DRAWING, CUTTING, AND SETTING ARCHES. 37

IS to be "keyed in" with an upright key, as Fiff. 27, the lines must be drawn to tho centre e.

Fiff 28

The method of drawing and taking off the moulds of the arch shown in Fig. 28, applies to any Gothic, whether greater or less than the regular equilateral arch.

The Ellipse Gothic (Fig. 29) is rather more diffi- cult in the working than the generality of Gothic arches, owing to the different striking points. To draw this arch, let the distance a b be set off equally on each side of the perpendicular line ; then divide it into four equal parts by marking the points c d, and with d as centre, and the distance D B as radius, describe the arc from b to E, mark the point b e equal with b d, draw the chord F E, and bisect it at g, from which point draw a line with the setsquare to any point o, and upon this line the centre is taken to draw the upper portion of that side of the arch as shown ;

38

BRICKLAYING.

the soffit curves are obtained in the same way. After the lines a f e b are drawn, they can be made to answer either for soffit or exirados, by striking the other parts greater or less than those named ; in this figure they represent the outer

Fig 28.

ring; but the centres will do for either. The moulds for this arch are taken in the same way as those in the camber. Fig. 25 ; that is, it must be traced over with the moulds, so that each course shall be exactly of one size, and the bevels must be taken separately.

It is of the greatest importance that the work- man should practise drawing this arch until he is thoroughly acquainted with every part ; for very

DRAWING, CUTTING, AND SETTING ARCHES. 39

often he may require quite a different kind of ellipse Gothic to the one here described, and by his understanding the principles of this one he will be better able to reduce or elevate them to suit his requirements. Perfect accuracy in all good brickwork cannot be too much impressed upon the mind of the bricklayer, and more par- ticularly in drawing and cutting arches.

Fig. 30 represents a semi-ellipsis arch, and is a great deal like the ellipse Gothic, the only dif-

Fig.30.

But the drawing

ferenee being in the crowns is quite, different. In drawing this arch, divide the span into three equal parts, as shown at a c d b, then, with d as centre and d b for radius, describe the arc from b to e equal to d b, and the same on the opposite side to f ; then, with d for centre and the distance d c for radius, describe an arc cutting the perpendicular line in g ; and from this point, with the distance g f, describe the arc r e : the

40 RRTCKLAYIXG.

oiiter curves are tuken from the same centres. The moulds for this arch must be traced in the same way as the camber and ellipse Gothic ; that is, take the thickness of the brick and set it equally on each side of the centre line at h, as shown ; then draw the lines to g ; this will give the size of the mould very nearly; then, if they are worked alternately down to the springing-liue, it will be seen where they want easing, should they require it. The bevels are all taken separately for each course, but the t bevel reversed will not answer for the top or outer curve of this arch.

Another method of drawing this arch is shown in Fig. 31. Take the distance a b, that is, the

Fig. 31.

span and also the depth of the arch, and set it off equal on each side of the centre line ; divide this into three equal parts by marking the points c and D ; then, with n as centre and dc for radius, describe an arc cutting the upright line in e. From this point draw a straight line through d to any point F, and another through c to h ; then with d as centre and d b for radius describe the arc f b, and

DRAWING, CUTTING, AND SETTING ARCHES. 4l

take c for centre and same radius for the opposite ellipse A H, and, lastly, e for centre and e h for radius, to describe the crown h f. The soffit-ring is drawn from the same points. It is thought by some that the moulds can be taken by drawing lines as shown from divisions on the outer curves ; but it is evident the bricks in the arch cannot be all of one size and shape if this is done, although there is little doubt the arch is stronger that way, owing to there being a better skewback at h and f for the crown than there would be if each course were cut to one mould ; it is unnecessary to say this is the easiest method. But the appearance is not so good, for it is an understood thing in the trade that all courses of an arch should be of one size.

The Wheel Arch, or Biiirs-etjc (Fig. 32).— Tn this arch the outer circle is divided out iu such a

42 BRICKLAYING.

manner that each line, a b, c d, shall be in the centre of the course ; or, in other words, that each of these points shall show a key brick, in the same way as one key is shown in the semi- circular arch.

Where two or more arches are set close to- gether, " saddles " ought always to be cut, as shown at a and b (Fig. 33), and not a continual

Fig. 83.

straight joint from c to D ; for although this is often done, there is no bond between the two arches. In all arch cutting the T bevel is by far the best to use, for by reversing, it frequently answers the purpose of two.

Moulding.

It has been already stated that moulding is also included in what is called gauge-work. And of late years there has been a very great deal of this work done, particularly in end about London. St. Paucras Station of the Midland Kailway ra;iy be taken as a fine specimen.

In many places Ihis is done by fiiinply making a template the form of (he brick required, and marking the brick, first on one side and ihcn on

DRAWING, CUTTING, AND SETTING ARCHEb. 43

the other, and so cutting or rubbing it down to these marks. But for moulding birds' mouths, splay, bulls* noses, and, in fact, almost any kind of work, it will be found much better if a box is made that will hold three or four bricks, either flat or on edge, as they may be required, taking care that the ends are both alike, and the exact shape of the brick required. If this method be properly worked it will be found very accurate, and done with a great deal less labour. The boxes for this purpose are usually covered with tin or sheet-iron to protect the wood from wearing away while working the bricks ; if not, the moulds are very apt to get out of their proper shape and so lead the workman wrong. Even with this precaution, it is very necessary to try them sometimes to see if they are correct.

"When bricks are moulded for arches, it is best to mould them first and cut them to the shape required afteawards ; for should they be cut first and then moulded the brick is often broken, and all the labour upon it is wasted.

But it must be remembered that when the bricks are moulded first the soflBt is not touched afterwards, or otherwise the bead, or splay, or whatever it is, will be rubbed out of shape. Therefore the brick must be brought down to the required bevel by rubbing down the side or " bed," so as to bring it thinner at the soffit end. This is called soffiting the brick from the side; and all bricks properly worked this way will go together equally as well as if they were bevelled

44 BRICKLAYING.

from the end, ip the same way 33 arches that are not moulded.

It has been said that where a great many arches are required, all of one size, either p^a in or moulded, it is best to send the moulds to the brickyard and have them cut while the earth is soft, and so burnt to the shape required. But if this is tried it will prove a total failure, for it is impossible to burn bricks with the accuracy re- quired for gauge work ; and it is always found to take almost as much labour in brinjjinj? them to proper order as it would have done to cut the bricks in the proper manner at first.

Let the bricklayer be careful to turn out his work in such a way that it shall reflect credit upon himself, and his employer will soon see which is the best and cheapest method of cutting gauge-work.

Settixg.

It has already been said that cutting is considered the most important branch of the trade, and to a great extent this is right. But it must be re- membered that, after the work is cut, there is almost as much skill required in setting it. For it very often happens tliat a vast amount of labour and skill is expended upon work while in the "cutter's" hands, and directly it is taken on to the building the beauty of it is all destroyed through the carelessness or inability of the setter. On the contrary, bad cut work is often made to look well through nothin<j but the skill of the setter.

DILWVING, CUTTING, AND SETTING ARCHES. 45

Therefore it is very necessary that this branch should be equally well uuderstood. In setting gauge- work of all kinds, it is necessary to take the thickness of the courses, and gauge the centre upon which the arch is to be turned ; and this is done by takiug the thickness of the brick and joint at the soffit. Each course should be marked on the centre from the key brick downwards. Never gauge from the springing or the skewback, as this often leads to mistakes when setting the arch.

The soffit of each course ought to fit the centre perfectly ; and in order that it should do so and that the courses should come in right at the key, it is often necessary to have a radius line; that is, a nail should be driven into the ledge of the centre at the point o (Fig. 23), for instance, and a piece of string fastened to it, and drawn up to each course of the arch as it is set, in the same manner as the line o D is drawn. This will pre- vent the setter getting his work too high or too low at the extrados of the arch. If this is not done he is working at random, and will very likely have to make his bricks smaller, or, other- wise, his bed-joint thicker when he gets to the key ; thereby depriving the arch of its strength, and so causing a settlement when the centres are struck. Gauged arches, as a rule, are set in grey lime putty, brought to the consistence of cream. This is put into an oblong wooden box, about 2 ft. by 1 ft. 9 in. deep, for the setter to dip that side of the brick where the bed-joint is reauired.

46 BRICKLAYING.

But in doing this care must be taken that the bricks are neither too wet nor too dry ; also that the putty is of such a thickness that it will give the brick just such a joint as the work requires: of course the brick should be held in the putty until it takes up the joint. If each course is bedded regularly throughout its thickness, the joint will be full and even on the face of the arch ; and should it project a little, which is often the case, it ought to be left untQ the building is cleaned down, then they can be rubbed off level with the bricks, and so leave the face of the arch perfectly regular. This method only applies to gauge- work.

AxEu Work

Is usually set in Portland cement ; and this is sometimes mixed with a little putty to make it work better; the brick is then "buttered" with the trowel and not dipped as gauge-work. By being buttered is meant a small portion of the cement drawn on the edges of the brick, and the middle left hollow to receive the cement grout which is run in after the work is set ; the joints are then raked out to receive the tuck pointing, which is done after the building is up. Whenever there is a long range of arches, one ought not to be set separately ; but a line drawn the whole length, so that when all are set, they shall be perfectly straight one with another.

DIFFERENT KINDS OF POINTING. 47

SECTION III.

DIFFERENT KIXDS OF POINTING.

PoLXTiNG of all kinds of work is another very important branch which the bricklayer has to deal with, and is more in practice at the present day than ever before, both on account of its cheapness and also its appearance. These may be classed under two heads — Tuck-pointing and flat-joint pointing. The first is of the most importance, and also requires the most skill, not only in the difierent methods of preparing and using the material, but also in preparing the work. Stock icork icith the white joint is most general in London ; and the first thing necessary is to mix the pointing stuff. It is often thought best to colour the work, even if it is a new building, to bring all the bricks to a uniform colour, because some bricks are much darker than others, and therefore have a bad appearance when finished. This colour as a rule is made with green copperas in the proportion of one pound of copperas to five gallons of water ; but in all cases it should be tried first upon some bricks placed in the same position as the front which is to be coloured ; that is, if the front face the south, place the bricks towards the same quarter, as it is often found that work di-ied in the sun, £ind that which is dried ia the shade, are quite different

48 hUlCKLAYING.

Mix up as much colour as will complete the whole job, as two mixings might not be alike. The longer this copperas is kept the stronger it gets ; therefore if it cannot all be used at once, it is best to weaken it every morning by putting half a pint of water to every gallon of colour ; if this is not looked to, the last part which is done will be much darker than the first. If the work is wetted before the colour is laid on, one gallon of colour will do 100 feet, more or less, according to the bricks and the season of the year.

Telloic Stopping. — This is made with grey lime, putty, and fine washed sand, in the proportion of one bushel of the former to three of the latter, and will take about 2 lbs. of yellow ochre to each hodful of stopping. But of course the workman will regulate it to suit the colour of the brick. This also must be tried in the same way as the < opperas, and in all cases let the stopping be a shade darker than the brick when it is dry. This will give the putty joint a better appear- ance when it is laid on. In no case should copperas be used to colour the stopping.

White Putty. — This is generally made with chalk lime (because it dries much whiter than grey lime, and gives the work a better appear- ance), and silversand, or marble dust ; the latter should be used whenever it can be obtained, on account of its giving the joint a beautiful glaze. It is usual to heat the pieces of marble until they fall to a powder, then screen it througl. a very fine screen or sieve before mixing it

DIFFERENT KINDS OF POINTING. 49

with the lime. But silver sand is more generally used.

The lime is slaked and sifted through a fine sieve. Sometimes oil or size is mixed with it to make it work better, and also to give it greater binding properties ; but this must be done while the lime is hot and dry, and one pint of either to half a bushel of lime is enough.

If chalk lime is used, one peek of silver sand is sufficient for half a bushel of lime ; but if grey lime is used, it will take double that quantity of sand. If work is to be pointed, it must be well cleaned down from top to bottom, and well rubbed with pieces of the same brick as the wall is built with ; this will give the work a level surface. Brush off all dust, and wet it well, then follow with the colour and give it one coat throughout ; if it should require two coats, let one get well set before the second is laid on ; but if it only requires one coat, the work is ready for the stopping. It is usual to do this in lengths of about 8 feet; this is about the length that two men will work when laying on the fine stuff; and if this is taken for the length and 5 feet for the height, it will be quite enough at one time.

We sometimes see houses stopped in from top to bottom before ever a putty joint is laid on ; but the man who does this evidently knows but very little about tuck-pointing, for, whenever this is done, the stopping gets so dry and hard that the putty will not combine with it as it ought, and it will fall off in a very short time,

D

dO bricklaying.

The work is also so besmeared with the white stuflf, that it has more the appearance of being plaotered than tuck-pointed.

TThen the length, as before stated, is stopped in, it is usual to rub it well with a piece of dry sacking, or something of that kind, to give the stopping and bricks the appearance of being one uniform block. Brush ofi all dust, and, if neces- sary, damp it with the stock-brush carefully, so as not to disturb the stopping ; then gauge the joints at each end of the rule as a guide for holding it, so that each course is of the same thickness, and each joint perfectly level through- out. This gauging must be applied to all work, whether yellow, white, or red, and it would be best to have a gauge-rod expressly for this pur- pose. The cross-joints should be perfectly plumb from top to bottom of the building. The rule that is used to lay on the bed-joints (if it is done with the jointers) is about 8 feet long, 5 inches wide, and about | inch thick ; and there ought to be two or three pieces of cork a quarter of an inch thick nailed on to the back, to keep the rule from the work, so as to allow room for the waste putty that is cut from the joint to fall clear to the ground. The fine stuff is spread upon this rule, and afterwards taken off it with the jointer and laid on the work that is stopped in, according to the rule when it is held to the gauge-marks. After this the rough edges are cut off with a knife, or " Frenchman," as it is called. This is the process for yellow or stock-work pointing.

DIFFERENT KINDS OF POINTING. 5]

Bed brickwork Is treated in many respects quitt differently. The colour used for this is composed of 1 lb. of Venetian red, and 1 lb. of Spanish brown to IJ gallons of water ; but it ought to be tried in the same way as copperas. This colour has no setting properties, therefore it is necessary to mix something with it that has, or else the first shower of rain will surely wash it off.

One of the best things to use for this purpose is white copperas. This must be dissolved in warm water, and 1 lb. will set about 3 gallons of colour. Alum is also used in the same propor- tions ; and sometimes half a gallon of stale beer to the same quantity of colour for setting.

Bed Stopping is composed of 1 part of grey lime to 3 parts of fine washed sand (red sand would be better, as it would take less colouring). This is coloured with Venetian red and a small portion of vegetable black. But in this case no propor- tions can be given as there are so many different kinds of red brick, and the colour that would suit one would look very badly if applied to an- other ; therefore it is best for the workman to try these colours, and match them with the bricks before he begins to point the real work, and in all cases mix enough for the whole of the point- ing, allowing three hods of stopping to 200 feet of work.

This class of work is done in the same way as stock-work, the only difierence being in the using the colour. Red work is coloured throughout first, and then a second coat is laid on after it has

T>2

52 BRICKLATIXG.

been stopped ; this is done very lightly, so as not to rub up the stopping.

But in stock- vrork, colouring over the stopping should never be done, for the copperas being so strong it will bring out a white hue, and make the stopping almost as white as the putty joint, giving the whole of the work a very bad appear- ance. The putty for red work is just the same as that used for stock- work.

WJiife BricJiicork. — When the bricks used for this work are sand- made, they only require well rubbing down before pointing ; but should there be any flesh-coloured ones among them, it is best to leave the dust on the face after rubbing it, and give the whole a coat of alum-water ; this will set the dust so securely on the face of the bricks, that no quantity of water will wash it oflf, and will give the whole front a regular appearance. This is made with 1 lb. of alum dissolved in 3 gallons of hot water ; and if it can be laid on the work when warm, so much the better.

The stopping for this kind of work seldom wants any colouring, the sand making it suffi- ciently dark to match the bricks.

There are three sorts of putty used for this work ; white, black, and sometimes red.

The method of mixing the first has already been explained, therefore it is unnecessary to repeat it.

Black Putty requires \ bushel of grey lime, slaked and finely sifted; \\ bushels of very fine washed, or silver sand and 12 lbs. of lamp-black

DIFFERENT KINDS OF POINTING. 63

or vegetable black : the last named is much easier to mix with the lime and sand. Care must be taken that these are well worked into one another, if not, the joint will have a bad appearance when laid on the work.

lied Puff I/. — This is made in the same way as the black, only the colouring is different, this being done with Spanish brown. But, as in red stopping, the colour must be mixed to the shade required.

It is not always necessary to colour brickwork ; and if the bricks are all of one colour, such as Suffolk whites, best reds, or malms, it is much better not to do so.

But if, on the contrary, the bricks are inferior, they cannot bo brought to a uniform colour without it.

The putty-joint in all tuck-pointing ought not to exceed a quarter of an inch in thickness. Arches of all kinds, except those that are gauged, are pointed in the same way as plain brickwork, but the joint ought to be smaller.

Old Brickwork. — ^Vhen this is repointed all the old mortar must be raked out of the joints. The whole front is then well rubbed with pieces of brick to clean off the grease and dirt, and well swept down with a hard broom perfectly clean, so that the colour may enter the face of the brick, and after this, it is given two coats of red colour or green copperas as the case may be, taking care that the first coat is dry before the second is laid on, also that both are dry before it is stopped in.

5i BRICKLAYING.

The stopping in old work is generally smoothed down level with the face of the bricks with the trowel, and not rubbed in the way that new work usually is ; for very often it is stopped with brown or black stopping, if it is stockwork, and, of course, it would never do to rub it.

Flat-Joint Pointing. — This is of three kinds. The first is laid on with the trowel and cut ofi" at the top only with the Frenchman, to give the joint the appearance of having been struck when tlie bricks were laid. The second kind is cut off top and bottom, and is sometimes called " half-tuck." And the third is simply done by filling up each joint flush with the brick ; then rub it over with a stock-brush or a piece of sacking, and next run a line in the centre with a jointer or anything that will mark it. Inside work which is to be whitewashed or coloured is the only work which is done with this kind of pointing. "Washed sand and lime made into a stiff mortar is the only pointing material required for flat-joint pointing, but the darker the sand the better, and in this case, as in all kinds of pointing, the work should be kept well damped, for upon this depends the soundness of the pointing.

PAVING, TILING, USE OF MATERIALS, ETC. 55

SECTION lY.

PAVING, TILING, USE OF LIATERIALS, Etc.

Paving.

Brick-paving. — This kind of flooring is less used in London than it is in the country, as it is often the practice to lay the floors of dwelling-houses in many parts with this material ; but this is seldom done in the metropolis, unless it is the cellar floors, and these are usually done with the stockbricks ; good paviours and Dutch clinkers being used only for stables, coach-houses, &c. These are laid in various ways, such as brick-flat, brick-on-edge, and sometimes it is herringboned. Plain Paving is that which is laid in parallel courses. This needs no explanation further than

r				3
		V	-
1		xXxxxyxxX/		^
r	)			A

Fig. »4.

that which will be given in connection with the other kinds. But herringbone paving. Fig. 34, will be found much more difficult, both in setting out and also after it is set out, in the working.

66 BR1CK.LAY1-NG.

The first thing that must be done is to get the floor-line, at any point such as a, and, if necessary, drive a stake into the ground as a starting-point to take the levels from. From this point level to each corner of the room, taking care to reverse the level every length, for very often the level is not correct, and the work is thereby thrown out. But if this is done it cannot happen. After the levels are taken, the ground must be dug out deep enough to receive the brick and its bed below the level line; if this is hrkh-Hat, 3 inches will be enough, but if on edge, it will take 5 inches ; then with a pair of lines lay a temporary course of brick, as shown from d to c and from a to b, and the line is drawn to these courses to keep the work level on the surface and also to show if the points of the herringbone are correct, as shown by the line E F. Iso bricks ought to be cut against the straight temporary courses, but leave them as a toothing to be filled up afterwards. All diagonal joints should cut in a line, in the same way as those explained in Figs. 7 and 8, and those figures will serve for a guide for hruk-on-edge paving, Fig. 34 representing hrich-Ji<it only. But the straight temporary courses are laid for all sorts of brick paving.

2'ih -paving is very much in practice, both plain and ornamental, notwithstandiag the great quan- tities of asphalte Portland cement and York paving used. These tiles vary in thickness from two inches to three-eighths of an inch. Plain tiling is generally done with tiles, 12, 9, and

PAAHNG, TILING, USE OF MATERIALS, ETC. 57

G inches square ; aud these are laid in parallel courses with one side of the room, yard, or surface that requires paving. Should the tiles be of dif- ferent colours, it is usual to lay them diagonally, 80 that the different colours form diamonds. The methods of executing this kind of paving are much the same as the others. But for very thin or ornamental tiling the whole surface is *' screeded " perfectly level with Portland cement mixed with sand ; and when sufficiently hard, the tdes are laid with a thin bed of pure cement, according to a design ; by frequently applying the straight-edge, the work will be brought to a uniform surface.

Tiling.

Roofing-tiles. — These are of two kinds, plain tiles, which are quite flat, with two holes near the head of the tile, through which oak pins are placed, aud by this means the tiles are laid or hung to the laths of the roof; and pantiles, which are much larger. These are hollow, or curve- shaped, and are hung on the laths with a project- ing ear, which is called the nob of the tile ; and each course overlaps the previous one with a roll. This tiling is done much better in the country than in London, owing, in a great measure, to the tiles being made with greater care, and better shaped. If this work is properly gauged, the courses ought to fit perfectly close one to the other, so as to prevent the wind getting under them and lifting them off. u3

58 BRICKLAYING.

In preparing the roof for tiling, it is necessary to lath it with inch laths. These are called pan- iiJe Mhs. To do this, each outside rafter (that is, the rafter that is nearest to each gable) should be gauged out according to the gauge of the tiles. This is done from the eaves to the ridge, taking care to allow for the eaves projecting over the wall- plates, so as to carry off the water. This is easily ascertained by fitting a tile on to the eaves before gauging the roof. Nails are then temporarily driven into the rafter at each length of the gauge, and to these nails a line is drawn, as a guide line for lathing the roof.

Where these tiles are used for dwelling houses, each space between the pantile laths is covered with small laths, and these are covered with a bed of mortar, to answer for a bed for the tile, and also to keep out the wind ; but in common tiling this is not done, as pointing the tiles inside answers much the same purpose. The roof ought to be gauged out lengthways also, the width of each course, so as to finish exactly even courses at the gable. For not unfrequently we see roofs covered at random, and finished with a broken or cut course against the gable, and this will generally be found to be the first place where the water penetrates through, thereby causing a great deal of injury to the roof, ceilings, &c.

Plmn Tiling is worked much in the same way; but of course the gauge is less. They are some- times hung with two little nobs instead of pins. In plain tiling, the roof needs only to be gauged

PAVING, TILING, USE OF MATERIALS, ETC. 59

from the eaves to the ridge ; the guide length- ways is simply to keep the second course half bond on the first, and so on throughout the roof. The setting of ridge-tiles needs no explanation, as it is only necessary to keep them level and straight along the ridge-tree ; the difierent gauges will be given further on.

It is the practice in buildings of any import- ance to construct fireproof floors, and this is

Fig.es.

sometimes done by turning brick arches upon wrought iron girders as shown in Fig. 35. But of late years it has been found that plain tiles will answer this purpose equally as well as bricks, without the disadvantage of being so heavy. Not only that, but the depth of the girder can be greatly reduced, for often where a 6-inch girder would be required for brick arches, those 3 inches in depth would do for tiles, so saving the 3 inches in the thickness of the flooring. And not only fireproof floors, but many flat roofs have been covered with two or three courses of tiles, either

Fig. 36.

laid flat upon the girders, as shown in Fig. 36, or arched as Fig. 35 ; but by all means let them break joint. The tiles should be well wetted, and the finer the sand used with the cement for

60 BRrCKiAYINQ.

bedding them the better. This construction of floors, &c., although appearing very slight, will carry an immense weight, if the cement used is of good quality.

Scaffolding.

One of the principal things necessary to the carrying out of a building is the scaflolding, and great care ought to be taken in selecting the men that are to do it, for upon their care and foresight often depends the lives of the other men engaged on the work. Scaffold- ing in general use for brickwork consists of standards, ledgers, putlogs, and boards. The standards and ledgers are of fir, and of various lengths up to 50 feet, and are about 7 inches diameter at the butt end. Foreign poles are much better adapted for scaffolding than English, on account of their freedom from knots, and their being thinner according to the length. Putlogs are usually made of birch 4 inches square by 6 feet in length. Cords and wedges are used to fasten the standards, ledgers, and putlogs in their proper places. Standards are placed up- right about 5 feet from the wall and 10 feet apart throughout the length of the building.

The ledgers are tied up horizontally to the standards to support the putlogs; these are placed crossways with one end resting on the ledger, and the other in the wall, and upon these putlogs the boards are laid to complete the scaffold ; the latter are of diflerent lengths up to

I'AVING, TILING, USE OF MATERIALS, ETC. 61

14 or] 6 feet; in no case should scaffolding be used if it is rotten, or likely to break ; it some- limes happens that the butts are decayed a little and the other parts of the pole perfectly sound ; in this case it is best to cut off the bad part. The standards should be let into the ground about two feet, and the earth firmly rammed round them, to keep them upright ; and where the soil is soft, pieces of brick or stones should first be rammed in the bottom of the hole, to keep the pole from settling down when the scaffold is loaded ; for should the poles sink the putlogs will act as levers and overturn the wall.

When one length of poles is not sufficient, two are lashed together, top and butt, and diagonal braces are then fixed, to prevent the scaffold from moving in auy way.

Relieving Arches.

All openings in walls for doorways, windows, &c., where wood lintels are used as attachments for internal fittings, should be arched over with relieving arches throughout the whole thickness of the wall. And the springing of such arches ought always to be beyond the end of the lintel. If beams of any kind or joists are to be built into the walls, it is best to leave recesses for the timber, so that the brickwork is not built upon it, as it is liable to lead to settlements, and frequently the cause of the fronts of houses being bulged out just where the joist runs into the inside of the wall.

When iron girders enter brick walls to support

62 BRICKLAYING.

fireproof floors, iron bressummers (to support the other \^ork over shop fronts, &c.), York stone templates are bedded in the wall for the ends of the girders to rest upon, so as to distribute the weight over as large a bearing-area as possible.

Bakers' Ovens.

To construct a baker's oven to heat with coals : the size of the base having been arranged, it should be carried up to the height of the furnace door, and the ashpit left according to the width of the door and the length of the furnace-bars, allowing for the door being set 4^ inches from the face of the brickwork. Let the frame and door be about a foot square, like the fumace-door of a copper, and the bars about 20 inches long, and level with the bottom of the oven and of the door. Let the flue be about 16 inches square, for the fire to shoot into the oven from the shoulder where the furnace is straight across to the opposite angle of the OTen, and by the fire catching the crown in its course it will spread all round. Let a register be fixed in the flue, aud the copper five or six inches above the furnace, not so as to get too hot, for it is usually tcarm water only that is required in a bakehouse. A register should be fixed within a little of where the flue enters the oven, and rise slanting ; which, being stopped when the oven is hot enough, leads into the chimney flue. The general rise of the crown above the floor is from 18 to 20 inches. Sometimes the oven is con- structed without the copper. And perhaps it is

PAVING, TILING, USE OF MATERIALS, ETC. 63

the best plan ; for it is certain the two will act better apart than they do together ; but of course the latter is a little the cheapest as regards fuel.

But in building ovens, as well as many other things, the work is done according to the situa- tion and the owner's convenience. At all events, the side walls, from which the crown of the oven springs, ought not to be less than 2|^ bricks thick, and the crown sj)ringing from about 9 inches above the floor. The angles should all intersect, and all be laid with as close joint as possible.

When the oven is " domed," spread some sand on the top, so that when the work gets dry the sand may fill up any cracks.

Smoky Chimneys.

The causes of these are so various, that it is impossible to lay down any general rule as a cure. But perhaps the following remarks may be found useful : —

The evil is generally in the construction. The flues are often too large or too small, or otherwise the chimney-shaft is not carried up high enough to prevent the wind from blowing over the roofs adjoining, and so the smoke is prevented from rising. And again, it is not unfrequently we see pots placed upon the chimneys of a house all of a uniform size and shape. It matters not whether the flue leads from a draw- ing-room fire or a kitchen, while perhaps the latter produces nearly double the smoke of the former ; the result is, the kitchen chimnej

64 BRICKLAYING.

smokes, owing to tlie flue being cramped up at the top. Another cause of kitchen chimneys smoking, is when other flues are connected with them ; lor instance, when cooking apparatus is fixed in a kitchen, it is thought well to connect the flue with the flue from the kitchen-rano-e : and this is usually done about 2 or 3 feet above the fire- place. This may answer very well if the two are always in use at the same time. But, should the kitchen fire alone be required, it is very likely the cold air from the flue of the apparatus will enter straight into the kitchen-flue, just at the entrauce of the shaft, and prevent the smoke from rising.

The author has proved the whole of these evils, and therefore knows them to exist.

No chimney-flue of a dweUiug-house ought to be less than 9 inches by 14 ; and the kitchen flue ought to be 14 inches square throughout the entire length of the chimney.

The shaft ought to be carried up above the highest part of the roof; and if chimney-pots are used, they ought to be all of one height, and the area of the end of the pot equal the top of the fine. In building the flues, turn them first one way and then the other, so as to prevent the rain Irom falling down the chimney, and also to give it a sharper draught. But care must be taken that the flues have the same tt£K)m for the smok&

PAVING, TILING, USE OF MATERIALS. ETC. 65

To Proportio:n "Windows to Rooms.

To give the proper light, neither too much nor too little, multiply the length of the room by the breadth, and that product by the height, and out of this extract the square root, which root will be the space to give the proper light for the room, and may be divided into as many windows as the room will allow.

Suppose the room to be 22 feet long by 18 feet wide, the product will be 396, and multiplied by the height, 11 feet, the product will be 4,356, whose square root is 66, which will be the area of light space of the room, and may be divided iuto 3 windows of 22 feet each. This is thought to be the best rule for the purpose.

Materials, their Use, etc.

A rod of brickwork laid 4 courses to 11| inches requires 4,530 stock bricks.

A rod of brickwork laid 4 courses to the foot, 4,350 bricks.

N.B. — 420 stocks weigh about 1 ton, and 460 go to a cubic yard. Sometimes the number of bricks to a rod of brickwork will be 4,500 allow- ing for waste, and the amount of lime and sand to equal the above would be about 22 bushels of the former to 77 of the latter.

But, of course, this is beyond what it really takes for ordinary buildings ; but some require a great deal more cutting, and so a greater quantity

G6 BRICKLAYING.

of bricks are spoiled. For dwelling-houses, &c., 4,300 to a rod is sufficient.

If laid dr}', 5,370 bricks to tke rod.

And in wells and circular cesspools, 4,900.

Should there be any odd feet in the calculations for buildings in general, it is usual to reckon 16 bricks to the foot standard thickness.

A rod of brickwork, laid 4 courses to the foot, contains 235 cubic feet of bricks and 71 cubic feet of mortar, and weighs about 14| tons ; but, of course, this depends upon the bricks, whether they are wet or dry.

A rod of brickwork measures 16^ feet square, 1| bricks thick (which is called the reduced or standard thickness), or 272 feet 3 inches super- ficial; or 306 cubic feet, or II5 cubic yards. These are the measurements in general use. But sometimes 18 feet are allowed to the rod, that is, 324 square feet ; and also the rod of 21 feet long and 3 feet high, that is 63 square feet. In this case no regard is paid to the thickness of the wall in measuring. But the price is regulated accord- ing to the thickness.

Nevertheless, all calculations in this little work will be to the rod of 272 feet 3 inches.

A rod of brickwork requires 1^ cubic yards of chalk lime and 3 single loads of sand, or one cubic yard of grey lime and 3| loads of sand, or 24 bushels of Portland cement and 48 bushels of sharp sand.

A cubic yard of mortar requires 7 bushels of grey lime and 23 bushels of sand.

PAVING, TILING, USE OF MATERIALS, 1-TC. 67

Lime and sand and also cement and sand lose one-third of their bulk when made up into mortar ; therefore the proportion of mortar or cement when made up is to the lime and sand or cement and sand, as when dry, 2 to 3.

Lime or cement and sand to make mortar require as much water as equals one- third of their bulk.

A standard yard of brickwork laid 4 courses to the foot, requires f bushel of cement and I5 bushel of sand and 150 bricks.

One barrel of cement, containing 5 bushels, cask included, weighs about 3f hundreds.

A yard of 9-inch wall requires ^ bushel of cement, 1 bushel of sand, and 100 stock bricks.

4|-inch facing requires 7 bricks per superficial foot.

45-inch gauged-work requires 10 bricks per superficial foot.

Brick noggin g per yard superficial requires 30 bricks on edge, or 47 laid flat.

30 hods of mortar equal one load.

A measure of lime is 27 cubic feet, and contains 21 striked bushels.

27 cubic feet, or one cubic yard, is called a single load ; and two cubic yards a double load.

A hundred of lime is 25 bushels.

The weight of a bushel of well-burnt chalk lime is from 36 to 38 lbs. ; and grey stone lime from 46 to 59 lbs.

Paving with bricks or tiles requires 1 yard of

68

BRICKLAYING.

sand to every 12 yards, or if laid and grouted in with mortar, 1| bushels of lime and 4 bushels of sand to 12 yards.

Stock brick, flat paving, requires 36 per yard super.

„ ou edge		52	ji
Paving bricks, laid flat		36	n
„ on edge Dutch clinkers, laid iiat		82 70	» >9
„ on edge 12- inch paving tiles lO-iiich „ 6-inch „		140 9 13 36	1»
Tiling. Description. With pantiles . .	Gaupe in inches. . 12 .	Number required persqiuixe. . 150
99 • •	. 11		. 160
	. 10		. ISO
With plain tiles . »	. 4 . 3 . 3	\'-	. 600 . 700 . 800

N.B. — These figures are quite near enough as regards quan- tities ; but as a rule the tiles are tried before the roof is laihed, to find the correct gauge, as they are of various shapes and sizes.

A square of pan tiling requires 2 bundles of 5 ft. laths, and 1,000 of sixpenny nails, if small lathed.

A square of plain tiling requires about 1 bundle of oak laths, 5 score to the bundle, 5 feet long — if 4 feet long there is 6 score, and if 3 feet long, 8 score, to the bundle; 450 nails ; 3 hods of mortar, or lime and hair ; and, if the tiles are hung with pins, between half a peck and a peck will be required ; oak j^ins are those usually used.

All pantiling is executed by working from the eaves to the ridge each course, and from the right-hand end of the roof to the left. But plain tiles are hung in horizontal courses the whole length of the roof from right to left.

Flat plain tiling for floors, flat roofs, &c., if

PAVING, TILING, USE OF MATERIALS, ETC. 6P

two courses thick, 420 tiles, 3 bushels of Portland cement, and 6 bushels of sharp washed sand for a square superficial; and 210 tiles, 1| bushels of cement, and 3 bushels of sand for every extra course.

A measure, yard, or load, of lime, sand, or earth is 27 cubic feet or 21 striked bushels.

A chaldron is 41 cubic feet, and contains 32 bushels.

A labourer's hod measures 1 foot 4 inches by 9 inches by 9, and will hold 14 bricks, or three- quarters of a cubic foot of mortar or cement.

The following is a table of sizes and weights of various articles used by the bricklayer : —

Description.	Length.	Breadth.	Thick- ness.	Weight.
	ft.	in.	ft.	in.	ft.	in.	lbs. 0Z8.
Siock bricks, each . .	0	9	0	H	0	H	0 4
Paving „ „ . .	0	9	0	H	0	H	4 0
Dutch clinkers, each .	0	ll|	0	3	0	n	1 8
r2-in. paving tiles, each	0	0	111	0	H	13 0
10-in. „ „	0	H	0	H	0	H	9 0
9-in. „ ,,	0	H	0	H	0	H	7 5
Pantiles, each . . .	1	2|	0	H	0	Of	5 4
Plain tiles, each . . .	0	11	0	6i	0	H	2 5
Pantile laths per 10 ft. ^ bundle j	120	0	0	H	0	1	4 6
Ditto per 12 ft. bundle	144	0	0	H	0	1	0 0
(N.B. — A bundle con-
tains 12 laths.)
Plain tile laths per ) bundle |	500	0	0	1	0	H	0 12
(30 bundles 1 load.)

A square of pantiling requires 1 bundle of pantile laths 12 feet long, and 144 2- inch nails.

70 BRICKLAYING.

SECTION V.

SLATER AND TLASTEEER'S WORK.

Ix many parts of the country the slater's business, &c., is done by the bricklayer. And where such is the case, all materials for shelves, cisterns, baths, lavatories, &c., are worked by the stone mason ; for, as a rule, there is not suflBcient work in small towns to keep a slater exclusively for that busi- ness, and in many country towns and villages slates are not used for anything but the covering of roofs. As a general rule, all men in the build- ing trade understand what tools the slater uses, and also what they are used for ; therefore it is quite unnecessary to describe them.

It is best in all cases, if possible, that the quan- tity of slates required for the roof should be brought to the building before the slater begins to woi'k ; then he will see the whole of them, and sort them out accordingly : this is done by divid- ing the slates into three thicknesses, — these are thicks, middlings, and thins ; this is done so that the thickest slates should be at the bottom, the middling ones next, and the thinnest nearest the ridge ; it is also essential to the soundness as well as the appearance of slating. After this they are all dressed to one size, and the edges trimmed perfectlj'' straight, gauged, and the holes made.

The upper surface of a slate is called its back ; the under surface the bed; the top edge the head;

SLATER AND PLASTEREIl's WORIi.

71

and the bottom the tail ; that part of the slate which is exposed to view when hung, the " mar- gin " of the course ; and the width of the margin is the gauge ; the " lap " is that distance by which the tail of the third course overlaps the head of the first, as shown in Fig, 37. In some

Fig.37.

cases the slate Is fastened with the nails driven as near the head as possible ; but it will be found much better, both for the soundness and also appearance, if the nails for the second course are driven in just above the head of the first, because if the slate is fastened with the nails near the middle, it is evident the wind cannot have the leverage that it would if it were fastened at the head. The gauge of all kinds of slates used for covering roof will be equal to half the distance from the tail to the head, less the lap. For instance, suppose the lap to be 2 inches, and a countess slate 20 inches from tail to head, first deduct 2 inches, the lap, from 20 inches, the length, of the slate, this leaves 18 inches ; half 18 inches is therefore the gauge of a countess slate with a 2-inch lap.

72 BRICKLAYING.

After the slates are gauged, perhaps it would be best to lay one of them on the roof at the eaves, letting it project over for the drip, according to arrangement — this is generally about 3 inches ; and by so doing it will easily be seen where the first lath should be nailed on the rafters, and from the top of the first lath to the top of the second, and so on, is the gauge. The first lath at the eaves ought to be a little thicker than the others, 80 as to give the first course of slates its springing ; and the ends of the lath, at the gables, ought also to be raised up about three-eighths of an inch to throw the water off; if not, it will frequently soak between the cement fillets or under the lead flushing and so enter the roof.

All slating laths should be from two to three inches wide and five-eighths of an inch thick. The nails used should be either copper or zinc. Iron nails are sometimes used, but they are very liable to rust, and so after a short time become of no use. All slates ought to be fastened with two nails. Doubles and Ladies are sometimes fastened with only one, on account of their smallness, but it is inferior work.

The TVelsh slates are generally considered the best, and are of a light sky-blue colour. West- moreland slates are of a greenish hue. It fre- quently happens, when roofs are covered with these slates, that the slater has to deal with those of various sizes, and of course this requires more skill, for he not only has to arrange them so that they shall break joint one with another, but the

SLATER AND PLASTERETl S WORK.

73

latliiDg must also be gauged accordingly. In this case the largest and thickest slates are hung at the bottom, and the smallest and thinnest at the top, nearest the ridge ; and a great deal of care must be taken in trimming and sorting them.

The gauge is taken in the same way as other kinds of slating, that is, according to the length.

The following is a table of sizes and gauges of roofing slates : —

	Size.	Gauge	Weight	Number per Squaie.
Names.		m Inclies.	per Squaie.
Len^h.	Breadth	Slates.	Nails.
	ft. in.	ft. in.		lbs.
Doubles . .	1 1	0 6	5h	672	480	9G0
Ladies . . .	1 4	0 8	7	886	300	600
Countesses	1 8	0 10	8^	6o7	180	300
Duchesses, .	2 0	1 0	Wh	712	130	2G0
EagSjQunens "i
and West- |
morelands, 1-	A square of these we	ighs abo	ut half a ton.
of various 1 sizes . . J

Thr methods of hanging slates vary according to the different situations and also the slates that are used. But in all plain work it is best, if pos- sible, to strain a line for the eaves* course, and so fix the slates to it ; also, to run each course hori- zontally throughout the length of the roof. This is done by gauging the margin of the course at each end upon the first course, and straining a chalked line from end to end, so making a mark

E

74 BRICKLAYING,

for a guide to get the second course perfectly straight and parallel with the first.

^yhen the roof is slated as high up as it is pos- sible to reach from the eavt-.s, a scafibld is erected. This is sometimes done with a scaffold-pole, or a piece of quartering being hung from the ridge- tree with scaffold-cords. But it is much better to make it with hano'ing trestles in the form of an equal-sided triangle, with an iron hook at the top, so as to fasten it to the ridge with cords ; after which scaffold-boards are laid upon them. This will be a much more convenient scaffold than the previous one, and is easily raised or lowered as required. For all hips and valleys it is usual to fix the trimming-block to one of the rafters or somewhere convenient, so that each slate can be cut according to the shape required with- out the necessity of going off the roof.

It is sometimes thought best to point slating inside with lime and hair ; but, certainly, if the slating is properly executed, this is unnecessary ; and if it is to keep out the little wind that would otherwise pass between them one would think they would be belter without it, for we all know how very hot buildings that are slated usually are, particularly in summer time.

Plasterer.

The business of the plasterer chiefly consists in covering walls, ceilings, brick or wood partitions, floors, &c., with cements, limes, and plaster, in order to bring them to a uniform surface to re-

SLATER AND PLASTERERS WORK. iO

ceive the painting, paper-hanging, or distemper- ing. This part is usually done by the bricklayer in small towns and villages, but in London it forms a separate trade. But the decorative por- tions of the finishing of buildings, such as run- ning cornices, mouldings, making and fixing centre flowers, &c., is almost exclusively done by the plasterer. All internal plastering, as a rule, is done with chalk lime, hair, plaster of Paris, and Keen's and Martin's cements. The following are the different methods of mixing them : —

Li))ie and Hair, or Coarse Stuff. — For this pur- pose the sand should be clean, sharp, and screened. Then form a pan to receive the lime. This is slacked in a tub, and sufiicient water is afterwards added to bring it to the consistence of cream, and is then run through a fine oieve into the pan formed with the sand. After a sufficient quantity is run out to carry the sand, the hair is thrown into the lime, and thoroughly raked about with a two-pronged rake, so as to part the hair and mix it well with the mortar ; but it would be better to run the lime into putty, as for fine stuff, and when cold mix the hair with it ; this will not be so apt to rot the hair, and so add to the stability of the work

For this purpose bullocks' hair is generally used, and this should be well beaten with small laths, or else laid in water a day or two before it is mixed with the lime. The whole is then mixed, and allowed to lie for a short time.

Fine Stuff', or Putty, is made of pure lime, and

76 BRICKLAYING.

is mixed in the same way as lime used for coarse stuff; but instead of running it into a pan of sand, this is run into a " putty bin," built with bricks according to the size required, and allowed to remain there until the evaporation of the water has brought it to a proper thickness for use : if the water rise to the top, it can be drawn off if required, and the putty will get dry the sooner.

For lime stucco the sand is mixed with the putty according to the quantity required. This stucco, when left for painting, is left smooth from the trowel. AVhen plaster of Paris is to be used for the purpose of setting either coarse or fine stuff, the mortar or putty is made into a little pan in the banker. The water is poured in, and afterwards the plaster, so that the latter is well soaked before it is rais:"! with the mortar. This is called gauged stuff, and is used for running cornices, mouldings, and in fact all kinds of work which ought to be finished by one operation.

The various cements and other compositions made use of by the plasterer are very numerous ; but those principally used for inside decorations, are Keen's, Martin's, and Parian cements ; these are well adapted for plastering where hardness and beautiful finish are required ; Keen's cement is used for skirtings, dados, angle beads, &c., because of its extreme hardness.

Portland, Roman, and lias cements are those generally in use for all external plastering ; and as regards quality and cheapness, Portland ia decidedly the best.

SLATER AXD PLASTERERS "WORK. it

All enrichments, such as flowers or fruit cornices, centre flowers, &c., are first moulded in clay and afterwards cast in plaster of Paris, or made oi papier-mache.

The Operations of Plastering. — Almost the first thing the plasterer does is the lathing, so he can get all the woodwork rendered first, as this takes longer to dry than the brickwork. And for this purpose he uses single, one and a half, and double laths. These names denote the different thicknesses. The laths are generally of fir. Care ought to be taken that the thickest laths are used for the ceilings, on account of there being a greater strain when in an horizontal position than when upright. The first coat of plastering of coarse stufi" upon the laths of ceilings is called pricking tip, and is used very stifi", to prevent its dropping ofi" again.

But the first coat on walls is the rendering; the second the screeding, or floating, from its being brought to a level surface with the screeding rule and hand-float ; and the third or last is called the setting ov fining ojf.

The first coat is laid on rough, and afterwards scratched with a piece of lath, to form a key for the second coat. The operation of floating walls is perform* d by fixing upright stripes of plastering about 6 or 8 inches wide, and about 6 feet apart, if only one man is to work upon them ; these form the screeds : and the method of obtaining them is by setting small pieces of plaster at each angle of the wall that is to be plastered. These

78 BRICKLAYING.

are called " dots," and the dot nearest the ceiling should be plumb with that nearest the floor ; after this a line is drawn along the ceiling from one to the other, and the intermediate ones fixed to it. Then repeat the operation with those dots nearest the floor ; these ought to be gauged with a little plaster of Paris, so as to make them set quicker ; the screeds maj^ then be filled up, and floated level with these dots. The bays formed by the screeds may then be plastered with coarse stuS!, and floated perfectly level with the floating rule. The second coating of ceilings is performed in the same way, only one is upright and the other is level.

In two-coat work the rendering and screeding are performed at one time upon brickwork. After the work has been brought to a level surface with the floating-rule, should there be any deficiencies caused by stones or knots of hair, they are made good with the hand-float.

Sometimes it is thought best to either sweep the floated work, or else put a nail through the float, so as to project a little on the face of it, and then rub it over the work, and so give it a key for the fine stufl". The floating should be allowed to get hard, but not too dry, before the fine stuff is laid on ; at all events, unless the wall is in a damp situation, it ought to be sprinkled with water from the stock-brush. Fine stuff is some- times laid on with the lajang-on trowel, and sometimes with the hand- float, at all events the latter is used to bring: the fine stuff to a rejrular

SLATER AND PLASTETIEr's W(>RK. 79

surface before it is trowelled off. This is done by well rubbing it, either with the laying-on oi gauging trowel, alternately wetting it with thfe stock-brush until a fine and smooth surface is obtained. Stucco, which is left smooth on the face, and gauge stuff, are treated in the same way.

All work left from the trowel ought to be watched for a day or two, and if any small cracks are seen, they ought to be well wetted and trowelled over ; but these are seldom seen in stucco work, the sand preventing this to a great extent.

Rough Stucco is sometimes used for halls, stair- cases, passages, &c. ; this is left from the float, und sometimes a little extra sand is put with the finishing coat ; but in other respects it is executed in the same way as smooth stucco.

Laid Work. — This is simply a coat of coarse stuff laid upon brickwork, or lathing, to receive limewhiting or colouring, and is often done in cellars, outhouses, &c., where a better kind of plastering is thought unnecessary. If cellar ceilings are covered with this rough plastering, it prevents the wind from passing through the. floor-boards to the rooms above, which is often very uncomfortable. But of late years it has become the practice to mnke the floors fireproof as well as airproof ; and this is sometimes done by "pugging," that is, lining the spaces between the floor-joist with concrete two or three inches thick ; and to receive this, fillets are nailed on each side of the joists, and a rough boarding iq laid upon them.

80 BRICKLAYING.

Portland cement is used by the plasterer to a great extent for making floors, and there is little doubt of its answering that purpose if it is laid sufficiently thick, and the materials are gauged in a proper manner. For this purpose (as well as all others) the cement ought to be gauged with sharp sand, free from clay, in equal quantities, both for the first coat and also for the second j for if the first coat is gauged with a greater quantity of sand than the second, they will not bind together ; besides pure cement swells more in setting than cement and sand does when mixed up together ; therefore if the finishing coat is made finer than the first, it will be very liable to blister, and so destroy the floor. The sand for the last coat ought to be well washed, and the two coats need not exceed an inch in thickness. In many parts of England, where there are plaster mills in the vicinity, it is usual to lay floors of that material. But this plaster is of a much rougher kind than that which is generally used ; in fact it is a sort of dross from the mills. These floors arc laid about 2 inches or 25 inches in thickness, and finished at one operation. A plaster floor of "Welsh lime is thought to be equally as good as grey plaster, and can be done for one-third less.

In some of the eastern counties the fronts of houses are plastei'cd with a rough stucco, and while it is damp well dashed with small stones ; this answers very well for renewing old fronts, where they have previously been plastered, for by

SLATER AND PLASTERER's WORK. 81

pulling off the old mortar, and replastering and dashing it, the front will be well repaired and still retain its original appearance.

Plastering may be summed up as follows : — The commonest kind of work consists of only one coat, this is called rendering on. brickwork, and laying, if on laths ; when a second coat is added , it becomes two-coat woi'k, as render set, or lath hy and set ; and when the work is floated, it is three- coat work, and is laf/i lay float and set for ceilings and partitions, and render float and set for brick- work.

The following remarks may be found useful : —

100 yards of lathing require 20 bundles of laths and 7,600 nails.

' 100 yards of rendering, or laying, 20 bushels of chalk lime, 40 bushels of sand, and 3 bushels of hair,

100 yards of floating requires about half as much as rendering.

And setting requires 10 bushels of lime, 2 bushels of white hair and a little sand if required.

Bender set requires per 100 yards, 30 bushels of lime, 42 bushels of sand, and 5 bushels of hair.

Render float and set, 40 bushels of lime, G2 bushels of sand, and 7 bushels of hair, to 100 yards.

A bushel and a half of Portland cement will plaster two yards superficial three-quarters of an inch thick.

e3

82 rrickjatixg-

Artificial Stoxe.

The following may be found very useful, both on account of its cheapness, simplicity, and durability : —

Take 7 parts of coke dust, screened through a quarter bar screen, to 1 part of Portland cement, for all kinds of ornamental purposes, such as small columns, capitals, balustrades, mouldings for cornices, chimney-pieces, &c. But for pavement, steps, window-sills, hearth-stones, or any rougher kind of work, o parts of coke dust, and 3 parts of any hard substance, such as burnt earth, broken brick, &c. ; but these also should be screened before they are mixed with the cement. Moulds are then made of wood, or in some cases iron, to the shape required, care being taken that they are a little smaller at the bottom than they are at the top, so that the moulded work shall turn out of the mould freely when set ; the moulds should be well greased first, and a little pure cement mixed up very thin thrown into them ; the cement and coke dust, or cement, coke dust, and broken bricks, are then mixed with water to form a sort of con- crete, and gently put into the moulds ; if this is done properly the soft, pure cement will flow all round the inside of the mould, and so give a facing to the coarser stuflf; the top is finished ofi" level with the mould with the trowel. This work should be left until it is perfectly hard, which will take two or three days. There is one fault attached to this composition, that ie, when it is used for

SLATER AND PLASTER EIl's WORK. 83

steps, stair-cases, or pavement, it is liable to get very smooth and slippery ; but in otber respects it answers very well.

Distempering of Ceilings, Walis, Etc.

For this purpose the work should be well washed with clean water and scraped with the trowel, so as to thoroughly clean off all old whitening. Of course, if the walls and ceilings are new they do not require this. After they are dry they should be clear-cokd, that is, sized over with clear size, taking care in melting the size that it does not boil, but only heated sufficient to melt it. If glue is used instead of size, put 1| pints of water to each pound of glue. When this is done, the work is ready to receive the whitewash. To mix this, break the whitening into a vessel containing suffi- cient water to cover it, and let it soak well, and if any water remains on the top, pour it off, and mix the size with the whitening, which will be about 4 lbs. to the ball, more or less as required ; and strain a little blue-black or ultramarine blue into the vessel containing them, and w^ell mix the whole together. This mixing is usually done the day before the whitening is required for use; then the size will get set, and by stirring well before using it, the whole will work up into a jelly. Should there be any water stains in the ceilings, they should be well washed with strong soft soap and water, and if this fail, paint them previous to white-washing the ceiling. All work ou^ht to receive two coats.

84 BRICKLAYING.

SECTION YI.

PRACTICAL GEOMETRY AND MENSURATION.

The problems here given are those only which it is absolutely necessary for the bricklayer to understand before he can be considered a pro- ficient tradesinan.

1. A solid is a figure, or a body having three dimensions, viz., length, breadth, and thickness. The boundaries of a solid are surfices or super- ficies.

2. A superficies, or surfice, has length and breadth only ; the boundaries of a surfice are lines.

3. A line is length without breadth, and is formed by the motion of a point. The extremities of a line are points.

5. A point is that which has no parts or magnitude; it is indivisible; it has no length, breadth, nor thickness.

6. When a straight lino, b d, standing on another, a C, makes the angle i) b a equal to the angle d b c, each of these angles is called a right angle ; the measure of the angle d b a is 90 degrees,

or the fourth part of 3G0 degrees.

7. An acute angle is less than a right angle, as

D B O.

PRACTICAL GEOMETRY AND MENSURATION. 85

8. An obtiis. angle is greater than aright angle, as c B o.

9. A plane triangle is the space in- closed by three straight lines, and has three angles, as b.

10. A right-angled triangle is that which has one of its angles right as A B c ; the side a c opposite the right angle is called the hypo- thenuse, the side b c the perpen- dicular, and b a the base.

11. An obtuse-angled triangle has one of its angles obtuse, as the tri- angle c.

12. An acute-angled triangle has all its three angles acute, as shown in figure b.

13. An equilateral triangle has all its sides and angles equal as u.

14. An isosceles triangle is that which has two of its sides equal, as e.

15. A scaline triangle is that which has all its sides unequal, as r.

16. A square is a four-sided figure having all its sides equal and all its anj^les riffht.

17. An oblong, or rectangle, is a right angled parallelogram, whose length exceeds its breadth, as g.

18. A rhombus is a parallelogram having all its sides equal, but its angles are not right angles, as h.

86

BRTC-KLAYING.

/"

z

r 19. A rhomboid is a parallelo-

\ / \ grain having its opposite sides

\ A equal, but its angles are not

right-angles, and its length ex- ceeds its breadth, as I.

20. A trapezium is a figure in- cluded by four straight lines, no two of which are parallel to each other, asK. Aline connecting any two of its opposite angles is called a diagonal.

21. A trapezoid is a four- sided figure having two of its opposite sides parallel, as m. 22. Polygons are those which have more than four sides. Thej^ receive particular names from the number of their sides ; thus a pentagon has five sides, a hexagon has six sides, a heptagon seven, an octagon eight, a nonagon nine, a decagon ten, an undecagon eleven, and a dodecagon has twelve sides.

If all the sides of each figure are equal, it is called a regular polygon ; but if unequal, an irregular polygon.

23. A circle is a plane figure contained by one line, called its circumference, which is every- where equally distant from a point within it called its centre, as o ; and an arc of a circle is any part of its circumference, as a b. 24. The diameter of a circle is a stiaight line

PRACTICAL GEOMETRY AND MENSURATION. 87

passing through the centre and terminated both

ways by the circumference ; thus

A B is the diameter of the circle ;

the diameter divides the circle

into two equal parts, each of

which is called a semicircle :

the diameter also divides the

circumference into two equal

parts each containing 180 degrees.

Any line drawn from the centre perpendicular to A B, it divides the semicircle into two equal parts, AGS and bos, each of which is called a quadrant, or one-fourth of a circle ; and the arcs A s and B s contain each 90 degrees ; and they are said to be the measure of the angles a g s and

BOS.

25. A chord of an arc is a straight line joining its extremities, and is less than the diameter ; c b is the chord of the arc c d b, or of the arc c a s b.

26. A segment of a circle is that part of the circle contained between the chord and the cir- cumference, and may be greater or less than a semicircle.

^

Problem I.

From a given point, p, in a straight line, a b, to erect a perpendicular.

1. On each side of the point, __,

p, take equal portions, P x, p/;

and from the centres, x/, with any radius greater

88

BRICKLAYING.

than p X, describe two arcs, cutting each other at D ; then the line joining d p will be perpen- dicular to A B.

When the point, P, is at the end of the line.

2. From any centre, c, out of the line, and with the distance, c b, as radius, de- scribe a circle, cutting a b in D, draw d c o, and the line joining the points o b will be perpendicular to a b.

Or thus :

Set one leg of the com- passes on B, and with any extent, b p, describe an arc, p X ; set off the same extent from T to q ; join p q ; from q as centre with the extent, p q, as radius describe an arc r, and the line joining r b will be perpendicular to a b.

Problem II.

Upon a given right line to describe an equilateral trianqle.

liCt A B be the given right line. From the centres a and b, with the given line a b as radius, describe two arcs cutting each other at c ; then the line drawn from the point c to the points

PRACTICAL GEOMETRY AND MENSURATION. 89

A and B will form with the Hue A b the triangle required.

Problem III.

To describe a triangle, hnmng the length of the three sides given.

Let A B, c D, e F, be the given lines, of which A B is the base line. From B as centre with c D as radius describe an arc, and from a as centre with e F as radius de- scribe another arc, cut- c 1

ting the first at o ; join ^ ''

A G, G B : this will give the triangle required.

Problem IV.

To find the centre of a given circle.

Draw any two chords A b, B c, and divide each into two equal parts, as shown at e and D ; draw the lines e o and o d at right angles to a b and b c, and where these lines intersect at o will be the centre of the given circle a b c.

Problem V.

I'o describe a regular pentagon upon a given line.

Let A B be the given line. With b as centre

and B A as radius describe the semicircle a c d;

then with a as centre, with same radius, describe

90

BRICKT.AYING.

an arc cutting the semicircle in c ; bisect a b at e, join c E, bisect the arc c b in f, join e f; then

with D as centre, E f for radius, cut the semicircle in G, and with o as centre, with same radius, cut the semicircle in h; draw the line h b and bisect it at i, and at this j)oint erect a perpendicular cutting the line E c in X ; this will be the centre of the circum- scribing circle.

Problem VI.

To describe a regular hexagon upon a given line.

Let A B be the given line. "VTith a as centre and A B as radius describe an arc, and with b as centre with same radius describe a second arc, cut- ting the first in c ; this point of intersection is the centre of the circumscribing circle.

TABLE OF POLYGONS.

No. of Sides.	^xme of Polygon.	Multiplier or Divisor.
5 6 7 8 9 10 11 12	Pentagon Hexagon Heptagon Octagon Nonagon Decagon TJndecagon Dodecagon	1 — 7 decimals ] 2 — 0 or radius 2—3 2—62 2—9 3—247 3 — 00 3—84

PRACTICAL GEOMETRY AND MEXSURATIOX.

91

The preceding Table may be found useful in describing regular polygons of any number of sides, from five to twelve inclusive.

Description of the above Tahle.

In the left-hand column will be found the number of sides of any polygon having from five to twelve sides. In the second column will be found the name of the polygon corresponding with the number in the first column. And the third column contains those figures by which the length of the side must be multiplied for the diameter of the circumscribing circle; or by which the length of the diameter of a given circle must be divided to give the length of the side of each polygon in a line with it in the opposite column.

Examples.

"What is the length of each side of a regular pentagon, the diameter of the circumscribing circle being 4 feet ?

Divisor . . 1-7) 4-0 (2-35 Ausm-pt, in feet nnd 3 4 decimal parts.

•6-0

5 1

90

•5 Rem.

Or thus : — 'What is the diameter of the circumscribing

92 BRICKIAYIXG.

circle of a nonagon, each side being 2 feet in length ?

2 feet length of side. 2-9 multiplier.

18

4

5-8 Answer.

Therefore the diameter of the circle is 5 feet and 8-lOths of a foot, -svhich is equal to 5 feet 9 inches and 5-8ths of an inch.

Problem YII.

To describe an ellipsis, having the longest diameter given.

Let A B be the given diameter. Erect the per- pendicular c D, and divide a b into four equal

parts at 1, 2, 3 ; then with 1 2 3 as centres, with radius 1 2, describe the three circles as shown ; then from f as centre with f e as radius describe the arc c, and with n as centre with same radius

PRACTICAL GEOMETRY AND MENSURATION. 93

describe the arc d. This will complete the ellipsis.

Another method of describing an ellipse.

Let A B, 0 D, be the given diameters drawn at right angles with each other. Then with c as

centre with a o as radius describe an arc cutting A B at e and/; then take a j)iece of string or very ■tine wire the length of a b, fix one end at e and the other at/; then draw the ellipse by running the pencil along the string, taking care the string is kept tight with the pencil.

Problem VIII.

To describe a circle about any triangle.

Bisect any two sides as shown at a and b, and draw perpendicular lines intersecting at c. This point of intersection is the centre from which the circle is drawn.

94

BRICKLAYIKG.

Problem IX.

To inscribe a circle within a triangle.

From A as centre with any radius describe an arc B c ; bisect it, and through the point of bi- section draw the line a o; bisect the angle deb, and draw the line o e. ^here the lines a o and 0 E intersect is the centre of the circl

Problem X. In a given circle to inscribe a square.

Draw any two diameters, a b, C D, at right angles to each other, then join their extremi- ties, and the figure thus formed will be a square inscribed in a given circle. And if a line be drawn from the centre o, bisect- ing A D, and produced to f, f d will be the length of one side of an octagon inscribed in the circle.

Problem XI.

In a gif^en circle, to inscribe any regular polygon ; or, to dicide the circumference of a given circle into any number of equal part^.

Divide the diameter a b into as many equal parts as the figure has sides; erect the perpen-

PRACTICAL GEOMETliY AND MENSURATION. 95

dicular o s from the centre o ; divide the ra- dius of into four equal parts, and set off three of these parts from /to s ; draw a line from s to the second division h of the diameter A B, and produce it to cut the circumference at c ; join A c, and it will be the side of the polygon required.

Problem XII.

To draw a straight line equal to any given arc of a circle.

Let A c B be the given arc of a circle ; divide the chord a b into four equal parts, and set off one of these parts from b to c ; join d c, and it will be the length of half the given arc, suffi- ciently near enough for practice.

Problem XIII.

To make a square equal in area to a gicen circle.

Divide the diameter a b into fourteen equal parts, and set off eleven of them from a to c ; from c erect the perpendicular c D and join a d, the square of which will be very nearly equal to the area of the given circle of which a D K is the half.

96 BRICKLAYING.

The foregoing geometrical problems arc those generally used by the bricklayer ; but for those who are anxious to proceed farther, there are many excellent manuals of instruction.

A FEW REilAravS (.»X ilENSURATION OF BKICKLAYERS' WORK. The area of any plane figure is the space con- tained within its boundaries, and is estimated bj' the number of square miles, yards, feet, inches, and parts which it contains. This squaring is generally estimated by the following rules of arithmetic, viz. : duodecimals, or cross multiplica- tion, decimals, and practice.

DUODECTMALS.

Rule 1. "Write the multiplier under the multi- plicand in such a manner that feet shall be under feet, inches under inches, and parts under parts.

2. Multiply each term of the multiplicand (beginning at the lowest) by the number of feet in the multiplier, and write each result under its respective term, taking care to carry one for every 12 from each lower denomination to its next superior, and sot down the remainder under the term last multiplied.

3. Next multiply the terms of the multiplicand by the number under the denomination of inches in the multiplier ; carry 1 for every 12, as before. But set down each remainder one place further to the right than as if multiplied by a number under the deromination of feet.

PR.\CTICAL GEOMETRY AND MENSURATION. 97

4. Proceed in the same manner with the second in the multiplier, setting each result one more place further to the right hand, and so on with thirds, fourths, &c.

5. Add the partial products thus obtained up, and their sum will be the product.

E.ramplcs. 1. Multiply 4 feet 7 inches by 3 feet 10 inches

	37 ft. 7 9 7 57 75	ft. in. 4 7 3 10
	13 9 3 9-10
	17 6-10
2. Multiply 5 parts.	feet 9 inches 3 parts by 7 feet 6 ft. in. ptg. 37 9 3 7 6 5	inches an(3
	264 4 9 18 10 7-6 1 3 8 • 0 • 3
	284 7 1 • 4-3
3. Multij.ly 4. Multiply 6. Multiply 6. Multiply 7. Multiply	in. ft. in. ft. 6 X 6 9 An.swer 43 8X76 „ 72 5 • 9 X 3 5 • 3 „ 25 9 X 9 5 .,643 9 X 17 7 „ 13^1	in. pte, 1 6 6 8 6 • 2 • 3 9 9 9 3

Decimal Fractions. In decimal fractions the intesrer or whole thing, as one yard, one foot, &c., is supposed to be divided into ten equal parts, and these parts into tenths, and so on without end.

F

98 BRICKLAYING.

These parts are distinguished from the wholo numbers by a point prefixed : thus — 0, which stands for 5-10th8, or half a whole number ; '26, which stands for 25-lOOths, or one-quarter of a whole number ; or '75, which stands for 75-lOOths, or three-quarters of a whole number.

"Whole numbers increase in ten-fold proportion to the left hand ; decimal parts decrease in ten- fold proportion to the right hand ; so that ciphers placed before decimal parts decrease their value by removing them further from the point ; or units placed thus — -5, is 5-lOths ; -05, is 5-lOOths ; and -005, is 5-lOOOths. But ciphers after decimal parts do not alter their value ; for '5, "50, •500 are each but 5-lOths, or half a whole number.

Huk. — In addition of decimals great care must be taken in setting down the figures to be added up, so that each figure shall come under another of the same value, whether this be a mixed number or pure decimal parts. And, iu order to do this, there must be a due regard had to the separating points, which ought always to stand in a direct line one with another; and, to the right hand of these, carefully place the decimal parts according to their respective values, and add them as in whole numbers.

To add 5 ft. 9 in., 7 ft. 6 in., 3 ft. 3 in., and 7 ft. 10 in. together.

PUACTICAI. GEOMETRY A>iD MENSURATION. 99

„. Decimal ^^- parts.

6-75 Equal 5 ft. 9 in.

7-6 „ 7 ft. 6 in.

8-25 ,. 3 ft. 3 in.

7-835 ,. 7 ft. 10 in.

24-335 Ans-wer, equal 24 ft. 4 in.

Subtraction of Decimals.

This differs but very little from whole numbers, only in placing the numbers, which must be carefully observed, as in addition.

Examples.

Subtract 2 395 from 7-62, and 5 ft. 9 in. from 27 ft. 3 in.

7-620 27-25

2-395 6-75

o"22o Answer. 21-50 = 21 ft. 6 in.

1. From -769 take -543 Answer -220

2. From 1-743 take -339 Answer 1-404

3. From 3-975 take 1-243 Answer 2-732

4. From 407-2 take 40-362 Answer 357-838

MriTlPLTCATlON OF DECIMALS.

Eule. — Place the decimal parts, and multiply them as in whole numbers ; and from the product cut off as many figures towards the right hand as there are figures representing decimal parts, both in the multiplier and multiplicand together; but should there not be so many places in the product, f2'

100 BRICKLAYING.

make up the defect by adding ciphers towards the left hand.

ETampks.

Srultiplf 3-795 Multiply 5 ft. 6 in. X 8 ft. 10 in.

By 2-43 0 5

8-S35

113S5

15180 275

7590 165

440

9-221 So 440

48-5925 . = 48 ft. '\ in.

Multiply 3074 X 25-93 Answer 79-70882 JIultiply 25-15 X 72-04 Answer 1S11-S060 Multiply -07 X 1"02 Answer -0714

Division of Decimals.

This is worked in the same way as whole numbers, the only difficulty is in valuing the quotient.

Biih 1. — The first figure in the quotient is always of the same value with that figure of the dividend which answers or stands over the place of units in the divisor.

Ruk 2. — The quotient should always have as many decimals as the dividend has more than the divisor.

Notf 1. — If the divisor and dividend have both the same number of decimal parts, the quotient will be a whole number.

Note 2. — If the dividend has not so mir.y places of decimnls as there are in the divisor,

niACriCAL GEOMETRY AXD MEXSURATIOX. 101

then so many ciphers must be added to the dividend as will make them equal, and the quo- tient will then be a whole number.

Kote 3. — And if, when the sum is done, the quotient has not so many figures as it should have places of decimals, then so many ciphers must be added as there are places wanting.

Brickwork is estimated at the rate of a brick and a half thick ; this is called the standard thick- ness, so that if a wall is either more or less than this thickness it must be reduced to it ; thus : — Multiply the superficial contents of the wall by the number of half-bricks in thickness, and divide the product by 3.

"When a piece of brickwork is to be measured, the first thing to be done is to ascertain what measures are to be employed : then, having mul- tiplied the length and breadth together, if the dimensions are feet, the product is divided by the divisor agreed upon, this is generally 272^ feet to the rod standard thickness, and the quotient will be the number of rods and feet contained within the dimensions taken.

In measuring work by the rod of 272^ feet, it is very seldom the odd quarter is used, owing to its taking more labour in figuring for a mere trifle.

Examples.

IIow many rods of brickwork (standard thick- ness) are there in a wall 34 feet 6 inches long by 23 feet 9 inches high, at 1| bricks thick ?

102

		BKICKLAYINO
		DCOUECIMAIS.
ft.	in.
34	6
23	9
102	0
68	0
11	6
25	10 ■	6

272) 819 4-6 (3 rds. 3 ft. 4} in. Answer. 816

Decimaia-

ft.

34 • 5 23 • 75

1725 2415 1"35

600

272) 819 • 375 (3 • 0124* rds. Anawei. 816

337 272

655 544

1110

1088

22

If the area of a wall be 3,700 feet, and the thickness 2} bricks, how many rods and feet does it contain ?

* lliis decimal fraction equals 3 ft. 4^ io.

PRACTICAL GEOMETRY AND MENSURATION. 103

Example.

3700 feet the area, by 5 half-bricks thick.

Standard divisor 3) 18500

272) 6166 (22 rds. 544

726 544

182 feet.

Chimney Shafts.

In measuring chimney breasts, when standing against any party wall, it is usual to take the width of the middle for the breadth, and the height of the story for the length : the thickness should be the same as the depth of the jambs ; and if the chimney is carried up square to the ceiling no deductions are made for the fire-place on account of the extra labour in gathering the with walls over to prepare for the hearth in the room above.

The chimney-shaft, or that portion which is above the roof, is measured by multiplying the height, width, and depth together. But in cases where t here is a greater amount of labour than usual, the quality of the work is taken into consideration, and the price allowed according to its class.

Chimney Shafts in the Form of a Circle. — In order to measure these it is necessary to obtain the diameter of the shaft midway between the base

104 BRICKLAYING.

and the top as they are usually battering. Square this diameter, and multiply the product by the decimal •7854* ; this will give the area of the circle, after cutting off the four fingers from the right hand ; and this area multiplied by the height will give the contents in cubic feet.

Example,

AVhat is the cubic contents of a shaft the mean

diameter of which is 4 feet and the height GO feet ?

4 diameter.

4

16 • 7854	square of diameter, decimal fraclioo.
64 80 128 112
12 • 5664 CO	area of circle. height.
753 • 0840	cubic contenta.

The diameter of a circle is to its circumference as 7 is to 22 ; therefore, if the diameter is not to be obtained by any other means, take the girth or circumference of the shaft, and as 22 is to 7, so is the circumference to the diameter.

Example. Let the girth of a circular shaft be 10 feet, then, \)y proportion, the diameter will be obtained in the following manner : —

• This decimal fraction equals the area of any circle whose diameter id 1, i.e. if the liiameter of the circle u I foot, thid fraction of a foot i^ the area.

rUACTICAL GEOMETRY AND MENSURATION. 105

ft. ft. 22 : 7 : : 10	ft. 10
22) 70 (3 66	• 18 Answer in	feet and part3.
40 22
180 176	Eemainder.
4

When the shaft is in the form of a regular polygon, the following table may be found useful i'or the purpose of ascertaining its area in feet or inches : —

Rule. — Square the length of the side of the polygon, and multiply the product by those figures in a line with the figure in the first column denoting the number of sides of the given polygon ; the product thus obtained will be the area. And this multiplied by the height of the chimney will give the cubic contents. And to bring this into rods, divide by 306 feet.

Number of Sides.	Multiplier.
3 5 6 7 8 9 10 11 12	■433 1-72 2- .98 3-634 4-828 6182 7-694 9 3G6 11-190

V '\

106

IJRICKI.AYIXG.

Vaulting. — In measuring circular, elliptical, or Gothic vaulting, the rule is to find the super- ficial contents of one end, and multiply it by the length of the vault ; or, take a piece of string or the tape, and ply it close to the soflBt from one side of the vavdt to the other, and this length by the length of the vault will give the superficial contents of soffit ; then multiply by the thickness for standard or cubic contents. But if this method is employed, the outside surface ought to be taken as well as the soffit. Add the two areas together, and divide by 2 for the exact superficial contents, and then multiply by the thickness for standard or cubic contents, as before explained.

Groim are generally measured by taking the length and breadth of the base and multiplying ihem together, and that product by the height. But sometimes one-tenth is deducted from the solidity thus found, and the remainder is reck- oned as the solid contents.

But if measuring for labour only, the groin- points are measured by running measures, the price being so much per foot.

Bakers' Orens. — It is usual in measuring these to cube the whole and divide by 306 to bring it to rods.

A T\Bi.E OF Brickwork,

Showing how many rods, feet, and inches are contained in any number of superficial feet, from 1 foot to 10,000 feet, and so on as far as required ;

PR-^CrnCAL GEOMETRY AND MENSURATION. 107

and from half a brick to two bricks, and, by addition, to any thickness.

This table also shows how many bricks are required to build a piece of brickwork, from 1 foot to 10,000 feet, from half a brick to two bricks, and this also, by addition only, to any thickness or number of feet required, at the rate of 16544 bricks to the foot standard thickness, or 4500 to the rod.

Explanation of the following Table.

At the head of this table, over each separate column, is stated the thickness of any wall from half a brick to two bricks, and beneath each of these is a double column, one for giving the rods, teet, and inches, contained in the wall, and the other the number of bricks contained in these rods, feet, and inches, standard measurement; and in the first column towards the left hand will be found the number of feet the wall contains by superficial measurement.

108

r.llICKIATTXG.

	.
	c
	^•3	<Mi»>«=ocoe^-«»>««o —	■fl-wXc^J-<j>©ao
ii	W'vwac^iMtci^csi^-*	«oaccccici-c; —
O	ETS	r^ ^ „ _ ^ C^) Ol	e4NP:«iMccrj'*
E	In
H	iz;
t£
O
s	5	•*ao©T*<ooOTCccO'*oc	©■«<«©'^0C©'*
n
! °	$4	i-ic^-^icccoccsoraw-*	ttJ^OCO — C^Tj-lC
	_i i-i .— 1 .-1	— »-"MMiMe*e<
BD
	§	ooococccoco	0©©©0©©0
a	-^
g	o
—		owcsoMCiiorJCiis —	sc»e — oc-r- — !>-•««
H	i-iCO'VWOCOi^M'WCSW	C5 — rTTT-racr: —
w	E-E	^^ 1-^ 1-^ f-H 1-^	r^D>C*IMMC^r<CO
o	|n
zi	fc
IL.
	H	oooocoooscc	©©©©©oo©
•< c	d	^c<icoTj<ia«t~ooC50-H	(Mro-*>c«t-ac©
^^ ^^
<	J
O	■S	ccoocc==soc	©o©©©©©©
«
	'*-
	o
	11 E"=	^lNTO->*'«JC3t^aCCiC —	CS5<5-^iS©t^aO»
	i^CSWiJ<«5®1^00Oi^!N	ec-'j'iciist-x©©
1 id	^«
O			1
	i	00-*O«-<J.OaC^CXi'*O0C-* = aC'9'C00
H a	d	O'^c^c^eo'*''<*<«so®t^acac:c:oo — !No«
o
	1	©coooccoooc	©_©©©©©©
	».
	c
	l^	CO — trrat^pOac-*C5«c —	OMt^MOCp;©-*
w	— — C^MWCC-«--«-0-.C	© j^ t^ ac oc ci C5 ©
o	11		'^
H	fc
c
		1
	_a	■woC'0-«'or_0'<roco-«"ac	©•va©'*x©-*
•<	d	©o — r-.-c>c^Mroc^rs	•^■^'■•rOO'C©©
R
	1	occccccoocc	©©©©©wOO
"1 ^	•a	— N«'*»o«ot^eo»o-"	NeC'»s>u5©t^aoo»
^i	'=

rRACTICAL GEOMETRY AND MENSL RATION. 109

"	^
	o .
	r 5	0-MTt--0«tr(M-<J.c030 — C<li.-?500C'MTj<or~
	0, ^	Tr.i::3coc^u-3t^05 — co«cocc-o<-^i-c-. — ^5
Ti<-q<'<)<ia>0>0>0>0<0<0;COt>-»<-t-t~t— OCOC
B	iz;
M o 3
	1
.a	OCO-*300-<1>000-*000-<*"OCOt(<000-<*<00
n
o	d	?OOOOSOC^e<3Tj<5Dt^OOO'-iC<l'*>OCC00050
^		C^C^(MCOMMPSe>3WeO->5.-<»<-^-*-*-»><Tj<-.}<lo
H	s
		osocoooocoocoooscoo
M	<>-l
O	o .
s	fcl	Ot^Tj<Ot^CC05CMCitDC^Oi«3<N05«3(MOO
	COTj<;c=CCi^r^-r — t^C2— •c^-^or-Oi"— iM
il	e'OcoMCQc3'<r-v-<p-<Ti-^-via>a>0'C«i>c;co
U	— r*i
3	;?;
^	fl
■< H •<		ooooooocooooooooooo
««-l	0-H<MCO-*>OWt^OOO>O^C<ICO-*«350r~=0
a 2		(N(N(NC^<M(N(NC«<M(NCOMC<SC<3CO«ieO?CM
•<	-a	ooooooooooooooooooo
Z	p^
O
	VI
	o
	^ s	0'-lMec•<*•u5«D^^ooal^-'--lMeo-*«^eooooi
		C^?3^ iOOr-OC050.— M-*wtcCt^CCC-. O-H
M	-«	e<>c4c^c^c^c<c-)c><wwwc<5:ocococTcc-<i''*
O	— ^
B
B	i^
c	.a	■<j.o«-*ooo-*c=c-»oao-<j<ooo->jtooo-<j<
si	eo-*-«>iC5Dcor^ooocooo^!Mc^ec-*-*«5
a	*M	"rt;z;;i;^^^^^r-ic^(N(N(Nuc^c^<NN
	y^	oooocooocoooooocooo
	«-i
	o .
	- "	o«£-Ht--c^t~Moo-*c:>c^«C'Mr~«co-fc-.
		i—--'>4'MMM-^'r>c'Ccrt^i^=cacc; c. oo
	;z;
O		1
s	.9	0CG;-<t<00C-fl>0CO'*0CO-V3CO-«»0CO-«l<00
a <	^	5Ct^t^i^3sooocc50JC3Coo — ^-<■^'c^■^^
	1	ooooooooooooooooooo
1 o	3 -a -'3	O — C^eO^iOCOt^OCOO — (NM— >O50j2=g
i-)C^p»c^c^c>»nino^c^coweoc<3coc<3eocoeo
1 ^

11 'J

liRlCKLAYIXG.

	<-
o a i	si ■2-- = a is
.S	o-*c»o-^ooo-<f<ooO'*«oooeo©'*oo
p H	a	(Mco-<*<ot^ooo>^'M-*>oeocooe>s«>oe<50 »— 1 i-H ^H C^
	M	©oooooooooooooooooo
H	^S
3 n	si -2-2 5(3	l-H i-H 1— t r-H CO
	a	ooooooooooooooooooo
a 5	d	C50--C^eO-*«5<©t^00050i-IOOOOOO
H O	S	ooooooooooooooooooo
"s
		OOC-J'M'i<>f5Ot^0C0»3 — i(Mi-(C^iMlM'M'l5 CO-f>OCOI~00050 — C'J-JiiOOOt^OOOSOO 1-1 <>»
H	^
	.g	OOO'^OOO'^OOO'^OOO'^OOOO^OaO'*
O	d	eoco^^ooooo500-^c<^(Ne<^•<i^O«OM00^3 (MiMIM(N(MWCCC«3eOe<3eoco«l-*'<li«0«DOCO
	S	ooooooooooooooooooo
	<w
u o 3		lOOO-Ht^cioccoos-^OuS'-'-'Or-i'r'i-ic-i « C^ C-l C3 CO Tf ■* lO 'O O 1^ t^ CO CO 00 Tf C5 'O O 1
•g	o-*ooo-»*«ooO'<*'»o-*<aooO'^ooo-*oo
•< M	a	00KlC0-*Tf.l<.C«0«5<0e0«>t^OC0C0Oe0«D
	•a	OOOOOOOOOOOOOOOOOOO
^5		00'-<MCO-*i>0«3t-0000-<000000 co-»r'*il<Tt<-*'<*<-<*<-«»<T(<-^u3i05D»--aoo>oo

PRACTICAL GEOMETRY AM) MENSURATION. Ill

		*<
		° .	CCr53C-*<0«SCCOcr-0'.-JOTj<OT}<'NO
		fc« 30	— n t^ ;c -*< "*• -c '-•5 — t- M C5 lo — ' t^ ec CO
	M O		,r oc o c-i 'i" ^ CO o — — c<i !M ^t ^ -S- >-■: o
	;C3C— 1?3 ~i^c:^'<i<O00OC<<-<i'5CCCO
	i^	_,^_Hr-Hr-ci<i'<j.a3ao^c<5»or~C5r>
		.-1 .— — — ^ i<l
	E-. 9)	^	1
		.3	=;-*xs-?<xo-?wc--t3:s'*x = -*
	«
	O	^	ac — c* w t^ o c^ lo » n «s 00 c-i «o 00 ■?» >o
	>		c^ ^ -N •■; •-< ■-■T .-1 ■«< — ' C5 'o CO -- X 'o eo
	H	»
		r^	-<-HC<lMCCC0-*-*r;-*iO5-*O5-*iO5^OS
		A	— — (N<MWe<3'J<'r
	^
	g	o .	r? t^ CQ ;= o >o C5 ^ X fi -o o -*| cc ci -o o
	5	c 3	O ^ 1~ -M X CC X -:< CC r^ t^ t<I w O '-•; C2 f
	H	C; -O ■M C; W5 7^ X >.1 O -O -- t^ 'M 30 M X -J<
	M	■*-^x=;--2"*2"'^^^^2^^-"'^
	"J	l-l ^ l-« -H
	a	^
	<	a	00000 = 000 = 0000000
	■<	^	XXX:00 = -i<^cr»'MT)<OOM— 00
•			c<i'Mc^>0'0>-oaoxci mo — o^iqo
1		.-1^ r-IJvl —1 .-<.-l c->— < c^
	H	i	,_lrtrtI<^^-1^^^3co^--H^oo<NlC!Ci«c^
.s	a	^^„e<is^?i«)eo
1		4-(
	o .	O-^-^t-OCOOOXXt-iOt— >Ct^5DTO
			O -J ^ — ' cq ->! r-l "N '■? X — -^ t~ O ^f CC 33
S		CC-:t>>C0t-XC300O— '-- — C-^'M'M'M
M	co■>f<-1«3^~XC:'^•^)^o — Lf^^t^xr-. o
o	15 12;	rt M ^3 TI. i.-S = t^ X o ^
P?	a
<	H
H	O
	1	.a	OX'*OX-^OX'*<OMtJ<OX-^O00
	z O	^	O -O -- X Tl) — < -O C<I >0 O X C5 n CO 'O CO »
		O-O;D'MC513>0<M'TiC5^C0C5^cn-^?3
		MCO ^^0<1 r-IC'l C<l ^ ^ -<
		•5	OO-Hn^rt^nM-fl^05C>l-i>t^G5'M-»<
		^	^ ^ rt rt o< C^
		Ck4	coot^xo — cj-^o^qicoxcjxcc-o
		,a.2
	w	tc c^ i-^ ro X "^ o '."^ o '-'^ o '-"^ o *-o ^^ o -^
	o	^<M<NC0C0-*l'l^>O-HO•^ll~^tXTj.c•. o
	B	= 5	rtrt(MC0COCO^^>O
	H	»
	M
	o
	2
	=3	.a	O-*<XO'*<00O-*00O-*XO-*XO-#
	3	d	oc«3;r:ocoox-^cO'<*i«S'*cot--xxcs
			o^;cooM;2cool^^x-?<coc5^r^— < o
		— •— '--c^c^ic-i ---<e<i -H!M
		1	OOOOOO-- — COrSTCOt^XCJ — <N
		r^ rl
	*. t	11	oooooocoooooooooo
	s 1	ooooocooc-oooooooo
	^ ;	""o	ec-i<>c-ot-xc:oooooooooo
	S	«	— CO r? -r ■•■; -.O t^ X c: O

112 KRICKLAVIXO.

Example 1st.

llow many rods and feet of standard work are there in a wall 59 feet in length and 12 feet 6 nches in height, and I5 bricks thick ?

KCLE.

ft 69 12	in. 0 6	the lengtli. the height
708 29	0 6
737	6	Area.

So by these figures we find the superficial area of the wall to be 737 feet 6 inches. Look in the first column towards the left hand for 700, and opposite that in the sixth column will be found 2 rods 156 feet ; look again in the first column for 37 feet, and opposite this, in the sixth column, is 37 feet ; add the 6 inches, and the product will be as follows : —

todB ft. in. 2 156 0 0 37 6

2 193 6 Answer.

Examjile 2itd.

How many rods, feet, and inches are there in a wall 95 feet long by 17 feet high, at 2 bricks thick ?

95 X 15 = 1015 ; this is the superficial con- tents of the wall. Look in the first column for the following numbers — 1000 feet, GOO feet, and 15 feet ; and opposite these respectively, under the heading " Two bricks thick," will be found

PRACTICAL GEOMETRY AND MENSURATION. 113

the following figures, which added up together will give the standard contents of the wall.

rods ft. in.

4 245 4

2 256 0

0 20 0

6 521 4 = 7rd8. 249 ft. 4 in.

The quantity of bricks required to build a wall containing any given number of superficial feet is taken in almost the same way.

Example ^rd.

llow many bricks are required to build a wall SO feet long by 27 feet high, at I5 bricks thick ?

80 X 27 = 2160 feet, the area. Look in the

first column for 2000 feet, 100 feet, and 60 feet,

and against these respectively, in the column

headed " One and a half bricks thick," will be

luu^nd the following figures, which, by addition

u>nl/, give the number of bricks that will build

the wall.

33088

1654

992

35734 Answer.

The superficial areas of the walls of a house amount to 2649 feet. Now 1200 feet is 2 bricks thick, 900 feet is 1^ brick thick, and 549 is one brick thick : how many bricks did tlie builder require to build the house?

Answer, by table, 47403.

114 BRICKLAYING.

All gauge-work is measured by superficial nieasureraeut (unless otherwise specified) ; and every part that is exposed to view ft taken in the dimensions.

Skewbacks, birds'-mouths, splays, beads, &c., are generally measured by the run. But if measured as gauge-work, it is usual to ply the tape, or a piece of string, close to every part of the brick that is moulded, and afterwards measure it to get the whole of the girth of the work, and this is multiplied by the length for the contents.

Arches are also measured by the girth multiplied by the length.

1000 new stock bricks stacked in bolts measure 50 feet cubic.

1000 old bricks cleaned and stacked in bolts measure 72 cubic feet.

Short axd TTseftl Tablb.

277i Clinic inches 1 gallon of water.

1 cubic foot contains 6 gallons 1 j pints.

144 square inches equal I square foot.

172S cubic inches „ 1 cubic foot.

9 square feet ,. 1 square yard.

27 cubic feet „ 1 culiic yard or load.

100 superficial feet „ 1 square.

Tiling and Slating is measured by the square of loo feet, and in many country places double measure is allowed for cutting hips and valleys, i.e. for valleys take the length of the ridge for one dimension and the depth from ridge to eaves for the other, and multiply one by the other for the superficial area ; and for hips take the length of the eaves and multiply the depth as before. This

TRACTICAL GEOMETRY AXD MENSURATION. 115

is SO allowed to pay for the amount of waste iu labour and material in cutting them.

But in London slating is not measured in this way, but for all hips, valleys, eaves, cuttings to skew gables, cheeks of dormers, &c., the length of the cutting is taken, and 1 foot allowed for the hips and valleys, and 6 inches allowed for eaves and the other cuttings above named. All plain work is measured net.

When the space taken up by sky-lights, chim- ney-shafts, &c., do not exceed 4 feet in area, no deductions are made on account of the extra labour in cutting round them.

The ridge is always taken separately at per running foot.

Where soakers are used they are reckoned by the dozen.

All plain or pantiling for roofs is measured by the square, and cutting and eaves are allowed for in the same way as slating.

Plain and ornamental tiling for floors, walls, ceilings, &c., is measured by the yard square, and all cufling per foot run.

Pludcring is either measured by the foot, yard, or square of 100 feet, and any surface under 1 foot (in taking revcils, &c.) is usually called a foot.

Cornices, beads, chamfers, and all mouldings arc taken b}' the foot run.

Mitres, stop, &c., are taken sepai-ately and priced at so much each.

Doorways, windows, fireplaces, &c., are de-

116 BRICKLAYING.

ducted, and ceiling and walls are measured sepa rately.

Trhite\vasliiug and colouring are measured in the same way as plain plastering — mostly by the yard square — and where this is done between principals, rafters, joists, &c., the tape must be applied to the whole of the surface covered by the brush.

This work is specified to be one, two, or three coat work.

THE END.

pmiXTtD BT J. 8. nuTTi Am '^o., I rurr^D tttt ro4o, u>!tr««>«.

THE

PRACTICAL BRICK AND TILE BOOK

PART III.

BKICKWOEK

A PRACTICAL TREATISE ON

BRICKLAYING, CUTTING, AND SETTING

By F. WALKEE

BRICKWORK;

A PRACTICAL TREATISE

EMBODYING THE GENEEAL AND HIGHER PRINCIPLES OF

BEICKLAnNCi, CUTTING, AND SETTING

■WITH

THE APPLICATION OF GEOMETRY TO ROOF TILING,

REMARKS ON THE DIFFERENT KINDS OF POINTING,

A DESCRIPTION OF THE MATERIALS USED BY THE BRICKLAYER

AND

A SERIES OF PROBLEMS IN APPLIED GEOMETRY By F. walker

CBRTIFICiTRD BY THE SCIEKCE AND ART DEPARTMENT IN BUILDIKO COXSTRtTCTIOK, PRACTICAL, PLANE AND SOLID GEOMETRY, ETC.

ILLUSTRATED WITH NINETY-OXE WOODCUTS

^cconb Cebition, glcbbrb nnb (Enlnrgtb

(2|)iom][u.i

LONDON

CROSBY LOCKWOOD AND CO.

7, STATIONERS' HALL COLTIT, LUDGATE HILL 1885

\_All rights reserved.]

LONDON' :

PRFNTED BY J. S. VIBTUE AXD CO., LIMITED,

CITT EOAD.

PEEFACE.

The object of this little work is to give tlie young artisan a general and practical insight into his trade, and to inspire him with a wish to become a useful and successful workman ; which means that he must work with his head as well as with his hands. The greater portion of the matter contained herein is such as to he indispensable to the proficient -workman. Though the work does not profess to be in any way an exhaustive treatise on a trade so varied as that of the brick- layer, yet the writer hopes that it may be a help to those who, through the division of labour or otherwise, have had their practice confined to one branch only of their trade ; and that it may not be considered altogether unworthy the notice of professional men, being to some extent the out- come of twenty-two years of practical experience iu building operations. It is, however, intended

IV PREFACE.

chiefly for that large majority of young men who enter the trade of the bricklayer (and all other trades in house-building) without any previous training or instruction to fit them for the calling, depending entirely upon the manipulatiye skill they may or may not acquire in the handling of their tools. The book commences with the site of a building, and goes through the successive stages of the bricklayer's trade, including roof tiling ; and concludes with a section on Applied Geometry, containing problems that may be useful in every-day practice.

Lo2n)OS, Sfjjfemicr, 18S4.

XOTE TO THE SECOND EDITION.

The very rapid and gratifying sale of the first edition, and the favourable manner in which it has been received by the various technical journals, have led the author to make several additions and a few alterations to the work, with a view to increasing its usefulness not only to the operative student, but also to those who may be preparing for the Science Examination in Building Con- struction.

CONTENTS.

SECTION I.

MATERIALS AND GENERAL PRINCIPLES OF CONSTRUCTION.

PAOB

Site 1

Establishing a Level or Datum 2

Setting out Building 2

Concrete 5

Cement 10

Drains 11

Mortar 14

Red Brickwork 14

Bricks 16

Characteristics of Good Bricks . . . . .19

Bond of Brickwork . 20

Old English Bond 21

Bond of Footings and Walls 22

Setting out the Bond 26

Heading Bond 28

Templates and Strings 30

Bats 30

Flemish Bond ........ 31

Various Bonds 34

Herring-bone Bond ....... 36

Dutch Bond 37

VI

Keeping the Perpends

Toothings

Grouting

Flues

CONTENTS.

PAOB

39 39 40 41

SECTION II.

ARCHES IN GENERAL.

Arches 46

Relie\-ing Arches 48

Plain Arches 49

The Skew or Oblique Arch 49

Skew Arch at Brondeshury 52

Water Conduit .56

Groined Vaulting: 58

SECTION III. GAUGED-WORK AND ARCH-CUTTING.

Gauged Work					61
Setting				63
Drawing and Cutting Arches .					64
The Bulls-eye					65
Semi and Segmental Arches					66
The Camber Ai-ch .					67
The Gothic Arch					69
The Ellipse Gothic Arcli .					72
The Semi-Ellipse Arch					72
The Venetian Arch .					74
The Scheme Arch					7.5
The Semi-Gothic Arch					76
Gothic on Circle Arch					77
To Find the Soffit Mould .					78

CONTENTS. Vll

SECTION lY. ORNAMENTAL BRICKWORK.

PAQE

The Niche 79

The Niche Mould 83

Moulded Courses 83

Ornamental Arches 84

The Oriel Window 85

Ornamental Gable or Pediment 87

Gothic Window . 88

SECTION V. ROOF-TILING, POINTING, ETC.

Tiling 92

Roofs having different Pitches 94

To obtain the necessary Angle of Hip or Valley Tiles . 96

Pointing 97

Flat-Joint Pointing 98

Burning Clay into Ballast 100

Building Additions to Old Work 102

Fire-proof Floors 102

SECTION VI. APPLIED GEOMETRY.

To draw a square •whose superficial area shall equal the

sum of two squares whose sides are given . . .103

To draw a right-angled triangle, base H inches, height

J- inch 104

To draw an arc by cross-sectional lines . . . .105

To describe a flat arc (camber for instance) by mechani- cal means 106

YUl CONTENTS.

PAOR

To find the joints of a flat arch without using the centre

of the circle of which the arc is a part . . . 106

To draw the joints of a semi-ellipse arch with mathemati- cal accuracy 107

To find the invisible arch contained in a camber . .108

Any two straight lines given to determine a curve by

■which they shall be connected 109

To find the form or curvature of a raking moulding that

shall unite correctlj' with a level one . . .111

To describe an ellipse by means of a carpenter's square

and a piece of notched lath 112

To draw a Gothic of any given height and span: or.

in other words, an Ellipse Gothic . . . .113

To draw the arch bricks of a Gothic arch, that is for the

cuivc in the previous problem 114

To find the ladius of any arc or arch, the rise and span

being given . . . 11 J

BRICKWORK.

SECTION I.

MATERIALS AND GENERAL PRINCIPLES OF

CONSTRUCTION.

Site.

Though the bricklayer is very seldom called upon to choose the site of a proposed building, he should nevertheless make himself acquainted with the essentials of a good foundation, and the characteristics of a bad one, as a subject not alto- gether foreign to his calling. The workman who rests satisfied with just the manipulative know- ledge of his own trade is not likely to realise the value of the word prof/rcss, and must of necessity be content to remain in the position in which he found himself placed as a workman. Though the bricklayer has no voice in the choice of site, he maj', as foreman or clerk of works, have to a great extent the power of minimising the evil effects of a bad one, if he be possessed of the necessary knowledge. For be it remembered that a good foundation is as necessary to the stability of a building, as good flues and drains are to the health and comfort of its occupants. The best sites to build upon are hard gravel, igneous and

iJ BRTCKWOKK.

metamorpliic rocks, limestones, sandstones, and chalk. A clay foundation should be well drained, as clay by its impervious nature retains moisture, and the whole area of the site covered with 6 inches of surface concrete, made up with Portland cement or ground blue lias lime, to keep back ground-damp, which will otherwise be attracted by the warm air within the building. "When building on a clay or sand foundation the building should be kept level throughout, as by building up one portion of the building and leaving down another, ugly fractures sometimes occur in the walls, caused by one portion of the work settling at one time, and other portions at another, which greatly mar the appearance of the structure.

Establishing a Level or Daixm.

Before excavating trenches to receive concrete for footings, a level, or datum as it is technically called, should be established. To do this, drive a large stake well into the ground where it will not be likeh' to get disturbed, and let the top of it be the ground-floor level, which must be taken off the drawings if not otherwise determined. To avoid the possibility of mistakes, all levels for excavations, concrete, and brickwork should be taken from this only.

Settixg git Building.

In setting out a building, one or other of the following methods is generally adopted. Either the extreme side walls are squared from

MATERIALS AND GENERAL PRINCIPLES.

the line of frontage, wticli is given, and the posi- tions of the intermediate walls established by parallels ; or, two centre lines are drawn at right angles, right through the plan of the building, and the walls set out at parallel distances from them ; taking all measurements from the centre lines. The positions of walls should not be laid down by measuring the distance of one wall from another in succession ; for if an error be made in the setting out of the first wall, it will, in this way, be perpetuated from one wall to another throughout the building. But by measuring from the centre line, an error would be confined to that particular wall in connection with which it was made, and would be readily discovered when checking the distances between the respective walls. In both methods we have assumed the building to be square. If the setting out is to be c

Fif?. 1.

done by means of a large square, which is generally the case, it should be tested or proved before use. To do this, draw a line a h along a straight b2

BRICKWORK.

edge (Fig. 1), not less than twice the length of the base of the square. Adjust the base of the square along this line from b, and draw a line c along the perpendicular blade until it meets the base line a h ; now reverse the square along the base line from a, and if the square be true its perpendicular will coincide with the perpendicu- lar line c. Another way of setting out the side walls from a given line of frontage is by means of a 10-feet rod. Having drawn a line tighth^ to represent the front of the building, along this line measure G feet from the quoin (French coin, a corner), and push through the line at the 6- feet point an ordinary brass pin. Draw another line in the same way as the first, approximately at right angles to it, and from the quoin again measure off 8 feet along this line, fixing another pin as before at the 8-feet point. "With one end fixed at the quoin, the other end of the line must be moved until there be a distance of 10 feet between the two pins measured across the angle. Tlie lines will then be square one with the other. Instead of G, 8, and 10, we could have taken 12, 16, and 20 ; but whatever figures be used must stand in the same ratio or proportion to each other as the above, and shown in Fig. 2.

Another Method. — From point B (Fig. 3), with

Fi?. 2.

MATERIALS AND GENERAL PRINCIPLES. O

steel measuring tape set off 30 feet, or more or less as conyenient, at an approximate angle of 45 degrees witli the given line a b. From d mea-

rig. 3.

sure off the same distance to a; from a draw a line through d, measuring from d to c 30 feet. A line drawn from b through c will be at right angles to the given line a b, the line of front- age ; B would be the quoin of building. This depends upon the principle that all triangles in a semicircle are right-angled triangles, and all the angles in the same segment of a circle are equal {Euclid, bk. iii. prob. 21).

Concrete.

The thickness for concrete varies from 1 to 3 feet, according to the nature of the subsoil upon which the building will stand ; but in some cases it is very much thicker, as in made-up ground, where, to ensure a good foundation, it is necessary

6 BRICKWORK.

to go down to the London clay, or some other firm substratum, depending upon the nature of the ground. The Metropolitan Building Act requires that the concrete shall not be less than 9 inches in depth, nor have a margin of less than 4 inches outside the first course of footings ; G inches is the usual margin in good work.

The following is a specification to govern the suppl}^ of materials, the mixing, and the putting into place of cement concrete. The whole of the cement to be Portland of the very best quality, very finely ground, weighing not less than 110 lbs. to the striked bushel, of which 90 per cent, must pass through a sieve of 2,500 meshes to the square inch, and it must be capable of maintaining a breaking weight of 350 lbs. per square inch, after being made in a bronze mould immersed in water during an interval of seven days.

The mixing to be carried on upon a clean plat- form made of 9 inch X 3 inch deals, bedded solidly on sand, that the cement may not run off through the joints in the pi'ocess of mixing. The concrete to be composed of four parts of broken bricks, broken porous stone, or Thames ballast ; two parts sharp clean sand, free from loam or other impuri- ties ; and one of cement of the specified quality. The parts to be measured in a half-yard cubic box (3 feet X 2 feet X 2| feet), and thoroughly mixed together in a dry state. The ballast or broken bricks to be capable of passing through a 2-inch mesh. The dry concrete to be heaped up and

MATERIALS AND GENERAL PRTNCirLES. /

turned over at least twice before wetting. The water to be applied through a rose, not more to be iised than is necessary to mix the whole very thoroughly. While the water is being sprinkled on, the mixture should be drawn down by " picks," while two or more other men turn it over, after being so drawn down, to another part of the platform, from which it must be again turned over until the parts are thoroughly incorporated. The concrete to be tipped from a height not ex- ceeding 4 feet, and to be steadily rammed or struck with the back of a shovel until the cement or matrix flushes to the surface. The whole to be left solid and clean.

In the treatment of concrete much depends upon experience and judgment, and it is there- fore the more difficult to lay down hard and fast rules to govern the proportion of the ingredients and the mixing of them. The one thing to be aimed at in the apportionment of the ingredients is homogeneity ; where this does not exist, strength will be wanting.

As regards "packing," or the practice of placing stones or other suitable material larger than the aggregate, in the mass of the con- crete, it is objectionable under certain condi- tions. In a thoroughly good Portland cement concrete, if properly treated, there will neither be contraction nor expansion to any perceptible degree in the setting ; and in such there is no objection to packing, if the stones or other material be uniformly distributed and solidly bedded in

5 BRICKWORK.

the mass. But in an inferior concrete subject to contraction or expansion, packing is decidedly objectionable, and likely to lead to injurious results; more especially if the packing be not evenly distributed throughout the concrete. This consideration has led engineers and architects to adopt in their specifications the precautionary clause that the aggregate shall be of an uniform size — generally, to pass through a 2 -inch or 2|-inch ring.

The quantity of water to be used depends almost entirely upon the nature of the aggregate ; ballast or any siliceous aggregate requiring only enough to thoroughly mix the cement, while that of a porous nature, such as broken bricks, would require more. The proportion of cement must be governed by circumstances, for while the Metro- politan Main Drainage "Works adopted one of cement to five and a-half of aggregate, we are informed by Mr. Picid On Concrete, that in the sea forts of Copenhagen the concrete was made in the following proportions: —

Portland cement .... 1

Sand 4

Fragments of stone . . . IG

and the concrete for filling in the terra-cotta at St. Paul's School, Kensington, consisted of one of Portland cement and ten of aggregate.

In Portland cement concrete, " a rotten or fri- able material is to be avoided, except where un- avoidable, and in that case only in combination with a large quantity of cement, so as to neutralise

MATERIALS AND GENEHAL PRINCIPLES. 9

as far as possible any tendency to weakness. Sand, where a clioice exists, should be as rough, and coarse as possible, and that made by the various natural or physical influences from sand- stone, limestone, or other similar rocky forma- tions, is to be preferred over those from flint or volcanic rocks. The former sands or shingles are more porous than the latter, and consequently better able to absorb the silicates of the cement when being mixed. For this reason it is advisable not to have the sand, gravel, or shingle too fully saturated with water ; if this is so, the matrix is unable to imbibe the fluid portion of the mixture, and consequently it is thrown off as waste from the concrete. This observation equally applies to the mischievous practice of over- wetting bricks in building with cement mortar. A dry brick is bad enough, but when saturation is carried to excess equally faulty results ensue. With regard to the acting properties of Portland cement when used with salt sand, or salt water, an experiment proved the use of salt water and salt sand per- fectly satisfactory, both with Portland cement and lias lime, but there was no question as to their setting being retarded by their use." — Brunei.

"When blue lias is used for concrete, the pro- portion of parts and the mixing is the same as described in cement concrete.

Burnt ballast is frequently used as an aggre- gate for concrete, but care should be taken that it be thoroughly burnt free from clay. Burnt bal- last concrete should be made rather sloppy on ac- r3

10 BRICKWORK.

count of its absorbent nature, or it will quickly absorb tbc moisture from the cement or lime with, which, it is mixed, to the injury of its setting pro- perties and ultimate strength.

Mixed with one- third of Thames ballast and a fair proportion of lime it will yield a good concrete for footings to walls.

Cemext.

Adie's No. 1 cement testing machine is very generally used for testing cements, but where one of these is not at hand they may be r -"^A roughly tested in the following man- )c^ ~~^ ner. Having mounted a briquette Fig. 4. (Fig. 4), whose sectional area is one square inch, or more as the case may be, after seven days' immersion let it be suspended from one end, and from the other end suspend a cement barrel containing sand, increasing the quantity until the briquette breaks or its power of resistance be overcome. The sand should not be thrown into the barrel, but slid into it by means of an inclined plane, and in small quantities. The weight of the cask with its contents will repre- sent the breaking weight. "With Adie's machine the briquette in the making is subjected to a slight pressure, which adds considerably to its tensile strength, so that the resistance to breaking of a briquette made by the machine •\^•ill be greater than that of a briquette of the same cement made by hand and not subjected to pressure. Another way : bed two bricks together (Fig. 5), and after

MATERIALS AND GENERAL PRINCIPLES. 11

a few days' immersion let them be suspended and treated in the same way as the briquette. This plan is suitable for ascertain- ing the comparative strength of cements, but in so doing the same kind of bricks, sand (if any used), and even water should be used, and the exact proportions maintained in the mixing, or, in other words, the conditions should be exactly the same. Bricks having a smooth impervious bed will be found to have less adhesion than those of a hard but comparatively porous nature — pressed bricks and hard stocks, for instance.

The bricklayer should make himself acquainted with the various limes and cements, and the in- gredients used in combination wath them ; also with concrete, as subjects belonging particularly to his trade, and which by reason of his occu- pation he has a better opportunity of doing than any other class of operatives. In large and im- portant public works these are generally subject to the inspection of a bricklayer.

Drains.

The laying of drains, at once the most impor- tant and too frequently the most neglected part of a building, should never be intrusted to unskilled workmen. The fall having been determined, which should not be less than one in sixty or one inch in five feet, the flange of each pipe should rest upon a bedded brick, that the joints may be

12 BRICKWORK.

caulked all round •v^•ith gaskin or oakum previ- ously to being made up with Portland cement. The object of caulking is to prevent the cement squeezing through into the pipe, a very common cause of stoppage in drains. They can now be bedded half way up in fine concrete, so as to form a cradle, care being taken not to disturb the joints. The inside joint of each length of pipe as it is laid should be stopped with Portland cement, and left solid and clean, free from any- thing approaching to burrs. The drains should be laid down air and water-tight, free from " dips," with no right-angled junctions nor sharp bends, and kept, if at all possible, outside the building, with inspection holes large enough for a man to work forcing-rods in ease of a stoppage. A length of pipe in the man-hole should have a movable top. This kind of pipe is called an operculum or " channel " pipe- In many in- stances only the invert half of the pipe is used in that portion of the drain passing through the man-hole, which is ventilated by a current of fresh air entering the man-hole, passing through the entire length of the drains, and finding an outlet through the open soil-pipe above the roof. In such an arrangement a trap shovdd intervene between the sewer and the man-hole, to prevent the possibility of sewer gas escaping through the fresh air inlet. But where fresh air is not intro- duced, the trap may be dispensed with, the soil- pipe serving as a ventilator both for the sewer and the drains.

MATERIALS AND GENERAL PRINCIPLES.

13

Six-inch pipes will be found large enough, for most buildings. As the subject of trapping, dis- connecting, and ventilating drains belongs to sanitar)^ science, it cannot be further noticed here beyond giving a plan and section of a dip-trap (Figs. 6 and 7) which the bricklayer is sometimes

		Flap.
		-*

Pi?. 6.

Pig. 7.

called upon to build. This trap should be used only where there is a copious and frequent supply of water (but not in connection with soil), as by its size and construction a greater quantity of water is required to trap it than the earthenware traps now more generally and preferably used.

14 brickwork.

Mortar.

Mortar used by the bricklayer is made either from stone lime, lias, or Portland cement, mixed with a proper proportion of sand. Chalk lime should not be used, as the only setting that takes place in it is the formation of a surface crust, bearing a small proportion to the bulk. Stone, or gray chalk lime, as it is sometimes called, is generally used ; it possesses slight hydraulic power, and will set if secluded from the air or in damp situations, and is capable of bearing three parts of sand to one of lime. For damp situations blue lias will be found to make the best lime-mortar. It is eminently hydraulic, and becomes very hard, especially in damp places ; but it will not bear so much sand as stone lime. The amount of sand should not exceed twice that of lime. Lump lias is used for mortar ; it should be well wetted, coTcred over with sand, and allowed a day to slack before being ground in the mortar mill. The sand used for all mortars should be a clean, sharp, angular grit. Cement has been already spoken of in connection with concrete, and elsewhere.

Red Brickwork.

Owing to the revival of the Queen Anne stylo of architecture, brickwork now occupies the fore- most position in building construction, of which very good samples may bo seen at Westwood House, Sydenham ; Fitz- John Avenue, llamp-

MATERIALS AND GENERAL TRINCIPLES. 15

Stead ; the Chelsea Embankment, and many other places in and about London. Our popular archi- tects delight to revel and indulge their fancies in red brickwork, as evidenced in several public buildings of recent erection. The Victorian age, from an architectural point of view, will be con- spicuous for its stuccoed buildings and its red brickwork— the former an expressionless imita- tion, the offspring of the speculator, and the Caliban of architecture. But Truth in architec- ture, as in all things, will assert herself; she breathes into the nostrils of a second Adam, and lo ! we have " a thing of beauty." _ We can remember, in our experience, when the life of the bricklayer was often made " bitter with hard bondage in mortar and in brick," by reason of the reign of stucco; but, thanks to the able advocacy of Mr. Tvuskin and the late Mr. E. Street, such rapid strides have been made in brickwork that one is almost surprised to see the amount of art-workmanship wrought in red-brick designs.

These will be found mostly in retired out-of-the- way streets, relieving, both by colour and detail, the dull monotony of the unbroken line of our vista-like old street architecture.

Some years ago the Philological School, St. Marylebone Eoad, was pointed out as a sample of ornamental brickwork. The ornamental features m this structure are made up of a judicious use and arrangement of polychrome bricks, and stone dressings. The building is, undoubtedly, a good one, possessing that repose almost peculiar to

16 BRICKWORK.

ecclesiastical architecture. But the term orna- mental brickwork is so closely associated in these days with the idea of form, that we are accustomed to exclude from the meaning of that term all brick designs characterized bj" an absence of pro- jection.

We know no better samples of red brickwork than St. Paul's Schools, and the City Guilds Technical Institute, Kensington ; and the Mid- land Hotel, St. Pancras Station.

Bricks.

In dealing with brickwork it is necessary that something should be said about bricks, though it is not intended to go into the chemical properties or other scientific matters connected with them, as we are^'presumably writing for persons in or con- nected with the trade of a bricklayer, but will just take a passing glance at the bricks commonly used in and about London, and state the purposes for which they are best adapted.

Stock bricks are divided into "picked " stocks (picked for colour and hardness), " washed " stocks, " grizzles," " place," and " shuffs." " Shuffs " are worthless, " place " are little better ; " grizzles " are those bricks which haye a good face or end with the other face or end underburnt, and similar in appearance to " place/* which are of a reddish colour. " Picked " are those which are suitable for good exterior facing. " "Washed " stocks, on account of their softness, are fit only for interior facing. The best stock

MATERIALS AND GENEllAL PRINCIPLES. 17

bricks for general facing purposes are those called "stippers," whicli, as their name implies, are sorted for shipping.

INEalms are a superior kind of stock bricks, made of washed clay and chalk, and are used for superior facing and for " cutting " purposes, but are not suitable for " gauged-Avork" on account of the numerous small air-cells contained in the bricks, which make it impossible to rub them up to an arris, which is indispensable to good setting.

Of red building bricks there are a great yariety in the London market, the best of which for colour and weathering properties arc Fareham reds, though rather irregular in shape. St. Thomas's Hospital, and the Nurses' Training Home, Queen Anne's Gate, St. James's Park, are faced with these. Sometimes they are rubbed down to obtain true faces ; but this should be avoided for the sake of preserving the deep red colour, which constitutes the beauty of these bricks. Fareham rubbers for " gauged-work " also stand first in quality, though they are not extensively used, as they are dearer than the other varieties in the market.

Next in quality come the Berkshire Builders and T. L. B. Rubbers, made by T. Lawrance, Bracknell, Berks. The Teynham bricks, stamped G. Richardson, Teynham, are good bricks, pos- sessing in a large degree the qualities that recom- mend the Farehams, and with the additional advantage of a fairly good shape. Gault bricks

18 BRICKWORK.

arc mucli used for facing ; they are much harder than stocks, and also dearer. Of ■white bricks Suffolks are the very best. They are a close, firm brick, suitable for first-class facing, either exterior or interior, or for " gauged- work." They are of a soft nature, but harden very much by exposure to the action of the atmosphere.

A very nice piece of work — three-light geo- metrical windows — executed in these bricks, and designed by Messrs. II. Saxon Snell and Sons, 22, Southampton Buildings, W.C, mny be seen in the chapel attached to the Rackham Street In- firmary, Netting Hill, "W. Staffordshire blue .bricks are the most suitable for external bases, plinths, and dwarf-walls for palisading, or wher- ever there is much trafRc.

Enamelled bricks are now very extensively used instead of tiles ; they can be obtained in various colours, and are suitable for facing dairies, &c., and areas where reflected or borrowed light is required. They are obtainable in double headers,

^ J viz. two ends enamelled for 9-

inch Avails, and double stretchers for 4 3 -inch walls, single headers

Fig. 8. ^^^^ stretchers for fticing, and

buUnose and chamfered bricks (Fig. 8) for jambs or reveals. The best kind are those bearing the stamp, " Cliff, "Wortlcy, Leeds." Firebricks should be used for all places exposed to the action of fire or intense heat. They are made of fireclay, and should be set with close joints in a mortar made of the same material,

MATERIALS AND GENERAL PRINCIPLES. 19

wetting the bricks before setting them. The mortar under the action of the fire will Titrify, and form one body with the bricks. In lining boiler furnaces, &c., bricklayers frequently use fireclay only with that portion of the work that will be subjected to the flame, but it may be set down as a rule that wherever it is necessary to use firebricks, it is also necessary to w&ejireclaij to bed them in. Nevertheless, when it is not readily obtainable, plaster of Paris and sand may be used as a very good substitute for small jobs, but on no account should cement be used, for being non- elastic it will fracture under the action of intense heat. Stourbridge bricks are much used as the best kind of ordinary fire-bricks, but Dr. Siemens has shown the Dinas firebricks to be the best, and to be capable of resisting the temperature of 4,000° to 5,000- Fahr.*

Characteristics of Good Bricks.

Soundness, freedom from flaws, cracks, or stones of any kind. They should contain no lumps of lime or limestone, however small; should be regular in shape and uniform in size, their length exceeding twice their breadth by the thickness of a mortar joint. They should not absorb at most more water than is equal to one-sixth of their dry weight. They should be hard, and burnt so thoroughly that there is incipient vitrification all through the brick. When struck together they should yield a clear metallic ring. (This last- * Dr. Siemena' "Chemical Society," 7th May, 1868.

20 BRlCKWOlUv.

mentioned characteristic belongs more to stocks and the harder kind of bricks.) Their texture should be homogeneous and compact. They should be regular in colour, with their arrises square, sharp, and well-defined. Pressed bricks, such as those from the midland counties and Ruabon, are almost non-absorbent, and for all practical pur- poses impervious to water. The nearer bricks approach to imperviousness the better will they be. The following is an analysis of the clay worked by Messrs. Monk, Is^ewell, and Bryon — Euabon —

Moisture .			lo4
Combined water			3-. 54
Silica			63-00
Alumina .			18-0
Sesquioxide of iron .			6-70
Protoxide of iron			1-9.5
Potash			2-37
Soda			3-10

100-20

Bricks and terra-cotta, manufactured from this clay, may be seen at the Northern Ilospital, Winchmore Hill, London, now in course of erection by Messrs. Wall Brothers, of London.

Bond of Brickwork.

We will now enter into what might be termed the scientific part of bricklaying, and it will not be out of place to repeat what Smeaton wrote half a century ago with reference to this sub- ject, and which is equally true to-day : " As the art of bricklaying is generally supposed to be so simple as to require little or no attention, it

MATERIALS AND GENERAL PRINCIPLES. 21

will be necessary to remove this false impression by a somewhat particuhir detfiil of the facts which relate to it. There are many persons, and even some workmen, who suppose that nothing more is required than that the bricks should be properly bedded and the work level and perpendicular. But the workman who would attain perfection in his business should acquaint himself with the different arrangements made use of in placing [bonding] the bricks, so that one part of the work shall strengthen another, and thus prevent one portion from a greater liabilitj' to give way than another." So much for the statement of an eminent engi- neer, than whom none knew better the value of bonding, as evidenced in the old Eddystone Light- house, which was so thoroughly bonded, one stone into another, and each into the whole, that nothing but the wearing away of the rock upon which it stood led (or was likely to lead) to its demolition.

Old English Bond.

Old English bond consists of alternate courses of headers and stretchers, while Flemish bond consists of alternate headers and stretchers in each course. Old English is the only true bond, the other bonds (and there are several) being merely arrangements to please the eye. Gwilt, referring to bond, remarks, in his " Encyclopedia of Architecture," that " previous to the reign of "William and !Mary all the brick buildings in the island were constructed in what is called English bond ; and subsequent to the reign in question,

22 BRICKWORK.

when in buildings as in many other eases Dutch fashions were introduced, we regret to say much to the injury of our houses' strength, the work- men have become so infatuated with what is called Flemish bond that it is difficult to drive them out of it. To the introduction of the latter has been attributed (in many cases with justice) the splitting of walls into two thicknesses ; to prevent which expedients have been adopted which would be altogether unnecessary if a return to the general use of English bond could be established."

Bond of Footixgs and Walls.

• The Metropolitan Building Act requires that the footings of all walls shall not be less than twice the thickness of the super- incumbent wall, or, as brick- layers call it, " the neat work." Fig. 9 represents the footing for a brick-and-a-half wall. A two- brick wall would require a four- brick footing, and so on, according to the size of the wall, setting back 2^ inches on each course of footings until the wall be brought into its proper size. Where a "bat " occurs in the footings, as in the second course, it

A should always be kept in

^ the centre. Fig. 10 shows

3

in elevation the footings and three courses of a 14-inch wall. It will be

Tig. 10.

seen that the " closer " is not used until the

MATERIALS AND GENERAL PRINCIPLES.

23

setting out of the bond for the " neat work." Figs. 11 and 12 are the plans of two successive courses of a one-and-a-half brick wall, showing the sectional bond. It will be seen by this that there are no two joints in the wall immediately one above the other, but that in the direction of the length of the wall there is a lap or bond of 2j inches of each brick over the two immediately below it in the next course, and a lap of 4^ inches in the width of the wall. This result is obtained by running the transverse joints right through tlie

Fig. 11.

Fig. 12.

wall from one side to the other. A simple prin- ciple, but seldom carried out even by bricklayers. The method in general practice is shown in Figs. 13 and 14. It will be seen that the trans- verse or "cross" joints do not run through the wall, but that the ends of the stretchers come in the middle of the headers, consequently the cross joints in the middle 4| inches of the wall are one over the other from the bottom to the top of the wall. This is caused by showing full "stretchers," a and h, in the internal angle, instead of letting them pass 2;^ inches into the return

24

BRICKWOBK,

wall, as in Figs. 11 and 12. Many bricklayers insist upon showing a whole "stretcher" in the angle in all cases ; but he who insists upon this has

—	61

Fig. 13.

Fis. 14.

yet to learn the bond of brickwork. The reader would be greatly helped to an understanding of bond by haying a few model bricks, and arranging

				>
- 1	i

Fig. 15. Fig. IC.

them as shown in these figures. Figs. 15 and 16 represent a straight jamb in a 14-inch wall. Here again, that the " cross " joints may run straight through the wall, it is necessary to introduce a

Fi3

Fit". IS.

three-quarter "stretcher" a, and to omit the "closer" in the next course above. Figs. 17 and 18 are the plans of two consecutive courses of a

MATERIALS AND GENEUAL rillNCIPLE?

25

pier 14 inches on the face and 18 inches deep. The face bond is made up of two three-quarter "stretchers" on one course,and of three " headers"

on the other.

Figs.

19 and 20 are two courses of

Fig. 19. rig. 20.

a wall two and a half bricks thick. In all walls of such a size as to take an odd half brick (two bricks and a half, three bricks and a half, &c.),the " stretcher " is always laid on the outside face in one course and on the inside face in the next course.

		\	D

zu

Fig. 21.

Fig. 22.

Figs. 21 and 22 show the " king closer," which in practice, owing to the trouble of cutting and the probability of breaking in the cutting, is seldom used. In this case two bricks are cut in

their whole length from 2j inches to 4j inches, but it is more frequently cut out ^*^- ^^■ of one brick, as in Fig. 23, and an adjoining " bat " is cut to fit it.

A great many instances of bond in diifcrcnt c

26

BRICKWORK.

sized walls and piers might be given, but as a thorough, knowledge of "bonding" can be obtained only by practice, we will not multiply examples.

If the bricklayer adhere to the principle of keeping the " cross " joints immediately opposite each other, and laying the bricks in one course quarter bond with the bricks in the course below it, he will experience little difficulty with any sized wall or pier.

Setting Out the Bond.

The chief thing in connection with brickwork is setting out the bond, for which a good brick- layer should be selected. This will be more readily conceded when we consider the strains to which a building is subject. The bond should be

r. . I, , I, 1.3

1 i n II

1:^5

r^

T^

I I ! ,1 I

:iL

3

I?

Fig. 24.

set out at least one course below the ground line, anl the positions of doors, windows, panels, or large apertures taken off the drawings. This is best don3 in a stretching course, setting a "perpend " for every reveal or jamb, and working the

MATEKIALS A>'D GENERAL PRINCIPLES.

27

1-L

u

7

" broken bond " under eacb window, or other aperture, as tbe case may be, as in Fig 24, a and b. Eeveals and jambs in point of bond should be treated as " quoins." Where a base occurs the " bond " should be so arranged that a whole brick will work in the internal angle above the plinth.

In Fig. 25 (plan and elevation) we have a 2i-inch plinth ; a "perpend " or vertical joint in the stretching course is

started 6| inches from , ' i I i ' ' 1 (

the angle at the base ; this joint " plumbed " up will be 9 inches, or a brick, from the angle above the plinth, and work proper or con- ventional "bond." In many cases the base is treated by bricklayers as if it were a detached part of the building, and the consequence is that " closers " are to be seen in the internal angles of many good buildings where whole bricks should be found. Such things, though small in themselves, go a long way to make up or to detract from the general effect and appearance of brickwork.

"Broken Bond " is the result of badly propor- tioned piers ; thus, in a pier 3 feet 2i inches long, the bricklayer would have to work four bricks and a quarter, but to do away with the quarter or " closer," a header and a three-quarter c 2

28 BRIC-KWORK.

" stretcher " are substituted for a " stretclier " aud the " closer," the three-quarter and " header " making up the " broken bond," and are kept as near as possible in the middle of the pier.

The work once above the ground, the building should be levelled all round, and a piece of hoop- iron fixed in a joint at each corner or angle to gauge or measure from, taking care that they are all in the same level course. A " gauge-rod," reaching from floor to floor, with all the courses and stone strings (if there be any) and heights of window sills and heads marked on it, should be given to the bricklaj-er to work to, by which means he can at any time see how his work is rising, which in London should not exceed nor be less than four courses to a foot ; and the care- less or inferior workman will then have no ex- cuse for not keeping his work level and to the gauge. Not working to a gauge- rod is the chief cause of thick and thin joints, though any compe- tent workman with a 2-feet rule should be able to keep his work right. The bricks in building should be wetted, but not to saturation, and the mortar of such a consistency that the "cross" joints between the bricks can be drawn up as the bricks are laid ; any open or partiallj' filled joints can then be filled by " flushing," which is to be preferred to " grouting," and shoidd be done on every course.

Heading Bond

is the name given to that arrangement in which the bricks are laid all " headers." This bond is used

MATERIALS AND GENERAL PRINCIPLES.

29

in circular and curved "walls of a short radius, and in round chimney stacks, so as to keep the wall within the " sweep," or arc, for if " stretchers" be used, every 9 inches of the wall will be a straight line, and when built will consist of projections and hollows, and will be in that state described by bricklayers as ''hatching and grinning." Heading bond should never be used on straight walls or where it can be avoided, as very little longitudi- nal strength is obtained, as will be seen by refer-

Fig. 27.

ence to Figs. 26 and 27, showing the angles of strain in two walls, one in heading bond and the other in English. The thick lines show the direction a fracture would take in the event of a settlement. They also show the space over which any given weight resting on either a or b would be distributed ; and this idea leads us to the consideration of the use of stone templates and strings in connection with brickwork.

30 brickwork.

Templates axd Strings. Templates under girders, principals, beams, &c., should always be of York, never of Portland or any similar stone, and should be at least 14 inches long — 18 inches would be better, but the length must be regulated by the weight which it has to carry. There is little doubt that " string courses " in the shape of a flush band were first introduced to impart strength to walls whose component parts were of diminutive dimensions (the Roman tile for instance, used in Roman walling), and that their ornamental feature was a secondary idea and an outgrowth of the former. String courses and bands are still used very ex- tensively for this purpose, and are placed gene- rally at the floor line, the window sill level, or the window head or springing line, and in some buildings in each and all of these positions.

Bats. A consideration of the previous remarks will have illustrated the evil attending the use of " bats." The greatest evil in connection with them is that workmen when walling, instead of fairly distributing them amongst the whole bricks, gene- rally allow them to accumulate on the scafibld, and when they have a quantity put them in the wall all together, much to its injury. Good work may be done with a fair proportion of " bats " if they be used with discretion ; and it is only fair to the builder that he be allowed to use the bats made on the job.

MATERIALS AND GENERAL PRINCIPLES.

31

Flemish Bond.

Having already pronounced upon the merits of this bond and given the opinion of an eminent authority (Gwilt), little remains to be said on this subject beyond explaining a few examples in diflEerent sized walls and piers.

Fiffs. 28 and 29 show a 14-inch wall with a

\n

Tig. 2S.

ri2

straight jamb, both sides Flemish bond, showing the way such a wall is generally bonded in prac- tice. The rule laid down to keep the " cross " joints straight through the wall is departed from in this example, consequently the joints in the middle of the wall are one over the other in the entire height of the wall. The proper method is showli in Figs. 30 and 31, in which the " closer "

a					h
				1
		1
	' ^ 1

Fig. 30.

Fig. 31.

is dispensed with, and two " headers," a, in one course and a three-quarter " stretcher," b, in the other are used. A heading and stretching course are obtained by laying whole headers on one face and "snapped headers" on the other. A still better bond would be obtained by laying the

32

BRICKWORK.

headers on each face, alternately "header" and " snap ; " but to prevent all " snaps " coming over each other and all whole headers over each other they (the ''snap headers" and the whole "headers") should be alternated in the height as well as on the level.

Figs. 32 and 33, the same wall, with the face

rig. 32. Fig. S3.

in Flemish and the back in English bond. A good strong wall can be obtained in this way, and where the inside has to be plastered it should always be so built.

Figs. 34 and 35, a two-brick wall, Flemish bond both sides. By snapping the headers in

riff. 34.

Fig. 35.

one course, 34, and putting them whole in the other, 35, a heading and a stretching course are obtained, Avhich gives a much better bond through the wall than if all whole headers were used. Fig. 3G, a quoin in isometric projection, showing the internal and external angle, and a perfect bond as far as obtainable in Flemish bonding with the in- side face built in Old English bond. Fig. 37 gives

MATERIALS AND GENERAL PRINCIPLES. 33

the bond of a two-and-a-half brick pier projecting from a wall. At r/ is shown a broken bond — two " stretchers" in one course and three "headers "

Fig. 36.

in the next course above them, which frequently occurs, and is the only legitimate " broken " bond in Flemish. Where a three-quarter " stretcher"

"Mil II	1 1
II II	II M
1 1 1 1 II	1 1
\ 1 1 II	1 1 II
) 1 1 1 1 II	1 1
- i	M . II

Fig. 37.

occurs as "broken" bond, it can be obviated or done away with by " reversing " the bond on one end of the pier or wall. Thus for a "stretcher" substitute a "header" and "closer." c 3

34 brickwork.

Yarious Bonds.

Chimney bond is a term applied only to 4|-inch external walls to chimney stacks. In this arrange- ment the disposition of the bricks is such as to obtain the greatest possible strength by bonding in the " withes " on every second course, and aToiding the use of bats as far as practicable.

Stacks of 4i-inch walls should never be built in Old English bond, for the reason that brick- layers, when cutting the half bricks to form " snap headers," will sometimes cut them 3J inches in depth instead of 4i inches, depending upon the par- getting or mortar to make up the thickness of the wall, which when the flue comes into use will shrink and crack, and falling away from the brickwork leave a stack, in many cases, built partly of closers. English bond is also objection- able on account of the numerous bats. Another practice in 45-inch stack building, and which cannot be too severely condemned, is that of "buttering" the cross joints with the point of the trowel; or, in plainer words, putting a mortar joint between the ends of the bricks, extending in about 1 inch from the face, the remaining 85 inches being left open, excepting what little may be filled up in the process of pargetting.

We believe this practice, together with that of plugging into 45 -inch chimney walls for fixing skirtings, to be a fruitful source of many fires, with accounts of which we are occasionally startled. The mortar or cement joints should be put n'^ht

MATERIALS AND GENERAL PRINCIPLES. 35

through the width of the bricks, and drawn up solid and tight. Stacks with 4|-inch walls may often be built with advantage in Flemish bond ; but the main thing to be attained is strength, which is to be obtained only by bonding in the "withes" or divisions between the flues. Another reason the author would advance in objection to 4|-inch walls for chimney stacks is that plumbers, in "flashing" roimd the base, cut out the joints for the purpose of turning in the lead ; and when wedging the same, thoughtless of the power exerted by the wedge, often break the bond of adhesion between the mortar and the course above the " flashing," leaving the stack in this condi- tion to withstand a wind pressure of from 40 to 50 lbs. on the square foot during a hurricane, often resulting in a coroner's inquest. Zinc "soakers" maybe used with much advantage in connection with stacks built with 4;^ inch walls, and the angles formed by the junction of the stack and the slating filled in with a small cement fillet, triangular in section, making a perfectly sound and water-tight job, doing away with the necessity of flashings, and preventing the evils that sometimes attend them.

English garden -wall bond consists of three courses of " stretchers" to one course of "headers." This bond may be said to have grown into disuse, excepting in the north of England, where five courses of "stretchers" to one course of "headers" are frequently used in general building. Flemish garden- wall bond consists of three " stretchers "

36

BRICKWOKK.

to one " header " in every course, as in Fig. 38. Garden-wall bond is used only, as its name implies, for 9-incli garden walls that have to be kept fair

I ,11

1 T

J, I I-

Fig. OS.

or smooth on both sides. The bricks vary most in their lengths ; the more ** headers" that are put through the wall will, therefore, add to the diflS- culty of keeping it straight.

Herring-bone Bond.

Figs. 39 and 40 represent a panel filled in with bricks laid " herring-bone." The former is gene-

Fig. 39.

Fig. 40.

rally the method used in paving, where the bricka are laid on their beds, 4| by 9 inches, in sand, and " grouted " up with cement or mortar. The latter is used for filliug in panels under windows and for tympana of arches, and are laid four

MATERIALS AND GENERAL r-RlNCIPLES. 37

courses to the foot. When a large area of paving has to be done in this way, the simplest way will be to work from a centre line, and lay the middle course first and at an angle of 45 degrees, the other courses will then follow, and the points may be kept right by means of a line drawn parallel to the centre line.

In a panel, the first brick starting from the corner should be set to a small set square, forming a right angle and two angles of 45 degrees, and measuring from the base to the apex 3 inches, or whatever the bricks will work.

Dutch Bond.

arrangement cs It is a modification of English bond, the " closer "

Fig. 41 is an arrangement called Dutch bond.

-izi~rTT:rT~in'7rT-]

' 1 I I I . I I III T'Tl

1 .1 ' L II , I I : I Vi

Fig. 4] .

being omitted and a three-quarter " stretcher " used on the " quoin." In every third stretching course a "Flemish header" is introduced next to the " quoin " brick, by which means the " stretchers " in that course arc pushed forward, and overlap the " stretchers " below 4| inches, instead of being " plumb " over them as in other

38 BRICKWORK.

bonds. The advantage of this bond is that addi- tional strength is imparted to the wall in the di- rection of its length, and that without diminishing its transverse strength. A writer in the Builder, from which Fig. 41 is taken, speaking of this sub- ject says : " As regards construction in common English and Flemish bonds, no greater tie in the direction of the wall is obtained than 2^ inches which one brick overlaps another. If, therefore, a fracture takes place, the crack runs down the wall, following the joint with only that small deviation from a perpendicular line ; but by the Dutch method a crack would have to follow 4 1 inches to the right or left in the courses containing the 'Flemish header,' or else break through the bricks. Clearly, therefore, wo have some additional strength, the lap between the courses of 'stretchers' being as much as 4 J inches."

The adjoining Fig. 42 shows the way in which buttresses and chimney ^^^' ^' stacks are reduced. They

are generally " tumbled in " at an angle of about 60 or 70 degrees. The beds of the bricks should always be at right angles to the " tumbling in." The bond on the " battering " jamb will be the same as on the upright jamb below.

materials and general principle?. 39

" Keeping the Perpends."

Architects usually specify that the " perpends " shall be kept, or, in other words, the yertical joints are to fall in plumb lines from top to bottom. Owing to the difference in the sizes of bricks, this cannot be done with bricks as they come to hand ; they must be sorted to a length, or cut where necessary, by the bricklayer as he proceeds with his work. This would add to the cost of the work, and, as cost has to be con- sidered in most buildings, it is seldom done. But if the bricklayer carry up a plumb line in the middle of large piers, and work his bricks between that and the plumb reveals or jambs, he will be able to keep his " perpends " tolerably regular. The " closers " should be cut to a 2i-inch gauge.

Toothings.

Toothings should not be allowed in a building where they can possibly be avoided ; they are a source of weakness, and very often a disfigurement to a building. When building into toothings, the bricklayer seldom takes the time or trouble to make solid work ; and where they have been can very often be traced in buildings that have been up but a short time by the pointing having fallen out right down the line of toothings. This is caused in frosty weather, by the expansion of moisture which has got into the hollow parts of the toothings, forcing the pointing from the brickwork, to be washed off by the first heavy

40 URICKWORK.

rainfall. Where toothings arc unavoidable, they should not be carried up in a straight line from bottom to top, as they usually are, but should be stepped back everj' few courses, so that the new work may be bedded solidly here and there. When building new work into old, a chase is preferable to a toothing, as the new work is left free to settle. But in a front where new work has to be built into an old toothing there should be no mortar used in the toothing ; the new work should be kept a trifle high above the old, and the joints of the toothing filled in after the building is up. Among the characteristics of good brick- work are solidity, perpendicularity, smoothness ; the vertical joints carrj- a plumb line from top to bottom; the "cross" joints of the "stretchers" fall immediately in the centre of the "headers," and the bed joints arc neither too thick nor too thin.

Grouting.

" Grouting " is the practice of using mortar or cement in a semi-liquid state to fill up the open joints in the work, the result of careless or bad workmanship. In some works every course is " grouted" in ; in others every four courses.

"Grouting " is not the best way to obtain solid walls, for the mortar being in a serai-fluid state, the excess water is absorbed into the bricks of which the work is composed, and, as a conse- quence, the "grouting" shrinks or subsides, leav- ing the joints or interstices only partially filled. A

MATERIALS AND GENERAL PRINCIPLES. 41

better process is tliat oi" lan'yinrj-up,'' wMcli is, after having laid a course of bricks on eacb side or face of the wall, to put a proper amount of mortar in the wall, and by the addition of water, and the use of trowels, shovels, or a larry, to reduce it to such a consistency as to be able to swim in the bricks solidly. Even in this practice there is a subsidence or shrinkage of the mortar, with the same effect, though in a less degree, as described in "grouting." But the best and proper plan is undoubtedly that of putting up the joints solidly through each brick as it is laid, and having the mortar of such a consistency as to be able to draw the joints up solidly when filling in the middle of the wall.

Flues.

Of the abominations of a bad building, bad flues are second only to bad drains. The causes of smoky flues are as follows. The sectional area of the flue is either too large or too small. Its sec- tiono.l area is cramped, the ** cramp" generally oc- curring in sharp bends, close to a floor, where the bricklayer has to make room for another fire- place. The flue is too short, or is not carried up high enough to be above some adjoining building or contiguous wall. There is too much air-space below the throat of the flue, or, in bricklayers' phraseology, the wing gatherings are not brought over fast enough. In considering the scientific principle of flues, we should remember that the properties of air in their action are very similar to

42 BRICKWORK.

those of water. A stream with a straight smooth course flows swiftly and regularly, while one with a rugged winding course is full of eddies and whirls, and flows with a retarded velocity. So it is with flues. An unused flue contains a column of cold air in equilibrium with the surrounding air. This column of cold air must be rarefied or heated before a good draught can be obtained, when the denser air rushes in, pushing the lighter up. This will account for the fact that a flue never draws so well when the fire is first started as it does some little time after.

Where the flue is unnecessarily large, a larger volume of air has to be rarefied, and it also admits of a possible down draught, or in other words an ascending and a descending column, inconsequence of the heated air not filling the flue. Where the flue is " cramped " somewhere in its length, the cause of smoking is that the smoke is checked in its ascent just were the "cramp" occurs, the smoke escaping with a retarded instead of an increasing velocity. Sharp bends have the same efi'ect, though in a less degree, as " cramps." Yet it is a common thing to hear bricklayers advocat- ing sharp bends in flues to increase their draught.

Every flue should be formed with sufiicient bend to prevent the daylight and rain falling upon the fire.

Where a flue terminates below an adjoining wall, it will often smoke in consequence of a down draught, caused by the wind striking against the wall and in its rebound passing

MATERIALS AND GENERAL PRINCIPLES. 43

down the flue, or at least obstructing for a time the passage of the smoke from the flue, which in efiect is similar to a down draught. "Where the throat of the flue is formed high up above the chimney bar there is a large volume of cold air collected which has to be heated or rarefied to get a proper draught ; until this takes place the smoke is obstructed in its ascent, and driven back into the room.

To cure these evils, innumerable contrivances have been invented, of various forms and difierent degrees of ugliness, and it is almost rare to see a house in the metropolis that is not surmoimted with one or more of these articles, each advertised as a panacea for smoky flues. These so-called remedies are (with the exception of the " blower ") always applied to the top of the flue, when in fact the remedy is generally required at the bottom or somewhere in the length of the flue. We would give the following advice for flue building. Form the throat of the flue as low down as possible, and let the sectional area be the same throughout its entire length, avoiding all bends beyond what is necessary to hide light. "NATiere bends cannot be avoided let them be as easy as possible, and carry the flue well up above con- tiguous structures, and let it be pargetted smoothly inside. In building flues " coring holes," 12 X 14 inches, should be left out on every floor, or at least where every bend occurs, and a piece of board put in to catch the mortar and brick rubbish that fall while in erection. By

44

BRICKWORK.

this method the flues may be easily " cored " or cleared without the aid of a chimney sweep. Flues for dwelling-houses arc generally for registers, 9 X 14 inches, and for kitchens 14 X 14 inches. Fig. 43 is the plan of a fireplace and flue for a register stove, which we insert by permission of the originator, H. Saxon Snell, Esq., F.R.I.B.A.

Fig. 43.

The peculiarity and advantage of this fireplace is that the sectional area or throat of the flue commences immediately on the chimney bar, doing away with the necessity of wing gather- ings and the possibility of cold air collecting round the base of the flue. This for its economy of construction and efficiency of action recom- mends itself for general use.

All chimney stacks from the part where they pass through a roof, or from the point where they separate from a wall with which they have been in junction, to their tops, should be built in cement and sand instead of with lime mortar.

Where several flues are grouped together in

MATERIALS AND GENERAL PRINCIPLES. 45

one stack, instead of dividing them with the usual 4|-inch brick " withes," Boyd's flue-plates (iron plates | inch thick, and about 12 inches square, fitting into each other with a tonguedand grooved joint, and built into the sides of the stack) are often introduced to economise space.

To ensure that flues shall have the same sectional area in their entirety, they are sometimes built round a wooden section-box, open at both ends and with a wooden " strap " to take hold of, that the box may be pulled up from time to time as the work progresses. The box is placed in the space intended to be occupied by the flue, and the bricks carefully laid with full joints against the box, which is drawn up about every two or three feet. In some cases the pargetting is dispensed with, and the joints struck instead. Good flues are undoubtedly obtained in this way. The same end is obtained by the use of Doulton's terra-cotta flue-pipes ; but when built in small detached piers (as they sometimes are), they prove a source of weakness by interfering with the bond of the work. Where they are grouped in stacks there should be a space of 4 J inches between each pipe, to admit of bonding the stack in the direction of its width.

46 BRICKWORK.

SECTION II.

AKCHES IX GENERAL.

Arches.

Arches are of various kinds, but those wliicli the bricklayer has to deal with are either circular, segmental, scheme, elliptic, or Gothic. To the young operative, and in many cases to the aged workman, they are veiled in mystery, though a little application and determination to understand .them would soon make them clear to the opera- tive who would be master of his trade. Time was when the arch-cutter would box himself up and carefully tack strips over the chinks between the boards that prying eyes might not penetrate into his cutting-shed and discover the craft by which he held himself superior to his fellow-workmen. This jealousy and exclusiveness is still alive, though it is being slowly trampled under by means of the flood of light that is spread abroad, and is still spreading, from technical classes and technical publications. If the young workman will but set to work in earnest, there is every facility to acquire technical knowledge, and to make himself, as a workman, superior to those who have gone before, and who,

" By geometric scale, Did gpauge the si/e of pots of ale."

Let him but catch that spirit breathed forth in

ARCHES IN GENERAL. 47

Longfellow's lines to Strasburg Cathedral, and success will surely be bis : —

" A great master of his craft, Edwin von Steinbach ; but not he alone, For many generations labour'd with him. Children that came to see these saints in stone, As day by day out of the blocks they rose. Grew old and died, and still the work went on, And on, and on, and is not yet completed.

The architect Built his great heart into these sculptured stones. And with him toil'd his children, and their lives "Were buUded with his own into these walls, As offerings to God."

The word arch implies an arrangement of bricks or other material in which all its parts — we might with equal propriety say particles — are in equilibrium ; or, in other words, that the pres- sure or thrust to which it is subjected is trans- mitted from one course to the other, and distri- buted throughout the whole of the arch, each course or voussoir taking its share. . Every brick- layer who has turned an arch will have noticed that this condition is not obtained by simply turning the arch on its centre and keying it in, the tendency being for the arch, by reason of its own weight, to spread out at the springing, or if this be prevented to buckle up at the haunches, to prevent which and bring about equilibrium, calculations have to be made so as to apportion the weight at the haunches to resist or counteract the thrust from the crown. Such mathematicians as Dr. Ilooke, Huygens, Leibnitz, and many others, devoted much time and attention to the solution of the principle of the arch under the

48 BRICKWORK.

name of the catenary curve (Latin catena, a chain) ; and the conclusion they arrived at was, that the true shape of an arch is that into which a chain would arrange itself if freely suspended from two points whose distance apart is equal to the span of the intended arch. We have mentioned these things because, considering the way in which arches are often thrown together, it is well that the artisan should know there is a principle involved in their construction.

Eelieving Arche?.

Relieving arches should be turned over all lintols where practicable, and should spring clear of their ends. They should not be built, as they generally are, solid on the brick " core," whereby the weight of the wall above is transmitted from the arch to the " core," from the " core " to the lintol, and from the lintol to the frame, very often to the great injury of the latter ; but should be built at least f inch clear of the " core." This can bo done by putting a layer of sand f inch thick on the core, and raking it out with a trowel or piece of hoop iron when the arch is turned, that it may take its own bearing. They should be turned in compo.

The above remarks apply to where the window and door frames are built into the brickwork during erection ; and more particularly to arches intended to relieve free-stone rectangular door and window heads. It is not an uncommon thing to see such heads fractured right through their

AKCHES IN GENERAL. 49

depth in about the middle of the openings which, they span, and kept from falling only by the weight of brickwork upon their ends ; though the architect has been careful to provide against superincumbent weight by the use of relieving arches, but which, through inexperience or want of judgment, or some other cause, have been built upon a solid " core."

Plain Akches.

All arches put in with bricks as they come from the brickfield come under the term plain arches, and are built in concentric rings of 4| inches laid as "headers" on edge, instead of bonding by " stretchers," to avoid the large joints that would unavoidably occur at the extrados, thereby decreasing the strength of the arch unless it were built with cement, or a strong hydraulic mortar, as lias.

The Skew or Oblique Arch.

This arch is used in the construction of bridges over roads or waterways where the bridge is not at right angles to the road passing under it.

Two very remarkable arches of this kind may be seen on the Metropolitan District Eailway at Brondesbury, and which the writer believes to be the only bridges so constructed. Of these we will speak hereafter.

To set out and understand drawings of the skew arch, a knowledge of solid or descriptive geometry is indispensable ; but as the setting out

D

50

BRICKWORK.

is generally performed by the engineer or in- spector of works, we will confine our remarks to that portion of the work which properly belongs

to the operative bricklayer. F

A B c D, Fig. 44,

Fig. U.

represents the plan of a skew arch of which e f c would be a section cut square with the abut- ments. E c A is called the angle of skew, for it shows how much out of square the face of the arch is with the road, a c is the face of the arch, and as the "bed" joints (called by engi- neers "coursing" joints) start square from the face, they must run in a diagonal direction across the centre, as seen in c d « b, which is a develop- ment of the soffit of the arch. To make this clear, we will suppose the courses to be pencilled on the centre, and a sheet of white paper folded round the centre and rubbed until the pencil marks be transferred to the paper. If the paper —

ARCHES IN GENERAL.

61

fastened at c d, the abutment line — be now un- folded from tbe centre and spread out on a level surface as in Fig. 44, we shall have a develop- ment of the soffit of the arch, c a is the length of the line on the centre from c to a. d 6 is the length of the line on the centre from d b, and is

Fig. 45.

parallel with ca. cb is the length of a line on the centre from c to b.

In long skew arches the bricks, instead of being laid on the skew all through the arch, are D 2

52

BRICKWORK.

arranged as iu Fig, 45, wliere the skew courses are intersected by courses laid parallel "svith tlie abutments. The skew courses are marked on the centre by means of a " coursing mould," which should be supplied by the engineer or inspector in charge of the work, a b is the plan of a line on the centre from a to b. All the courses on the centre will be so many spirals or screws parallel to each other. Each brick on the face of the arch will require a different bevel, but by far the easiest and the best way to get these will be to let the bricks stand well out in front of the face line, and cut them off to the line of work when the centre is struck. But when the bricks used are too hard to be cut, such as Staffordshire blue bricks, they must be moulded to the required bevels.

Tig. 4o.

Skew Arch at Brondesbury.

The remarkableness of this arch or skew is not alone in its construction, but in the angle that it makes with the roadway that it spans, the angle

ARCHES IN GENERAL.

53

being so acute as to cause tlie abutment line or skew-back of one side to fall without the abut- ment line of the other side. This is shown by the line a b at right angles to c c, d d, Fig. 46.

Fig. 47.

Let us imagine that across a given road we have to construct a bridge whose angle of skew

54 BRICKWORK.

shall be equal to that on the accompanying

rip. 4S. Fiff. 49,

Fig. 46. It is clear that we cannot construct it on the principle of the ordinary skew arch, viz.

ARCHES IN GENERAL. 65

to take tlie courses (starting square with tlie face of the arcla) as so many spirals across the centre, finding their abutment in the line c c, and as we have explained at page 60. An arch so con- structed could not stand, for the lines of force, or thrust, acting at right angles to the abut- ments, would find no resistance, and consequently collapse. But the engineer who designed the bridge in question, seeing this, fell back on the principle that should regulate the construction of all arches where strength is required, that the heel joints shall ho in the line of radii, and on the soffit parallel with the ahutment, and thus in the simplest, yet most eflPective manner, solved the otherwise difficult problem. Fig. 47 shows the sectional elevation on the line e f in plan. Fig. 48 the plan, and Fig. 49 the face arch in elevation of a bridge somewhat similar to that at Brondes- bury, constructed in the same way, and involving the same principles.

The plan of the abutments and skew-backs are shown by dotted line (Fig. 48).

The following are approximate dimensions of this bridge, which we have taken by step mea- surement : distance between abutments, 45 feet ; depth of bridge, measured along the abut- ment, 26 feet ; rise of arch from cord line to crown of soffit, 20 feet ; projection of one abut- ment beyond the other (d beyond a, for instance, Fig. 46), 36 feet. The arch is made up of twelve 4j-inch concentric rings of brickwork.

56

BRICKWORK.

Water Conduit.

Fig. 50, a section of a water conduit in Massa- chusetts, U.S.A., upon whieli the author was engaged as inspector of works, is worthy of notice, as showing the construction resorted to where a bad bottom occurs. In this case a large

Fig. 50.

portion of the work (which was eighteen miles in length) ran through very swampy ground, a natural watercourse that di'ained a large tract of the adjacent country, and at times so great was the pressure of the water as to cause it to rise in a natural fountain 6 or 7 feet above the exca- vations. When this occurred, stones of sizes similar to those of which the retaining walls were

ARCHES IN GENERAL. 67

built were shot into the hole until the water subsided or found an easier outlet elsewhere. It was also necessary to keep pumps working night and day.

The bottom consisted of 6 X 6 inch transoms, 18 inches apart, to which were spiked 2-inch planks, and these in turn were covered with 1-inch boards, with joints properly broken, as in floor- ing. The invert, when the side walls were built, was formed with concrete ready to receive the brickwork. The whole of the work, including concrete, was built in Rosendale cement, manu- factured in Hosendale, New York, from a stone found in that locality, which when manufactured is in colour very similar to Roman cement, but less quick in setting, and attaining a greater ultimate strength. It will be noticed that the sides of the invert are struck from the springing line a, and the bottom from h, and that to get the requi- site skew-back for the top and bottom beds, a pio'pose made brick is introduced, whose beds arc in the line of radii from a and h.

Sewers are constructed on the same principle as water conduits, with this difierence, that while strength and sound work suiSice for the latter, to these must be added smoothness for sewers, avoid- ing all " shoulders," " lips," protuberances, or other irregularities likely to increase friction, or in any way retard the velocity of the sewage. "Where the flow is intermittent they are generally built egg-shaped, to minimise the frictional area.

d3

58 BRICKWOKK.

Groined YArLTiyc.

Brick groin-Taulting (a very neat sample of which may be seen at the entrance to Winchester Flats, "Winchester Terrace. Chelsea Embankment) was at one time very much in practice, but moulded stone ribs finishing at the apex with a carved boss now generally take the places of the brick groins. Samples of this kind of work may be seen at St. Augustine's, Kilbum ; St. John's, Auckland Road, Upper Norwood, and the red brick church adjoining the Croydon railway station, all designed in that style known as the thirteenth century, or Early English, by John L. Pearson, E,.A. Some good Gothic vaulting in red brickwork may also be seen at the New Law Courts, London. In executing the groin the bricks must be cut so as to form a return on the intersecting arch or vault ; but a proper bond, as in square angles, cannot always be obtained, for, instead of the bricks returning from right to left and from left to right every other course, it will be found necessary to sometimes return several courses in succession, all from one side, before getting what bricklayers would call "a tie." This is caused by the groin not getting away fast enough from an imaginary line drawn across the arch from e to g Fig. 51. It is also impossible to keep the perpends regular near the groin, but they should be kept as regular as practicable with a good bond on the groin.

Before the bricklayer can cut his bricks, the

ARCHES IN GENERAL.

59

centres must be placed m position, and the bricks can then be cut to fit the intersection, which they should very accurately, and when the centres are " struck " present clean and well-defined arrises. Fig. 51 is the plan of two semi- cylindrical vaults, intersecting in the groins e f

Fig. 51.

and G H. The curve formed by the groin is an ellipse shown in angular elevation on e f by dotted curve. Sections of the vaults are shown on A B and c d. Sometimes instead of being as here shown, the intersecting arches are Gothics, or one Gothic and the other semi- cylin- drical ; but if what we have written be understood no difficulty will present itself. In all such cases the bricklayer must space his centre out into courses, and turn the arches as any other arch, with the exception of the groin, which must be treated as described.

In Gothic vaulting, as described above, in

60 BRICKWORK.

^hich the spaces between the stone springers are filled in M'ith brickwork, the setting out of the courses is done by marking upward from the intersection, or springing of the ribs, an equal distance along the cross rib and the diagonal or converging rib, and connecting these two points with a line. Upon another line at right angles with this, the courses may be pricked in from springing to apex, and their beds shown by lines parallel with the first line, connecting the ribs. A sample of fan-groining, in red brickwork, may be seen at the subway to the Crystal Palace, Sydenham.

GAUGED-WORK AND ARCH-CUTTING. 61

SECTION III.

GAUGED-WOEK AND AKCH-CUTTING, Gauged TTork.

" Cutting " is divided into " axed work " and " gauged work." In the former the bricks are finished with the Scotch, with just a rub or two round the rubbing stone to take off the irregulari- ties of the beds, allowing -nr of an inch joint for tuck-pointing. This work is intended to represent " gauged work," and is supposed to be a trifle cheaper. " Gauged work " is a very superior kind of brickwork, executed in soft bricks set with a white putty joint, which should not exceed the thickness of a new sixpence. The bricks used are Fareham rubbers and T. L. B. rubbers for red work ; and malm-cutters and sometimes white Suffolks for malm or stock work. Of red bricks Fareham Rubbers are the best ; they are of a close, firm texture, will carry a sharp arris, and weather well ; in colour they are cherry red. No. ones T. L. B.'s are good bricks, though less firm than Farehams, but of an even texture ; they are divided by colour into two classes — cherry-red and orange tint. The orange is gene- rally used, as they contrast well with the red building bricks, but will not carry so sharp an arris or weather so well as the darker bricks.

" Gauged work " is often objected to on the ground that it will not resist the action of the weather. This we can refute by our own ex-

62 BRICKWORK.

perience, for we have taken out old "gauged" arches in malms that have withstood for forty years the acids contained in London smoke, and have shown no signs of decay or disintegration. We can cite another instance of the indurating properties of " gauged work " in white Suflfolks when exposed to the action of the atmosphere. During the erection of the Rackham Street Marylebonc Infirmary, some geometrical win- dows in these bricks had to be cleaned down some three or four months after erection. This process had to be done by rasping the face of the brickwork, and so hard had become the bricks that it was with difficulty that an impression could be made at all, the rasps sliding ofi" the work and leaving a black mark ! Bricks in this condition are said by bricklayers to be case-hardened.

This so-called case-hardening we attribute to the process of setting. In good setting the bricks are always soaked (not to saturation) in water, which in a building in course of erection always contains more or less lime in solution, which is taken up by the brick while soaking, and by exposure to the atmosphere becomes carbonised and forms a hard coating, as it were, upon the face of the brick. This case-hardening is also attri- buted to " the silicic acid in the clay acting upon the cbalk so as to form some of it into a silicate of lime." Rubbers are purposely made much larger than the ordinary building bricks to allow for cutting and gauging them four courses to the foot, though as a rule they will not hold out or

GAUGED-WORK AND ARCH-CUTTING. 63

bed more than 11| inches with close joints. T. L. B.'s as they come from the brickfield measure lOj X 4| X 3| inches.

They are also obtainable 12 inches long, but bricks this length are only required for Camber arches, or Gothic arches whose bed joints radiate from the centre, as in Figs. 57 and 58, in which so much of the brick is cut away to form the long bevels on the soffit and crown, that the ordinary sized bricks will not " hold out " to the required lengths, and have therefore to be lengthened, where necessary, by forming the long ''stretchers" out of two three-quarter bricks (this will be best understood by examining a few actual camber arches) ; to obviate which, the 12 inch bricks are made.

Setting.

In setting "gauged work" the joint is taken up by absorption by holding the bed of the brick in contact with the putty, which must have the proper consistency and be kept in a small putty- box made with a level top, so that the setter can rest or steady his arm upon it while " dipping " his brick. Before putting the brick in place, the putty is scraped off the middle of the "bed," that it may set or joint more evenly. The joint should not be touched after the brick is "bed- ded," but should be left full like a small bead. Stone lime should be used for setting, as chalk lime is not fit for out-door work. Axed-work is generally set with putty and cement. If the

64 BRICKWORK.

work has to be carved deeply, it is best to build it all " headers," and " grout" it in solidly at back with Portland cement, that the bricks may not break up or get disturbed under the chisel of the carver. A composition of whitening and patent knotting is more frequently used than lime-putty for bedding or setting work intended to be carved, and for ornamental key-blocks made up of two or more bricks. It will be found most convenient to put such keys or blocks together in the cutting- shed, and take them upon the building to be set as one piece of work. These remarks apply equally well to the niche hood in every particular. Gauged work intended to be bedded in the above composition should be quite free from moisture ; but the bricks should not be placed round a fire for this purpose, as they often are, for by so doing they are made fragile and are easily broken. It is, therefore, very imperative that a good water- tight cutting-shed be made for the bricklayer and another shed for the bricks.

Drawing and Cutting Arches.

This forms a very important branch in the trade of the bricklayer, and a thorough knowledge of it is indispensable to the operative who would be master of his trade. In this section we will endeavour to make clear not only the setting out of the various arches, but how to take off the bevels and moulds, and apply them to arch-cutting.

An understanding of this will not be so difficult as may at first sight appear. The tools required

GAUGED-WORK AND ARCH-CDTTIXG. 65

for this work are — the rubbing-stone (which should not exceed in diameter 14 inches), hammer, boaster, Scotch, scriber, and tin-saw. The scriber is a small tin saw, used for marking the beds and bevels on the bricks.

The Bulls-Eye

Should have four keys, a, b, c, d, which when possible should be " stretchers ;" but as this cannot always be done unless rz

by very much reducing the size of the courses (techni- cally called roussoirs), they r{:^z=L. f-^-^^-^6 are, therefore, frequently put in as in Fig. 52. The face mould for this arch is obtained by making a wooden Fig. 52.

pattern, as at d, on which the actual length of the brick is marked, and also its bevel, which is taken off the drawing by placing the stock of the bevel along the bed joint, and moving the blade until it coincides or is in line with the soffit of that particular brick whose bevel is required. All the courses have the same bevel and the same length. It is usual to have two moulds made, so as to trace or traverse the courses round the arch, to ensure that the key brick will come in rightly (though one mould and two parallel straight edges would do equally as well) ; for if the mould be in the least inaccurate, the inaccuracy will be trans- mitted to each brick, and this multiplied by the

66 BRICKWORK.

number of courses in the arch (in this case 36), supposing the inaccuracy to be iV of an inch, would amount to 2j inches, in all probability the thickness of a course. Having proved the moulds, the pattern brick or soffit is marked lower down on the mould, that the brick when cut will be the thickness of a joint less than the brick shown on the setting out. The bevel of the thick end or c.rtrados, as it is named, is the same as that of the soffit.

The arch cutter will find it most convenient to have a square piece of wood, 4| by 9 inches, with parallel sides, which held flush with the soffit will give the exact place and bevel of the cross joint, and held longwise the length of the brick and its end bevel.

In cutting, the first operation is to square the bed and face of the brick, after which the soffit is bevelled. The brick is then placed on a bedding board (a piece of slate or wood with a straight even surface) in the same position that it will have in the arch. The face mould is applied to the brick with the soffit mark against the soffit of the brick, and the scriber drawn along the top edge of the mould marks the wedge shape which the brick will have when finished. The back of the brick is marked in the same way, and is then finished with theboaster, Scotch, and rubbing stone.

Semi and Skgmknt.vl Arches.

What has been said of the bulls-eye applies in every respect to the semi (Fig. 70) and the seg-

GAUGED-WORK AND ARCH-CUTTING.

67

i^.''''

Tig. 53.

ment arch. To draw the curve (Fig. 53), tlie span and rise being given, bisect the line a 1) with c d; join eb, and bisect this line •withih; a line drawn from ^ through b will give the line of skew- back. Taking the dis- tance i b in the com- pass, with one leg- fixed at /, the lower curve may be drawn from b to a. Nine inches measured along the skew- back from b will give the point from which to draw the outer curve. On the outer curve, with c d as centre line, set out 3 inches, or whatever a brick with its joint will hold out, and with the mould (shown by dotted lines) trace the courses down to the skewback, increasing or diminishing the thickness of the brick as may be required by raising or lowering the mould.

The Camber Arch.

Fig. 54 is a camber, 12 inches deep, in Flemish bond. The skewback is obtained by taking in the compass the distance a b, and from these points, with a b as radius, drawing the inverted Gothic ; a line from c through b will be the line of skewback, or springing. To draw this arch when the skewback is given — say 4i inches — from the centre line set off the distance between the reveals from a b; 12 inches above the springing.

68

BRICKWORK.

draw the line d c, and from centre Kne along d e measure off a distance 4| inches beyond the reveal ; from this point draw a line through b, intersecting the central line in c. On d e measure off 1| inch each side of the centre line, or whatever a brick with its joint will measure. Lines drawn from these two points to e will represent the key, and also the face mould. Make two moulds 9 inches

(4| inches at each end) longer than the key. With the mould, shown by dotted lines, upon the key, on one of its edges,/; where a h meets it, make a pencil mark. Put the other mould on top of this and transfer the mark to it. "With the two moulds, keeping the pencil mark always on the line a h, traverse the courses in down to the skewback as described in the bulls-eye. Take off the bevels, starting from the skewback, and pencil

GAUGED- WORK AND ARCH-CUTTING. 69

them upon the mould, 1, 2, 3, and so on, as shown in Fig. 00, a, which is a mould with the lengths and bevels of each course upon it. One-half only of the arch need be set out. The cross joints may be cut in the courses with the saw and parallel board, as previously described, always working from the soffit. For greater accuracy and distinctness, the bevels may be pencilled on the back of the mould, at the top end, keeping them some little distance apart, and numbering them as already described. The courses may be traversed in by working from the. top line d e, instead of from the soffit, marking on the mould,

downward from the top mark, the length of each course. Having thoroughly understood the set- ting out and cutting of this arch, no difficulty will be experienced with any of the ordinary arches.

The soffit generally cambers \ of an inch to the foot.

The camber is not suited for large openings, or where any considerable weight has to be carried, as it is in reality not an arch at all, but simply an arrangement or scheme.

The Gothic Arch.

Bisect the line a b, Fig. 56, with c d, and draw ad; from these two points with the compass

^0

BRICKWORK.

opened to more than half their distance draw the arcs s f. Through their intersections draw a line meeting « 6 in y, from which point with the

compass opened to a, draw the curve a i d, and by extending the compass, its parallel curve. From h draw the curves on the right-hand side. The bed joints radiate from // and g, as shown by-

Fig. 57.

dotted lines. To do away with the very wedge- shaped key, the joints are sometimes radiated from the centre, as in Fig. 57. This key is also

GAUGED- WORK AND ARCH-CUTTING. 7.1

objected to by some on account of the oddness of its appearance at the key — a " stretcher" on one side and two "headers" on the other (this is what bricklayers call keying in with a joint), to pre- vent which a " birdsmouthed " key is used, Fig. 58. In the last arrangement the arch has an odd number of bricks, in the two former an even number. Whatever objections may be urged

riff. 5s.

against the appearance of Figs. 56 and 57, the birdsmouthed key in Fig. 58 is decidedly wrong : —

*' The essential character of the Gothic arch is derived from the absence of the key-stone, and from the presence of the perpendicular joint or opening in the centre where the archivolts rest against each other. Until we find this feature, Gothic architecture does not exist," — Normand)/ : Archifcctiirc of the Middle Ages.

Fig. 56 is made up of two segments of a circle, and the mould is obtained in the same way as that for the segment. The moulds for Figs. 57 and 58 are obtained in the same way as that for the camber, the bricks being all of a

72

BRICKTVORK.

different bevel and length. These like the cam- ber are schemes, not arches, as the bed joints do not fall -within the lines of radii.

The Ellipse Gothic Arch. Divide the span a b, Fig. 59, into three equal parts ; take two parts in the compass, and with one leg fixed at a draw the arc d e, and from d

Fig. 59.

the arc a e. In the same way draw the arcs l f, cf. Through e and d draw the line eg; through c f the line / //. TTith d as centre, radius d b, draw the arc b i, and from e, radius e i, the arc ij. The points from which the joints radiate are shown by dotted lines. Two different face moulds are required for this arch.

The Semi-Ellipse Arch.

Divide the span a b, Fig. 60, into two equal parts, a c, c b, and a c, into six equal parts, 1, 2,

GAUGED-WOKK AND AROH-CUTTINO.

'3

3, 4, &c. From c towards b measure off two of those parts, and with the distance 4 d in the com- pass, and one leg fixed at 4, draw an arc cutting- the centre line in e. Through e cl draw the line ef; with d as centre, radius d b, draw the arc b g, and from e Avith radius e g, the arc g h. Two ways are here shown of putting in the courses — one in which the joints radiate from their centres

or foci d e, the other from c the centre of the opening. In the second method the lengths and bevels of each brick would be different. The first is an arch, the second a scheme, and is never adopted except in face work when, in the opinion of some people, it is desirable to have the courses all one thickness, even at the loss of strength. In the second method the mould, lengths, and bevels are taken off in the same way as those of the camber.

74

BRICKWORK.

The Yexetian Arch.

This so-called arch, Fig. 61, is made up of the camber and semi, and was a few years ago very much used in the construction of three-lig-ht

Fi?.i:i.

windows, sometimes with and sometimes nithout supporting muUions. Without mullions it is a very weak construction, and incapable of carrying much weight. But in this case it is generally allowed to have a bearing on the head of the solid window frame by showing less than 4^ inches on the soffit. It is sometimes relieved by a gauged discharging arch above it. Having drawn the

GAUGED-WORK A^'D ARCH-CUTT1^■G.

75

semi, draw the parallel lines a b, e d, and through their points of intersection e f the line eg. A line from g through a will be the line of skew- back. This re]3eated on the opposite side will find /. Next draw the angle brick j, the joints in the semi radiating from //, and the joints in the camber from /. Two diflferent face moulds are required, which with the lengths and bevels of the courses must be taken off in the same way as described in the camber.

The Scheme Arch.

Fig. 62 is the same as the segment, with this di£terence, that instead of springing from its

proper skewback c h, and its courses radiating from c, the curve is brought down to a level line or very near it, and the joints radiated from the centre of the opening in the level line. The scheme is the offspring of an antiquated and bad taste, and is not much used in the present day. One would think that its ugliness and want of truth would entirely forbid its use. It is treated by the cutter in the same way as the camber arch. e2

BRICKWORK.

Tic. 03.

The Semi-Gothic Arch.

To draw the semi- Gothic, Fig. 63, bisect (divide

into two equal parts) 1 the line a h with the

perpendicular c d, and Laving determined the height of the apex d, from d draw the line d h, and from these two points the arcs through which the line € f passes, inter- secting the cord a l in e. Now with the distance e h in the compass draw the Gothic or outside curve. Repeat this operation on the other side and the outline of the arch will be drawn. To fill in the courses divide the sofiit or semi into equal parts, whatever a brick will work or " hold out," and from the centre c through these parts radiate the courses as shown. The moulds are taken off as described in the buUs- cve, and traversed from the key downward to the springing, taking care that the soffit mark on the mould always comes on the soffit of the arch. Having done this, mark on the mould the length of each course, which will also give the bevels of the top ends of the courses. The mould is shown on the springing course with the length and the outside bevel marked on it ; g is the soffit mark to cut to; allowance must be made for the joint.

GAL'GED-AVORK AND ARCH-CUTTIXG.

77

Gothic on Circle Arch.

rig. 64 shows the way to set out the moulds

for a Gothic arch in a turret or bay that

is circular in plan. Draw the elevation of the

arch and the plan of the wall. A little considera-

Fig. 64.

tion will show that the face of each course has a different curvature or "sweep," that at the spring- ing having the greatest — equal to the wall itself — and the key the least, the curvature becoming less as the courses approach towards an upright position. A separate section mould must therefore be obtained for each course. Divide the bed

78 BRICKWORK.

joint of tlie course d whose curvature is required into a number of equal parts, from which drop lines square with ./■ ?/, and intersecting the outside curve in o, 1, 2, 3, 4 in plan. Draw o p parallel with X y, and transfer the distances 1, 2, 3, 4 from 0 p in plan to lines or ordinates square with the bed joint of the course whose curvature we are obtaining. A line drawn through these points will be the curvature of the section or soffit mould. By the same method the curvature of each course may be obtained. If all the soffit moulds were drawn connectedly, as a r., we should have what would be called a development of the soffit. The Gothic on circle is the same principle as circle on circle.

To Find the Soffit Mould.

From a drop down the two left-hand lines passing through the circular wall below x y. From their intersection with the two curves draw lines parallel with .>■ y. Take the thickness of the soffit in the compasses, and with one leg fixed anywhere in the upper line draw an arc cutting the lower line ; these four points connected will give the soffit mould a. Moulds for two course, a and h, are shown ; the others are obtained in the same way. This arch in practice is generally cut by rule of thumb, or what workmen call " near enough," and rubbed down to a suitable shape when the building is up, and its faults hidden with stopping of the colour of the bricks. But where perfect accuracy is required the moulds must be obtained as shown.

ORNAMENTAL BRICKWOKK. 79

SECTION IV.

ORNAMENTAL BEICKWOEK.

Ornamental brickwork in this coimtiy has reached its greatest height in connection with the Queen Anne style of architecture, as elabo- rated in the present day. The oriel windows of the Tudor, the ornamental gables and picturesque chimneys of the Elizabethan, are all merged into it, and with such a profusion of carving as to be unprecedented in any former age. Indeed, to such an extent is this being carried as to call forth from one of our most popular architects the asser- tion that we are fast departing from the yernacular of our street architecture. Let us rather say, if we may use the expression, that we have entered into the Augustan age of brickwork, in which the stuccoed front with its hidden carcass of "shuffs" and "place bricks" — often the refuse of the brick-field — is superseded by that which is what it appears to be, bearing on its face the unmistakable stamp of truth !

The Niche.

Figs. 65, 66, and 67 are the elevation plan and section of a niche in Flemish bond. This is con- sidered by bricklayers to be one of the most artistic pieces of work in connection with their trade. There are two kinds of niches, the semi and the

80

BRICKWORF.

elliptic. In tlie former it is circular in plan and elevation, in the latter it is elliptic in plan and circular in elevation. If that in our illustration be understood, no difficulty will be experienced with

Tig. cc.

the others. The back or upright part is built to a template forming a semicircle, and the bond set out as shown on plan Fig. G6, the joints of one course being shown by thick lines, and those of the

ORNAMENTAL BRICKWORK.

81

course below by dotted lines. But ft is the hood, the more difficult part, that we wish to explain. To make the centre, two pieces of wood, each a semi of the same circle as the niche, are nailed together with brackets in the internal angle (Fig. 68), and the space between the brackets filled in with core, pieces of bricks and mortar, and the surface finished with plaster of Paris, by means of a template a little more than a quarter of a circle (called the generating circle) fixed with a gimlet to the back of the bottom semi. The

0. CcnJbre/

of (jbrdtrfj

Fig. 68.

template rotating upon the gimlet as an axis, with the other end of it carried round the edge of the upright semi, a quarter of a sphere will be described or generated.

"We have now got the centre or turning piece.

Next draw the front arch as an ordinary semi arch,

and mark the same number of courses on the top

of the centre to represent the soffits. Then with

E 3

82

BRICKWORK.

a plianth straiglit-edge or the rotating template, mark tlie courses on the plaster centre, all meet- ing in a needle-point where the gimlet entered ; but as the bricks cannot be so finely cut, a small semicircle or " boss " is introduced of such a size that the bricks at the points where they meet it will be in thickness about half an inch. The courses are all of the same length and bevel, and the soffits must be bevelled in the same way as those

J^-..-.-- ;

i — -''"

1 I

Fig. 69.

of an ordinary semi arch ; and by looking at the elevation and section we see that the hood is made up of a series of semies increasing in size from the " boss " to the face arch.

ornamental brickwork. 83

The Niche Mould.

The lengtli of the course must be measured from where it meets the " boss " to the outside of the 9-inch face arch. From h, Fig. 69, draw a line square with c d, and on it mark a distance / h equal to the arc a c, and from /a distance /gr equal to c e, making g k equal to r/' Ic in elevation (Fig. 65) ; connecting these two points with the circle h we obtain the mould. The length of c a is obtained by dividing it into small spaces and transfering them along the line h /; / g is the ^'s-^^-

length of the key brick, and is shown turned up into its proper position c e.

Moulded Courses.

It is the work of the bricklayer to cut and form all kinds of mouldings, dentils, entasis columns, flutings, and such like members in gauged work, leaving the more intricate, such as design and foliage, to be executed by the carver. Fig. 71 shows the kind of box that is used for cutting moulded bricks to any required section — in this case an ogee. The box is generally made to hold two headers or one stretcher. The brick or bricks, having been squared and rubbed down to the required thickness, are placed in this box and with the bow-saw roughly cut out, and then rubbed down to the section of the box with a

84

BRICKWORK.

rasp, and sometimes a piece of straight gas-pipe to form the hollow members, the bricks being

Fig. 71.

very soft. Care must be taken that the bricks be not wedged up or cramped too tightly in the box so as to " flush " the edges ; and here we miffht mention that it is sometimes advisable to work the bricks a little wide, that in case of " flushing " they may be brought up to an arris by a rub or two on the stone. The cross piece or pieces on the top of the box are omitted for the sake of clearness.

Ornamental Arches

are those that have movdded soffits ; and in such as the semi and segment, and in fact all that have the courses to one bevel, the moulding may be worked square, and applying the face mould cut in every respect similar to an arch with a square soffit. In this case one bed (the bottom one) will be square with the soffit.

ORNAMENTAL BRICKWORK. 85

and the other very much wedge-shaped. The courses must be cut rights and lefts, but the key and two springing bricks must be wedge-shaped from both beds, otherwise they will want bedding up with large joints to fit the centre, and thus spoil the appearance of the arch.

"When a camber, or any arch whose courses have different bevels, has to be moulded on the soffit, the bricks must first be bevelled and after- wards moulded, and, lastly cut to the required shape and length by the application of the face mould, as before described.

The Oriel "Window

belongs peculiarly to ornamental brickwork (stone constructions being entirely excluded from this work), and we may add red brickwork. The first thing to be considered in connection with the oriel is its counterbalance. In all heavy projections in brickwork York flagging stones are employed ; they are built into the main wall from which the projection starts, pro- jecting to a distance suitable for the work. The weight of the projection on the stones is counter- balanced by the greater weight of brickwork on the other ends of the York slabs. But in the present case a girder or rolled iron joist, running in the direction of the wall line, and entering some 12 inches into the brick wall forming the side jambs, would have to be placed sufficiently low to allow the floor boards to pass over it. The flags and the weight upon them would be counter-

86

BRICKWORK.

balanced by tbe girder. Tbe principle of counterbalance is known to bricklayers by the name of " tailing down."

The whole of the oriel (Fig. 72) as shown

Fig. 72.

would be in brickwork, " gauged " and set in putty. The projecting courses, as the moulded string h, and the window-sill would be covered with 5-lb. lead, slightly projecting to form a drip for the water or rain.

ORNAMENTAI. BBICK"WORK. 87

The base liere shown would be surmounted with mullions in brick or wood (most likely wood on account of its comparative lightness), and finished either with a semi-coned tiled roof or a balustrade. TVindows of this type may be seen at Carlyle House, Chelsea Embankment ; and the Agnew Picture Gallery, New Bond Street.

The bricklayer when setting out the work must strike all the successive courses from one point, c, regulating the length of the radius-rod for each course. Each course must radiate from Cy as shown in plan, and the face of each brick be worked to the required sweep or curve. The bevels (which will be different for each and every course) will be obtained by placing the stock of the bevel on the line representing the bed, and bringing the blade to coincide with that portion of the curve representing the course we are about to cut. Let the bevel of the course marked a be required. Place the stock of the bevel on the third line below the moulded string h, and shift the blade \mtil it fit the curve of the course a. The bevels for each course must be obtained in the same way. The plan in this figure may be considered as a horizontal section just above the string course h.

Orxa:mental Gable or Pediment.

Figs. 73 and 74 are part front and end eleva- tions of an ornamental gable or pediment. The moulding is composed of the members known as

88

I3RICKAV0UK

the ovolo, the cavetto, and the ogee. In orna- mental brick copings it is usual to form the top fillet with two courses of red tiles, well soaked and closely and neatly set in cement, with the

1 1
1 !
' 1 ' 1
1 1
1 1
1 1
1 1
^^^^'^V^

Fig. 73.

joints proj^erly broken, as here shown. Some- times lead is substituted for tiles. Here we have shown a gablet^ a, but in practice the tiles are more frequently brought down to the bottom of the coping, the gablet being dispensed with.

Gothic 'WI^'DO"^v.

Fig. 75 is a two-light ornamental Gothic window with 2-inch beaded or chamfered reveals. The whole of the work under the large arch would be recessed back from the general wall line. The side piers a and b for uniformity sake might be built in half bond, similar to that

ORNAMENTAL BRICKWORK.

89

of the 9-inch inuUion ; but the proper bond would be to start from the reveal with a header and closer, the same as that shown on the reveal under the large arch. The tympanum is filled in

with 45- inch work in 9-inch blocks, each block being made up of three bricks, and called "blocking courses."

The label or dripstone, c e, enclosing the large arch, for the sake of contrast might be in Port- land stone. The whole of the work here shown, excepting the reveals of the large opening, might be in "gauged" work or in " axed " work ; or the

90 BRICKWORK.

arches alone miglit be "gauged" or axed, with the tympanum filled in with good building bricks, selected for colour and shape and neatly pointed, making a Tery effective as well as economical ornamental feature.

The saddle-back springer on the mullion might with advantage be in stone. "Windows of this kind may be built for cased frames with sliding sashes, but they are more generally built in neat work inside and out, with 9-inch jambs, grooved to receive lead lights. Ornamental brickwork is a subject in itself, that to adequately describe would require more space than can be given to it in a treatise of this dimension.

Mr. Euskin, advocating its use, says : " Here let me pause for a moment to note what one should have thought was well enough known in England, yet I could not, perhaps, touch upon anything less considered — the real use of brick. Our fields of good clay were never given us to be made into oblong morsels of one size. They were given us that we might play with them, and that men who could not handle a chisel might knead out some expression of human thought. In the ancient architecture of the clay districts of Italy, every possible adap- tation of the material is found, exemplified from the coarsest and most brittle kinds, used in the mass of the structure, to bricks for arches and plinths, cast in the most perfect curves, and of almost every size, strength and hardness; and moulded bricks wrought into flower work and

ORNAMENTAL BRICKWORK. 91

tracery as fine as raised patterns upon china. And just as many of the finest works of the Italian sculptors were executed in porcelain, many of the best thoughts of their architects were expressed in bricks, or in the softer material of terra-cotta ; and if this were so in Italy where there is not one city from whose towers we may not descry the blue outline of the Alps or Appen- nines — everlasting quarries of granite and marble — how much more ought it to be so among the fields of England." — Stones of Venice, vol. ii., p. 260.

Judging by the remarks in the above quotation, one is led to think that the brickmakers of mediocval Italy were more skilled in their craft, or at least happier in results, than their fraternity of modern times ; for, with few exceptions, we have found moulded work wanting in that truth- fulness of form which distinguishes cut or gauged work. Doubtless this, in great measure, is due to the large amount of unskilled and juvenile labour employed in our brickworks, to the careless manipulation of the work, and the hurried de- mand for the material. To be assured that true form can be obtained in ceramic wares, one has only to look at the Natural History Museum, London.

92 BRICKWORK.

SECTION Y.

r.OOF-TILIXG, POINTING, Eic.

Tiling.

Tiling is a branch of the bricklayer's trade, and owing to the rage for red-brick buildings is now very much in use. One advantage of the tiled roof is that it is cool in summer and warm in winter, but on acount of their weight stronger timbers are required than for slates. The Broseley tiles are considered the best ; they are 10| inches long, 6 inches wide, and f of an inch thick, and have three nibs or projections at the head for hanging. Good tiles are fairly smooth and slightly vitrified. Those of a bright red or clayey colour, with no vitrification, are absorbent, and not so capable of resisting the weather. Six kinds are used in good work, viz. under-eaves or three-quarter tiles, plain tiles, hips and valleys, ridge tiles and tile-and-a half, the last being used for cutting up to valleys and hips, and forming gables, so as to do away with the half tile that would be required to break joint. Valley and hip tiles are purposely made to suit the angles of the roof. As the tiles come to the hand of the tiler he should throw out the straight ones to be used by themselves, while those that have a hollow bed should be also kept by them- selves, as the straights will not lie close on the hollows. Good tiling is characterised by the tails of each course fitting closely upon the backs of the tiles in the course below them ; by the cross

ROOF-TILING, POINTING, ETC. 93

joints or "perpends" running in straight and regular lines from eaves to ridge, the vertical joint between each Uyo tiles coming immediately in the middle of the tile below them ; by the hips and valleys being in the same plane as the sides of the roof of which they form a part. It is a common sight to see hips standing up above the roof, so as to have more the appearance of ridges than hips. As the tiles are ordered before the roof is on, the angles should be set out and sent to the tile-maker to insure getting them to the required angle. The contained angle of hip tiles is made 10^ greater than the contained angle formed by the intersection at the hip of the two sides or planes of the roof, to allow for the tilt and the thickness of the two eaves-tiles. For the same rea- son the valley-tile is made 10° more than the re- entering angle of the roof. In our experience we have frequently found that the contained angle has been guessed at or obtained by some " rule of thumb," and with the consequence that generally ensues from such work, viz. that the angle con- tained within the hip tile has been either too acute or too obtuse.

Tiles are either laid dry on close boards, with battens above for hanging them, or on open bat- tens, in which case they should be bedded in lime and hair mortar. The most modern and improved way of hanging is shown in Fig. 76. The boards are 6 inches wide and are feather-edged, the top edge being ^ of an inch thick. Here we have a boarded roof without battens, and one that will

94

BRICKWORK.

keep out the weather if the tiles should get broken, for the rain would cause the wood to expand, and thus tighten the joints of the boards, to the exclu- sion of all rain. The first course — the eaves and under-eaves — should be bedded in hair mortar. The " lap " (the distance that the tail of the third tile overlaps the head of the first) should be

rig. 70.

3 inches. The "gauge" (the distance between the tails of two consecutive courses) can always be ob- tained by dividing the length of the tile (measured from the under side of the hanging nibs) less the lap by two. Thus, (IQi - 3) -r 2 = 3f , the "gauge."

Pioors HAVING Different Pitctiks. "SYhen roofs of different pitches intersecting in hips and valleys occur, the tiler has generally a

ROOF-TILING, POINTING, ETC.

95

deal of trouble, and consequent waste of time, through carpenters frequently insisting upon intersecting the battens ; and very often after much time has been wasted, and a portion of the tiling done, it is found necessary to tear off all the battens to correct the error.

The following rule will prevent such an error. Draw the plan of the two roofs (Fig 77), of

different pitch, and from the centre of the valley set out two parallel lines, a h, c d, representing the true width of the tails of the valley tiles, which is from 1| to 2 inches. On a-// at right angles with the eaves of the main roof draw its section, on which set out the gauge 1, 2, 3, &c.,

96 imicK\voniv.

and drop lines square with xy and intersecting the line a h. From these points of intersection square the short lines across the valley, and from where they intersect the parallel c d draw lines square with x y and intersecting a section of the smaller roof. The distance between any two points on y' g will be the "gauge" for the smaller roof. The line 3 on each section is drawn to their intersection, which is not in the centre of the valley, but very much on one side of it, thus proving the popular error of intersecting the battens in the middle of the valle}'.

The "gauge" for hips should be obtained in the same way, excepting that the parallel lines, a b, c d, must be the same distance apart as the extreme points of the tail of the hip tile, measured in a straight line from point to point square with the hip.

To OBTAIN THE NeCESSAPvY AxgLE OF Ilir OF

Valley Tiles.

Draw a h, Fig. 78, the plan of the hip, and erect a perpendicular, a c, the true height of the top of the hip. Draw a line from c to b, and the angle a h c will be the true inclination of the liip. Draw ed square with a b, cutting the eaves, and from ./'a line square with c b ; with this as radius, from the point ./' draw the semicircle, and from where it cuts a b draw the lines er/, d g; e (J d is the angle required for the hip tiles, or in other words it is a section or cut through the roof at right angles with the hip. The angle for

ROOF-TILIKG, POINTING, ETC. 97

valley tiles is obtained in the same way, remem-

bering that tbe hip is a salient ai gle and the valley a re-entering angle.

Pointing.

Pointing is divided into two classes, tuck- pointing and flat-joint pointing. In tuck-point- ing the joints of the brickwork are filled in with mortar or stopping, of generally the same colour as the bricks, and rubbed down to a level surface with a piece of sacking or soft brick of the same colour as the work, and a putty joint made of lime and silver-sand placed upon it. Stone lime should be used for outside work.

The mode of working is to have a parallel rule from 8 to 10 feet long, 5 inches wide, and 5 an inch thick, with one feather edge and four cleats -fV of an inch thick tacked on to the back to

93 BRICKWORK-

afford room for the putty that is cut off to fall through. The putty is spread out on the rule from which the bricklayers, one at each end, take it off with their jointers, and with the rule against the "waU, working on the top edge, trans- fer it to the wall. The ragged edges are then cut off with the Frenchman or knife, and the loose particles brushed off with a soft brush. Tuck-pointing is not suitable for outside work, as the putty joints projecting beyond the general surface arrest the weather and are consequently soon destroyed, unless protected by heavy pro- jections.

Flat-joixt Pointing.

This is the most general and durable kind of pointing. It should be made up of washed sand and stone lime several days at least before using it, that it may by the process of retempering acquire toughness, which will add very much to its durability and facility of working. The joints should be finished flush with the work (excepting in " weather-jointing," when the top of the joint should be kept back ^ of an inch, and the bottom flush to shed the rain) and neatly cut off top and bottom with the Frenchman, and brushed off. To ensure good pointing, the work should be well raked out and wetted not sparingly. If the joints are deep they should be filled in by going over them twice with tolerably stiff mortar to prevent cracking, and the work done with point- ing trowels. Jointers should not be used under

ROOF- TILING, POINTING, ETC. 99

.any pretext. In first-class work the pointing is done as the work proceeds during erection, and forming one body with the building will, if the mortar be good, last for many years.

Malm work for tuck-pointing is generally stopped in with mortar, coloured with yellow ochre (21bs. of ochre to each hod of mortar), but it will bo found best to use no colour in the stopping, as by its earthy nature it very much injures the setting and hardening properties of the lime, which in a great measure accounts for so much pointing perishing soon after it is done. Stop the work in with good mortar, as described in flat-joint pointing, and rub it down with a soft malm, leaving the dust on the work, and with a soft stock brush go over it lightly with hot alum water. One pound of alum to 3 gallons of water.

White Suflfolk bricks for tuck-pointing, are treated in the same way, rubbing the work with a soft white Sufiblk instead of with a malm.

Red work for tuck- pointing is stopped in with mortar coloured with Venetian red and Spanish brown, with sometimes a little vegetable black added. The colour of the stopping must be determined by the colour of the bricks, so as to match them. It is best to avoid colourinff the bricks, but when stopped in rub them down with a soft brick, and apply alum water or white cop- peras, as already described. One pound of cop- peras to 3 gallons of water. The appearance of red brickwork is often spoilt through the applica- tion of colour.

F 2

100 BRICKWORK.

To clean down red work, mix a pint of spirits of salts with a pailful of water. This applied with a stock brush will leave the work clear of all lime spots, &c. It maybe done on work recently erected, in which the joints have been struck during erection, and without injuring them.

Copperas is very much used in connection with stock work, especially when the bricks are in- ferior or of a bad colour. One pound of green copperas is melted down with every 5 gallons of water. It should be mixed several days before required, and enough made to finish the job, that it may be all one colour. A small nob of lime mixed with the copperas very much heightens its colour. The copperas should be tried on the work to match it before being generally used, and weakened down by the addition of water if found necessary.

Burning Cl.vy into Ballast.

The use of burnt ballast is increasing every day, both for purposes of mortar and concrete. The chief reason for this is its cheapness in comparison with the cost of sand, for while sand costs from OS. to 7s. a cube yard, varying according to the locality, burnt ballast can be produced, including all materials and digging of clay, with a run of about 60 yards, at 2s. 6d. a cube yard. While we reiterate that for mortar nothing better than clean sand of a sharp angular grit can be used, we do not wish to be understood as condemning the use of burnt ballast. Thoroughly burnt and cool, with

KOOF-TILING, POINTING, ETC.

101

the large aggregations (sponge- like lumps whose parts touch each other here and there, and are held in contact by vitreous matter) broken up, and the whole mixed with a fair proportion of Thames ballast or clean gravel (see previous re- marks on this subject in Article on Concrete), is capable of making a good concrete, for the ab- sorbent nature of the ballast attracting the sili- cates of the cement or lime, which entering the pores form so many threads or ties binding the whole mass together, and unlike Thames ballast, with its non-absorbent and smoothly water-worn surfaces, which simply beds itself in the matrix with comparatively little adhesion.

Stiff or strong clay, just as it is dug up, is the best for burning, as it requires the least firing and will make the best ballast. The heap is com- menced by forming a cone of clay, about 3 feet in diameter and 5 feet in height, formed round a piece of pole placed on end as a centre. Fires are then made round the cone by placing bricks on edge forming a channel leading up to the centre. These are filled with wood and coal, and covered over and cased with a layer of clay about 6 inches thick before lighting. As the fire burns through it must be drawn down, which is done by means of long-handled prongs made specially for the work, and strewn with small coal called '' slack," and covered with another layer of clay. The thickness of the layers of clay may be increased as the work proceeds, until they become from 18 to 24 inches, not forgetting the sprinkling of

102 BRICKWORK.

" slack " on each layer of clay. Care must be taken that the fire be drawn down, as it naturally draws to the top, and the unburnt portions thrown up into the fire. "When the clay is thoroughly burnt the fire will go out.

Building Additions to Old "Work.

When building additions to old buildings, it frequently occurs that the old work is found to be considerably out of perpendicular, generally overhanging. In such a case it is best to carry up with the new work, just where it joins with the old, a pier or pilaster, forming a break in the wall line, which will enable the bricklayer to keep the new work upright and hide the fault of the old, which otherwise would be exposed by junction with the new. The projection of the pilaster will of course be regulated by the amount that the work is out of the upright.

Fire-proof Floors.

Fire-proof floors are now very rarely constructed in bricks, being almost entirely superseded by tile arches brought to a level with concrete, or con- structed with rolled joists and concrete alone, or with cement and breeze, but more generally with Dennett's Patent, which is a concrete composed of broken bricks and gypsum. But in very large warehouses, and where great weights have to be carried, the fire-proof floors are still constructed with brick rings carried on rolled girders.

APPLIED GEOMETRY.

103

SECTIO]S' YI.

APPLIED GEOMETEY.

Geometry of all studies is to the artisan the most attractive and useful. The problems given here are such as may be applied by the bricklayer to every-day practice, and therefore come within the meaning of the term applied geometry. But we would advise the young artisan not to rest satisfied with a Icnowledge of the few problems given herein, but to take up the subject as a separate study, and familiarise his mind with its principles, so as to be able to apply them generally and with understanding.

To draw a square u-hose siqyerjicial area shall equal the sum of two squares whose sides are given.

Let A B (Fig. 79) be the given sides. Draw the lines c d, e f at right angles, and from g set oflf G H equal to a, and g k equal to b : a line drawn from H to K will be the side of the required square. On G K complete the square G M, N. K ; and on g h the square ii l e g ; and on h k the square ii k o p. The area oi this square will equal the combined areas of the two smaller

104 BRICKWORK.

squares. To make this more clear, suppose the line A to be 8 inches and b 6 inches. The square of A would be 8 X 8 equal to 64 ; and the square of 6 would be 6 X 6 equal to 36, which added to 64 makes 100. By drawing a and b square with each other and joining their extremes with a straight line, we will find that line to measure ex- actly 10 inches, and the square of that wiU be 100. The principle of this problem is that a square erected on the hypothenuse (the longest side) of a right-angled triangle is equal to the sum of two squares, erected on the base and perpendicular of the same triangle. Its application to practice is shown in the article on " Setting out Bmlding."

To draic a right-angled triangle, base 1\ inches, height \ inch.

Draw a semicircle of H inch diameter (Fig. 80), and from d erect the per- pendicular d e : a line drawn from e, | inch above the base line a c, will cut the semicircle in b ; lines drawn from a and c to i will form the required triangle. The principle of this is that aU triangles within a semicircle are right-angled triangles. If the lines be drawn from a c to e or to any other point in the semicircle, we shall get a right-angled triangle. Its practical application is seen in the article on " Setting out Building."

APPLIED GEOMETRY. 105

To draw an arc by cross-sectional lines.

On a b, the span (Fig 81), erect the perpen- c.- diciilars, d e, equal to

twice the required rise. Divide a e into any number of equal parts, 1, 2, 3, 4, and e b into the same number of parts, and draw cross-sectional lines as shown. A curve traced through the intersections will be the required arc.

Another method practised (we do not recom- mend its use) sometimes by carpenters for getting out turning-pieces for the bricklayer. Span 6 feet, rise 1\ inch. Divide the span into a number of equal parts, say six, and from the points erect perpendiculars, measuring upward ^ inch on the first, an inch on the second, and 1| inch on the third, which in this case is the centre line. Treat the other half of the span in the same way, and with a flexible straight-edge fixed at the springing points a b (Fig. 81) force it upward until it stand over the distance marks on the perpendiculars, and with a pencil trace the arc or curve.

The foregoing methods do away with the neces- sity of laying down a large platform and getting out a long radius-rod ; the camber, for instance, which is the segment of a circle described by a radius-rod of 70 feet 2| inches in length.

f3

106

BRICKWORK.

To describe a Jlat arc (camber for instance) by mechanical means. Let a b (Fig. 82) be the cord of the arc. Bisect

a b at c by the perpendicular c d, and make c d equal to the height of the segment. Draw d e parallel to a b, and make d e a, little larger than a d. This template should be got out of a piece of timber, and by moving the whole of the tem- plate, so that the two edges d a and d e may slide on two pins, a and d, the angular point d of the template will describe the segment required, and if the pin be taken out of a and put in the point b, the other portion d b of the segment a d b wiU be described in the same manner. This method should be practised in preference to the methods previously described.

To find the joints of a flat arch icithout using the centre of the circle of which the arc is a part. Having determined the number of voussoirs or

Fig. b3.

courses," 1, 2, 3, 4, &c. (Fig. 83), from these points

APPLIED GEOXTETRY.

107

erect perpendiculars by intersecting arcs ; these perpendiculars represent the joints. AVe need hardly to say that the practical application of this problem is to enable the workman to draw the courses or voussoirs in an arch similar to that given in the previous problem.

To draw the joints of a semi ellipse arch icith mathe- matical accuracy. The point d (Fig. 84) is the middle of the arch,

>-^

/ ./■■		U-	'.''''S\
1 y *
1 ^j''--'"'	c .	\i^	1
^^■~~^		-^S

Fig. S4.

and the point c the middle of the springing line. "With the distance c a or c b, from the point d describe an arc cutting a b at e, and also at/; cf are the foci. Let a joint be required at g. From e and / draw lines passing through g, and bisect the angle they make with each other, and from the point g erect a perpendicular, which will represent the required joint. The other joints are obtained in a similar manner.

108

BRICKWORK.

To find the invisible arch contained in a camber.

Bisect the springing line a h (Fig. 85) with the perpendicular c d, and produce the skewback h b until it cut the per- pendicular in c. Fromr, with distance c b draw the arc a d b, and with distance c g its concen- tric arc g fh. a g hb is the invisible arch. The soffit of the camber below the arc a d b i& upheld by the cohesion of its parts with the invisible arch. Here we would add that bricklayers Lave no fixed rule to determine the angle of skewback for the camber, some giving 4^ inches skewback for all open- ings, others 65 inches, and in many cases giving a skew of from f to 1 inch for every foot that the opening is wide ; as 3 inches for 3 feet, 4 inches for 4 feet, and so on. ^Ve would advise that the skew or angle of thrust should never exceed 6 inches, for as the skew becomes more acute the carrying strength of the camber becomes less, in consequence of the invisible arch contained therein being thrown higher up, as shown by the middle arc struck from k with distance /.- b.

Fig. 85.

APPLIED GEOMETRY.

109

Ani/ two straight lines given to determine a curve by which they shall he connected.

Let ah, cd (Fig. 86), be the given lines, and c b

•-•v

Fig. 86.

the points to be connected. Produce the lines until they meet in e ; bisect the angle ceh with the line ef\ from c and b draw lines at right angles to ah and c d meeting ef in g. From g, with distance g c or g b describe the connecting curve. The given lines may be taken as two brick walls that have to be connected or formed with a round corner.

Fig. 87 is an example in which the given lines

Fig. 87.

are parallel. From point b draw /a; at rig^^ angles with a h ; and from c, c e, at right a'

/

es

110

BRICKWORK.

witli c d. On /mark a point h any distance from h less than b c. Draw A- / througli A- parallel to h c and cutting c c m L From / as centre with the distance / c, which is equal to h h, describe the arc cm. Join Im and produce it in the same straight line towards m to meet/.r in n. From n as centre, with the distance u b or n rn, describe the arc b m. The given straight lines ab, c d are connected by the curve b m c.

If the given straight lines are not parallel, but would meet if one or both were produced, as ^ A (Fig. 88), produced meets ab m. a, forming the

Fig. 8S.

small angle gab, draw, as before, /> and ^ o at right angles i<i ab and g h respectively. Take any point, A-, in bf; make^yy; equal to bk, and join kj). Bisect hp in q, and draw qr perpendicular to kp, meeting/ J" in ;•. Join r p, and irovap as ."entre, at the distance g p, describe the arc g s, Xi '^ting rp in s. Then from the centre r, at the «^^ ce r 6 or r «, describe the arc completing the

APPLIED GEOMETRY. Ill

curve bs gyhj wliicli the given straight lines a b, g h are connected.

To find the form or ciirvahire of a raking moulding that shall unite correctly tcith a level one.

Let abed (Fig. 89) be part of the level

	h
^":^£
3 c- Fig. 89.	CO

moulding (which we will here suppose to be an ovolo or quarter round), a and c the points where the raking moulding takes its rise on the angle, fc g the angle the raking moulding makes with the level one. Draw c/at the given angle, and from a draw a e parallel to it ; continue b a io h, and from c make c h perpendicular to Ah. Divide c h into any number of equal parts, as 1,2, 3, 4, and draw lines parallel to h a, as 1^, 2^ 2>^, 4^ ; and then in any part of the raking moulding, as f , draw i k, perpendicular to e a, and divide it into the same number of equal parts as h c is divided into; and draw 1% 2^ 3°, 4^ parallel to e a. Then transfer the distances l'"", 2^, 3^ 4*^, and a curve drawn through these points will be the form of the curve required for the raking moulding.

112 BRICKWORK.

The method here shown is for an ovolo, but it would be just the same for any other formed moulding, as a cavetto, ogee, &c. This problem can be applied in the construction of pediments in " gauged " work.

To describe an ellipse by means of a carpenter's square and a piece of notched lath.

Having drawn two lines to represent the diameters of the ellipse required, fasten the square so that the internal angle, or meeting of the blade and stock shall be at the centre of the ellipse. Then take a piece of wood, or a lath, and cut it to the length of half the longest diameter, and from one end cut out a piece equal to half the shortest diameter, and there will then be a piece remaining at one end equal to the difference of the half of the two diameters. Place this projecting piece of the lath in such a manner that it may rest against the square on the edge which corresponds to the two diameters ; and then turning it round horizontally, the two ends of the projection will slide along the two internal edges of the square, and if a pencil be fixed at the other end of the lath it will describe oae quarter of an ellipse. The square must then be moved for the successive quarters of the ellipse, and the whole figure wiU thus be easily formed. This method is on the principle of the trammel. There are several other ways of drawing an ellipse, but for these the reader must be referred to a work on geometry.

APPLIED GEOMETRY.

113

To draw a Gothic of any given height and span ; or, in other words, an Ellipse Gothic.

Let A B (Fig. 90) be the span and cd the height. Draw the line a b and bisect or centre it at c ;

Fig. 90.

draw c D, and make c i equal to c d. Divide c d into three equal parts, and draw a g, b h parallel with c D, and equal to two-thirds (f). of c d. Make c F equal to one-third of c d, and draw a f, f b. Divide a f into any number of equal parts, 1, 2, 3, 4, and from i draw il, i2, i3, {4. Divide a g into the same number of parts as a f, and draw Id, 2d, 3d, 4d, and the intersection of lines will give the points in the curve, which must be drawn by hand. The other half must be found in the same way.

114

BRICKWORK.

To draw the arch bricks of a Gothic arch, that is for the curve in the jjrevious problem.

Having formed the angles c d g and c d h as before, from d (Fig. 91) draw d l perpendicular

Fig. 91.

to D H. Make b f and e d each equal to b ii ; join E F, and from the middle of e f draw i i, per- pendicular with E F. Draw l f, l and f are the points from which the joints of the arch will radiate.

To find the radius of any arc or arch, the rise am span being given.

Let a b represent the span, c d the rise ; a b equal 4 feet, c d 2 feet, a c (half the span) mul- tiplied by itself will be 2 X 2, or 4 feet ; divided hjcd will be ^, or 2 feet, c d added to this will be 4 feet, which divided by 2 will give 2 feet as the length of radius that will describe the required arc whose span and rise are given. In this case we have chosen a semicircle for the sake of simplicity and self-demonstration, but the rule may be applied to any arc of any circle. In

APPLIED GEOMETRY. 115

mathematical formula our calculation would stand thus :

(d (? \

— + c d ]■— 2 =r the length of radius re- c a I

quired. Or in plain words a c square, divided by c d, plus c d divided by 2 equal the length of radius. In the above explanation we have gone out of the beaten track for the purpose of making the rule clear to those of our readers who may not be familiar with trigonometrical and alge- braic expressions.

It will, however, be recognised by some as the square of half the cord divided by the versed sine, plus the versed sine divided by 2 equal the radius.

For mensuration of brickwork the Author refers the reader to Mr. Hammond's "Practical Bricklaying," forming vol. 189 in this series.

I J^ D E X.

A DDiTioxs TO Old Wokk, 102. ■^ Angle of hip or valley IQcs,

to obtain, 96. Angle of skew, 50. of strain, 29. Apertures, 26. Arc, to draw bv cross sectional

lines, 10.5. Arches, 46.

cutting of, 64. principles of, 47. whose courses have different bevels, S5. Axed work, 63.

"Dase, Boxc of, 27. ^ treatment of, 27. Battering jamb, S8. Bats, 30, 34. Bedding board, 66. Bends. 12.

Berkshire builders, 17. Birdsmouthed key, 7 1 .

objection to, 71. Blocking courses, 89. Blue lias, 9. Boaster, 6.5. Bond of brickwork, 20.

underrated, 20.

of footings and walls, 22.

Gwilt on, 21.

Smeaton on, 20. Bovd's flue-plates, 45. BrickS; 16.

characteristics of good, 19.

differences in sizes of, 39.

case hardening of, 62.

wetting of, 28.

Brick groins, 58. Brickwork, 2*.

characteristics of good, 40.

good, samples of, 16. Broken bond, 27.

cause of, 27.

in Flemish, 33. Brondesbury bridge, 5.5. Broseley tiles, 92. Building new work into old, 40. Bull's-eye, 65.

Burning clay into ballast, 100. Burnt ballast, 9. Buttering joints, evil of, 34.

Pamber arch, 64, 68. ^ invisible arch in, 108.

mould, 69.

to describe by mechanical means, 69.

to take off lengths and bevels of courses, 68. Carved work, 64.

gauged-work, composition for setting, 60. Catenary curve, 48. Cement- testing machine. 10. Centre for niche head, 81. Ceramic wares, 91. Chalk lime, 14. Chimney bond, 34. Chinoncy stacks, 34.

wtJls of 4^ inches, 34. Closer or Closure, 22, 31. Colour in stopping, objection to,

99. Concrete, 2.

for filling in terxa-cotta, 8.

INDEX.

ii:

Concrete, Mr. Keid on, 8.

"packing," 7-

proportion of ingredients, 8.

quantity of water in mix- ing, 8.

specitieation of mixing, G.

thickness of, 5. Construction of arclies, 55. Copperas, 99. Coring holes, 43. Counterbalance, 85. Coursing joints, 50.

mould, 52. Cross joints, 21. Cutting-shed, G4.

TiEN.NETr'S PATENT, 102.

-*^ Development of soffit of

skew arch, 51. Dipping, 63. Dips in drains, 12. Dip-trap, 13. Doors, positions of, 26. Doulton's terra-cotta flue p:pes,

45. Drains, laving of, 11.

fall of, 11.

cause of stoppage, 12.

ventilation of, 12. Drain-pipes, sizes of, 13. 1 )rawing and cutting arches, 6 1. Dutch bond, 37.

advantages claimed for, 3S

"pARTHENWARE TRAPS, 13.

^ Ellipse, to describe, 112. Ellipse Gothic arch, 72.

to describe by cross sec- tional lines, 113. Eaamellcd bricks, 18. English garden wall bond, 35. English bond in chimney stac ks,

34. Excavations, 2. Extrados, 66.

"P.VCE MOULD, 65, 66. -"- Fan-groining, sample of, 60. Fareham biicks, 17, CI. Fire bricks, 18.

Fireclay, 19.

Fireplace for register stove, 44.

Fireproof floors, 102.

Flat joint pointing, 98.

Flashing to chimney-stacks, 35.

Flat arch, to find joints of, 106.

Flemish, 22, 31.

Flemish garden wall bond, 35.

Flues, 41.

building of, 43. down draught, 12. disadvantage of too large sectional area, 42.

Flues, sizes of, 44.

Flushing, 28.

Footings, 6, 22.

Forcing-rods, 12.

Furmation of centre for niche head, 81.

Foundations, 1.

Freestone lintels, cause of frac- turing, 48.

GAKLET, 88. Gauge of tiles, 95, 96.

Gauge-rod, 25. Gauged work, 17, 61. Gault bricks, 17. Geometry, 103. Gothic arches, 63, 70, 71-

to draw arch bricks of, 114.

on circle arch, 77.

vaulting, 58, 59, GO.

window, 89. Grizzles, 16. Groined vaulting, o8. Groimd blue lias, 2. Ground-damp, 2. Grouting, 28, 40.

ni;.\Di>-G liOXD, 28. Ileiring-bone bond, 36. Hip tiles, 92, 93. 96.

T

NSPECTION HOLES, 10.

Tamu, 26.

" Jointers, 98.

118

INDEX.

KINO CLOSURK, 2o. Kneeler, 88.

T AERTIXG rp, 41.

■*-' Level or datum, 2.

Lime, 14.

Lines offeree or thrust, bb.

Line of frontage, 3.

Line of radii, 55, 57.

Lines, to connect by means of

a curve, 109. Lintels, 48. London clay, 6. Lons skew arches, treatment

of, 51. Lump lias, 14.

MADE-rP GROUND, 6. Malms, 17, Gl. action of London smoke on, 62. •Man-hole, 12. Mortar, 14, 28. Moulded courses, S3.

■work, 91. Mullions, 74, 89.

"^ICHK, 79.

^^ hood, 81. mould, S3.

length and bevel of courses to, 82.

Aid ExoLisH bond, 21. ^ Open soil-pipe, 12. Operculum or channel-pipe, 12. Oriel window, 85.' Ornamental arches, 84. Ornamental brickwork, 79, 90. Ornamental gable or pediment, 88.

PABGETTIKG, 34. PaA-ing. 36, 37. Perpends, 39. Philological School, l.'j. Picked stocks, 16. Place bricks, 16. Plain arches, 49. Plan of skew arch, 50.

Plinth, 27. Pointing. 39, 97. Polychrome bricks, 15. Portland c*ment, 2, 6. Portland cement concrete, 7. Pressed bricks. 20. Principle of ordinarv skew arch,

54. Projecting courses, 86. Purpose-made brick, 57.

QUEEN AvXK's style OF ABCUI- TECTURE, 79.

revival of, 14. Quoin, 4, 32.

"DADirS-ROD, LKXGTU OP, FOB ^*- CAMBER, 105.

to obtain by formula, 114. Raking moulding. 111. Bed brickwork, 14.

to clean down. 100. Red building bricks. 17. Relie\-iDg arches, 48. Eeveal, 26.

bond of, 27. Beversing the bond, 33. Right-angled junctions, 12. Roman tile, 30. Roofs of different pitch, 94. Rosendalc cement, 57. Ruabon clay, analysis, 20.

bricks and tf-rra-cotta, 20. Rubber?, 17, 61. Ruskin, inHuence of on red- brick designs, 15.

advocacy of oroameDtal brickwork, 90.

SAND, 9, 14. Scheme, 73. Scheme arch, 75. "Scotch," 65. • Scriber, 65. Section -box, 84. mould, 78. Section of niche, 79. Semi-ellipse arch, 73, 107. Semi and segmental arches, 66. Semi-Gk)thic arch, 76.

INDEX,

119

Setting, 63, 64.

Setting out and cutting, 62.

Setting out building, 2.

Setting out the bond, 26.

Sewer gas, 12.

Sewers, 57.

Sharp bends in flues, evil oT, 42.

Shippers, 17.

Site, 1.

Skew arch, 49, o2.

Skewback of camber, 103.

Smoky flues, 41.

Snapped headers, 31, 34.

Soakers, 35.

Soffit-mould of Gothic on circle,

78. Stacks in 4^-inch walla, 34. Staffordshire blue bricks, 18, 52. Stock bricks, 16. Stookwork, 01. Stone lime, 14, 63. Stone strings, 28. Stoppins: in pointing, 97. 99. Stourbridge fire bricks, 19. String courses, 30. Stuccoed buildings, 15. Subsoil, 5. Surface concrete, 2.

Tailing dowx, 86. -'- Taking oflf bevel?, 65. Templates and strings, 30. Testing cement, 10. Tevnham bricks, 1 7. Thames ballast, 10, 101. Thick and thin joints, 28.

Three-quarter stretcher, 24, 27. Tiled roof, advantage of, 92. Tiling, 92.

characteristics of good, 92. Tile fillet, 88. Tiles, characteristics of good, 92.

improved method of hang- ing, 93. Timber foundation, 57. T. L. B. Rubbers, CI. To find the radius of any arc or

arch, 114. Tools for arch cutting, 64. Toothings, 39. Transverse joints, 23. Transversing the courses, 65. Triangle, 104. Tuck-pointing, 97, 99. Tumbling in buttresses, &c., 38. TjTnpana of arches, 36, 89.

"\'''alley tiles, 96. ' Valleys. 94. Various bonds, 34. Venetian arch, 74. Voussoirs, 47, 05.

TTTall in Flemish face and '' English back, 32. "Washed stocks, 16. Water conduit, 56. Weather-jointing, 98. AMiito SufTolks, 18, 62. Windows, 27. Wing gatherings, 41, 44. Withes, 34, 35, 45.

THE END.

PKIXTK3 BY J. ?. YIETU» AND CO., LIHITXD, CrTY ROAD, LDXDOJI.

Uniform icith this volume, price \s. 6d.

THE EUDIMEXTS OF PRACTI- CAL BRICKLAYING. In Six Sections :— General Principles of Bricklaying — Arch Draw- ing, Cutting, and Setting — DifiFerent Kinds of Pointing — Paving, Tiling, Materials — Slating and Plastering — Practical Geometry, Mensura- tion, kc. By Adam Hammoxd. Illustrated with Sixty- eight \Voodcut3. Pifth Edition, carefully Eerised, \rith Additions.

" This is the work of a practical bricklayer, and is intended for the junior members of the important, if laborious, pro- fession to which the author belongs- It is fall of details concerning all the parts of the shell of a building, firom foundation to tiles. To any workman anxious after improve- ment this volume will prove a valuable investment." — Iron.

"Contains a considerable amount of practical information. with sound instructions on general matters, and useful recipes connected with both brickwork and plastering." — BrUUh ArchiUtt.

" ilr. Hammond's practical treatise will be found of great value to students." — Bmlding Stws.

"Any young bricklayer who reads Mr. Hammond's book careful^ will become a proficient craftsman." — Englith Mechanic.

CBOSBY LOCK^OOD & CO., 7, SiATiONEss' Hall Corai, Loxoos, E.C.

^

I