THE BUILDING MATERIALS OF OTAGO AND SOUTH NEW ZEALAND GENERALLY. BY W. N. BLAIE, M. Inst. O.E. PAPERS ORIGINALLY READ AT THE OTAGO INSTITUTE REVISED AND EXTENDED. DTJNEDIN: J. WILKIE & CO., PRINCES STREET. 1 8 7 9. PREFACE. During the progress of the Public "Works under my charge, I have frequently been at a loss to know what material was best suited for the work in hand, and to what uses the local materials could be best applied. There were also frequent diffe- rences of opinion as to the identity of many articles, and continual differences as to their properties. This led me to collect and note any authentic informa- tion on the subject I met with. These notes grew into the Papers originally read at the Otago Institute, and the Papers have in turn expanded into the volume now published. If it is found to contribute in the slightest degree towards the development of the natural resources of the Colony, I shall be amply rewarded for any trouble it has cost me. W. N. BLAIR. Dunedin, 14th June, 1879. CONTENTS. Pages INTRODUCTORY i_iv. SECTION I. STONES, BRICKS, CONCRETE, AND ROOFING SLATES. CHAPTER I. — Description op Building- Stones 1 9 Classification,!. Properties of Building Stones, 1. Tests, 7. Artificial Induration, 8. CHAPTER II. — Geographical Distribution 9 12 Localities, 9. Products of Geological Formations, 11. CHAPTER III. — Habdstones 12—24 Granites, 13— True Granite, 13 ; Syenite, 14 ; Pegmatite, 15 ; Constituents, 15. MetamorpMc Rocks, 16. Volcanic and Trap Rocks, 17— Varieties, 17; Basalts, 18; Bluestone, 18; Greenstone, 19 ; Dolerite, 19; Phonolite, 18; Ti- marzite, 20 ; Breccias and Trachytes, 20 ; Breccia, 22 ; Trachytes, 23. CHAPTER IV.— Freestones 24—57 Marbles, 25— Horse Range, 25 ; Tokomairiro, 25 ; Otekaike, 26; Cljde, 26; West Coast, 26; Canterbury, 28. Lime- stones, 30 — Classification, 30; Wakatipu, 30; Horse Range, 31 ; Peninsula, 31 ; Kakanui, 31 ; Waiareka, 32 ; Waihola, 32; Pleasant Valley, 33; Oamaru Stone, 33; Upper Waihemo Valley, 44; Southland, 46; Canter- bury, 48. Sandstones, 48— General, 48 ; Grits, 49 ; Sili- cious Sandstones, 49 ; Hard Sandstones, 50 ; Ordinary Sandstones, 53 ; Soft Sandstones, 55. Conclusion, 57. CHAPTER V.— Bricks 57—62 Locality and Raw Materials, 57. Manufacture, 60. Pottery and Tile Works, 61. CHAPTER VI.— Concrete .' 62—72 General, 62. Uses, 65. Making Concrete, 66. Experi- ments, 70. vi. Contents. CHAPTER Vlf.— Comparison or Various Building Ma- terials 72—79 Strength, 72. Cost, 75. CHAPTER YIIL— Roofing Slates 80—89 Locality, 80. Extent, 82. Quality, 82. Products, 87. Cost, 88. SECTION II. LIMES, CEMENTS, AND THEIR AGGREGATES. CHAPTER I.— Description of Cementing Materials Definition of Terms, 90. Classification, 91. Composition, 91. Quality of Limestones, 93. Properties, 95. Use of Aggregates, 97. Strength, 97. CHAPTER II.— Geographical Distribution Limestones, 98. Cement Stones, 99. Clays, 99. Aggre- gates, 99. CHAPTER III.— Analyses CHAPTER IV.— Rich Limes Types, 100. Otago Stones, 101 CHAPTER V.- Poor Limes CHAPTER VI. — Hydraulic Limes General, 107. Types, 108. Oamaru, 109. Peninsula and Lower Harbour, 109. Auckland, 115. Taranaki, 115. Canterbury, 116. CHAPTER VII.— Hydraulic Cements Septaria, 117. Experiments, 118. CHAPTER VIII.— Artificial Cements CHAPTER IX.— Aggregates CHAPTER X. — Recapitulation and Cost Uses, 124. Comparison, 125. General, 127. TABLES. — Table I. Analyses of Otago Limestones that furnish Rich Limes, with English and Foreign Types. Table II. Ana^ses of Otago Limestones that furnish Poor Limes, with English and Foreign Types. Table III. Analyses of Otago Limestones that furnish Hydraulic Limes, with English and Foreign Types. Table IV. Analyses of Otago Cement Stones, with English and Foreign Types. Table V. Tensile Strength of Waihola Lime Mortar, with different Sands. 90-98 98—99 100 100-105 106— 107 107— 116 117—119 120—122 123— 124 124— 128 1 a p > % a Contents. vn. SECTION III. TIMBERS. CHAPTER I. — Prope rt ie3 of Timbers 129—142 Structure, 129. Growth, 130. Felling, 133. Qualities of Timber, 136. Seasoning, 137. Decay and Preserva- tion, 138. CHAPTER II. — Nomenclature op Timber Trees 142—143 CHAPTER III. — Geographical Distribution and Classi- fication 143 — 145 Geographical Distribution, 143. Classification, 145. CHAPTER IV— Habd Woods 146—163 Mapaus, 146— Black Mapaus, 146 ; Turpentine, 147 ; Red Mapau, 147 ; White Mapau, 148. Manuka and Rata, 143 — Manuka, 14S; Rata, 151 — Kowhai, 153; Fuschia, 155 ; Broadleaf, 155 ; Kamai, 156. PoJcaJcos, 160 — Ribbon Woods, 161 ; Grass Tree, 162. CHAPTER V— Soft Woods .. 163—191 Pines, 163— Cedar, 164. Podocarpus, 169— Miro, 169 ; To- tara, 172 ; Black Pine, 175 ; White Pine, 177. Dacry- dium, 180— Red Pine, 181 ; Yellow Pine, 186 ; West- land Pine, 187; Silver Pine, 187 ; Celery Pine, 189. CHAPTER VI.— Soft Woods Continued 191—206 Birches, 191— Silver Birch, 194; Red Birch, 197; Black Heart Birch, 203. General, 206. CHAPTER VII.— Recapitulation 206— 217 Dimensions, 207. Felling, 207. Seasoning, 208. Strength, 210. Conclusion, 216. TABLES.— Table VI. Names of Otago Timber Trees ... 218—222 Table VII. Approximate Dimensions and Growth of the Principal Timber Trees of Otago 223 Table VIII. Seasoning of Otago Timbers 224 Table IX. Strength of Timbers, Abstract Results of Ex- periments made at Dunedin in 1878 225 Table X. Weight and Strength of Otago Timbers, with English and Foreign Examples 226—227 Table XI. Properties and Uses of Otago Timbers ... 228—229 SECTION IV. METALS 230-230 General, 230. Iron, 230. Copper, 237. Lead and Tin, 238. Index 240-244 THE BUILDING MATERIALS OF OTAGO. Introductory. ^NY information we have on the building materials of Otago is so interspersed with extraneous matter that it is compara- tively useless. Even the initiated, whose duties require frequent reference to the subject, have considerable difficulty in availing themselves of the researches that have been made. The object of these papers is to present, in a concise form, the more valuable portions of the information already published, as well as to record my own observations and experience during the past few years. As some of the earlier information is not quite trust- worthy, I have endeavoured to confirm all state- ments of facts by recent investigations. I do not, however, wish the papers to be considered ex- haustive, or entirely free from errors ; on the contrary, they only claim to be an introduction to a thorough investigation of the subject, which is A ii. Introductory. one of the utmost importance to the Colony at large. Although considerable care has been taken to avoid mis-statements, it is quite possible such may exist, and I look to my professional brethren and the members of the Otago Institute for their correction. The natural resources of New Zealand generally, are equal to those of many old countries that take a prominent position in the affairs of the world, and, although Otago seems deficient in some of the products which are usually calculated to ensure prosperity — such as bituminous coal and metals — there is an abundant supply of good building materials of every description, and, with the ex- ception of one or two articles, they are well distributed throughout the Province. Although I believe these papers will reveal a number of new facts, the researches that I have made in compiling them enable me to say, without reser- vation, that our resources are still practically un- known. Many of the best supplies are untouched, and, in all probability, the best of each kind is not yet discovered. It will, therefore, be many years be- fore the extent of our resources in building materials is known, or the properties of even what has already been discovered, thoroughly understood. A still longer time must elapse before our stores are deve- loped and utilized — this can only be effected by the increase of settlement and wealth, and improved faci- lities for transit. Although these causes are daily ac- quiring strength, they cannot exert a direct in- fluence on the question till the cost of producing the native article comes nearer that of the imported one. Introductory. hi. The importance that is attached to the collec- tion and diffusion of knowledge of this kind throughout the colony was on one occasion forcibly "brought under my notice by seeing in the newspapers that it was proposed to build the Auckland docks of Aberdeen granite. Undoubtedly granite is the best building stone in existence, but it is also the dearest, and for this purpose it is no better than the stone of which the Port Chalmers dock is built. The price of granite in rough blocks at Aberdeen is from 2s. 6d. to 3s. per cubic foot, and in London from 4s. 6d. to 5s. There are no regular traders between Aberdeen and Auckland that could carry the stone in small quantities, and no large ship would take a full cargo to come direct, consequently the shipment must be made at London. The cost of the stone in the Colony cannot therefore be less than 7s. per cubic foot. Port Chalmers stone in the same state can be put on board a coasting craft or steamer for Is. 6d. Taking the freight and -other charges the same as from London, Ave have the stone landed at Auckland for 3s. 6d. per cubic foot — exactly half the price of granite ; and there would also be a considerable saving in labour, as the Colonial stone is much easier worked. The impor- tation of granite under these circumstances is carrying the principles of free-trade a little too far. There was no time in the history of New .Zealand when the choice of a building material had so much importance as the present. To borrow the plan adopted by ethnologists, we may divide Colonial architecture into periods or ages : First, the wattle-and-dab period, with its contemporaneous but iv. Introductory. more advanced varieties of fern-tree and totara- bark ; second, the timber period ; and third, the masonry period. On the gold-fields, timber is pre- ceded by calico and corrugated iron. The Colony is now in a state of transition between the timber and masonry periods ; we are exchanging the frail and ephemeral, for the strong and enduring. It is therefore our duty to spare no pains in selecting the materials that are most conducive to health and comfort, and that will remain for generations a. record of our skill, forethought, and good taste. In treating of the Building Materials of Otago, L shall consider the subject under the following heads : — First, Stones, Bricks, Concrete, and Hoof- ing Slates; Second, Limes, Cements and their Aggre- gates ; Third, Timbers ; and Fourth, Metals. SECTION I. STONES, BRICKS, CONCRETE AND ROOFING SLATES. CHAPTER I. Description of Building Stones. Classification. UILDING stones are usually divided into three classes, determined by their compo- sition — viz., Silicious, Argillaceous, and Calcareous. Although this is, perhaps, the most natural and distinct classification that can be adopted, it is objectionable as bringing together stones of very different characters. For instance, granite and sandstone in the first class, and por- phyry and clay-slate in the second. I purpose, therefore, to consider them under two heads, with the conventional names of Sard Stones and Free Stones. Properties of Building Stones. — Before proceed- ing to treat in detail the individual members of these classes, it would be well to consider the pro- 2 Building Materials of Otago. perties of building stones generally, with special reference to the causes that lead to decay, and the means of preventing it. The principal bases of stone are silica, alumina, and lime. As can readily be inferred from the most superficial knowledge of these earths, the hardest and most durable stones are those in which the former predominates ; many of them, such as granite and basalt, being practi- cally indestructible. The building stones most subject to decay are sand and limestones. In the former it is caused chiefly by the mechanical action of winds, rains, and frosts, and in the latter by these and chemical agencies combined. Sandstone is composed almost entirely of silica or quartz grains or dust, cemented together by lime, alumina, magnesia, or iron ; and sometimes by a combination of two or more of these minerals. As the particles of quartz are, like the stones already mentioned, practically indestructible, the durability of sandstone depends entirely on the cementing material. When this is nothing but alumina or clayey matter, the stone is of an inferior quality, that base being deficient in adhesive properties, and generally soluble in water. The stone is therefore peculiarly susceptible to the action of the weather. The presence of an undue preponderance of clayey matters in sandstone may frequently be detected by washing small pieces in water. Craigleith sandstone, the best in Great Britain, contains : — Silica ... ... ... 98.3 Carbonate of Lime ... ... i.L Iron, Alumina ... ... ... 0.6 100.0 Description of Building Stones. 3 Caversham stone, on the other hand, contains : — Silica ... ■•• Carbonate of lime and magnesia Alumina Soluble clay Oxide of iron Water and loss ... 100.0 The reddish sandstones generally contain iron in considerable quantities ; when the iron is naturally in a low state of oxidation, the stone has a tendency to decay on exposure. Changes from wet to dry seem to prevent rather than assist the cementing process. But when the iron is highly oxidised, and the whole a perfectly homogeneous and compact mass, the stone is not affected by the changes of the weather, and may therefore be taken as durable. Sandstone is deposited under water, and har- dened by pressure and drying, consequently it has a distinct natural bed. The stone is often of such a uniform colour and consistency that the lines of stratification are quite invisible, and as the stratum may not have retained its originally horizontal posi- tion, the mere inspection of a specimen in a museum, or of a block in a quarry, will not give the bed of the stone. It is, however, easily determined by the quarrymen from the facility of working in a par- ticular direction. As a general rule, sandstones are hardest and most compact when formed at the lower side of a thick stra- tum, or in the vicinity of basaltic dykes, or other vol- canic rocks that may have disturbed them. The fa- cilities for drainage afforded by the lie of the adjoin- in g land has also considerable influence on the con- 24.4 53.0 17.6 1.5 1.4 2.1 4 Building Materials of Otago. sistency of the softer sedimentary rocks. In build- ing with stones from stratified rocks, it is absolutely necessary that they be laid on their natural bed. A disregard for this rule is the sole cause of decay in a large majority of cases where buildings have failed. When the stones are placed in an inclined position, they afford the greatest facility for absorb- ing moisture ; and, when vertical, the superincum- bent weight has a tendency to split them. The latter evil is often greatly aggravated by a practice that exists among masons of working the beds slightly hollow so as to ensure a neat joint. The appearance of some of our soft-stone buildings fully bears out the above remarks as to the necessity of laying stones on their natural bed ; some of them are smooth and solid after many years' exposure, while others, from the same quarry, and under exactly the same conditions, are in an advanced state of disintegration. This state of affairs could be prevented by simply marking the stones in the quarries where the lines of stratification are easily determined, and generally well-known. Indepen- dently of the increased durability, it is advisable to lay all stones on their natural bed, for they are a fourth stronger in that position than in any other. Calcareous stones are less subject to decay from the mechanical action of the weather than sandstones, but are more susceptible to chemical agencies. As the cementing material is always the same, the du- rability depends entirely on the aggregates, and the proportions in which they are mixed. The compact and crystalline limestones are believed to be un- stratified, consequently they are not liable to Description of Building Stones. 5 exfoliation, and may be used in any position ; lout some of the softer kinds give indications of having "been deposited in horizontal layers, in which case it is necessary to build with the stone on its natural bed. Although limestone is generally more com- pact than sandstone, it absorbs more water ; but, on the other hand, the water affects it much less than sandstone. The compactness of limestone seems to keep the water from freezing, and so neu- tralizes its most powerful disintegrating property. All the softer limestones are hardened by exposure to the atmosphere ; at the same time the atmosphere contains the elements of their destruction. The indurating process is not, as is sometimes supposed, attributable to the absorption of carbonic acid from the atmosphere, like the setting of mortar. The lime in the stone, being already a carbonate, cannot in this way absorb more of the acid. The harden- ing on exposure is caused entirely by the evapora- tion or drainage of the moisture contained in the pores of the stone. The ingredients in the atmosphere that have themost deleterious effect on stones are muriatic and sulphuric acid, both of which have an affinity for lime, and com- bine readily with it, thus rendering the stone soluble in water. The former acid is always present in the atmosphere near the sea, and the latter in manu- facturing towns where coal is burnt. All the softer limestones are more or less subject to the pernicious effects of both these acids, and when magnesia enters into their composition they are particularly susceptible to the action of sulphuric acid. The English Houses of Parliament are built of mag- 6 Building Materials of Otago. nesian limestone from the Bolsover quarries in Derbyshire, its composition being as follows : — Silica ... ... ... 3.6 Carbonate of Lime ... ... 51.1 Carbonate of Magnesia ... ... 40.2 Iron, Alumina ... ... ... 1.8 Water and Loss ... ... 3.3 100.0 II is well known that this stone has been a de- cided failure ; the buildings were not many years finished when they began to show symptoms of de- cay. This result is due entirely to the sulphuric acid with which the smoky atmosphere in London is impregnated. The selection of the Bolsover stone for such an important work is perhaps the most curious instance on record of the miscarriage of skill, experience, and good intention. The English Government, fully alive to the necessity of having the Houses of Parliament built of the best stone procurable, appointed a Scientific Commission for the purpose of enquiring into the qualities of the various building stones in Great Britain. The Commissioners were men of the highest standing, whether as regarded their disinterestedness or scien- tific attainments ; they had carte blanche to ex- amine, enquire into, and experiment on every stone in the Kingdom ; in short, their instructions appear to have simply been — select the best. After a long, laborious, and expensive investigation, and with the best possible intentions, the Commissioners selected " the magnesian limestone or dolomite of Bolsover," and it has turned out one of the most worthless stones for the purpose in Great Britain. The sole reason for this untoward result is in the Description of Building Stones. 7 fact that at that time the peculiar affinity of mag- nesian lime for sulphur was unknown, and the Commissioners had the strongest possible proof of the durability of the stone in Southwell Minster, where it had withstood the action of the weather for 800 years. This was, however, in the pure air of a small country town — a condition that differs materially from that which the material occupied when exposed to the smoky and acidulous atmo- sphere of the metropolis. Tests. — Except in rare cases, such as the arches of a long-spanned bridge and the lower courses in a spire or chimney, the pressure on stones in a build- ing never approaches then crushing weight ; their cohesive properties may therefore be disregarded in a popular investigation like the present one. I shall, however, consider shortly the proofs or tests of durability that should be observed in building with freestones. Generally speaking, the hardest, heaviest, and least absorbent stones in a class such as sand or limestone, are the best; but this is no criterion when comparing classes. In sandstones the chemical test is the maximum amount of silica and minimum of alumina ; the proportions of the other ingredients being within certain limits ap- parently of no consequence. The best limestones are those that approach nearest the crystalline state. Uniformity of tint and homogeneity of structure are also favourable indications. So far as strength and beauty, as well as durability under ordinary circum- stances, are concerned, the magnesian limestones are best when the lime and magesia are in equal 8 Building Materials of Otago. proportion. This, however, as already shown, seems the worst proportion for a smoky town. The absorbent properties of stones can "be tested by subjecting them to the action of water under a slight pressure. "With 14 lb. on the square inch, English ■Sandstones absorb from one-seventh to one-fourth of their entire bulk ; Limestones, one-ninth to one- fifth ; Oolites and Dolomites, ons-fifth to one-fourth. The resistance of stone to disintegration can be tested by what is called Brard's process. This con- sists in boiling specimens in a solution of sulphate of soda (glauber salts), and afterwards dipping them at intervals into the cold solution for a few days. The action of this salt closely resembles that of frost, end Mon. Vicat has calculated that the effect after two days' application is equal to the force exerted by frost at 21deg. Pahr. on wet stone. The hardest granite is segregated by Brard's process in thirty days. Artificial Induration. — The artificial induration of building stones is a problem that has occupied the attention of scientific men for years, and numerous processes have been tried with varying degrees of success. All the earlier experiments were confined to oils and bituminous matters, but these have, in most cases, proved more liable to decay than the stone they were intended to preserve. Latterly, the means of preservation have been sought for in acids and solutions that form new chemical combinations calculated to arrest and resist the progress of decay. Silicate of potash, chloride of calcium, and other compounds of a similar character, have been used in various ways with considerable sue- Geographical Distribution. 9 cess, and it is thought that through such agency a perfect remedy will ultimately be discovered — a very great desideratum when the relative cost of building in hard and soft stone is considered. It seems to me, however, that there will always be a difficulty in applying the indurating fluid in the most effective manner. If it is simply spread on the vertical face of a building with a brush, as is usually done, it is not only apt to be washed off by rain, out it cannot possibly penetrate any great distance into the stone, which is thus covered with a hard skin liable to peel off. A liquid might be forced into the heart of the stone by hydraulic pressure before being placed in the building, but in all probability the power required to do so would impair its cohesive properties ; and the cost of the process would necessarily be considerable. CHAPTER II. Geographical Distribution. Localities. jSSf PfjllE geography of the Otago building stones >->i Kf> °onies more properly under the conside- JiN*v^ ration of the Provincial Geologist, and is J^-^P^ clearly shown on Professor Hutton's map.* It is, however, necessary, for the com- pleteness of this paper, that a general indica- tion of the localities be given. Commencing with the older rocks, we have true * Geology of Otago, 1875. 10 Building Materials of Otago. granite in mass at Preservation Inlet, and in nume- rous veins and isolated blocks in Stewart's Island, and along the whole of the West Coast. Syenite and other granite rocks are also found in large quantities in the same localities ; and the Bluff Hill is chiefly- composed of the former. Gneiss, mica schists, and other crystalline rocks of a similar character, which compose the Manipori formations, abound from Preservation Inlet to Martin's Bay, and inland to Manipori and the Te Anau Lakes. Schists and clay- slates exist in the Wanaka formation, a broad zone extending from the Taieri Plain and Waikou- aiti to Lake Wanaka, and which is flanked on each side by narrower belts of the newer slates, and possibly limestones of the Kakanui formation. Al- though the two groups last mentioned are gene- rally the repositories of the most valuable metallic lodes, they are the least productive in building stones. Hoofing slates and a few varieties of lime- stones and marbles are, however, found in them. The Kakanui or Carboniferous formation comes next in order. It extends in a narrow strip parallel to the schists and clay slates, from Balclutha, via Switzers and the Eyre Mountains, to Martin's Bay. ThereJ are also large areas between the Big Biver and the Monowai Lake, at Orepuki, Stewart's Island, and the Upper Waitaki; with small patches at the Bluff, the Takatimos, Akatore, and the Horse Hange. The Triassic, otherwise Maitai and Putaki formations, occupy the whole of the country be- tween the Clutha and Mataura as far inland as Gore, thence extending in an irregular chain to the Takatimo range. The Waipai or Cretaceous Geographical Distribution. 11 formation is represented in this Province by a strip of limited area extending from Shag Point to Otepopo, and a small patch at Mount Hamilton. The Oamaru, Pareora, and Wanganui series corres- ponding to the Eocene, Miocene, and Pliocene of geological chronology, occupy portions of the coast from the Clutha to the Waitaki, including the Waitaki Plain. The Maniototo Plain, Ida Valley, Manuherikia Valley, and the Tokomairiro Plain, all belong to this group, and an irregular belt of the same runs from Orepuki to the head of the Te Anau Lake. The economic products of the Pleisto- cene Formation are chiefly clays, gravels, and sands, which will be considered further on. The volcanic rocks of Otago yield valuable building materials, and are situated chiefly between Saddle Hill and Waikouaiti, but there are isolated patches at Apa- rima, Waihola, and Upper Taieri, and also between Shag Valley and Oamaru. Products of Geological Formations. Adopting Professor Hutton's numbers and classification of the Otago rocks, the following table gives the industrial products of the various forma- tions : — No Age. Formation. Products. 1 2 3 4 Pleistocene ... Pliocene Upper Miocene Upper Eocene Pleistocene . . . Wanganui ^ Pareora \- Oamaru J C Clays, Shingles, Gravels, \ and Sands. Clays, Shingles, Gravels, Sands, and Limestones, Building Stones, Brown Coal, Cement Stones or Septaria. 12 Building Materials of Otago. Age. Cretaceous Jurassic Triassic Carboniferous Silurian < L Laurentian ... 1 r i Eruptive -j I L Formation. Waipara Pukitaka Maitai Kaikorai Kakanui "Wanaka Manipora Basalt Trachyte Granite Products. Marbie,Limestones. Flint- Sandstones and Lime- stones for building pur- poses, Hydraulic Limes,. Coal, and Ironstone. Best Sandstonefor build- ing purposes, Marbles. Limestones for mortar,. Ironstones, Lead Ore, True Coal, Bitumen, Shale, and Fire Clay. Roofing — Slates, Flag- stones, Minerals, Ores of Tin, Copper, and Lend. C Marble, Serpentine, Me- ( tals and Precious Stones. BuildingStone,Road Me- tal, Pozzolanas and other Natural Cements, Sulphur, Borax, and Precious Stones. CHAPTER III. Haedstones. HE hardstones suitable for building pur- poses in Otago are — First. True, granite and syenites, with, their varieties : syenitic or hornblendic granite and pegmatite or congealed granite. Second. Metamorphic rocks : gneiss, clay-slates, schist, and quartz rock. Third. Volcanic and trap rocks : basalt, blue- stcne, greenstcne, dolomite, phonolite, timarzite, Hardstones. 13 "breccia, and trachytes, with an endless variety of intermediate links and gradations. Granites. Granite is the monarch of building stones ; although hard and tough, it is not difficult to work with the hammer, pick, or chisel. It can he got in any sized blocks, and takes a polish like marble. Granite has been used for centuries in engineering works and other structures, that are calculated to last for ages, but it is only of late years that it has been extensively used for ordinary architectural purposes. The introduction of stone-cutting and dressing machinery into the granite quarries has given this branch of the trade a great impetus, and it is possible that within a few years granite will supersede freestone in the more important public liuildings of large cities. True Granite. — According to Professor Hutton, Preservation and Chalky Inlets are the only locali- ties in the Province where true granite is found in mountain masses, but it exists in large veins and blocks in Stewart Island and the whole of the "West Coast. Professor Black, in Stewart Island, and Dr. Hector, on the West Coast, report its occurrence at every step. In appearance, the Pre- servation Inlet granite is not unlike that found in the Island of Mull. It is of a pinkish tinge, with grey spots, and rather coarse in the grain. Al- though, in all probability, it is equal in strength and durability to most of the granites of the old country, and consequently suitable for kerbing, paving, and engineering purposes, its colour will be 14 Building Materials of Otago. an objection in architectural works. I haye no doubt our supply of granite for monumental and archi- tectural purposes will ultimately come from the veins and blocks that are so profusely scattered in the various localities above-mentioned. Some speci- mens already obtained are most beautiful in colour,, fine in the grain, and otherwise admirably adapted for the best class of work. There is a vein of light grey granite at Seal Island, the colour of which is. uniform and agreeable ; it has a white ground and dark spots, and the grain is very smooth. Similar veins of clear white granite, with spots of brown mica, have been found at George Sound. In one sample the mica is in mere specks, but in the other the mineral appears in large lustrous flakes. Both are extremely beautiful, and seem capable of taking a fine polish ; but it is possible the latter, from an excess of mica, would lose its appearance in an ex- posed situation. Syenite. — Syenite, as you are aware, differs from true granite, only in so far as it contains hornblende instead of mica. As mica and felspar are considered the perishable ingredients in these rocks, the dura- bility of syenite can never be questioned. It is also, on the whole, tougher and more compact than ordinary granite. This stone is found in various localities on the West Coast and in Stewart Island, but the chief supply now available for industrial purposes is at the Bluff. Practically, the whole of the Bluff Hill consists of this material. It could therefore scarcely be in a more accessible situation, the Bluff syenite is hard and compact, and of a uniformly bluish grey tint of great beauty ; conse- Hardstones. 15 quently, it is suitable for kerbing, paving, and mas- sive masonry, as well as monumental and architectu- ral works. In my opinion this stone is little, if any- thing, inferior to the famous Aberdeen granite, and I have no doubt the quarrying and dressing of it will, ere long, become an important industry. There is a curious variety of syenite found at Mil- ford Sound, the body colour of which is a pure opaque white, interspersed with oblong rectangular blotches of dark grey and black ; these blotches are occa- sionally an inch long by three- eighths of an inch in breadth. Another vein of syenitic granite exists at Isthmus Sound. The grain is rather coarse, but the colour, which is of a uniformly grey tint, is very good. Pegmatite. — Pegmatite, or compact granite, is found at Milf ord Sound and Paterson Inlet. The former is of a grey tinge, with large spots of silvery- white mica of great brilliancy. This is per- haps the most beautiful stone in Otago, but it is doubtful if its appearance would be permanent out of doors. The stone at Paterson Inlet has a pinkish ground, with grey spots, and is much coarser in the grain. "When the utilitarian appetite of the colonist has been satisfied, and he has means and leisure to be- stow on the ornamental, the beauties of the West Coast granites will no doubt be highly appreciated. Constituents. — Although the stones above de- scribed vary much in appearance, there is little difference in their composition, and they are all embraced in the generic name of granite. All granitic rocks are composed of felspar, quartz, mica, 16 Building Materials of Otago. and hornblende, and the variety is determined en- tirely by the number of ingredients that it contains, and the proportions in which they are mixed. An undue preponderance of mica and felspar in granite, particularly when the latter is alkaline, is supposed to render the stones liable to loss of colour and to decay, but with that exception, granite of all kinds is practically imperishable. I have compared Mr. Skey's analysis of the Otago granites with that of the European varieties given in "Juke's and Geikie's Geology," and Professor Hull's " Building and Ornamental Stones," and find that, though at opposite sides of the globe, their composition is practically the same ; the essential constituents in all cases being as follows : — Silica ... ... From 60 to 75 per cent. Alumina Oxides of Iron Lime Alkalies 12 to 16 2 to 6 2 to 5 4 to 10 Metamorphic Rocks. The second class of hard stones, forming the metamorphic rocks, is comparatively valueless as a building material — a few of the connecting links between them and granite, being of a crystalline texture, might be utilised; but as gneiss proper and the harder kinds of schist are composed of the granitic constituents in a stratified form, they will neither break nor cut across the grain, consequently can only be used in rough work. Much of the masonry on the Otago Goldfields is composed of schist, notably the piers of the Cromwell bridge, and the houses in the Teviot District. Although somewhat coarse and irregular, the work is by Hardstones. 17 no means unsightly. There are several crys- talline stones of the metamorphic formations of Otago that seem suitable for ornamental purposes. Granulite, of a light grey colour and fine grain, has been found at Breaksea Sound. Syenitic gneiss, of a grey flaky appearance, exists at " Connecting Arm," and brownish gneiss at Anchor Harbour. These all appear capable of being dressed or polished into columns or slabs for monumental purposes. The slates in this series of rocks should yield paving stone. It is reported that such exist at Chalky and Preservation Inlets on the West Coast, but I have no particulars regarding them. Volcanic and Trap Rocks. Varieties. — It is from this class that the prin- cipal supply of hard stone is at present obtained, therefore the fullest information on its products and their properties is of the utmost importance. So far as varieties are concerned, it is quite impossible to give even an indication of their extent. Although the area occupied by these rocks is comparatively limited, the building stones they yield are simply confusing in their profuseness. They comprise every texture and colour from the black basalt that yields to nothing softer than diamond, to white tufa that can be sliced with a pocket-knife. Generally all compact stones of volcanic origin are durable, and, being unstratified, there is no danger in using them in any position. As already stated, eruptive rocks are found in several localities in the Province, but so far as I am aware the Peninsula and the district between Otago Harbour and Blueskin Bay 18 Building Materials of Otago. are the only places that produce the trachytes, brec- cias, phonolites, and other stones of so varied a char- acter. There are few rocks of economic value outside this area except the ordinary blue and greenstones. Basalts. — Commencing with the hardest, we have black basalt and basaltic conglomerates at the Bluff, Dog Island, Purakanui, and Taiaroa Head, and various other places on the Peninsula, so hard that more steel than stone is removed in dressing them. They are therefore comparatively useless as building material, so it is unnecessary to consider them further. Bluestone. — Bluestone, which is so largely used for road metal and ordinary rubble masonry, is to be found in almost all districts that have been dis- turbed by volcanic agencies. Sometimes, it exists only in bombs and small columns, fit for nothing but road metal and pitching; but at other times, it occurs in large dykes, that yield valuable building stones. The best quarries in the Province are those in the Dunedin Town Belt, the valley of the Leith, and Boss Creek. The most of the bluestone used in Dunedin comes from those quarries. It forms excellent rubble, and with a little labour, picked ashlar ; but it is altogether too hard for chiselled work. The basements of nine-tenths of the build- ings in Dunedin are built of bluestone rubble, and many important edifices, such as St. Paul's Church, the Wesleyan Chapel, Knox Church, the Mercantile Agency Store, and the residences of the two Bishops, are built of coarse hammer- dressed rubble, with facing of lighter coloured materials, the effect of which is very pleasing. Sardstones. 19 Greenstone.- — Greenstone is simply bluestone, in a more tractable form, and is used for much the same class of work. There is, however, no supply near the centres of population, so its use hitherto has been comparatively limited. Greenstone is found in the Mataura Valley, on the shores of Lake Wakatipu, and at Greenhills, in Southland ; its colour varies from light green to dark red. Dolerite. — Dolerite is a dark grey, or brownish stone, of vesicular texture, and harder, but more brittle, and easier worked than bluestone. It is usually found near volcanic centres, associated with the other basaltic rocks ; it is quarried for road metal at "Waihola and Tokomairiro. A small vein that yielded building stone, now exhausted, was at one time worked near the top of York Place. The base of the Colonial Bank, one of the finest pieces of massive masonry in the Province, is chiefly built of dolerite from this quarry. A large reef of this rock occurs at Timaru, where it is extensively used for basements. Phonolite. — Phonolite, or clinkstone, and por- phyry, are found in Bell Hill. As they do not exist in large blocks, they are not suitable for massive masonry, but answer admirably for ordinary build- ing, being easily worked ; some of them are remark- ably beautiful in colour and fine in texture, capable vof being used for ornamental purposes. A polished block of phonolite in the Museum shows an arrange- ment and blending of various shades of grey colours that excels the best efforts of the grainer. The Gaol and some of the other old buildings in Dunedin are built of clinkstone, as well as several of the most 20 Building Materials of Otago. recent structures, notably Mr. Howden's house at Anderson's Bay. Timarzite.- — Timarzite, an eruptive rock found on the Peninsula, resembles closely the Bluff syenite- in colour and consistency, the only difference being* that the latter has a slight tinge of green, instead of blue, intermixed with grey. It seems adapted for both useful and ornamental purposes, but has- hitherto been little used. Breccias and Trachytes. — The breccias and trac- hytes, with their connecting links, come next in order, and they are the most important class of hard- stones in Otago. They exist in large quantities in the vicinity of Port Chalmers and throughout the Peninsula, and in most cases the quarries are easy of access by rail or water. The Port Chalmers stone,, which was the first utilised, still holds the first place in point of strength and durability, and the facility presented for getting it in large blocks. It is, how- ever, inferior to some of the others in colour and smoothness of grain, which are essentials in archi- tectural work. The Port Chalmers stone is a true breccia of a bluish grey colour, with the rock frag- ments of all sizes, up to six inches. It is hard and tough, but yields readily to the pick. The Port Chalmers Graving Dock, one of the finest struc- tures in New Zealand, is built entirely of this stone, the quarry from which it was obtained being within 200 yards of the work. All the kerbing used in Dunedin and Port Chalmers is from the same locality- Most of the quarries now worked yield stone of a fine texture, easily dressed, and alto- gether well suited for any architectural works of a. Hardstones. 21 substantial character. Although the labour of rubbing this stone to a perfectly smooth surface is greater, there is not much difference between it and the hardest sandstone, when worked with the chisel and fine axe. Some good specimens of this class of work can be seen at the Mercantile Agency Store, the Union Bank, and Messrs. Sargood's "Warehouse. After that used at the Dock, the next good building stone discovered was at Sawyer's Bay. With the exception of colour, this stone is, to all intents and purposes, the same as the former. The colour is a light grey, about the same shade as Port- land cement, but with a slightly orange tinge. In consequence of its lighter colour and the proximity of the quarry to the railway, this stone soon became a favourite in Dunedin. It has been extensively used, both as ordinary rubble and dressed ashlar work ; the facing of St. Matthew's Church, Messrs. Boss and Glendining's warehouse, Messrs. Cargill's store, and a large number of private buildings are of this material. It may be interesting to note that the railway through Wales's quarry at Sawyer's Bay has revealed the fact that the white stone is only on the outside of the cliff. On penetrating a distance of 30 yards, the colour gradually changes to blue as found in the other quarries about Ko- putai Bay. On the other hand, the Deborah Bay tunnel, seven-eighths of a mile long, is almost en- tirely through Sawyer's Bay stone, the same colour, but much softer than in the quarry. It should be noted that the Sawyer's Bay stone does not retain its colour when exposed to the weather. Although .22 Building Materials of Otago. there is no symptom of decay, the stone in some of the older buildings is already considerably defaced by large stains. The quarries and railway cuttings show that the breccia rock extends from Sawyer's Bay to the township of Mansford, a distance of nearly two miles, and from sea level to the top of the range at Lean's Hock, a height of 500 feet. The width inland is not known, but were it only a crust on the mountain side five hundred yards thick, it could produce stones sufficient to make a Liverpool of Docks in Otago Harbour, with a Glasgow in each of the other Provinces. The accessibility of the Port Chalmers stone is also worthy of notice. Two railways run through it at different levels, and the Harbour, with deep water at several places, skirts the foot of the rocks. Breccia. — Breccia similar to that at Sawyer's Bay is found at Broad Bay, Castle Larnach, and several other localities in the Peninsula. "With the exception of Castle Larnach, which is chiefly built of this material, the Peninsula stone has not yet been much utilised. A breccia of much the same consistency, but of a, beautiful brown colour, exists on the northern slope of Puketapu. It seems capable of taking a •fine polish, and will probably be used for monu- mental purposes. Another stone of the same colour, but finer in texture — possibly, a trachyte — is found in small quantities at Kakanui mouth, and in considerable reefs near the Taieri Lake. The Hamilton Road Hardstones. 23 Bridge — a substantial piece of masonry — is built of this description of stone found on the spot. Trachytes. — The trachytes proper, as a class, furnish softer and easier-worked stones than the breccias ; they are therefore more suitable for the ordinary purposes of the builder. There is a large assortment of trachytes on the Peninsula, and in the vicinity of Port Chalmers. Many of the deep cuttings on the Northern Railway between Port Chalmers and Blueskin pass through masses of this material. Tomahawk Yalley produces a brown trachyte with bright orange spots : it is net much harder than some kinds of sandstone, and seems capable of being easily dressed. Although rather 4ark for the whole front of a building, it might be introduced into some portions with great effect. The Port Chalmers trachytes are generally light in -colour; one sample in the Museum is a delicate fawn of uniform tint and soft even texture. Those in the railway cuttings are of all conceivable colours and shades. I am not aware that either of the latter two has been utilized, but I have no doubt this could be done to advantage now that ready means of transit is provided. Some of the light coloured stone particularly should soon become popular in Dunedin, everything being so favourable to its use ; it is easy of access, easily worked, and can be obtained in moderately large blocks ; it has also -every appearance of durability. There is a peculiar looking- trachyte or tufa at Harbour Cone, on the Peninsula, which, so far as consistency is concerned, should be classed with the freestones. Its colour is a light brown, with white 24 Building Materials of Otago. spots, and the texture is much the same as Oamanr stone, but with less grit in it. The stone dresses as easily as an ordinary sandstone, and has a hand- some appearance with any kind of work — smooth dressed, chiselled, or picked. Although the chalky feel of its surface is a symptom of weakness, the class to which it belongs is a durable one, and it is therefore entitled to a fair trial. The steps at Lar- nach Castle are made of the Harbour Cone tufa in one length of eight feet. Although thus placed in the most trying situation, the stone is wearing re- markably well, and Professor Hutton says that soft trachyte is often as durable as basalt or bluestone. It has also the property of resisting fire, and on this account is used in building the lime kilns on the- Peninsula. A stone somewhat similar to that at Harbour Cone is found in large quantities in Blue- skin Bay, near the Township of Evansdale, and on the slopes below Merton. The latter, which is; more of a basaltic conglomerate, has recently been used in building the piers of the Waikouaiti Road Bridge. + CHAPTER IV. Freestones. fLASSIPICATIOJST. — The freestones of Otago are naturally subdivided into three classes: — First, Marbles; Second, Lime- stones; Third, Sandstones. As some of the trachytes and tufas just described might just as well be classed under the head of freestones, so, on Marbles. 25 the other hand, might the marhles and crystalline limestones he included with the hardstones. It is, however, less confusing to let each he considered with the other memhers of its own family, although its character accords "better with a stranger. Marbles. The marhles of Otago are still, practically speaking, unknown and untouched; the informa- tion collected ahout them is meagre in the extreme; and the few known deposits have not yet been utilised. Some important discoveries of marble have however been made across the border — in Canterbury, — and a good deal has been done towards opening out quarries, and developing a trade in the stone. Although the Canterbury mar- bles cannot be classed in the Building Materials of Otago, they are intimately connected therewith; consequently, we may give them some little con- . sideration. Horse Mange. — A grey variegated marble exists . at the Horse Hange, in considerable quantities ; it has all the characteristics of a true marble, and seems equal in every respect to the imported samples of the same variety. It has not, however, been worked, and there is little known as to the ex- tent of the seam. Tokomairiro. — Professor Hutton reports the existence of a handsome black marble with shells, " somewhere near Tokomairiro," the exact locality being unknown. I have made numerous enquiries on the subject, but can find no information as to .the position or extent of the deposit. The dis- 26 Building Materials of Otago. coverer is evidently not disposed to give particulars at present. Otekaike. — A bed of light brown marble has been discovered on the property of the Hon. Robert Campbell, M.L.C., at Otekaike. It is of a fine even texture. The colour is rather dull by itself, but it would look well in contrast with others of more de- cided and brighter tints, or if relieved by gold figuring. The extent of the deposit is unknown. Clyde. — Mr. Vincent Pyke, M.H.R., has sent me specimens of a beautiful white marble found on the eastern bank of the Clutha River, between Clyde and Cromwell. It occurs in a vein, the out- crop of which is about a foot square. The stone seems harder than ordinary European marble, and thin slabs are quite translucent, like alabaster. West Coast. — Dr. Hector reports the existence of marble of various colours and consistency in several localities on the West Coast. In no case, however, did he find the rock in situ; the specimens were always taken from large isolated blocks and boulders. They comprise pure white and the com- mon variety of colours, with others of a rarer description, such as white and green, specked with brown, and lead-coloured mica. The white is stated to be suitable for statuary ; the samples in the Museum show the grain to be rather coarse and crystalline for this purpose ; but in all probability this defect will not exist in stone from solid rock. The Hon. Capt. Eraser, M.L.C., has lately dis- covered this white marble " in the reef " at Annita Eay, Milford Sound. He has kindly given me the Marbles. 27 following description of the stone, and the locality in which it occurs : — " The Annita Bay marble, Milford Sound, discovered by me,, is a saccharine marble, resembling the purest loaf sugar in colour and texture, working freely in any direction, and not liable to splinter. Some of it is slightly translucent and capa- ble of taking a polish, but the greater part of it is too highly crystallized to be used for table-tops, &c. It works and rubs down to a smooth surface, and would be admirably adapted for pillars and ornamental architecture of every kind. The vein is twelve feet thick and about a hundred yards in length, and is immediately above high water mark. Blocks could be craned from the quarry to the vessel, as the water is deep alongside and nearly always calm." Mr. Macfarlane, the Government Agent at Jack- son's Bay, writes me that the small range enclosing Annita Bay seems to have heen detached from the main one behind, and that it is much shattered,, consequently it is possible that the solid reef at the shore may not" be of great extent. He is, however,, confident that the original deposit will be found in the main range. One of the finest samples of New Zealand mar- ble that I have yet seen comes from Caswell Sound.. The ground colour is bluish white, with faint streaks and pencillings through it, of a darker tint of the same colour. The texture is soft, even, and perfectly homogeneous. So far as I can judge, it is equal to any European variety. The stone is found in a solid reef twenty feet thick, situated close to the water's edge, in the most convenient place possible for shipping. Steps are now being taken to utilize the Caswell Sound marble. I shall be very much surprised if its quarrying and working does not yet grow into an important industry. "28 Building Materials of Otago. From a geological point of view the localities on the West Coast just mentioned, as well as the car- boniferous formations, are calculated to produce marbles of all kinds, so I trust they will ere long be thoroughly explored. A connecting link between marble and lime- stone is found at Crooked Arm, in the stone called Cipollino. It has all the appearance of coarse- grained loaf sugar, interspersed with small brown specks. The stone is very beautiful, and seems sufficiently hard and durable for at least ornamen- tal purposes indoors, but its general character as a building material is little known. Canterbury. — Mr. Munro, of Dunedin, has opened up marble deposits at the Kakahu River, seven miles from Geraldine. There are two dif- ferent kinds ; one is of a delicate dove colour, with beautiful shadings, and the other is bluish green and white, in distinct markings. The texture in both cases is soft and even. The dove coloured rock is very much shattered, so large blocks of stone cannot be obtained ; but the green variety exists in large masses. The extent of the marble deposits in the Kakahu District has not yet been determined. The only marble quarries in New Zealand that have been fairly opened up with a view to perma- nent working are at Malvern Hills, in Canterbury. An influential company was formed in 1876 to work them, and since then considerable progress has been made in developing the enterprise. The marble is found in reefs, in a conical hill about eight miles from the White Cliffs Railway Marbles. 29 Station, the extent of the deposit being practically- inexhaustible. There are two distinct varieties — the "Grey," and the "Imperial Red." The former has a bluish-black ground, with distinct white lines, the general effect being grey ; the latter is of a mottled light red colour of a peculiarly rich tone, something like Peterhead granite. The grey reef yields blocks of twenty tons weight and upwards. The red one is not quite so solid ; still, blocks can be obtained much larger than is required for ordinary "building and ornamental purposes. A large quantity of the Malvern Hill marble — worked into slabs, eolumns, and ornaments of various kinds — is exhi- bited in Christchurch ; they show that the stone is suitable for all the purposes to which European marble of similar colours is applied. There is every prospect of a considerable export trade in the Canterbury marbles. Authorities in Lon- don have reported favourably of them, particularly the red. They compare it with the "Jaune Eleuri" marble of France, but say that the former is much more valuable. The red Canterbury marble is stated to be worth from 20s. to 30s. per cube foot in London against 12s. to 15s., the price of its European proto- type. This difference is more than sufficient to turn the scale in favour of the Colonial article, and the price quoted shows that the trade is likely to be profitable. Professor Bickerton's analysis of Canterbury marble shows it to be identical in composition with those in other countries. The sample analysed con- tained " 98-53 per cent, of carbonate of lime, with an insoluble residue consisting of silica, alumina, c so Building Materials of Otago. and manganese, the colouring matter being due to the latter constituent." Limestones. Classification. — The limestones proper are as varied in colour and consistency as they are great in numbers. They comprise every shade and hue,, from dark grey and blue to pure white, and every texture and degree of hardness, from stone as hard as basalt to chalks and recent concretions that can be dug with a spade. There is often a difficulty in deciding as to whether certain stones should be called limestones or sandstones. Strictly speaking, they should be put in the class to which their pre- dominant ingredients belong ; but, like the purely chemical arrangement referred to at the outset, this brings unlikely relations together. For instance, Caversham stone is more than half lime, though it has all the appearance and attributes of a sandstone. The classification of doubtful specimens is therefore made on the general resemblance to their class, rather than on a chemical basis. Wahatipu. — Again, commencing with the hardest and most compact, we have large masses of lime- stone at the Twelve Mile Creek, on Lake Wakatipu. In colour and texture they closely resemble ordinary green or bluestone, possibly a little softer, but every bit as tough. The rock seems shattered on the surface, and incapable of yielding anything but materials for rubble-work and ordinary ashlar : but it is probable that large blocks will be obtained when quarries are opened out. The stone has not yet leen extensively used for building purposes ; but its excellent quality, and the ease with which Limestones. 31 it can be quarried and shipped, cannot fail to bring it into prominent notice. A further reference to this stone will be found in a subsequent chapter on Limes. Horse Hange. — A bluish-grey granular lime- stone is found associated with the marble in the Horse Eange. So far as strength, durability, and appearance is concerned, it would make an excellent building material. It is found on the Shag Valley side of the range, but I have no information as to the accessibility of the rock or the size of the blocks attainable. Peninsula. — There is a fine limestone in the Peninsula, darker in colour and harder, but closely resembling in general appearance the famous Bath stone of England. It has little or no grit, works freely, and seems durable. The colour is a peculiar tint of brown, rather sombre for building in a mass, but suitable for facings and monumental work. The stone exists in large quantities, and is procurable in moderately sized blocks. It should therefore become a popular building material when means of transit are provided. The deposit is in a very inaccessible situation, on the eastern side of the Peninsula, consequently the stone cannot be utilised at present. Kahanui. — A hard, shelly, white limestone has recently been discovered at Kakanui, and used in some structures in that locality. It is of a uni- form colour and consistency, nearly as hard as Sawyer's Bay stone, but much easier worked. It should prove a valuable addition to our stock of building materials. A variety of this stone from 32 Building Materials of Otago. the same place, similar in colour and consistency, but full of large fossil shells, has been quarried for the foundations of the new road bridge ; it is admi- rably adapted for work of that kind, but is alto- gether too rough for architectural purposes. These stones are both procurable in large blocks, and the supply is unlimited. Waiareka. — A coarse grey limestone, of uniform colour and consistency, is found in large quantities on the Totara Station, near the "Waiareka Creek. With the exception of the foundations of the Waiareka road bridge, it has hitherto been little used. Although considerably more friable, the stone is about as hard as the Tasmanian sandstone ; it has a beautiful warm tint of an agreeable shade, and seems capable of being dressed in any way from hammered to polished work. Waihola. — A valuable addition to the limestones has recently been worked at Waihola Gorge in the shape of a beautiful grey stone found on the western side of the Main Road, about half a mile from the railway. The stone, when newly quarried, is harder than the Oamaru stone when dry, consequently it must be very much harder after being exjDosed to the air for some time. It can be dressed in any way, is capable of taking a fine polish, and, being easy of access, it cannot fail to become popular as a building material, when better known. A solid face of stone, 20 feet thick, is already exposed in the quarry, consequently the appliances for handling and transporting blocks must alone determine their size. Both sides of the Waihola Gorge contain large Limestones. 33 quantities of the limestone that is used for lime- burning. This is a very hard, compact stone of a beautiful white or light cream-colour without a speck. So far as strength, appearance, and dura- bility are concerned, it makes good building stone, but hitherto it has not been found in blocks of sufficient size; the whole rock is shattered into layers a few inches thick. Pleasant Valley. — The blue and grey limestones of Pleasant Valley come next in order. Several varieties of them exist in large quantities, and they are all remarkable for beauty and uniformity of colour, fineness of texture, and the ease with which they can be dressed and carved. Such of them as do not contain an undue proportion of clay — notably the yellowish grey varieties found near Tumai — have all the appearance of durability, but a great many are too soft and friable for out-door work. The Bank of New Zealand, Waikouaiti, built of a handsome blue variety, was only a few years in existence when the stone showed symptoms of weathering, and the arrises and mouldings are now worn quite away. Oamaru Stone. — We now proceed to the conside- ration of the most important building material that hitherto has been utilised in Otago, viz., the Oamaru stone. The use of this material is coeval with the settlement of the district in which it occurs, but it was little known beyond till 1866, when an export trade commenced with Dunedin. The first large I building erected of this stone in the city was the Otago University — now the Colonial Bank. The Oamaru stone occupies that large tract of 34 Building Materials of Otago. country in the northern part of the Province, ex- tending northward from the Kakanuis to the Wai- taki Plain, and westward from the coast to the Kauroo River — an area altogether of ahout 100 square miles. The same class of stone is also found in the following localities : — Upper Waihemo Valley ; Riverton, to the head of Te Anau Lake ; Castle Rock, on the Taringtura Downs ; Limestone Ridge, in Waimea Plains ; and numerous places in Canterbury. Practically speaking, the supply of this material is inexhaustible. There are extensive quarries worked in the Oamaru district, from which a large quantity of stone is produced annually, both for local wants and export to other parts of the Colony and to Melbourne. The trade with the latter port is of recent birth, but it promises to be ulti- mately an important one. The principal quarries now at work in the Oamaru district are at Cave Valley and Kakanui. The Town of Oamaru is chiefly supplied from Cave Valley, and Duneclin and other southern districts from Kakanui. The trade to Dunedin alone is sufficient to keep one or two vessels constantly trading to Moeraki. Much has been said as to the relative merits of the Oamaru stone from different localities, but I do not think that there is any practical difference in similar samples. The constituents of the stone are almost the same throughout the Province, so any difference in colour or texture must be due to its proximity to foreign matter or facility of drainage. The Oamaru stone, correctly speaking, is a white granular limestone. It has a remarkable unifor- Limestones. 35 mity of colour and texture; not only can large blocks be got of the same tint and consistency, but whole cities might be built in which one stone could not be distinguished from another. According to Mr Skey, its component parts are — Carbonate of lime ... ... 9015 Alumina .., ... ••• l'v5 Oxide of iron ... ••• '55 Soluble silica ... •■• '45 Insoluble matter ... ... 7'15 Loss ... ... ••• '15 10000 The ordinary English building stone which most resembles this is the Ketton Oolite, its analysis being — Carbonate of lime ... ... 9217 Do. magnesia ... 4"10 Iron and alumina ... ... '90 Water and loss ... ... 2'83 100-00 The weight of Oamaru stone, wet from the quarry, is 105 pounds per cubic foot, and when perfectly dry 92 pounds. That of the Ketton Oolite, when dry, 128 pounds. The lightest limestone in England is the Bath Oolite, which weighs 115 pounds per cubic foot. The New Zealand product is therefore the lightest by about 23 pounds per cubic foot. Applying the chemical tests to the Oamaru stone we place it on a par with the oolites and ■ common limestones of England and the Caen stone of Prance ; and Professor Hutton in his Geology of Otago " says, that it is " exactly similar to the limestone of Malta, of which the town of Valetta is built." According to Dr Hector, 36- Building Materials of Otago. the resistance it offers to the disintegrating action of glauber salts is comparatively feeble. Its inferiority to the above mentioned stones consists chiefly in its excessive porosity. I have made several experiments "with the new of measuring its absorbent powers, the results of which are worth recording. A block of selected Kakanui stone, used as a footstool in my office for seven years, and consequently tho- roughly dry and hard, furnished the best possible materials for the tests. A piece of this stone,/ 7 inches square and 1-| inches thick, equal to 73 '5 cubic inches, weighing when dry 56oz. I7dwt, llgr. troy, was put in water. Witbin forty hours, it had ab- sorbed 12oz. Odwt. 15gr., equal to 31 per cent, of its entire bulk, and 21 per cent, of its weight. The specimen was allowed to remain in the water for sixteen days, when the quantity absorbed had in- creased to 14oz. 2dwt. 19gr., which gives 36 per cent, of the entire bulk, or 228 gallons of water in a cottage wall ten feet square and one foot thick. A bar of Oamaru stone 13 inches long and 1.65 inch square was next placed vertically in a glass of coloured water. It stood 3.2 inches into the liquid. In six hours the moisture was quite visible to the top of the bar, and in 12 hours the colouring matter had risen 7-J inches. As the stone in both these experiments was particularly dry, the maximum results were probably obtained. But on the other hand, the vertical position of the bar in the second experiment was less favourable to the absorption of moisture than that usually occupied by stones in a building, particularly the horizontal parts of mould- Limestones. ings, cornices, copings, and window sills. It should "be pointed out that the Oamaru stone ahsorhs 36 per cent, of its bulk without pressure, while the most porous English stone only absorbs 25 per cent, under a pressure of 14lbs. on the square inch. It is doubtful, however, if an increase of pressure in the former case would give corresponding results, the stone, being so excessively porous, gets com- pletely saturated at once. When the dry samples were first put into water the air rushing from the pores of the stone caused bubbles to rise to the sur- face for fully ten minutes. The first experiment shows that the stone is capable of absorbing 10 lbs. per cubic foot more water than it contains when in the quarry, a result to me quite unexpected and not easily explained. One of the most important points in connection with the use of Oamaru stone is the degree of indu- ration it attains in drying, and the loss sustained by subsequent exposure to moisture. So far as the hardening is concerned, I am quite satisfied that the largest blocks used in ordinary masonry become equally hard throughout in a few months, and possibly in a few weeks, under the influence of a warm, dry atmosphere. The hardness is not con- fined, as is sometimes supposed, to a thin crust on the surface of the stone, but penetrates to the centre making the whole a perfectly homogeneous mass. In consequence of the time required, I have- not been able to prove by direct experiment that a* stone once hardened becomes soft on exposure to wet. I fear, however, that such is the case ; the window sills and mouldings on the south side of 38 Building Materials of Otago. the Colonial Bank are now fully softer than when they left the quarry, and the chances are that these stones had acquired a considerable degree of hard- ness before being placed in the building. The cor- nice and parapet on Messrs Dalgety, Nichols, and Co.'s warehouse, although in a much more favour- able situation — on the sunny side of the street — are softer still ; the stone can be scratched out in hand- fuls by the finger nails. This is, however, one of the oldest, if not actually the oldest, piece of Oamaru stone masonry in Dunedin ; it is, therefore, possible the material was bad to begin with. Against these unfavourable examples, the bridge in Thames street, Oamaru, built in 1860, and several other buildings of the same age in that locality, are not decayed, nor unduly charged with moisture. The ultimate durability of our Oamaru stone buildings •cannot, of course, be determined at this early stage of their existence, and any estimate short of actual trial islittle more than conjecture. Professor Black might, however, give us his opinion as to whether it can long resist the action of the saline breezes from the Ocean Beach, the sulphurous fumes of the Green Island coal, and the other impurities that are now so rapidly accumulating in the atmosphere of Dun- odin. I should be loth to prophesy evil, but if the •durability of the Oamaru stone is to be measured by its power of resisting moisture, it is to be feared that the handsome spires and facades that now ornament the city will not transmit the names of their architects to many succeeding generations. Although the bad qualities of the Oamaru stone are quite apparent, there is on the other hand, so Limestones. 39 much, to recommend it, that it will always be a popular building material. I shall therefore con- sider the works for which it is well adapted and the precautions necessary to ensure the best results from its use. The stone is well adapted for any ordinary work in a dry, warm climate like that of Victoria, and it is unexcelled for internal decorations of all kinds and in all situations. It is suitable for eccle- siastical architecture generally, and forms a beauti- ful contrast as facings to darker stone. It should not be used in the southern side of buildings, par- ticularly if they are recessed, and it is altogether unfitted for window sills, parapets, and the upper side of large mouldings, and similar projections. Buildings of this material should be designed to have as few of these as possible, and where una- voidable, the flat tops of the stones might be covered with some preservative ; from an sesthetical point of view, this is the only part of a stone building where such should on any plea be permitted, unless the preservative used is perfectly transparent. Damp- ness can be prevented to a certain extent by an impervious foundation, internal lining, hollow walls, and other expedients of a similar nature. I have made several experiments with Oamaru stone to test the expediency of certain appliances occasionally used to prevent damp. A bar of dry stone, after receiving two coats of ordinary oil paint, was deposited in water. In 40 hours it had ab- sorbed 34 per cent, of its bulk, including the weight of the paint, against 31 per cent, absorbed by un- protected stone in the same time. Another sample coated with soluble glass — the principal indurating 40 Building Materials of Otago. ingredient in artificial stone— absorbed 27 per cent., exclusive of the weight of the solution, which was 4 per cent. more. Although these experiments give an indication of the results to be derived from the application of the materials referred to, they are altogether too crude to be advanced as conclusive. The oil in the paint was absorbed to such an extent by the stone, that the colouring matter which re- mained on the surface could be washed off by water. It is therefore probable that much better results would be obtained by more coats, and the use of heavier pigments like red lead. With reference to the use of soluble glass as a remedy for damp, I am not sure that this is a property to which it lays special claim. Although porosity is a primary cause of decay, it may be possible to increase the hardness and durability of stone without removing the lesser evil. Besides, the method of applying the solution adopted by me may not be exactly correct. The following is a recapitulation of the results ob- tained by the various experiments on Oamaru stone : Pounds per m _ . , cubic foot. "Weight when fresh from quarry ... ... 105 „ „ quite dry _ ... ... ... 92 „ after 40 hours' immersion in water ... Ill „ : , 16 days' immersion in water ... 115 „ painted stone, after 40 hours' immersion in water, including paint ... ... m „ of stone coated with soluble glass, after 40 hours' immersion, including solution ... Ill The principal buildings, entirely of Oamaru stone, in Dunedin are the Colonial Bank, First Church and Manse, Union and New South Wales Banks, Eernhill, and the Pier Hotel. In Oamaru, nine-tenths of the buildings are of this material, and Limestones. 41 several of them, such as the National Bank and the Star and Garter Hotel, are worthy of a place with the architecture of the Old World. The private residences in that district can also be classed along with the country houses of England, notably Wind- sor Park, Elderslie, Awamoa, Totara, and Ote- kaike ; the latter, now approaching completion, is one of the finest houses in the Colony. Oamaru stone has also been used in numerous road and railway bridges, many of them of considerable span. The above remarks on the quality of Oamaru stone, which appeared in the original papers, gave rise to a considerable amount of adverse criticism, .and I was pressed to consider the subject further to see whether I could not modify my views and give the stone a more unqualified recommendation. I readily undertook the task, and have embraced every opportunity that presented itself of getting further information on the subject during the three years that have elapsed since the first paper was prepared. So far as pointing out the valuable properties of the stone is concerned, it has probably not received full justice. On the other hand, its bad qualities have not been exaggerated. It is quite unrivalled for purposes of internal decoration. The ordinary freestones of the old world do not offer anything like the same facilities for the sculptor's art. The Oamaru stone carvings of studies in foliage, animals and traceries of various kinds, by Mr Godfrey, of Dunedin, are not surpassed in chasteness of design or delicacy of manipulation by the works of the mediaeval artists. 42 Building Materials of Otago. Professor Ulricli informs me that the subject of the induration of Oamaru stone was somewhat fully investigated in Melbourne, when it was discovered that the exposure of smoothly dressed samples to the action of a dry atmosphere resulted in the for- mation of a tolerably impervious and durable crust on the surface. The crust, which is exceedingly thin, is not supposed to form at all in a damp situa- tion, where the growth of vegetation is faster than the indurating process ; neither will it form a second time when once broken off. Any stone, therefore, that gets its upper edges injured is not much benefited by the hardness of the face ; on the contrary, the imperviousness of the face accelerates decay, by retaining the moisture that comes in above. Still, with all these drawbacks, the discovery is a valuable one, inasmuch as it indicates that proper care in disposing and protecting Oamaru stone may mate- rially enhance its value. The decay in the Colonial Bank referred to in the original paper, is attributed to the stones having been subjected to the action of sea water during shipment at Oamaru and Moeraki. There is some ground for this conclusion, for the instances of decay in the district in which the stone is found are comparatively few, whereas they are common enough in Dunedin. It is not, how- ever, certain that the particular stones that are decaying were subjected to the action of salt water ; and further, it is questionable whether the water would have the effect of seriously disintegrating after such a lapse of years. If salt water is the cause of decay in this case, it only bears out my Limestones. 43 former remarks as to the result to be anticipated from the continued action of the saline breezes of the Ocean Beach, combined with the smoky atmos- phere of the city. The Oamaru stone will not resist the action of frost. I observed some monuments of compara- tively recent date in the Queenstown Cemetery fast falling into decay from this cause. As my former experiments with reference to the absorbent powers of the Oamaru stone were chal- lenged, I obtained, through the Oamaru Stone Quarrying Company, picked samples from the Weston Quarries. On subjecting them to the same treatment, I found that they absorbed almost the same quantity of water as the stone from the Kakanui quarries referred to in the original paper. The Weston stones were cut into blocks 8 inches long, 3i inches broad, and 2 inches thick. One of them was coated with oil by Mr Munro of Dunedin, in the manner practised and recommended by him, another was thickly painted, and two were left un- protected. All the samples were placed together on edge in half an inch of water for eighteen hours, then totally immersed for eighteen hours, with the following results, which are the weights per cubic foot in the different conditions : Unprotected Oiled Painted stone. stone. stone. Weight dry 95 93 94 „ after partial immer- sion ... 115 97 94 „ „ total immersion 115 112 94i 44 Building Materials of Otago. In addition to confirming the accuracy of the former experiments on unprotected stone, these show that thorough painting renders the stone almost perfectly impervious, hut that oiling is not so efficacious ; further that the latter process is sufficient to resist damp arising from occasional showers, but not the action of protracted wet weather. Upper Waihemo Valley. — There are two varieties of freestone in this locality, that may be classed with the Oamaru stone — one of a bluish grey, and the other a yellowish white colour. The bluish variety is a hard, compact, fine- grained limestone of much the same consistency as the Craigleith sandstone. It comes hard from the quarry, consequently it cannot be worked with saws and other carpenters' tools like the Oamaru stone. It is, however, suitable for quoins, lintels, door- steps, and similar purposes, where little labour is required, and where hardness is an advantage. "When struck with a metallic substance, this stone emits a peculiar sulphurous smell something like that of gas. The supply of the bluish stone is compara- tively limited, and large blocks cannot be obtained. The yellowish white variety, which I shall call "Waihemo Freestone," is a compact granular lime- stone, somewhat coarser in the grain and more gritty than Oamaru stone, but considerably harder and less porous. Its colour is a dull white with a yellowish or orange tinge of a soft and pleasant tone. The stone is very soft when quarried, so it can be turned and worked with carpenters' tools to any degree of ornamentation. It retains its softness for Limestones. 45 a long time, but ultimately becomes excessively bard. A complete analysis bas never been made of tbe Waibemo freestone, but it is believed to be cbiefly carbonate of lime, and a trace of carbonate of mag- nesia, with a small proportion of silica in tbe form of grains scattered mecbanically tlirougb it. In all probability tbe colour is derived from a sligbt ad- mixture of iron. Tbis composition resembles that of the English Portland stone. Although not very extensively used, the Waihemo freestone has acquired a high character for dura- bility and the power to resist moisture. The Wai- hemo Hotel, built about 1862, and several station buildings in the neighbourhood of even earlier date, .are still as fresh as when erected, and the stone has become very hard. I was particularly struck by the way in which the hotel doorstep had withstood the heavy traffic for such a long time. The build- ings above referred to are all of rough stone ; the only case in which there has been a tria] of the stone in a dressed state is in Sir E. D. Bell's house at Shag Valley Station, erected in 1871-2. So far as can be judged from this short experience tbe result is likely to be satisfactory, there being no discolouration, neither the least appearance of wea- thering on the edges. The Waihemo freestone when fresh from the quarries is very porous. I found it to absorb 17f pounds of water per cubic foot when partially im- mersed, and 22 pounds when fully immersed, for thirty days. It was tested alongside a sample of Oamaru stone of the same size, and except that the D 46 Building Materials of Otago. latter took in the water somewhat faster, there wa& no practical difference in its effect on both. The Waihemo stone, however, gets hard and impervious on exposure in almost any situation, and there seems to he no limit to the process. The outcrop of the rock is nearly as hard as marble, and some of the stones in the older buildings seem to be gra- dually approaching that condition. The imper- viousness also increases with age ; the walls in Sir Francis D. Bell's house, already referred to, are quite watertight. Prom the peculiarity of the paper- hangings it is impossible for the least damp to come through the stone without being at once detected. The supply of the "Waihemo freestone is practi- cally inexhaustible. The principal deposits occur in what is known as the Green Valley, about twenty miles from Palmerston. Quarries have been opened in several places very convenient for working, and blocks of a large size can be obtained. Southland. — The granular limestone found in Southland belongs to the same class as the Oamaru stone. It exists in a broad zone extending across, the country from the Mataura to the Waiau. The principal outcrops of the rock at present known occur at the Limestone Ridge on the Waimea Plain, Castle Rock in the Taringatura Downs, and the- ranges in the Aparima, Mararoa, and Waiau valleys. This, which I shall call the " Southland Stone," is a granular limestone of a yellowish white colour, much harder and heavier than the Oamaru stone, but coarser in the grain and not so good a colour. A sample from Aparima, analysed by Dr Hector, was found to contain — Limestones. 47 Carbonate of Lime ... ... 9220 Oxide of Iron ... ... ... 2'20 Insoluble matter ... ... 5-60 100-00 This composition resembles that of some of the carboniferous limestones of Great Britain. In consequence of its remoteness from the centres of population, the Southland stone is prac- tically unknown as a building material. Its use has hitherto been confined to the erection of an occasional building on an up-country run. But there is now every chance of its being utilised, as the railways are fast penetrating into the districts in which it occurs. I have made some experiments on the absorbing powers of two samples from the Castle Rock. One of them has been in my possession for three years, and the other was recently sent me by Mr Pratt, of Invercargill. They were both, however, freshly dressed at the time of testing. The same process was followed as in the case of the Oamaru stone just described, with the following results, the figures being the weight per cubic foot in the various con- conditions : Castle-Eock Stone. Old Sample. New Sample. Weight dry after partial immersion „ „ total immersion 134 139 144 135 143 146 It will thus be seen that the Southland stone is one- half heavier to begin with than the Oamaru stone, and that it only absorbs about one-third the quantity of water when partially immersed, and one-half when 48 Description of Building Stones. totally immersed. The Southland stone unpro- tected is far more impervious than the Oamaru one when prepared with oil. The imperviousness of the Southland stone has "been well proved at the residence of Mr G. M. Bell, Waimea Plains. A nine-inch wall on the shady side of the house was papered on the hare stone, and the papering re- mained intact for six years. Canterbury. — The low ranges on the eastern side •of the main range throughout the whole length of Canterbury contain immense quantities of granular limestone, of various kinds. It has heen used to a considerable extent in Christchurch and other places, hut I am not aware of any investigation having heen made as to its qualities and con- stituents. Sandstones. General. — The sandstones of Otago are as varied in consistency, and more numerous than the lime- stones, hut excel them in diversity of colour. The extremes in the latter are generally connected hy gradations of "blue and grey, hut sandstones merge into all conceivahle shades and hues. As already stated, the Craigleith sandstone — the analysis of which has heen given — is the hest in Great Britain. It is, however, too hard for many purposes, so the Midland and Scotch stones that have 5 or 1 0 per cent, less silica may he taken as the type of a good .and useful huilding material. A corresponding type in the Colonial product is found in the Tasnia- nian freestone, of which the High School, C ustom House, and Cargill Monument are "built ; it contains 86 per cent, of silica. Any Otago sandstone that Sandstones. 49 lias so much of this base and has a hard compact texture, may be considered strong, durable, and dry. The sandstones proper, which embrace all sedimentary rocks in situ, are found in immense quantities throughout the Province. Unfortu- nately, the more accessible supplies are of an infe- rior quality ; consequently this stone has hitherto been little used for building purposes. Grits. — The highest class of sandstones, as regards their relation with the hard stones, are grits. These abound throughout the Province, chiefly in the form of large boulders, or erratic blocks, like the Sarsen or Druid stones of the south of England. Numbers of them exist on the ranges about Blue- skin, Kaikorai, North Taieri, Tokomairiro, and Kaitangata. They yield stone of a red or brownish colour that varies in texture from coarse sandstone to conglomerate with large pebbles. The blocks are usually harder than ordinary sandstone, but are sometimes wanting in cementing material, so much so that the stone easily reverts under pressure to its original gravel. The grits furnish good building material for massive coarse work, but are compara- tively valueless for architectural purposes. The railway bridges at Chain Hills and Glenore are built of this kind of stone ; that in the former work is comparatively fine in the grain, but the others are coarse and full of pebbles. They are both used in large blocks, which, along with the dark colour of the stone, tends to give the structures a massive appearance very appropriate to this class of work. Silicious Sandstones. — Closely allied to the grits, and existing under much the same circumstances in the same localities, we have numerous fresh- 50 Building Materials of Otago. water sandstones. They are of various colours, but are all extremely hard and compact, apparently highly charged with silica. A very handsome stone of this kind, found in the Hillend district, has been used in the abutments of the Clutha Railway bridge ; it is of a silver-grey colour, and of an even hard texture, resembling closely the Tasniaman stone. The same stone occurs again at Tapanui. It exists in masses sufficiently extensive to consti- tute a solid reef. Other samples, found in the Olutha and Chain Hills districts, are of a reddish- white colour and equally compact in texture. There is a good specimen of white sandstone in the Mu- seum, from Murison's Gully, on the Rough Ridge ; in all probability it belongs to this class. The silicious sandstones above mentioned are too hard to be economically used in ornamental work, but they are unexcelled for plain masonry, and for all purposes where strength and durability are the principal desiderata. A connecting link between the grit and sandstone proper is found on the western side of the Waihola Lake, from Mary Hill to the Gorge. It has a tough granular texture, capable of being easily dressed with the pick or chisel, but too hard for smooth work ; its colour is a light warm brown, very suit- able for architectural purposes. The stone is sup- posed to exist in large quantities, but has hitherto been little used. Mr Duff's house is the only building of it that I know. Hard Sandstones. — The hardest sedimentary rocks are of course met with in the older geological formations, but deposits of a similar character fre- quently occur in recent formations — the induration Sandstones. 51 in the latter case being due to local causes. The Kaikoura, Maitai, and Pukitaka formation — the localities of which were given in a previous chapter — yield the former class, and the best known deposits occur between the Clutha and Mataura rivers. One •of the hardest sandstones in Otago is that at the Palls at Gore township, and other places on the Ma- taura river. It is of a light green or bluish tint, almost as hard as bluestone, and equally unwork- able. It is found in large blocks, with natural joints and beds, and so is very suitable for massive, coarse work. The two bridges over the Mataura are built of this material. A similar stone — though scarcely so hard — is found on the Oreti river, at Benmore ; it is utilised in Invercargill for basements of buildings. The same variety occurs again at the Kaikiku, the road bridge over that stream being built of it. Waikava, as might be expected from the geo- logical character of the district, produces a compact hard sandstone, suitable for building. The only sample in the Museum is rather dark for architec- tural purposes, but I have no doubt there is an abundant supply of all kinds between the Clutha and the Mataura. In 1865 Dr Hector said of this stone, " It has a disagreeable colour, but its tex- ture and stability are superior to any of the sand- stones in the Province which have as yet been examined, although others have been seen that will probably prove of quite as good quality." The Waikava sandstone contains 80 per cent, of silica, which is a near approximation to the Tasmanian stone in its essential constituents. 52 Building Materials of Otago. Mount Hamilton, in Southland, produces an ex- cellent sandstone of much the sams character as that of Waikava, but firmer in the grain, and of a bluish colour. Altogether this is a first-class building material, but I have no information as to the extent of the deposit or the facilities presented for working the stone. The same remarks apply to a specimen of stone lately sent me from the Mataura district ; the pro- prietor of the land would not, however, tell me the exact locality. Hard sandstones from the older formations have been found at several places on the West Coast, notably Jackson's Bay. The Government Agent there, Mr. Macfarland, sent me a block of excellent quality and colour. He says that the supply is in- exhaustible. The hard sandstones of the recent formations are widely dispersed throughout Otago. One of the best deposits known is at Pew's Creek, on Lake Wakatipu, where three distinct varieties occur, the respective tints being yellow, red, and green. The former, which is the most common, has been utilised at Queenstown for building and monumen- tal purposes. It is hard and compact, and has a particularly smooth even texture. The deposit is located on the margin of the Lake, in a most con- venient position for shipping. Several varieties of hard sandstone found in the vicinity of Palmerston form excellent building materials, notably the dark grey stone used in the Presbyterian Church, and the bluish- grey one of which the road bridge is built. The former is found Sandstones. 53. in the Horse Range, and the latter on the northern slope of Puketapu. The last-named locality also produces a yellow stone, of much the same consis- tency ; it is sometimes found in the same vein as the blue variety, and the two colours frequently merge into each other in a curious manner. There is a sample in the Museum of a smooth-grained dark red ferruginous stone from the Upper Horse Range, that belongs to this class of rocks. The above are only quoted as examples of what the district referred to can produce. There are numerous places in the vicinity of the railway be- tween Pleasant Valley and Trotter's Creek where good sandstone is obtainable. The whole range of country along the sea-board between the Waikou- aiti and Kakanui Rivers contains an immense as- sortment of sandstone ; many of them, like a por- tion of the cliffs in Trotter's Gorge, are too soft and friable for building stones, but there are a great number of isolated blocks and veins that yield good building materials of the kind just described. Ordinary Sandstones. — Under this heading I shall consider the class of sandstones that come nearest in consistency to the popular definition of freestone — those that are so soft as to be easily worked and at the same time sufficiently hard to resist the action of the weather. A hard brown sandstone of this description has recently been discovered and worked on the north side of the Otepopo Hill. It was used in lining the railway tunnel through that range. Although hard, the stone dresses readily with the axe. It is found in large blocks, with regular vertical cleavages in 54 Building Materials of Otago. both directions, at right angles to each o^her, which gives the stones two natural faces almost as true as > 22 Brickwork ... ... ... 23| Bubble masonry ... ... #> . 28 The increased thickness of walls in rubble ma- sonry is not determined by deficient strength, but by the difficulty in building thin walls with rough stone. Cost. Having discussed the properties of stone, bricks, and concrete, the materials of which the walls of our buildings are composed, I shall consider shortly their relative cost. Of course, timber is still in general use for walls, as well as its more legitimate functions of roofing and internal fittings; but having properties and uses peculiar to itself, it will be treated at length in another chapter. I shall, however, at this stage compare the cost of timber in the walls of buildings with those of the other materials mentioned. It is impossible to determine a general rule on 76 Building Materials of Otago. the subject of cost and suitability, as they depend so much, on the resources of the locality and the purpose in view, not to mention the wider range of individual tastes. The following conclusions are applicable to Dunedin, but they will give at least indications of results in other parts of the Province by making the allowance due to a difference in the value of materials and labour. It is authoritatively stated that the cost of con- crete in London is only one-half that of brickwork for the same thickness of wall, and the beton ag- glomere sewers in Paris are calculated to have cost 20 per cent, less than any other material procurable of the same quality. It must, however, be borne in mind that in both these places the circumstances are very much in favour of this result. The ce- menting ingredients are manufactured on the spot, consequently concrete is on a par with brickwork, and has an advantage over stone which comes from a distance. In Otago the conditions are exactly reversed. Brick and stone being in the locality, can be procured at a moderate rate, while cement has to bear the heavy charges inseparable from the importation of a low-priced article. "When the manufacture of Portland cement is established in New Zealand, the relative costs of the three build- ing materials will in all probability approach nearer the European proportion. The price of concrete in plain walls, near London, with cement at 8s. per cask, is from 9s. to lis. 6d. per cubic yard. Beton agglomere in Paris for the same work, with cement at 8s. per cask, hydraulic lime about one-half that price, and labour 3s. per day, costs from 20s. to 24s. Comparison of Various Building Materials. 77 per cubic yard. The greater cost of the latter is a- proof that there is more labour and care bestowed on its preparation than is done with concrete in England. The price of concrete for ordinary engineering purposes in Dunedin is about 35s. per cubic yard ; and Mr. Petre, who has had considerable practice In building with concrete, informs me that its price In a plain wall is about Ms. 6d. ; if to this is added the cost of outside plastering, which is indispensable in any class of dwelling-house, we bring it up to 450s. I am not aware of any building having been erected in Otago in strict accordance with the method adopted in Prance, so there is no way of getting at the cost from actual experience ; but the data at command are sufficient to fix 60s. as a close approximation. In America, the price of beton is estimated at from 36s. to Ms. for labour and ma- terials alone, and those are much cheaper than with us. The following statement gives the comparative 18 0 37 0 3 8 \ 6 10 0 4 G 11 0 6 G 78 Building Materials of Otago. At those prices, and the standard thicknesses of wall formerly established, the relative cost of build- ing in Dunedin, with the various materials at com- mand, is as follows : — This proportion is not, however, applicable to the whole building, for the value of the masonry is generally less than half the total cost. Further- more, the high-priced materials are seldom used in large quantities. The front of a business place in a street, or the facings in an isolated dwelling- house are all that is required to be of this class. Mr. Lawson estimates the difference in cost of brick over timber in an ordinary dwelling-house at from 33 to 50 per cent. Taking it at a mean of those rates, a wooden house worth £1,000 would cost £1,400 in brick, the cost of the walls being respectively £300 and £700. The interest of the amount saved is sufficient to rebuild the walls every ten years, which is oftener than required, but it is not sufficient to renew the whole house when the walls decay — a very probable contingency — for the renewal of the walls entails, practically, the entire reconstruction of the building. Besides, the in- terior of a wooden house is more subject to dete- rioration and injury than that of a brick or stone Brickwork ... Concrete Beton agglomere Hough rubble Coursed rubble Freestone ashlar Hardstone asblar, rock-faced .. Hardstone asblar, fine-dressed Ordinary timber-work in walls 1.00 1.11 1.33 0.91 1.25 2.70 2.70 3.90 0.41 Comparison of Various Building Materials. 79 one ; and the permanent charges, snch as repairs, painting, and insurance, are always much higher. Independently of the increased comfort and security obtained, I believe that even now it is true economy to build our houses with the more durable materials ; and when the railways are in full work- ing order, north and south, the matter will be placed beyond doubt. At present Oamaru stone costs 5d. per cubic foot, in blocks at the quarries, and 3s , 6d. in the same state in Dunedin. When the railway is opened it should be brought into Dunedin at Is. 6d., the price when laid being 2s. 6cl., which is a saving of 44 per cent on current rates. The brown and grey freestones of Waihola are already within reach of railway carriage, and will be conveyed to town for about 4d. per cubic foot, so that they can be sold for Is. 6d. As already stated, the former is too hard for fine work, but the latter is an admirable substitute for the Oamaru stone ; it is a compact limestone of the proper consistency — soft enough to be easily worked, but sufficiently hard to stand the weather. I trust, therefore, that one of the first benefits our city will derive from the establishment of railway communication is the improvement of its architecture. so Building Materials of Otago. CHAPTER VIII. Roofing Slates. Locality. ^HEN I began to collect data for these papers I did not expect that anything would be said on this head further than to report that no good roofing mate- rials had yet been discovered in Otago. I am glad to state that this blank in our resources has within the last few months been filled up by the discovery of a valuable deposit of slate in the Otepopo dis- trict. The existence of a seam in this locality has been the subject of rumour for some years, but it remained for Mr. Short, of the Land Office, to place the matter beyond doubt. He first discovered slate at Mount Domett, but knowing that it was too remote to be worked to advantage, he traced the reef back towards the sea, and eventually found workable deposits on the Kauroo stream and its tributaries, at which point the reef approaches nearest the coast and the settled districts. As stated in a former paper, roofing slate should be found in the Kakanui or Silurian formation, which, according to Professor Hutton, exists in this Province in two large zones, extending from east to west across the country ; that in the north begins at Otepopo and terminates at the Hawea Roofing Slates. 81 Lake. It embraces the Kakanui and Hawkdun Mountain Ranges. The southern belt commences at Tapanui, and sweeps round by Athol and the head of Lake Wakatipu to the Forbes Mountains. A connection between these zones, along the western seaboard, can be traced in isolated patches at Waitahuna, Akatore, Otakia, and the Silver Peaks. Although this extensive tract of country is en- tirely slate, in the geological sense of the word, it does not follow that the supply of roofing material is proportionately great, for the conditions that seem necessary for the production of the slate of commerce do not occur frequently in the clay-slate formations of any conntry. As already stated, Mr. Short discovered what he takes to be a good roofing slate at Mount Domett, in a position tolerably accessible from the Mare- whenua country, and the same quality is known to exist at the Lindis Pass. Both these places are too remote to be available at present, but it is satis- factory to know that the store of wealth is there, although it may not be realised for many years. The exact locality of the Otepopo slate reef is about half a mile west from Charles Peak, at the confluence of a small tributary of the Kauroo with the main stream, the distance from the township of Herbert, in a direct line, being about eight miles. The West Coast has been well prospected for slate by Mr. Mclnnes, a practical quarrier, but he discovered nothing better than the hard, coarse variety discovered at Preservation Inlet, specimens of which are in the Museum. This result is to be 82 Building Materials of Otago. expected, for the rocks on that side of the island are too old and crystalline to produce a good article. Extent. — The slate deposits on the Kauroo are of a vast extent. Professor Hutton, in a recent report on the subject, says : — " The thickness of the bed forming the present face cannot be as yet ascertained, but is no doubt considerable. The side of the valley, above the quarry, rises very abruptly, so that be- fore long the height of the workings will be over 100 feet, and will continue to rise to 500 feet, so that a comparatively thin bed even would produce an enormous quantity of slates. In addition to this bed, there are at least two others higher up the valley, both of which will be available for working when the fallen rubbish is cleared from the surface. Higher up the hill other outcrops of good slates are seen, so that no doubt the supply is practically inexhaustible." Mr. Macpherson, a practical slate quarry sur- veyor, from Wales, bears similar testimony to the extent of the deposits, and states further that the quality of the slates and the facility for working the quarries, are superior to anything he has seen in the Old Country. In .England, slates are usually obtained from comparatively thin layers surrounded and embedded in hard rock. The best vein at Bangor is only 60 feet thick. At Otepopo there seems to be a whole mountain of the material, per- fectly homogenous, and nearly all available. Quality. — The value of our slate deposits is very much enhanced by the fact that the product is in- finitely superior to anything hitherto discovered in the other Australian colonies. I have compared the Otago slates with samples from various parts of England, America, Australia, and Tasmania, and Hoofing Slates. 83 so far as I can judge, the Blue "Welsh, is the only- rival it has. Indeed, the resemhlance between them is so great, that when similarly grained speci- mens of the two kinds are placed together, the best judge can scarcely distinguish them. It will also be seen from the following compara- tive analysis of American, "Welsh, and Otago slates, that the little difference in chemical composition between the Welsh and Otago samples is in favour of the latter, inasmuch as it has a slight preponde- rance of the imperishable ingredients : — Welsh. American. Otago. Silica G0.50 5G.G5 65.44 Alumina ... 19.70 19.33 21.04 Protoxide of Irou ... 7.83 7.12 G.20 Lime 1.12 2.77 0.75 Magnesia 2.20 1.00 0.44 Alkalies ... 5.38 8.30 4.49 Water ... 3.30 5.15 3.75 100.03 100.32 102.11 The analysis of the "Welsh slate is given on the authority of Professor Hull, of Dublin, and the other two were made by Mr. P. S. Hay, M.A., of the Otago University. The following analysis of "Welsh slate from BondrofP, is given by Dr. Bischoff, who found that there was no practical difference in the composition of thirty-six analyses made by him. It will be observed that this sample approaches still closer to 84 Building Materials of Otago. the Otago slate in its essential constituents tliais the one by Professor Hull : — Silica 62.50 Alumina ... 16.8S x rotoiiut) ui -Lruii ... 8.42 Liuie ... ... 0.24 Magnesia ... 2.26 Potash 3.31 Oxide of Copper 0.13 Carbonate of Lime ... 1.22 Water 4.03 Carbon and Loss 0.92 100.00 Referring to the quality of Otepopo slate, Pro- fessor Hutton says : — " On my first visit to the district, when slates bad only been found in tbe upper part of the valley, I doubted their being equal to Welsh slates, although I then reported to the Govern- ment that ' they would be found nearly equal to them for roof- ing.' But the bed now opened up lower down the valley is of a very superior quality, and quite equal, I think, to the Scotch and Welsh slates. The slates split easily, and with a perfectly flat cleavage. They are of a dark blue colour, and have a fine silky lustre. They can be made quite as thin as desirable. They cut well without splintering, and stand a hole being knocked through them with a hammer or chisel. Their hardness is quite sufficient,, and that they will stand the weather perfectly is proved by the excellent state of preservation of surfaces long exposed to the weather. I have seen large blocks looking as sharp and fresh as if they had just been detached from the rock, which were almost buried in the vegetation that had grown up around them ; while the very small amount of vegetation (confined to lichens): Roofing Slates. 85 growing on the exposed surfaces showed that they do not readily absorb moisture." These observations and conclusions agree en- tirely with my own. Roofing slates are found of all colours from a creamy white to black, but ex- perience proves that the bluish- grey coloured varie- ties like the Otago ones are decidedly the best. In addition to being an indication of liability to decay, nearly all the other colours fade on exposure. The other essentials of good roofing slate are — compact- ness of texture, impermeability, and the facility with which they can be split parallel and without twist. The Otepopo slate possesses all these properties in a pre-eminent degree. I placed a Welsh and an Otago slate side by side in water for 48 hours, and found that while the moisture rose from three- eighths to half an inch in the imported article, it did not rise at all in the colonial ; which proves that the latter is the more compact and impervious of the two. The facility of splitting is also fully established, for the many samples to hand are of all thicknesses and perfectly true to shape, and I have seen the slates split well with a common pick instead of the broad chisels used by the quarriers. As a matter of experiment the splitters frequently take sixteen slates from one inch of stone. The following gives the relative weight of various sizes of Otago and Welsh slate. The weight of the Otago slates is calculated from the dray loads as they leave the quarries, consequently all qualities are included, but " first quality " only is included in the Welsh 86 Building Materials of Otago. weights. This makes a further difference of light- ness in favour of the native article. Comparative weight of Slates, per thousand : — Sizes. Otago. Welsh. Average of allqualities First quality. Cwts. Cwts. 20 inches by 10 inches 26 3 18 „ „ 9 „ 22 25 16 „ „ 8 in 21 14 „ „ 8 „ 18± 12 „ G „ 10 10| Professor Hutton, in his " Geology of Otago," informs us that there is a considerable difference between the cleavage of the Otago and English slate ; instead of being at an angle to the strata, it is parallel to them. He alludes to this as a possible defect in the colonial article, but at the same time states that the property of splitting readily is not due to lamination, but cleavage ; consequently the pressure that gave this property must have been applied in a vertical rather than a horizontal di- rection. Without venturing to express an opinion on such an important geological question, it seems to me that the idea of a regular vertical pressure, induced or aided by attraction of gravity, is more natural than a horizontal one ; not only is the pressure in the former case abnormal, but we must pre-suppose the existence of a solid mould which prevented the lateral extension of the material. It is popularly believed that the roofing slates of England are nearly all extracted from beds with inclined cleavage, and those taken from a horizontal Roofing Slates. 87 stratum, where the angle of the cleavage planes is greatest, are supposed to be the readiest split, and otherwise the best; but recent authorities show that, although general, this is not invariably the case. Cleavage occurs at almost all angles, and in some of the best slate veins it is nearly parallel with the bedding. Messrs. Langley and Bellamy, in a paper contributed to the Institution of Civil Engi- neers, give a section of the Festiniog District, in which the angle between the planes of stratification and cleavage is only 15 degrees ; and Mr. D. C. Davies, in his new book on " Slates, and Slate Quarrying," referring to a quarry in Carnarvon- shire, states that owing to the curvings of the lines of bedding, "the lines of cleavage some- times nearly coincide with them." The exist- ence of a cleavage of this kind in the clay-slate formation is well known. Darwin noticed it in the Andes ; and Geikie says : — "Cleavage may either coincide with the original lamination of the rock, or cut across it at all angles." It is, therefore, possible that the excep- tion in the Old Country is the rule at the antipodes. Under any circumstances the question cannot affect the industrial importance of the Otago slate. "While we are satisfied that it splits freely,, and is durable and impervious, its geological peculiarities may be disregarded. Products. — The Otepopo Slate Quarries have been taken up by a Dunedin company, and are now worked in a systematic manner. Nearly half a million slates of various kinds have already been obtained. The great drawback to the rapid deve- 88 Building Materials of Otago. lopment of the industry is the inaccessible situation of the quarries. Although only twelve or fourteen miles from the railway, the intervening country is rather rough, so it will he necessary to construct a road or tramway to hring the slates to the market. In addition to roofing material, slate quarries yield slahs for paving, hearths, mantel-pieces, and other works of a similar kind ; the finer sorts are usually too smooth and soft for street pavements, hut I have no douht varieties suitahle for this pur- pose will he found in the same locality. Cost. — Following the plan adopted with the other materials, I shall devote a few remarks to the con- sideration of the comparative cost of slate and its principal substitute — corrugated iron. It is popularly supposed that there is a great diffe- rence in the cost, hut such is not the case. Having occasion lately to decide on a covering for my own house, I calculated the difference carefully, and found that, with Countess slates at £15 per thou- sand, and galvanized iron at £37 per ton — which were then the current retail prices — the cost of the two materials was identical for the same space of roof. There is, however, a difference in favour of the iron in cartage, timber-work, and labour, amounting to 10s. per square, or 16 per cent, on materials and labour combined. This is a large proportion, as such, but when we consider that it only amounts to about £10 on a house 40 feet square, the wonder is that any iron is used. Whether regarded as a matter of appearance, free- dom from sound and extremes of temperature, or durability, the superiority of slate over iron is un- Roofing Slates. 89 doubted ; and were the difference in cost twice as great, the balance of advantages would still be on the same side. General. — According to the Customs Returns, the value of roofing materials imported into New Zealand during 1876 was £115,734 ; if to this be added charges of importation and the importers* profits and the value of native shingles, it makes a total of £160,000 or £170,000. Assuming that £40,000 worth of iron is used for the walls of houses, fencing, and similar purposes, we have a balance of £120,000 or £130,000 as sent out of the colony for roofing materials which, in all probability, we have at our doors. In addition to this home consump- tion the absence of good roofing slate in Australia* makes the development of an export trade a mere matter of time. I question the wisdom of fostering or encou- raging, at this early stage of our history, every industry that may ultimately be required or that may succeed in the colony at some future time ; but in the case of a low-priced article like slates, the value of which is doubled by freight, and the other charges of importation, there is little wanted to turn the scale in favour of the native production. I believe the enterprise that establishes and car- ries on the industry, and the individual support it receives, are sufficient to do so. We may therefore hope to see the imported roofing material fairly supplanted by the native article at no distant day, and that ultimately the export trade will become so extensive as to influence the finance of the colony generally. SECTION II. LIMES. CEMENTS, AND THEIR AGGREGATES. CHAPTER I. Description of Cementing Materials. Definition of Terms. EEOUE proceeding to treat in detail the native productions, it is necessary to con- sider the properties of limes and cements generally. In doing so, I should begin by stating that the terms " Lime," and " Cement," although always used to denote different and dis- tinct articles, are applicable to either of them. The cementing ingredients are the same in both cases, the only difference being in the proportions in which they occur. Pure lime is practically worth- less for building purposes ; it never acquires the necessary cohesive strength in any situation, and never hardens at all in a damp place. In order to make good mortar, the limestone must contain a mixture of clay ; the proportion varies from 8 per Description of Cementing Materials. 91 cent, in ordinary building lime to 35 per cent, in strong hydraulic cement. If it were necessary to have a clear dividing line between limes and ce- ments, the best place to strike it would be at the neutral point where the adhesive and cohesive forces are equal. The particles of rich and mode- rately hydraulic limes adhere more readily to a foreign substance than to each other, but the con- ditions are reversed with strong hydraulic limes and cements. This gives the only tangible diffe- rence I can imagine between the two articles, but as it does not admit of a practical application, the distinction would only be valuable from a scientific point of view. Classification. — Limes and cements are usually divided into four classes, according to their proper- ties and strength : — 1st. The Common or Rich Limes that contain less than 10 per cent, of clay other or impurities. 2nd. Poor Limes, in which the impurities con- sist of from 10 to 25 per cent, of sand and other insoluble ingredients that will not enter into chemical combination with the lime. 3rd. Hydraulic Limes, such as contain from 10 to 30 per cent, of alumina and soluble silica. 4th. Hydraulic Cements, containing from 30 to 4s0 per cent of alumina, soluble silica, and other impurities. Composition. — In addition to the ingredients named each of the above classes frequently contains small quantities of iron, maganese, magnesia, potash or soda, with sulphuric and other acids, which do not seem to have an injurious effect on the cementitious t)2 Building Materials of Otago. properties of the article ; on the contrary, some of theni, such as iron, and soda, and some of the acids, are always present in the best cements ; the quan- tity, however, of all foreign substances, except silica and alumina, seldom exceeds 5 per cent. We may therefore assume, shortly, that our mor- tars are simply lime and clay in varying propor- tions. As already stated, the common or rich limes are comparatively useless where strength is required, and absolutely worthless in a damp situation. They are easily burned and slaked, swell to a great extent in slaking, shrink in drying, and are soluble in water when set. Their adhesive properties are stronger than their cohesive ones, consequently thev cannot be used without a large admixture of sand. It is common to hear the expression that mortar is injured by too much sand, but the chances are that its bad qualities are the result of the opposite condition, and, above all, that the sand and lime are not properly mixed. If greater care was exercised in this behoof, so that an approach could be made to the theoretical maximum of an atom of sand alternating with an atom of lime, the result would be an immediate doubling of the strength of rich lime mortar. Poor Limes possess all the bad qualities of the rich ones, and have an additional drawback in irre- gularity of consistency through not slaking so rea- dily, which necessitates grinding. Hydraulic Limes are frequently subdivided into three or four sections, ranging from "slightly" to " eminently" hydraulic, the former being practically Description of Cementing Materials. 93 a rich lime, and the latter a cement. These limes do not slake readily, nor do they expand much in the pro- cess. The higher kinds slake so slowly and so im- perfectly that they are always pulverised by grind- ing. Hydraulic limes set under water in from three to fourteen days, according to the strength of the sample. Hydraulic cements cannot be slaked by water in the usual way; they are, properly speaking, not calcined, but vitrified. The produce of the kilns resembles slag from a blast furnace, and it requires the aid of stone-breakers, iron rollers, and French burr millstones, to convert it into the cement of com- merce. In common with the higher kinds of hy- draulic lime, cement does not require any admixture of sand to make it into mortar ; the maximum strength is obtained by using it in a pure state. .Some hydraulic cements set under water in a few minutes, but the best kinds take a few hours. In seven days the latter attain a tensile strength of 250 pounds to the square inch. Quality of Limestones. — The quality of lime- stones cannot be determined by a knowledge of the geological formation in which they occur, nor by their general appearance. Hydraulic limes are perhaps more plentiful in what may be called the mediaeval rocks — cretaceous to carboniferous — than in any others ; but as they are frequently met with in the formations above and below those named, we may give them an almost universal range of lo- cality. The character of the stone seems to be determined chiefly by its immediate surroundings — the outer beds are argillaceous or silicious — Gr 94 Building Materials of Otago. according as the adjoining stratum is clay or sand,, and the whole rock is influenced by the manner in which it was deposited, and the subsequent changes to which it has been subj ected. If the lime had been deposited in still, clean water, on a rocky bottom, and had attained a considerable degree of hardness before being disturbed by convulsions from below,, or pressure from above, we might expect it to be comparatively pure ; but if deposited in an estuary where the water is muddy and the bottom soft, and where floods leave occasional beds of silt and sand, the stone cannot fail to contain impurities. Even after the deposit has taken place the stone may be altered by mechanical and chemical agencies, there being a peculiar affinity between the lime and clay in hydraulic limestone that seems to be easily affected by external causes. A good illustration of the influence of its surroundings on the character of the stone is found at Mr. Macdonald's quarries, Otago Peninsula. The rock is much shattered, and divided into large blocks by " backs " running through it in all directions. The blocks in one of the beds produce two distinct varieties of stone, the analyses of which are given in Nos. 13 and 15, Table III. The light- coloured stone occupies from two to three feet of the outside of the block, and gradually merges into the dark one which composes the heart ; they vary little in consistency, but, as will be seen from the table, there is a great diffe- rence in their composition. Assuming the block was originally homogeneous, of which there can be little doubt, we find that the crust has lost 4 per oent. of carbonate of lime, and 2J per cent, of car- Description of Cementing Materials. 95 bonate of magnesia, while, on the other hand, it has gained 2 per cent, of iron, in addition to the increased percentage of silica and alumina due to the ahstraction of the lime and magnesia. Hydraulic limestones are generally compact in texture and dark in colour — grey, blue, drab, or brown, being the prevailing colours ; white indi- cates pure lime. It does not, however, follow that all the dark-coloured limestones are hydraulic, for they may contain sand and other insoluble matters that neutralize the effect of the clay ; and the darkest of all limestones — black marble — is almost pure carbonate of lime. Still, a rule may be estab- lished in a negative manner by saying that no white limestones produce hydraulic lime. Properties. — Notwithstanding the advance made in all the practical sciences within the last few years, there is still a doubt as to the causes that produce the setting and hardening of lime and cement mortar. The old theory was that all mor- tars hardened by the absorption of carbonic acid from the atmosphere, and it was supposed that, in time, the quantity absorbed would equal that ex- pelled in burning, so that the mortar would revert to its original carbonate, and become again a lime- stone. It is true that rich limes will not set with- out carbonic acid. The mortar in the inside of a bastion at Strasbourg was found, after 160 years, to be quite soft, and the same thing was observed in a masonry pillar, nine feet in diameter, at St. Peter's, Berlin, its age being 80 years. It has also been found by experiment that a mortar of rich lime will not set in the exhausted receiver of an air 96 Building Materials of Otago. pump. But carbonic acid alone will not perfect the hardening process, consequently it is supposed to be assisted by the crystallization of the carbonate of lime between and around the particles of the aggregates. Without such extraneous aid it is difficult to account for the hardening of mortar in thick walls. The operation proceeds from the out- side, consequently every advance made is a barrier to the next in so much that it excludes the air from the softer mortar inside. There is every reason to believe that hydrate of lime, when exposed to the atmosphere, will revert to its original carbonate; but the process is such a slow one that it may be almost classed with the geological epochs. The oldest mortar in the world, that from a Phoenecian temple in Cyprus, is still far short of the ingre- dients it possessed when a limestone. The induration of hydraulic mortars is attributa- ble in a small degree to the same causes as affect the rich ones, but principally to the formation and crystallization of complex silicates of lime and alumina, the precise nature of which is imperfectly understood. It is quite evident that the absorption of carbonic acid has very little to do with the set- ting of hydraulic mortar, for against its slow action, already noticed, we have the fact that large blocks of cement concrete harden uniformly to the con- sistency of stone in a few months under water, which proves that the setting property is inherent, and not the result of external influences. The treatment they receive in burning has a con- siderable effect on the quality of limes and cements of all kinds, but more particularly on those that Description of Cementing Materials. 97 are only moderately hydraulic. Under burning has been known to impart a spurious hydraulicifcy to rich limes, and over burning occasionally de- stroys that property in cement, but as a rule there is little trouble in obtaining maximum results with these extreme classes. The burning of hydraulic limes is a much more delicate operation, the niceties of which can only be acquired by long experience in the art generally, and considerable practice with the actual materials that are to be operated on. Use of Aggregates. — As already indicated, the or- dinary aggregates are essential to the induration of rich limes, but in the higher hydraulic varieties, and in cements, they are simply dilutents. As rich limes do not possess the faculty of expelling any excess of moisture with which they are in contact, it is advisable to employ a porous aggregate, such as the sands produced by aluminous and calcareous rock, but when the aggregate is only employed to weaken the mortar by making it go further, there is little danger in using hard silicious sand, provided it is free from earthy impurities ; indeed, this is an indispensable condition in all aggregates. It has been ascertained by experiment that the best pro- portion of sand for rich limes is 1\ to 1, and for ordinary hydraulic limes If to 1. This explains the partiality of builders to rich limes. It will, in their own phraseology, " carry more sand," which means that strength and comfort are sacri- ficed for an insignificant saving in cost. Strength. — In order to institute a comparison be- tween the various articles under discussion, I give the following table of tensile strength per square 98 Building Materials of Otago. inch in pounds on limes, cement, and mortar, one year old. Cement and Limes unmixed. Portland cement ... Roman „ Good hydraulic lime Ordinary „ „ Rich lime Mortars. Portland cement with 1 of sand. 33 33 33 w 33 q 33 33 3 3 V 33 4 3 3 3 3 3 ) " 33 33 33 33 O 33 Good hydraulic mortar ... Ordinary „ „ Good mortar of rich limes Bad ,, ,, 500 pounds 185 „ 170 „ 120 „ 40 „ 310 pounds 205 140 „ 100 ,., 50 „ 140 pounds 85 „ 50 ,; 20 „ CHAPTER II. Geographical Distribution. Ijr — ^ Limestones. ^jfflpT was shown in a former paper that lime- stone, as a geological formation, occupies an immense area of Otago, hut it does not fol- low that the supply of lime for industrial purposes is equally extensive, many of the calcareous rocks heing incapahle of producing lime of good quality. There is, however, no scarcity of lime suit- able for building and agricultural purposes through- Geographical Distribution. 99 out the province. It is known to exist in considerable quantities in the following districts — Oamaru, Ote- popo, Waihemo, Maniototo Plains, Waikouaiti, Lower Harbour, Peninsula, Waihola, "Waimea, Winton, Aparima, Waiau, and Wakatipu. These lo- calities are so widely dispersed that we may safely calculate on a supply being available for any demand that can arise. Cement Stones. — The only natural cement hither- to discovered in Otago is the well-known Septaria or cement boulders of the Moeraki district, which resemble in every respect the English stones from which Roman cement was originally manufactured. According to Dr. Haast, the boulders follow the coast from Shag Point to the Terapupu Creek, thence run in a straight line to the Little Kuri Creek, which is struck at a point about half a mile from the sea. In the first four miles the deposit is a mere line of boulders lying on the beach or imbed- ded in the cliffs, but on leaving the coast it expands into a belt from 20 to 30 chains wide and 5 -J miles long. Clays. — Many of the volcanic clays that exist in such profusion along the sea-board from Saddle Hill to Oamaru possess cementitious properties similar to the Pozzuolanas of Italy and the Ty- rass of the Rhine, but as they are only used in com- bination with lime, they will be considered along with the other aggregates, or as a component part of artificial cement. Aggregates. — The aggregates proper consist of shingle, gravel, and sand, which have an almost universal distribution throughout the Province. 100 Building Materials of Otago. CHAPTER III. Jggs> Analyses. j^fHE subjoined Tables Nos. I. to IV. give the analyses of the principal lime and ce- ment stones hitherto discovered in Otago, together with English and foreign types. They are arranged into the four classes already re- ferred to, viz. — 1st, Rich Limes ; 2nd, Poor Limes ; 3rd, Hydraulic Limes ; and 4th, Cements. A large number of the analyses of Otago stones are from the Jurors' Report of the New Zealand Exhibition and the publications of the Colonial Museum, but all the recent ones are by Professor Black, to whom I am very much indebted for assistance in investi- gating this subject. Under his direction fifteen analyses of limestones and clays were made specially for the purpose of this paper by Mr. P. S. Hay, M.A. These analyses were done with great care and accu- racy, and in the most exhaustive manner, conse- quently they form a valuable contribution to our in- formation on one of the most important Colonial resources. 1 CHAPTER IV. Rich Limes. Types. IGHT examples of English and Eoreign types are given in Table L, they range S> in purity from statuary marble, a pure carbonate of lime, to the carboniferous limestone of Whitef ord, in Wales, that has ten per Rich Limes. 101 cent, of impurities. It will be observed that ordinary white chalk approaches next to marble in purity, it only contains \ per cent of foreign ingredients. Otago Stones. — Analyses are given of fifteen Otago limestones that furnish rich limes, which shall now be considered seriatim. No 9 is a white, compact, crystalline stone from Southland, locality unknown, probably Winton. Its constituents are 98*80 per cent, of carbonate of lime, and 1*20 per cent, of soluble silica. It is thus en- tirely worthless as a cementing material. No. 10. A compact crystalline stone of faint yel- low colour from Winton, evidently closely allied in all its essential properties to the preceding one, and equally deficient in cementitious qualities. I be- lieve that these two specimens are fair samples of the stone in the vicinity of Lime Hills, Winton, of which there are about 1,000 acres. No. 11. Possiliferous, compact, and very hard stone of a dirty yellow colour from Kakanui. This specimen was analyzed by Professor Black for Mr. Cairns. It contains 98 per cent, of carbonate of lime and magnesia, and 1^ per cent of sand, conse- quently must be placed in the same category as the Southland limes. The stone is burned extensively for building purposes, so I am sure the houses in which it is used cannot be very dry. No. 12. Yellow fossiliferous stone from the Oa- maru district, the precise locality unknown. It is referred to by Dr. Hector as a stone largely em- ployed by Mr. Hutcheson for burning into lime. Erom the analysis and description given it must be closely allied to the preceding specimen. 102 Building Materials of Otago. No. 13. Soft fossiliferous stone from the eastern side of "Waihola Gorge, white in colour, granular in texture, and very absorbent. This is not so abun- dant nor so much used as the hard variety No. 16. No. 14. Yellow lithographic stone from the Oa- maru district. It has all the external appearance of a lithographic stone, but does not exist in large quantities ; it is found associated in the same rocks with No. 12. No. 15. Grey and yellow travertine limestone of a porous texture from the Dunstan Gorge. This stone, which is sometimes called calcareous spar, is framed by the deposition of lime held in solution in the water of streams and springs. The water ac- quires the lime in flowing over or through rocks containing this mineral, and it is deposited in con- cretionary masses on the banks. Travertine is found in the small creeks that flow into the Olutha and Kawarau rivers between Roxburgh and the Shot- over. This stone was first burned for lime in 1864, when it was used in the masonry of the Gentle Annie Bridge. Most of the houses in the Clutha Valley are built with mortar of this lime. I might remark that many of the famous buildings of ancient Italy are built of Travertine, notably the Colosseum. I have not seen any of the Otago deposits suffi- ciently hard and compact to be used as building stones. No. 16. White, compact, and very hard stone from Waihola. This is the stone from which the well-known Waihola lime is produced. It exists in •large quantities in available positions on both sides of the gorge through which the railway runs. The Rich Limes. 103 rock is very much shattered and dislocated, few of the horizontal joints being more than six inches apart. This facilitates quarrying and "breaking, and to some extent balances the excessive hardness, which otherwise would he a great harrier to cheap working. I regret that the Waihola limestone cannot he pronounced good, as, from its favourable situ- ation, it would be an immense boon to Dunedin and the surrounding districts. The limestone contains 94J per cent, of carbonate of lime, which is de- cidedly too rich for building in a damp situation, or where strength is required. This, and analysis No. 13, by Dr. Hector, are copied from an old advertise- ment of Mr. Croft's ; they refer to specimens taken from the eastern side of the gorge, but I believe the stone now used, on the western side, is equally pure with No. 16. Indeed, it was lately stated in the papers that it contained 98 per cent, of carbonate of lime, which, if correct, makes the matter still worse. No. 17. Grey granular stone from Oamaru, found in the same locality as Nos. 12 and 14. It contains 2-§- per cent, less carbonate of lime than the former, and is therefore so much better in quality. No. 18. Bluish-grey compact stone from Dow- ling bay. This is a sample from the top seam. Al- though a rich lime, it contains small quantities of all the ingredients that give hydraulicity with little sand, consequently it will make fair mortar for ordinary work in a dry situation. It forms one of five beds of limestone that occur at Dowling Bay, Lower Harbour, the particulars of which will be given further on. 104 Building Materials of Otago. No. 19. Pawn coloured, incoherent, and absor- bent stone from Aparima, in Southland. It eon- tains 92 per cent, of carbonate of lime, and 5J per cent, of insoluble matter, the precise nature of which is not stated. As the chances are that this is not all sand, we may pronounce the sample a good lime of its class. No. 20. Compact grey stone from Pew's Creek, Lake Wakatipu. According to the analysis, this sample contains 4^ per cent, of insoluble matter not detailed out, but Dr. Hector says that this consists of black sand, iron pyrites, and bituminous matter, in which case the quantity of sand must be inappre- ciable. The stone will yield lime suitable for ordi- nary building purposes in the dry atmosphere of the Lake district in which it occurs. Another specimen of stone from this locality was analyzed by Profes- sor Black, with the results given in item No. 16, Table II. It contains 12J per cent, of sand, so I had no hesitation in putting it in the class of poor limes. There is nothing strange in the discrepancy between the two analyses. They may both be cor- rect, although the samples had been collected within a few feet of each other. Impure limestone deposits all over the world have the same character of irregularity in composition between the various strata. The difference may therefore be accepted as a favourable indication of the quality of the Wakatipu limestone. In all probability the inter- mediate beds will produce strong hydraulic limes. In his " Geology of Otago," Professor Hutton esti- mates the thickness of the calcareous deposits in the vicinity of Pew's Creek at 600 feet, and reports the Poor Limes. 105 existence of similar rock at Afton Burn, on the west side of the lake, and at Stony Creek, on the Upper Shotover. No. 21. Bluish compact stone from the Horse Range. This stone belongs to the higher class of crystalline limestones, such as partake of the char- acter of marbles ; indeed, it merges into true marble in many places. The deposit occupies a large area of the western side of the range, near Palmerston, in accessible situations for working. "With proper treatment this stone would yield a lime suitable for the ordinary purposes of the house builder. The analysis shows a deficiency of alumina, which indi- cates slow setting, but its ultimate induration is not thereby affected. No. 22. Grey shelly limestone from Southland, locality unknown. Although the analysis is not com- plete, it shows this to be a very good lime of its class, probably the best hitherto discovered in Southland. No. 23. "White granular stone from the Oamaru district. This is the well-known building stone. So far as can be judged from the analysis, it would furnish a much better lime for building purposes than the stone usually burned in the locality. 106 Building Materials of Otago. CHAPTER V. Poor Limes. NALYSES of two foreign and nineteen Otago stones that furnish poor limes, are given in Table II. This Table is intro- duced more for the purpose of showing those stones that are to be avoided, than as a basis for the consideration of their properties. It will be ob- served that with the exception of No. 16 from Wa- katipu, all the stones contain upwards of 20 per cent, of silica in the form of sand, consequently their character as poor limes is fully established. The great majority of the samples are from what may be termed the Caversham stones, varieties of which occur at Waihemo, Waikouaiti, Upper Harbour, and Kaikorai. No. 12 is a portion of a Moeraki boulder analyzed by Professor Black, and found to contain 21*00 per cent, of sand. No. 18 is the grey building stone that over- lies the white limestone on the eastern side of "Waihola Gorge. Although objectionable in a ce- menting material, the excess of sand is an advan- tage when the stone is used for building purposes. It is worthy of note that instead of being black, as might be expected from the appearance of the stone, the sand it contains is found to be pure white. No. 16 above mentioned is a compact dark stone from the same locality as No. 20 in the class of rich limes. It has been referred to at some length in considering the properties of the latter, but I might Hydraulic Limes. add that possibly the presence of 12-J- per cent, of sand is not sufficient to neutralize the other good qualities. If it were entirely absent the compo- sition of the stone would resemble that of the English ones, which yield quick setting Roman cement. ==ee£©B kauri, ±. Decay and Preservation. — The causes of decay in timber are of three kinds :— 1st. Chemical decay — • » natural decomposition by the action of the air and moisture ; 2nd. Vegetable decay or dry rot, a Properties of Timbers. 139 decomposition that takes place through the growth of fungi ; and 3rd. Animal decay — waste by the destruction caused by worms and insects. The first of these is, to all intents and purposes, a slow combustion, effected by the acids of the atmosphere, and greatly accelerated by changes from wet to dry. Most timbers will last a long time if kept constantly wet or constantly dry in an equable temperature, but the best only will stand exposure to severe al- ternations from wet to dry ; the most trying situation for timber in this respect is in posts in the ground, decay always attacks it first at the surface. I am not aware of any cure for this natural decay ; charring, painting, or tarring will retard its progress, but the only safe course is the use of a durable timber well seasoned. In con- nection with this I may notice a practice that exists among our settlers of inverting posts when putting them in the ground, to increase their durability ; like the lunar influence already noticed, this was long thought to be only an imaginary benefit, but lately the matter has become an established fact. Experiments made in] England on oak posts from the same tree showed those put in the ground with the top upwards, as they grew, to be rotten in twelve years, while their neighbours that were in- verted showed no symptoms of decay in sixteen years. This is explained by assuming that the capillary tubes are provided with valves which open upwards ; on inverting the post these valves oppose the rising of moisture. The relative durability of the timbers in common .use in England has been ascertained by inserting 140 Building Materials of Otago. pieces 2f inches square into the ground ; they de- cayed in the following order : — Lime, American Birch, Alder, and Aspen 3 years. "Willow, Horse Chestnut, and Plane ... 4 „ Birch... ... ••• ••• 5 » Elm, Ash, Hornbeam, and Lombardy Poplar 7 „ Oak, Scotch Fir, Weymouth Pine, and Silver Fir •were only affected to a depth of half an inch in seven years ; and Larch, Juniper, and Arbor Vitae were not touched at all in that time. Vegetable decay, or dry rot, is a regular disease induced in unseasoned timber by defective ventila- tion. In most parts of the world this is the worst enemy that timber has ; we hear of ships being de- stroyed, and houses being made uninhabitable in an incredibly short time through its ravages, and even cargoes of timber are seriously affected on the voy- age from America to England. Hitherto this dis- ease has been little known in Otago, not because any precautions are taken against it, but simply on account of the defects in our wooden buildings, which give ample ventilation. I have seen several instances of dry rot in brick and stone buildings in Dunedin, but few in wooden ones ; it is, however, very common in the timber-work of mines. The third cause of decay in timber, that by ani- mals, is also of minor importance in Otago ; the marine animals have caused some little trouble, but the land ones are scarcely known as destroyers in material that has been used. The latter class con- sist of a small beetle supposed to be much the same as the English one, and the large white worm that used to be eaten by the Maoris. These beetles are Properties of Timbers. 141 very destructive, particularly in carvings, but they are easily destroyed by fumigations ; the large worm is very common in old trees lying in the forest, and I have seen it in piles that had not been barked but never in wrought timber. The marine animals most destructive to timber are the Teredo navalis, or marine worm, and Lim~ noria terebrans, a small boring crab of the leech family, both of which are common in New Zealand waters. Professor Hutton finds that our Teredo is somewhat different from the European one, conse- quently it is called the Teredo antaretica. The Teredo is a worm-like animal from three to twenty- four inches in length, and from a quarter to an inch in diameter, according to the nature of the wood in which it has taken up its abode. It is furnished with a wonderful boring apparatus, like a pair of shell augurs, by which it perforates the hardest tim- ber with astonishing rapidity. The smaller animal, which Professor Kirk says is allied to Limnoria lig- norum, although scarcely larger than a grain of rice, is as destructive as the Teredo. Large numbers attack the timber and speedily destroy it by fairly eating it away ; indeed, some animals of this species are able to penetrate stone. The effectual preservation of timber in all condi- tions is a problem not yet solved. Oleaginous and bituminous substances retard the progress of de- composition, but, without thorough seasoning and ventilation, they are of little value. On the con- trary, anything that closes the pores of the timber while containing sap, promotes decay. One of the 142 Building Materials of Otago. "best preservatives of timber is the creosoting pro- cess, invented 40 years ago by Mr. Bethell, which consists in extracting the natural juices by pumping, and then refilling the pores with creosote. Timber prepared in this manner resists decay of all kinds for a long time, but on account of the inflammable nature of the preparation, and its obnoxious smell, timber that has undergone the process cannot be utilized in ordinary architectural work. CHAPTER II. Nomenclature op Timber Trees. 0 subject connected with New Zealand Timbers is in such an unsatisfactory state as the nomenclature. The ut- (o^^^P most confusion exists in the names of many kinds, and there are very few that bear the same name throughout all parts of the colony. In consequence of our ignorance on this point many of the best timbers have been rejected, and inferior ones accepted in their place, a proceeding which has led to disappointment and loss, both in private buildings and public works. With the view to remedy this evil I have prepared a table (No. VI.) hereto appended, showing the various names of all the principal Otago woods. The popular name is that by which the tree is best known, whether bo- tanical, native, or given by the settlers, and the Nomenclature oj Timber Trees. 143 synonyms consist of the proper botanical name, and any native or vernacular names that have been ap- plied to the plant. Many of the trees were formerly known by other botanical names, but the one given is now universally accepted, consequently the others are not required. The great majority of all these old botanical names can be found in "Hooker's New Zealand Flora," and "Gordon's Pinetum.' , As the leading colonial authorities have been con- sulted in preparing this table, I have considerable confidence in its accuracy and completeness. The identity of two or three of the smaller plants with some of the native and vernacular names is not fully established, but there is little or no doubt with regard to all the principal timber trees. CHAPTER III. Oeographical Distribution and Classification. Geographical Distribution. •CCOKDING to a return made to Parlia- ^^^ment in 1874, Otago possesses about ^Sff|§F 2,250,000 acres, or 3,500 square miles of "te/@)y forest lands. With the exception of a block of 600 square miles in the north, which is almost treeless, the forests are well dispersed throughout the Province, and the largest supplies are in very accessible situations. Practically there is a belt of forest along nine- 144 Building Materials of Otago. tenths of the Otago coast. It is quite unbroken from the north-west boundary at Martin's Bay to Biverton, a distance of 200 miles, and the gaps from thence to Waikouaiti, near the north-east boundary, are few and short. The West Coast belt extends with greater or less continuity right across the country to the Waiau valley, its resources being comparatively unknown. The timber on the seaboard is good, but that in the interior is supposed to be scrubby. There is a considerable quantity of birch in the seaboard forest from Martin's Bay to Preservation Inlet, but round the south and east coasts they consist of pines and the other common varieties. Stewart Island is one large pine forest, with a fair sprinkling of rata. Southland is re- markably well supplied with timber. A glance at the map shows an alternation of bush and open country that resembles the conception of a land- scape gardener more than a natural arrangement. These isolated patches of forest embrace the whole width of the country, and extend 50 miles inland. One of the largest bushes in the interior of the. Province extends along the face of the Eyre mountains from the Pive rivers to the Te Anau lake, including the Mararoa district. It covers about 400 square miles. This and the Lake forests, altogether about 400,000 acres, are all birch. The principal forests now available near the sea, in Southland, are from Biverton to the Waiau, six- teen miles long by twelve broad ; and the Seaward bush, from Invercargill to the Mataura, twenty miles long, and from two to three broad. The Oto- Geographical Distribution and Classification. 145 tara, Waikiwi, and Makarewa bushes in the vicinity of Invercargill are also of considerable extent. Following up the coast the next large forest is the Tautuku bush, extending from Waipapa point to the Clutha river, a distance of forty-five miles, and inland about twelve. We have then smaller patches at Kaitangata, Akatore, Dunedin, Waikou- aiti, and Otepopo. The principal isolated bushes in the interior occur at Waipori, Tapanui, and Swit- zers. Except on the west coast, where it descends to sea level, birch does not exist in forests below an altitude of 900 feet. The principal supply of provincial timber for the Dunedin market comes from Southland and Catlin's river, where the forests are accessible to water and railway carriage. Although Stewart Island is par- ticularly well favoured in respect to harbour ac- commodation, its isolated situation has hitherto been a barrier to the development of the timber trade, and the west coast supplies have never been touched. Classification. — Timbers are usually arranged into classes, according to their botanical or structural affinities and peculiarities. The most common ar- rangement at Home is to divide them into leafwoods and pinewoods, which keeps the hard and soft kinds separate ; but this mode of classification would not have the same result in New Zealand. I shall therefore consider the Otago timbers under two heads, with the conventional names of "Hardwoods" and " Softwoods." 146 Building Materials of Otago. CHAPTEE IV. Hard Woods. mapatts. JtefPtfHE trees in this family are too small to £3 yield useful building materials ; but it is JjLn^A) important in furnishing the strongest wood ^ in Otago ; I have therefore given it the first place in the Tables. The five trees that will be considered under the generic name of Mapau are not all members of the same botani- cal order. The first three are pittosporea ; the fourth — red mapau — is the only Otago represen- tative of a large New Zealand family ; and the fifth — white mapau — although belonging to an extensive order, has no immediate relatives in the colony. The mapaus are found in all the low-lying forests, and are particularly plentiful in the neighbourhood of Dunedin. No. 1. Black Mapau — JBittosporum tenui folium. A small tree, seldom exceeding 30 feet in height and twelve inches in diameter. It has pale green shining leaves and purple flowers. The wood, which is of a dirty white colour, is tough and fibrous. Mr. Balfour's experiments at the New Zealand Exhibition showed it to be nearly 90 per cent, stronger than English oak. No. 2. Black Mapau — Bittosporum Colensoi. With the exception of being generally larger, this Hard Woods. 147 tree is identical with the former ; indeed, some authorities suppose that they are merely varieties of the same species. No. 3. Turpentine — Pittosporum eugenioides. This is the largest of the mapau family ; it some- times attains a height of 40 feet, with a diameter of 24 inches. The hark is thin, and of a light colour, the leaves are silvery green, and the flowers pale yel- low. Altogether, this is one of the handsomest trees in Otago. The hark exudes a thick gum, and the juice of the leaves, which is somewhat similar,, was formerly used hy the Maoris as a perfume, hut I fear it is too resinous for European tastes. The three trees ahove described yield a close, compact, heavy wood, hard, tough and fibrous in the grain, hut much given to warping when used green. It is not durable in fencing posts, or simi- larly exposed situations, but answers well for rails. Hitherto this timber has not been used in construc- tions of any kind ; it is not suitable for many building purposes, but would do for handles and implements where strength is required. No. 4i. Red Mapau — Myrsine TJrvillei. This is a small tree, well known to everyone from its conical shape and dark foliage. It seldom exceeds fifteen inches in thickness, but is much prized by settlers on account of its durability and straightness of grain. The timber is strong, heavy, and compact, like English beech, but much darker in colour. Red mapau will not stand long in the ground ; but, so far as ordinary decay is concerned, it seems almost indestructible in most other situations. 148 Building Materials of Otago. Many of the braces in the old Dunedin jetty, erected seventeen years ago and recently removed, were of mapau saplings three or four inches in dia- meter. They were nearly all in good preservation, and free from the ravages of marine worms. Slight symptoms of approaching decay were observed in the braces that had their butt ends in the water, but all others were quite sound. The timber is, how- ever, very subject to the attacks of a small boring beetle when kept dry. Hitherto red mapau has only been used for firewood and fencing, but it is suitable for making furniture and carpenters' tools. No. 5. White Mapau — CarpodeUis serratus. A small tree like the black mapau, No. 1. It has mottled green leaves, and large white flowers ; the wood is white and fibrous. Although its absolute strength is not so great as that of the red mapau, it is tougher, and consequently better suited for the handles of tools. According to observations made by Mr. T. Baber 9 C.E., Auckland, young trees of the mapau family attain a height of thirteen to seventeen feet in ten years. MANUKA AND RATA. These trees belong to different branches of the Myrtle family, one of the most extensive in the world. They resemble each other in the quality and appearance of the timber and bark, but are very different in size of trunk and character of foliage ; they also affect different localities and soils. No, 6. Manuka — Leptospermum scoparium. This is the variety known as white manuka, which is Hard Woods. 149 much, smaller than the red. It grows best on stiff clayey soils that will scarcely produce anything else, but is common on the margin of large bushes in all the low-lying districts of the Province, where it acts as a breakwind to less hardy plants. This tree is best known as an ornamental shrub, but occasionally attains to a diameter of from nine to fifteen inches* Its properties as a timber are generally the same as those of the next variety, consequently they will be considered further together. No. 7. Manuka — Leptospermum ericoides — Is common in isolated positions on the whole of the eastern seaboard, and occurs in considerable quanti- ties in the vicinity of Dunedin, Purakanui, and Ote- popo. The tree occasionally attains a height of sixty feet with a diameter of from two to three feet at the butt, but these are extreme sizes* — logs thirty feet long and ten inches diameter at the smaller end may be considered the practical limit of workable timber. So far as habits and habitat are concerned, this tree is identical with the preceding variety. Like most other hardwoods manuka does not grow straight, and is much, given to warping and cracking ; but I do not know that it inherits these defects to a greater extent than is done by jarrah, ironbark, and other Australian timbers of the same class, and it is freer from heart shakes and knots. Manuka is noted for its great strength and hard- ness, combined with a considerable amount of toughness. Although, as a class, it did not give the Mghest average, one specimen stood the greatest 150 Building Materials of Otago. transverse strain of any Australasian timber tested at the New Zealand Exhibition. Manuka is one of the best timbers in Otago for firewood, consequently there has been a great demand for it, particularly in the vicinity of Dunedin, and the supply is run- ning short ; but it is satisfactory to note that young trees grow up rapidly when the old ones are re- moved. This timber is well adapted for piles in situations where they are kept constantly wet, for swingletrees, spokes, and handles of tools, also for the teeth of wheels. This last is a purpose that re- quires wood of a particularly good quality, and although not quite so suitable as rata, manuka has been found to answer admirably. The teeth in the spur-wheels of the "Express" and other coasting steamers are made of manuka, and they are wearing remarkably well. The old settlers had a high opinion of the dura- bility of manuka, and used it extensively in fencing posts, house blocks, and similar situations of the most trying kind, but it has not proved equal to their expectations. Under ordinary circumstances manuka will decay in the ground in from six to ten years, according to the situation. The longest lived fence that I have heard of is at the Beaumont Perry, where the posts were not decayed quite through in eleven years. This is, however, an exceptional case, as the fence was erected on dry, porous, alluvial soil, that did not retain moisture. Manuka has proved very durable in marine works; the great majority of the piles in the old Dunedin jetty, erected seventeen years ago, were of this tim- Hard Woods. 151 ber, and remained quite sound till its removal re- cently. The George jetty at Port Chalmers, erected a year later, is in the same condition, but here the test has been more complete — all the other timbers are very much affected by the Limnoria, and the manuka is untouched. Professor Kirk, in 1874, re- ported that he had seen manuka fender piles at Port Chalmers much perforated by the Teredo ; but the piles he refers to must have been removed since his visit, for there are no signs of the worm in the manuka piles now. The only evidence of its having attacked this timber is in the Bowen Pier, erected four years ago, where one white manuka pile has been perforated to a small extent. No. 8. Rata — Metrosideros lucida. This tree- grows on high ground at Catlin's River and the Longwood Ranges, but descends to sea level at the Bluff, Stewart Island, and the West Coast. It grows best on a light gravelly soil, and attains to a height of from thirty to forty feet, and an extreme diameter of about six. Logs can be obtained twenty-four feet long, and three feet diameter. The tree sometimes grows with a clear, straight stem of this height, but frequently it divides into large branches three or four feet from the ground this kind furnishes valuable bent timbers for ship- building. Rata has a thin stringy bark like manuka, but larger leaves, and beautiful red flowers. The timber is the heaviest in Otago, being a little heavier than water. It is very dense and solid,, with little or no sap-wood, and of a dark red colour like mahogany. Although not nearly so strong, 152 Building Materials of Otago. rata is suited for many of the purposes to which manuka is applicable, and has an additional advan- tage in being larger, straight er grained, and less liable to warp. Its dark colour might render it suitable for furniture, but I fear the absence of figure will be an objection. Hitherto rata has been little utilized; the construction of railway wag- gons at Invercargill, and the making of teeth and bushes, are almost the only purposes to which it has been applied, but the result is very satisfactory. The bearings of a water-wheel at Waikava are in good order after eighteen years' service, and the railway waggons are pronounced equal to those made from imported timber. Mr. M £ Queen prefers rata to any other native wood for teeth and bushes. He says that manuka and kowhai do not wear so well — they wear off in grit or threads, whereas fric- tion only increases the glassy hardness of rata. This timber is particularly well suited for ship tim- bers — natural bends of all kinds being easily obtain- able. Rata is extensively used on the West Coast for firewood, and it is lamentable to see valuable trees, fit for the highest purposes of construction, destroyed in this manner. Although this timber has not been used in situ- ations that would test its durability, there is every reason to believe that it possesses this property to a considerable extent. I possess a sample taken from an old log on a part of the Kaihiku Ranges, where no living rata tree has existed since the settlement of the Province. It is still quite sound, and there is a large quantity in the same condition. Hard Woods. 153 No. 9. Kowliai — Sophora tetraptera. This is the sole New Zealand representative of a large genus of the pea tribe, but it is intimately related to the well-known Clianthus of our gardens. The tree s which is of solitary habits, is found in shady, damp situations, and on light soils in all the seaboard forests. It grows to a height of about forty feet, and has a clear, straight stem about twenty-five feet long, and from eighteen inches to three feet in dia- meter. It seldom exceeds two feet in the vicinity of Dunedin, but from that to three feet is quite common in Southland, particularly at Forest Hill. Kowhai when young has a smooth, tough, and stringy bark, which gets coarse and brittle as the tree approaches maturity. It has beautiful droop- ing foliage of a feathery appearance, and yellow flowers like laburnum. Altogether the plant is one of the handsomest in our forests. It is popularly supposed that kowhai is a very slow grower, and the settlers believe that it takes twenty years to produce an axe handle, but this is an erroneous idea. So far as can be determined from the annular rings, an ordinary sized tree reaches maturity in from 150 to 200 years. It should also be noticed that the tree is easily raised from seed, and easily transplanted. The timber is remarkably straight grained and free from knots, but it is subject to a heart-shake that impairs the strength of beams and induces splitting in piles. It is stronger than rata, but weaker than manuka. It is, however, superior to both in toughness, and warps very little. The sap- 154 Building Materials of Otago. wood, which is clearly defined, is very small ; in abont 200 logs, ranging from six to twenty-two inches in diameter, it never exceeded one and a half inches in thickness. The wood is of a yellow colour like laburnum, but resembles oak in grain and figure. It contains a strong resin or gum, the peculiar smell of which never leaves the timber, however well seasoned. Kowhai is used for the same purposes as manuka and rata, together with fencing posts, house blocks, piles and similar work in a damp situation, for which it is better adapted than either. The screw shaft bearings of the " Betsy Douglas," and the pins and bushes of the paddle floats of the " Coomerang" are of kowhai, and Mr. Sparrow pronounces it equal to lignum vita? for such work. Messrs. Guthrie and Larnach use this timber extensivelv for curved work, such as the rims for carriage wheels, the top of circular windows, and tilt frames. A good proof of its toughness and straightness of fibre is given in the teeth and bows of hay rakes. The latter are turned to the diameter of a quarter - of an inch, and bent into a semicircle of nine inches without sign of giving way. The durability of kowhai is thoroughly esta- blished. It has never been known to fail in any situation in which it has been tried. Eut it was scarcely necessary to make a trial, for the old trunks that have been lying in the forests from time immemorial are still as sound as when they fell. Indeed, this old timber is frequently used for fencing posts and house blocks. Kowhai has been. Hard Woods. 155 little used in marine works. The only instance that I know of is some bracing in the old Dunedin jetty, which was perfectly sound after being in place for seventeen years. The same remark applies to fencing and house blocks that have been in use for a much longer period. No. 10. Fuchsia — Fuchsia excorticata. The fuchsia, which is the parent of many of the cultivated vari- eties, can scarcely be called a timber tree, but as it possesses many good qualities, and has been applied to useful purposes, it is entitled to a passing notice. The tree, which is found along the seaboard, some- times attains a height of thirty feet, and a diameter of two feet, but it is so twisted and gnarled that it seldom yields a straight fencing post. The timber is hard, tough, and imperishable, but much given to warping and cracking. It has been used in house blocks for 20 years without showing symptoms of decay, and can scarcely be burned in an ordinary fire. No. 11. Broadleqf- — Griselinia littoralis. There .are few trees in the bush so conspicuous, or so well known as the broadleaf, which is the sole Otago re- presentative of its species. It is found in all the low-lying forests, but attains its maximum size on the East Coast. It grows to a height of fifty or sixty feet, and a diameter of from three to six ; the bark is coarse and fibrous, and the leaves a beautiful deep green of great brilliancy. Although much larger, this tree, like the fuchsia, furnishes very little serviceable timber ; it is bent and twisted, irregular outside, and hollow in the heart. The timber is 156 Building Materials of Otago. very hard and brittle, and, although crooked, is easily split. It is red in colour, and sometimes prettily marked, and not liable to crack or warp, consequently it would make furniture. Hitherto ifc has only been used in fencing, house blocks, and knees for boat- building. The durability of broad- leaf in any situation is fully established; it has never been known to fail, and old settlers consider it the most lasting of Otago timbers. No. 12. Kamai — Weinmannia racemosa. There are two trees of this species in New Zealand, but this is the only one in Otago. It belongs, however, to the same order as white mapau, whioh it resem- bles slightly. The properties of this timber, and its identity, have for the last year or two been the cause of considerable misconception and confusion throughout the Province. I shall therefore endea- vour to describe it so as to clear up all doubts. As will be seen by the tables of names, kamai is called black birch in the Catlin's River district and Southland, which name is given on account of a supposed resemblance to the " birches," or, more correctly, "beeches," a number of which occur in that locality. I cannot understand how such an idea could have originated, for, except in the case of the bark of one, there is not the slightest resem- blance between the birches and kamai. further- more, the birch that is like in bark is quite unlike in foliage, and it does not grow in the same forest as kamai. Whatever be the reason, the misapplica- tion of names is complete, for the birches are still commonly called kamai in Southland, and this has Hard Woods. 157 brought the latter into disrepute, the birch with which it is most frequently confounded being very- subject to decay in damp situations. Kamai is little known on the East Coast, north of the Clutha River, but is common from thence right round the South and West Coast to Martin's Bay, and particularly plentiful at Catlins River and the western districts. Like the pines, it is rare on high altitudes. Hitherto this timber has been considered of little value by scientific and professional men ; it is de- scribed as small, and inferior in strength and dura- bility. Professor Kirk questions all its good qualities, and Dr. Hector says — "the use of this timber must be guarded against, as it is perfectly worth- less.' , I hope to give it a much better character. Kamai is generally from fifty to seventy feet high, with a trunk from twenty to twenty-five feet long, and eighteen inches to three feet in diameter, but frequently it attains a height of from eighty to one hundred feet, and a diameter of from three to four. I am assured that trees of this size are quite com- mon on the flat land south of Catlins River. Like most hard-woods, this tree does not grow quite straight, but the bends are not so great as to become a serious defect. The bark, which is of a light grey colour, is very thin, and adheres firmly to the trunk even when dry; the leaves are of a brownish colour, about two inches long and one inch broad, with prickly edges and a sharp stiff point. The wood, which is straight-grained, dense, and heavy, has a light brown ground colour, with grey and red figures and streaks, and very conspicuous medullary 158 Building Materials of Otago. rays. The streaks are sometimes very curious — they look like the broad strokes of a carpenter's pencil drawn at random from top to bottom of the timber, when dry they form a depression in its surface. Kamai has little or no sap-wood at any stage of its growth, so may be utilized, however small. The growing trees are very much subject to heart decay, few of the oldest ones being fit for sawing into large scantling. "When sawn up green and exposed to the sun, this timber cracks and twists to a great extent. A number of logs lately in Messrs. Guthrie and Larnach's yard were almost useless through this cause. I find, however, that there is no inordi- nate splitting or warping in timber that has been seasoned gradually with the bark on, and the ulti- mate shrinkage under any circumstances is not excessive. Prom experiments made on thirty- eight samples I find that Kamai is about the same strength as Baltic deal, and considerably stronger than totara, Oregon pine, and kauri. Although not very flexible it gives fair warning before breaking. The bark of kamai is rich in tannic acid, consequently it is suitable for tanning leather. An analysis by Mr. Skey, of the bark of towai, a variety found in the North Island, gave thirty-one per cent, of tannic acid, which is nine per cent, richer than the bark of young oak, the best tanning material in England. This timber is suitable for fencing posts, house blocks, railway sleepers, piles, beams, and general framing, but not for boarding or joiners' work. Being prettily marked, it might be used for turning and other small cabinet-makers' work. Hard Woods. 159 The durability of kamai under the most trying circumstances, is, in my opinion, thoroughly esta- blished. Professor Kirk says that he found old speci- mens in the forest that were much decayed and worm-eaten, but I have never seen any in which the heart- wood was so affected, and kamai used by the settlers has never been known to fail. I have in my possession a section of a tree cut in Seaward Bush, in April, 1862, and which had lain in the for- est till 1876 ; it is quite sound and fresh right out to the bark. I also have samples of a tramway sleeper, made from a young tree, that has been in use at the Kew Sawmills, Southland, for ten years ; it is still in good preservation. Mr. A. C. Purdie kindly collected some valuable information on the subject for me at Catlins River. He found a log that had lain partly buried in the earth for thirteen years quite sound, except about a quarter of an inch of the outside sap, which was beginning to decay. He also was shown saplings that had been used in tramway sleepers for five or six years. Although thus made of immature timber, and tried in the most severe manner, they are still as fresh as when put in. On a recent visit to the West Coast I was very much gratified to find that kamai is almost exclusively used in house blocks, bridge piles, and other exposed situations, and that it has acquired a high character for durability. Many of the piles in the Grey mouth wharf, and nearly all the sleepers in the Greymouth and Kumara tramway are of ka- mai. The tramway, for its entire length runs through or alongside a forest teeming with all kinds 160 Building Materials of Otago. of timber, consequently the choice of kamai — one of the scarcest — must be taken as a strong testi- mony to its suitability. Kamai piles, twelve years old, in a road bridge near Greymouth, are still in good preservation. I found that this timber was invariably called " Red Birch" on the West Coast It is known by the name of " Brown Birch " in Nelson, and as such has acquired a high reputation for durability in the most exposed situations. I could multiply similar proofs from other districts, and on undoubted authority, so I have no hesitation in giving it a high place for durability. I believe the doubts that exist on the question are due en- tirely to mistakes in the identity of the tree. As noticed by Professor Kirk, it is subject to the ravages of a small boring worm, but the damage done by this animal is too insignificant to be con- sidered a defect in the works for which the timber is best adapted. POKAKOS — EMOCAEPTJS. The only two trees of this genus in New Zealand occur throughout the whole eastern seaboard of Otago, and are very common in the vicinity of Dunedin. So far as habitat, size of trunk, and general habits are concerned, they resemble closely the kowhai, but differ greatly from it in character of leaves and timber. No. 13. Fokako — fflceocarpus hookerianus. This tree grows to a height of sixty feet, with a clear trunk of from thirty to forty feet long, and two and a half feet diameter at the base. The sap-wood is of a dirty white colour, and the heart a blotched or Hard Woods. 161 marbled brown. There is, however, very little heart- wood. A tree three feet in diameter will have at least six inches of sap all round. The wood is tough and flexible and difficult to split, but not durable in a damp situation. Pokako is frequently- sawn up and sold as white pine, and used for the same purposes as that timber. It has also been made into earth wagons on the Southland railways, and found to answer admirably. The heart- wood is suited for turning or light cabinet work. No. 14. JBokako — Elceocarpus dentatus. This is recognized as a distinct tree from the last in the North Island, but not so in Otago. The two are found together, and are almost identical in size and appearance, but the wood is different. This one yields a much harder and more lasting timber than the other. It is also freer from sap-wood and easier split. The wood has a pinkish brown colour. Having been little used here in exposed situations we cannot speak as to the durability of pokako, but it is much prized for this property in the North, where it is known by the name of Hinau. Professor Kirk found mine props and tramway sleepers quite sound after being in use for nine years. This tim- ber is used in Otago for much the same purpose as the preceding variety. Mibbon Woods. Table VI. gives the name of three different trees ( Nos. 15, 16, 17 ) that are popularly known by the name of Uibbon-wood. They are, botanically, quite distinct, but possess some proper- ties in common, and are of little economic value, consequently I shall treat them collectively. The 162 Building Materials of Otago. trees are seldom more than eighteen inches in diameter. The wood is white or light hrown, with strongly marked medullary rays, tough and easily split, but quite worthless in point of durability. One variety is so straight- grained that long rails can be split quite parallel though only an inch thick- Por this reason the timber was formerly in great demand for fencing and shingles, but experience of its liability to decay has brought it into disrepute. Ribbon-wood is not durable in any situation that is in the least exposed to the action of the weather. No. 18. Grass Tree — Panax crassifolium, is com- mon everywhere throughout the Province, and well known from its unique appearance. It grows to a height of twenty-five feet, but the trunk sel- dom exceeds twelve inches in diameter. When young the leaves are from twelve to eigheeen inches in length, and droop against the stem, but as the tree grows old they gradually decrease to three or four inches, and become quite erect and rigid. The timber is hard, strong, and durable. The young wood being particularly tough and elastic is suitable for axe handles and similar purposes. The piles in the first jetty erected by the settlers at Port Chal- mers in 1850 were of grass tree. A portion of it, still in existence, shows the timber to be in good preservation, and perfectly free from the ravages of marine animals. A piece of the piles between high and low water mark is discoloured and soft, but the fibre of the wood is still intact, and the remainder of the piles are as sound as when erected. It is worthy of remark that these piles emit a strong Hard Woods. 163 offensive smell like that from a cow byre, and that cattle will not eat the leaves of any of the grass trees, which is quite in keeping with the general character of the ivy tribe to which they belong. They have all a strong smell more pungent than agreeable. Probably this may account for the fact that the piles at Port Chalmers were not molested by marine animals. CHAPTER V. Soft Woods, pines. ^ O far as the constructive arts are con- cerned this is the most important division - .2 "a. a a Remarks. o 6 i 1 a Grey Yalley, ") No. 1) Do. do. No. 2 Do. do. No. 3 Do. do. No. 4 10 10 10 10 164-75 163 141-8 158-1 186 185 162 172 142 144.5 123 129 (From a tree 3ft. 6in. -j dia. ; estimated age, ( 264 years. Do. 2ft. 6in.; do. 240 yrs. Do. 3ft. ; do. 310 years. Do. 3ft.; do. 230 years. Averages Wakatipu Five Rivers Catlins River ... Blue Mountains 40 12 11 33 3 15691 19279 146-82 117-36 154 186 262 5 193 210 189 123 171 115-5 105 119 C All the West Coast (, samples. Averages 59 156-83 262-5 105 (All the East Coast ( samples. Averages 99 156-86 262-5 105 All Blair's experiments. Recapitulation. 215 In addition to the advantage of a greater number of experiments, the above table shows such a uniformity in my results as would indicate them to be a fairer average of the strength of red birch than those determined by Mr. Balfour. The Foreign timbers enumerated in Table IX., were broken chiefly for the purpose of comparing their fractures with those of the native varieties, but in a few cases, notably Californian redwood and Oregon pine, all the results will be useful, as there are no other recorded experiments on those two timbers. It is worth noticing that there is no ground for the popular impression as to the great strength of Oregon pine, so extensively used in New Zealand; although fibrous and elastic, its absolute strengh is less than that of any of the Otago pine woods. The difference in the results obtained from the few experiments already made on New Zealand timbers points to the necessity of a thorough inves- tigation of the whole subject, as recommended by Mr Balfour in 1865. The experiments hitherto made have been on pieces an inch square. I observe that Mr Laslett, who tested the strength of most of the principal woods in the world for the Admiralty, used pieces six feet long and two inches square, supported at both ends. As his results will probably be the standard in future, any further experiments in New Zealand should be on the same scale. Table X., hereto appended, gives the main results of Mr Balfour's, and of my own experiments, put 216 Building Materials of Otago. into a more popular form than the one originally adopted by him, which was intended for profes- sional men. My table simply gives the weight, strength, elasticity, toughness, and safety of the principal Otago timbers, with examples of well- known varieties from other countries. In the New Zealand timbers the "weight" and "elasticity" columns are entirely from Balfour's experiments ; the "strength" is either his or mine, accord- ing to what seemed the most trustworthy results in each case ; and the two last columns, " tough- ness " and " safety," are entirely from my experi- ments. The two latter are of little scientific value, but they may be found useful in making compari- sons, and otherwise determining the general char- acter of the timber. They also give a rough indi- cation of the extent to which a beam can be. loaded with safety. Table XI., the last of those I have prepared, is intended as a guide in the selection of native timber for special purposes. It gives an abstract of the properties and uses of the various kinds referred to in the paper. Conclusion. In conclusion, I claim to have shown that Otago, and New Zealand generally, is well provided with good timber suitable for all the purposes of the constructive and mechanical arts ; but, hitherto, our resources have not been utilised to the best advan- tage. We are still importing £120,000 worth annually from foreign countries, and no practical steps have been taken to conserve our natural sup- Recajoitulation. 217 plies, nor to provide artificial ones when these are exhausted. Neither have the properties of the timbers been fully investigated. As this is a sub- ject of the utmost importance to the Colony at large, I trust that in future it will receive more public attention than has been bestowed on it in the past. Note on Chapter VI. Black Heart Birch— Just as these sheets were going- through the press, an agitation arose in the Oxford District about the use of this timber in railway worts, and at a public meeting of the residents it was resolved to collect information, regarding its durability. The result has been communicated to me by Mr. Ingram, as follows -.—There is a hut at Mr. Pearson's station, Burnt Hill, erected in 1851, the piles of which are still in good preservation. Mr. Higgins, of Tara, has had Black Heart Birch in the ground for eighteen years without showing symptoms of decay. Mr. Chapman, of Springbank, put this timber into stock- yard posts sixteen years ago, and the heart- wood is still quite sound. Similar testimony is given by Mr. Blackett, Eangiora, who haa- used the timber for fifteen years ; Mr. D. Eisher, who has used it for twenty years ; and Mr. Denby, who has used it for eighteen years. Mr. Burt, Eangiora, produces a post that has been in the- ground fifteen years, and Mr. C. A. White a piece of a tramway- sleeper seventeen years old — the timber in both cases being quite sound. Mr. J. Evans Brown, M.H.E., pronounces the Oxford birch durable ; and the Hon. Edward Eichardson, C.M.Gr., says : " I am quite satisfied that under certain conditions the heart of black birch is almost imperishable, comparatively speaking, and infinitely superior to the black pine or totara of the Middle Island. The conditions I refer to are— first, that the timber be eut at the proper season of the year ; and, secondly — and pro- bably more important — that the timber is grown on tolerably stiff soil, and not subject to be flooded." The above evidence is quite sufficient to warrant us in con- cluding that black birch is a durable timber. W. N. B. 218 Building Materials of Otago. TABLE VI. NAMES OF OTAGO TIMBER TREES. HARD WOODS. Popular Name. Black mapau- Black mapatj — TUKPENTINE— Red mapau- White mapau— Synonyms. Piftosporum tenu ifolium Kohuhu ... Tawhiwhi Tarata ... Tipau Maple ... Pittosjjorum, colensoi Mapauriki Tarata ... Tipau Maple ... Pittasporum eugenioides Tarata ... Kohuku ... Manuka — White mapau Maple ... Myrsine nrvillei ... Tipau Mapau ... Maple ... Carpodetus serratus Piripiriwhata Tawiri ... Kohu-kohu Leptospermum scoparium Kahikatoa Tea or ti tree Red manuka Authority Hooker , Maoris , Settlers . , Hooker ., Maoris... )> Settlers... Hooker , Maoris , >) Buchanan Settlers Hooker . Maoris . Settlers . Hooker , Maoris . Remarks. Hooker . Maoris . Settlers . Botanical name. According to Colenso. I » )! » I ., „ Lindsay. I „ „ Buchanan] Occasionally so called. | Botanical name. (According to Cunning! ( ham. „ „ Kirk. ,, ,, BuchananJ Occasionally so called/l Botanical name. According to Colenso. I „ „ Kirk. (Almost as common ass ( "turpentine." Occasionally so called. I Botanical name. According to Colenso. /-\ "• " " Occasionally so called. Botanical name. (According to Cunning-i ( ham. i Balfour, quoting Bu- chanan in Jurors' Re- port, N.Z. Exhibition. Not seen elsewhere. [ (Also native name, Co- ) lenso. Botanical name. According to Colenso. Names of Otago Timber Trees. HARD WOODS — Continued, 219 Popular Name. Manuka— 8 Rata— Kowhai— 10 11 12 Fuchsia— Beoadleaf — Kamai— 13 14 POKAKO — POKAKO— Synonyms. Leptospermum ericoides Manuka-rau-riki ... Rawiri ... Tea or ti tree White manuka ... Mctrosideros lucida, Ironwood Soplwra tetraptera New Zealand acacia Fuchsia excorticata . Konini ... Kohutuhutu Kotukutuku Gfriselinia littoralis Pukatea... New Zealand laurel Weinmannia racemosa Tawhero... Tawero ... Karmahi... Towai ... Tawai ... Black birch Red birch Brown birch Elceocarpus Iwolwrianus Hinau ... Elceocarpus dentatus Hinau ... Authority Hooker . . Maoris .. Settlers.. Hooker . Settlers. Hooker . Settlers. Hookar Maoris Hooker . Maoris . Settlers . Hooker , Maoris , Settlers . Hooker , Maoris , Hooker , Maoris Remarks. Also native name. Botanical name. According to Colenso. „ Kirk. Also native name, Lyall. Botanical name (Also native name, Co« ( lenso. Botanical name. According to Colenso. Botanical name. According to Buchanan. „ ,, Colenso. „ Colenso. Botanical name. According to Colenso. ( Frequently used in Aus- [ tralia. Also native name. Botanical name According to Lyall. „ Kirk. „ „ Hector. „ „ Colenso. ( „ „ Cunning- ( ham. So called at Catlins river. ( „ in North Island \ and South Otago. West Coast and Nelson. (Also native name, Co- l lenso. Botanical name. (According to Cunning- | ham. (Also native name, Co- | lenso. Botanical name. According to Raoul. Building Materials of Otago. HARD WOODS — Continued. 6 Popular Name. Synonyms. Authority Remarks. 15 Ribbon- wood — Plagianthus betulinus Whau-whi Lace-bark tree Hooker . . . Maoris ... Settlers... Botanical name. According to Hector. „ „ Buchanan, 10 Ribbon- wood — HoJieria populnea Howhere... Houi Whau-whi Hooker ... Maoris ... Botanical name. | According to Colenso. 17 Ribbon -wood — Pennant ia corymbosa Kaikomako Hooker . . . Maoris ... Botanical name. According to Colenso. 18 GrEASS f EEE — Panax crassi folium, Boroeka... Lance-wood Umbrella-tree Sooker . . . Maoris ... Settlers... Botanical name. According to Colenso. SOFT WOODS. g\ Popular Name. 1 Cedae — 2 MlEO— Synonyms. Liboeedrus bidwillii, or L. doniana Kawaka ... Pahautea Moko-piko Totara-kiri-kotukutuku Arbor vitce Cypress ... Podocarpus ferruginea Podocarpus spicata Toromiro (Black pine Authority Remarks. Hooker , Maoris . Settlers... Hooker ... Maoris ... ISettlers . . . Botanical names. (Applied to L. doniana? \ according to Colenso. (Applied to L. bidwillii, ( according to Colenso. (Do. do. according to- ( Bidwill. /Applied to L. doniana, \ according to Mantell. Also native name. Correct botanical name. {Erroneously so called in Jurors' Reports N.Z. Exhibition. Old name now obsolete. Names of Otago Timber Trees. 221 SOFT WOODS — Continued. 6 Popular Name. Synonyms. Authority Remarks. 3 TOTARA — Podocarpus totara [looker ... Also native name. Botanical name. 4 5 Black Pine- White Pine — Podocarpus spieata Podocarpus ferruginea Matai ... ... Mai Black rue Podocarpus dacrydioides ... Kahikatea Kaikatea Swamp pine Hooker . . . Maoris ... Settlers . . . Hooker ... Maoris ... Settlers . . . Correct botanical name. [ Erroneously so called in -J Jurors' Reports N.Z. f Exhibition. ( Now coming into use as | a popular name, j According to Cunning- 1 ham. j According to Hector and ( Buchanan. Botanical name. According to Colenso. j Probably a corruption of ( the preceeding name. In North Island. € Red Pine — Dacrydium cu pressi/ium . . . Rimu Hooker . . . Maoris ... Botanical name. (Now becoming popular 1 also. 7 Yellow Pine— Dacrydium colensoi Manoao ... Silver pine Tar- wood Hooker ... Maoris ... Settlers . . . Botanical name. According to Colenso. jSo called on the West ) Coast. ( So called in vicinity of | Dunedin. Westland Pine Dacrydium ivestlandicum ... Yellow pine Silver pine White silver pine ... Huon pine Kirk ... Settlers... )> Botanical name. i V According to Kirk. H. Gordon. S Silver Pine — Dacrydium intermedium ... Yellow silver pine Mountain pine Kirk ... Settlers... Botanical name. According to Kirk. „ „ H. Gordon. 10 Celery Pine— Phyllocladus alpina Tanekaha Toa-toa ... Hickory ... Hooker ... jMaoris ... ! Settlers... [ Botanical name. According to Colenso. So called in Southland. P 222 Building Materials of Otago. SOFT WOODS — Continued . Popular Name. Synonyms. Authority Kemarks. 11 SlLVEE BlECH- 12 Red Biech — 13 Black Heaet Biech — Fagu-v menziesii Tawai Tawhai ... Towai White birch White kamai Fag us f uvea Hututawhai Towai Tawai Tawhai-rau-nui Black birch Red Kamai Far/us solandri, or F. clif- fort wide? Tawhai ... Tawai-rau-riki White birch Silver birch Black birch Hooker Maoris Settlers. Hooker . Maoris . Settlers . Hooker . Maoris . Settlers. (Most popular name in \ Otago. Botanical name. According to Colenso. i) » )j „ „ Balfour. ( Frequently so called in | Otago. So called in South Otago. I {Common throughout Otago and South Island generally. Botanical name. According to Kirk. „ „ Balfour „ „ Bidwill „ „ Colenso. So called in the Northern provinces and by Bal- four, but not in Otago. So called in South Otago. Botanical names. According to Colenso. i „ „ Geological ) Survey. i Commonly applied when the timber is mostly] white. Occasionally so called. ( Very common in all the \ South Island. Dimensions and Growth of Timber Trees of Otago. 223 TABLE VII. APPROXIMATE DIMENSIONS AND GROWTH OF THE PRINCIPAL TIMBER TREES OF OTAGO. Name. Manuka Rata - - Kowhai Broadleaf - Pokaka Cedar Miro - Totara Black pine • White pine - Red pine - Yellow Pine Silver birch Red birch - Black-heart birch Ordinary Dimensions. Feet. 30 to 60 30 to 40 20 to 40 15 to 25 60 20 to 40 20 to 50 20 to 80 20 to 40 40 20 to 80 10 to 20 20 to 80 20 to 60 50 to 80 Inches. 12 to 24 24 to 48 18 to 36 36 to 72 30 18 to 42 18 to 36 36 to 60 24 to 42 30 to 48 30 to 48 30 20 to 45 30 to 60 24 to 45 Approximate Age. No. of Annual Rings in an Inch. Thickness of Sap- wood. Years. Inches. 100 to 250 20 l 2 200 to 450 19 1 140 to 270 15 lto 3 340 to 700 19 2 200 14 4 150 to 400 15 to 28 lto 4 150 to 300 20 3 to 12 470 to 800 26 3 to 6 270 to 400 23 2 to 4 370 to 600 25 12 400 to 650 27 3 to 6 300 21 1 150 to 330 12 to 19 130 to 300 10 to 17 1 to 4 80 to 180 6 to 9 3 224 Building Materials of Otago. TABLE VIII. SEASONING OF OTAGO TIMBERS. Name. Turpentine - Eata - Kowhai Broadleaf - Kamai Pokaka ) ( E. hookerianus ) ] Ribbon-wood ) (P. populnea ) \ Kauri - Cedar - >) Miro - Totara » Black pine - )> n " White pine - » j> Bed Pine - Yellow pine Celery pine Silver birch Bed birch - » » Black-heart Birch £.2 Pi > Kamai 38 - 75 157-35 544-4 1768 Blair Pokaka, E. dentatus ... 35-03 125-00 200-70 Balfour Cedar 39-69 99-98 293-9 1094 Blair Miro 49-07 220-14 230-24 678-0 5314 >> Totara 35-17 1 42-50 124-60 427-6 2067 Black Pine ... 40-74 192-01 156-22 426-3 3153 » White Pine... 30-43 106-00 127-10 Balfour ±ted rme 39-25 175-44 143-38 438-6 3024 Blair Silver Birch... 38-99 175-50 116-00 438-7 3763 Red Birch ... 48-62 156-84 219-50 489-4 2335 » Black Heart Birch ... 40-00 169-76 536-4 1141 Etiglisli and Foveicj'Ti Examples — Balfour Australian Ironbark ... 70-92 282-70 297-00 271-54 564-8 2590 Blair „ Bluegum... 60-66 214-80 259-60 Balfour » » 259-33 534-2 1468 Blair „ Greygum... 223-12 526-6 388 „ Stringybark 60-67 205-50 239.30 Balfour » J? 215-87 582-8 1023 Blair English Oak 51-72 176-40 Laslett „ Ash 46-00 188-50 Tamanian Blackwood 194-16 644-6 3277 Blair 45-99 232-80 218-80 Balfour ,, ,, ... 193-79 499-9 2573 Blair Riga Fir 33-81 131-20 Laslett English Elm 34-87 86.00 » Kauri 34-31 157-42 » ••• ••• 38-96 165-50 Balfour » ••• ••• ••• 137*17 329-2 1478 Blair y 0 j b j-j— 8- /W- f Weight and Strength of Otago Timhen TABLE X. — {Continued). 227 Name. Baltic Pitch Pine Jarrah )> Baltic Deal ... American Oak Baltic Spruce Calif ornian Redwood Oregon Pine Sydney Cedar w 63-12 28-86 S 188-93 150-00 176-05 157-90 155-00 147-14 142-57 139-68 120-75 128-16 134-46 Toughness. Safety. Experimenter. T y 385-4 3000 Blair Laslett 422-5 2014 Blair 354-8 1610 » 514-6 3047 317-8 1009 ii 199-6 450 ii 259-8 1413 ii Balfour 289-6 2220 Blair NOTES ON TABLE X. The « Strength " given in column S is the weight in pounds required to break pieces twelve inches long and one inch square supported at one end and loaded at the other. " Elasticity " is the greatest weight in pounds carried with unimpaired elasticity divided by the deflection caused by it in inches, the specimen being the same size and loaded as above. "Toughness" is the breaking weight given in Table IX, multiplied by the deflection caused by it in inches at the instant of rupture. "Safety" is the breaking weight given in Table IX, multiplied by the length of fracture. Rule.-To find the breaking weight of a beam from the table, multiply together eight times the breadth of the beam in inches, the square of its depth in inches and the tabular number S ; the result divided by the distance between the supports m feet, gives the breaking weight in pounds distributed over the entire length of the beam. Example- A kowhai beam twelve feet long between the supports, twelve inches deep and six inches broad, will break with 53 tons 7 cwts. 16 lbs, thus— 8x6x12x12x207-5 . =119,520 lbs.=53 tons 7 cwts. 16 lbs. 12 When the.load is confined to the centre, the beam breaks with half this weighty Building Materials of Otago. TABLE XI. PROPERTIES AND USES OF OTAGO TIMBERS. Approximately in order op Superiority and Fitness. Durability. Strength. Elasticity. Toughness. Kowhai Broadleaf Fuchsia Black Pine Totara Cedar Kamai Red Birch Yellow Pine Black Mapau Manuka Miro Kowhai Rata Red Mapau Black Pine Silver Birch Red Pine Black Heart Birch Rata Manuka Miro Red Birch Black Mapau Pokaka Kowhai Red Mapau Miro Kamai Black Heart JBirch Kowhai Red Birch Silver Birch Red Pine Totara Black Pine Weight. Lightness. | Hardness. Softness. Kowhai Black Pine Miro Rata Red Pine Broadleaf Turpentine Yellow Pine Cedar Silver Birch White Pine Celery Pine Pokaka Red Birch Red Pine Totara Rata Manuka Fuchsia Grass Tree Kowhai Broadleaf Kamai Black Pine Silver Birch White Pine Cedar Celery Pine Red Birch Engineering Purposes. Piles. Beams. Sleepers. Planking. Kowhai Black Pine Kamai Totara Black Heart Birch Rata Red Birch Cedar Kowhai Rata Black Pine Black Heart Birch Kamai Red Birch Black Pine Totara Red Birch Kamai Cedar Black Heart Birch Black Pine Black Heart Birch Kamai Red Birch Properties and Uses of Otago Timbers. 220 TABLE XI. — ( Continued.) Machinery Framing Implements and Wheelwright's Work Teeth and Bearings. Fatterns. Manuka Kowhai Miro Red Birch Black Pine Manuka Kowhai Rata Black Heart Birch Black Pine Rata Kowhai Manuka Broadleaf Silver Birch White Pine Cedar Red Birch Building and General Purposes. Fencing and House Blocks. Framing. Beams and Joists. Flooring and Weather Boards. As per Durability- List All the Pines and Birches. Miro Black Pine Silver Birch Red Pine Black Heart Birch Kamai Red Birch White Pine Silver Birch Red Birch Red Pine Totara Internal Joiners' Work. Furniture. Ship Timbers. Firewood. Silver Birch White Pine Bed Birch Cedar Totara Black Pine Miro Ked Pine Kamai Black Heart Birch Miro Red Pine Rata Kowhai Pokaka Mapau Red Birch Manuka Rata Kowhai Manuka Broadleaf Kamai Black Heart Birch Manuka Rata Kowhai Black Pine Red Birch SECTION IV. METALS. General. TREATISE on the building materials of any country or district would not be complete without a reference to its metals. It is principally for this reason that a chapter is devoted to the subject, as the building metals of New Zealand are comparatively little known and altogether undeveloped. It is, however, desirable to record here what discoveries of metallic ores have been made, and to consider what prospect there is of utilising them. The metals most used in the constructive arts are Iron, Copper, Lead, and Tin. I shall discuss them briefly in the order here given. Iron.— The economic iron ores are naturally divided into two classes, determined by their chemi- cal constituents and affinities ; these and their principal sub-divisions being as follows : — 1st. Oxides. — Magnetic ores or Loadstones, Hematite or Specular ore, and Brown or Bog ores. 2nd. Carbonates. — Spathic or Sparry ores, Black Band Ironstones, and Clay Ironstones. Metals. 231 The amount of metallic iron in the first class ranges from 40 to 70 per cent., and in the second from 25 to 40 per cent. Although the richer ores are extensively used, the greater portion of the iron of Great Britain is manufactured from the poorer kinds. This is in consequence of the latter being more easily reduced. Frequently a mixture of two or more ores is employed with the view of getting the largest return at the minimum cost. As a rule the richest ores produce the best metals. The famous steel blades of olden times — the high-class native iron of India and Japan, and the well-known Swedish bars — are all products of rich ores. With the exception of black band veins at Col- lingwood, in Nelson, and a small specimen from Bank's Peninsula, all the New Zealand ores hitherto discovered belong to the higher class. Professor Hutton refers to samples from Marewhenua and Tokomairiro as " Clay Iron ore," but according to Professor Black's analyses they do not contain car- bonate of iron, consequently they must be classed with the Oxides. Numerous deposits of iron ore are found at inter- vals throughout the whole length of New Zealand, the most plentiful being the well-known iron sand of the golclfields and sea beaches. This sand is found in small quantities in most of the larger rivers, and abounds on the sea-shore of the West Coast of both Islands ; also on the South Eastern Coast at Tokomairiro and Stewart Island. The largest deposits occur at Taranaki, where the beach is covered for miles to a depth of several feet. 232 Building Materials of Otago. The compact ores are also well diffused through- out the Colony ; the largest deposit being at Para Para, in Nelson, where a hill of hematite or bog ore occurs, estimated to contain nearly 53,000,000 tons of ore. In Otago compact iron ores have been discovered at Marewhenua, Wakatipu, Dunstan, Tokomairiro, and Clutha. A very complete list of the iron ores discovered in New Zealand, with their properties, is given by Dr. Hector in the Parliamentary Papers of 1873. Professor Black's Eeports also gave analyses of a large number. Prom these documents I have com- piled the following table, showing the principal economic iron ores of New Zealand, together with a statement of their character and value, a few examples from other countries being added for comparison : — OXIDES. Kew Zealand Ohes. Magnetite — Sands — Buller Eiver, Nelson Clutha Eiver, Otago "Wakatipu „ Mataura Eiver „ Stewart Island ... Hokitika Beach ... Taieri „ Taranaki „ Tauranga „ Magnetite — Compact Ores — 1. Manukau, Auckland 70 2. Dunstan Gorge, Otago ... 64 Metallic Iron. 59 to 70 59 to 66 53 61 57 to 70 54 50 to 53 56 to 70 68 Metals. 233 Examples. Magnetite — Compact Ores — Dartmoor, England ... ... 57 Eosedale „ ... ... 36 to 49 Sweden ... ... ... ... 72 New Zealand Obes. Hematite — Sands — Tuapeka, Otago ... ... ... 64 Hematite — Compact Ores — 3. Wakatipu, Otago 68 4. Dun Mountain, Nelson ... 63 5. Maramarua, Auckland ... 62 6. Clutha, Otago 46 7. Cromwell „ 49 Examples. Hematite — Compact Ores — "Whitehaven, England 66 to 69 Illverstone „ 60 to 66 South Wales „ 48 New Zealand Oees. Brown or Bog Ores- — 8. Spring Swamp, Auckland ... 51 9. Raglan „ ... 51 10. Kawau „ ... 48 11. Para Para, Nelson ... ... 44 to 56 12. "Waihemo Valley, Otago ... 35 13. Marewhenua „ ... 38 14. Tokomairiro „ ... 56 Examples. Brown or Bog Ores — Dean Eorest, England 23 to 63 Weardale „ 43 to 50 Northamptonshire, England ... 24 to 53 Pennsylvania, America ... ... 60 234 Building Materials of Otago. CAKBONATES. New Zealand Ores. Black Band — 15. Collingwood, Nelson... 35 to 46 Examples. Spathic Ores — Durham, England Somersetshire, England ... 38 34 Black Bands and Clay Ironstones — Scotland 28 to 41 Yorkshire 29 to 34 Staffordshire 25 to 41 South "Wales 29 to 56 In consequence of the profuseness of the iron sand deposits, and the facility with which the ore can be obtained, considerable attention has, from time to time, been devoted to the question of utilising them. Numerous experiments have been made, and large sums of money sunk in works, but hitherto without success. The metal cannot be produced in sufficient quantities nor at such a price as will in any way compete with the imported article. Furthermore, there is no immediate pros- pect of a different result; the subject has been thoroughly investigated in various parts of the world, and the unanimous conclusion is, that those sands, and other rich ores of a similar character, cannot be profitably reduced in quantity with the fluxes and appliances at present known. Under these circumstances it would not be wise to risk more capital in attempting to establish the manu. facture in New Zealand. Metals. 235 The foregoing table givss the names of fifteen compact iron ores of New Zealand, abont which some information has been collected. Of this number, four — Nos. 1, 2, 8, and 10 — are in all pro- bability unworkable. The extent of the deposit in the case of three — Nos. 4, 5, and 7 — is unknown, and the supply of lime and fuel in the localities in which they occur is limited, consequently there is no immediate prospect of the ores being utilised. Eour others — Nos. 6, 12, 13, and 14 — are favourably situated as regards fuel and fluxes, but no estimate has been formed of the quantity of ore. This reduces the number of ores about which we have anything like positive information to three, viz., Nos. 3, 11, and 15. No. 3, the "Wakatipu Hematite, is found on the Shotover River, in a lode 6 feet thick. Both Dr. Hector and Professor Hutton report favourably as to the quality of the ore, the facility of obtaining fuel and lime, and the prospect there is of establish- ing ironworks in the neighbourhood. Nos. 11 and 15, representing the two main classes of iron ores, occur in the Collingwood district, Nelson, within four miles of each other. No. 11 is the hematite or brown ore, already referred to, the supply of which is practically unlimited. No. 15 is probably the only genuine sample of black band ore yet discovered in New Zealand; it occurs in three distinct veins from 10 to 20 inches thick, the extent of the field being about 12 square miles. There is a plentiful supply of lime, timber, and 236 Building Materials of Otago. fire clay in the neighbourhood, and, according to Dr. Hector, the finest coal in the Colony is found associated with the black band ore. The coal is estimated at 50,000,000 tons. So far as explored, the seams are only from three to four feet in thick- ness, but they have every appearance of increasing. All authorities are agreed in giving the iron ores of Collingwood a high place. Mr. Tatlock, Public Analyst for Glasgow, in a report to Mr. George Turnbull, of Dunedin, on the hematite ore, says : — " This ore is very rich in iron, and in this respect is equal to good Cumberland hematite, and even superior to the Spanish ores which are now used in the manufacture of Bessemer pig iron." Some of the ore was sent to Melbourne and smelted ; it made excellent iron. I have seen a sample tested alongside one of Lowmoor, and so far as could be judged by inspection, the Colonial product was the better of the two ; it could be bent and twisted in all directions, cold, without breaking, and at the same time it did not seem to be exces- sively soft. The Para Para ore is usually called " hematite, " but it should more properly be placed in the next lower sub- division, named indifferently Limonites, Brown, or Bog ores. In addition to the other advantages above enu- merated, the Collingwood district has considerable facilities for shipping its products ; so altogether it may be pronounced the most favourable place in the Colony for the establishment of the manufac- ture of iron. The Government is now advertising Metals. 237 in England and America for tenders for 100,000 tons of steel rails, to be manufactured within the Colony from New Zealand ores. 1 believe that this is sufficient to give the necessary impetus to a thriving and permanent industry. The Para Para hematite ore has for years been extensively and successfully used in the manufac- ture of paint. Two factories have been in operation in Nelson, and their products are rapidly super- seding the imported article. The native paint is giving unqualified satisfaction wherever it has been tried. Copper. — Numerous specimens of copper ores have been found in New Zealand, notably in Otago, Nelson, and the Thames Gold Fields. Many of the economic ores have been discovered, but the infor- mation regarding them is by no means complete. The chemical constituents have, in most cases, been determined, but the extent of the deposits and facility for working them are practically unknown. Copper mining has recently been commenced in D'Urville Island and Dusky Sound ; the prospects are fair, but there has not been sufficient work done to warrant a decided opinion on the subject. Copper is found in Otago at Waipori, Tokomairiro, Clutha Yalley, Carrick Range, and Moke Creek. The deposit in the latter case is described by Mr. Hackett as a true lode 18 inches thick, but Mr. Bradshaw reported it to be from three to five feet in places. The New Zealand ores are generally copper pyrites — the one from which English copper is chiefly manufactured. They are also found in Q 238 Building Materials of Otago. gneiss and schist rocks, the matrix of the best ores in all countries. The English ores seldom produce more than 10 per cent, of metallic copper, and 6 or 7 per cent, pays to work in Cornwall. The New Zealand ores generally contain from 10 to 25 per cent, of metal. The manufacture of copper is an expensive pro- cess, and the demand for the metal in the Colonies is limited, consequently there is no immediate pros- pect of successfully establishing smelting works. But the richness of the ore might warrant sending it to England in the raw state, particularly as the localities of some of the deposits present great faci- lities for shipping. Lead and Tin. — Lead ores have been found in New Zealand in much the same localities as copper, and bars of the Colonial metal were shown at the Philadelphia Exhibition ; still the information on the subject is very meagre. The character of the ore and the quantity of metal have in some cases been determined, but the extent of deposits are al- together unknown. According to Dr. Hector there is a vein at Collingwood two to five feet thick, but it is so intermixed with zinc ore that the two cannot be reduced separately. The greater number of the specimens hitherto found in New Zealand are of sulphide of lead or galena, one of the most useful lead ores. Until about two years ago, no tin had been dis- covered in New Zealand, but at that time several specimens from the interior of Otago were sent to Professor Black for analysis. They were of the Metals. 239 variety known as " stream tin," which occurs in the form of round flat gravel on pebbles. In this case the sizes of the pieces ranged from that of swan shot to small bullets. The ore was supposed to have come from Waitahuna and Cardrona, but there is no information as to the exact locality nor the extent of the deposits. Lead and tin are of much less importance in the constructive arts than iron and copper, still they perform useful parts, and as such demand conside- ration. Independently, however, of this, the work of reducing the ores is comparatively easy, so it might be made a reproductive industry in New Zealand if the raw materials were only obtainable in sufficient quantities. THE END. INDEX. A. Aberthaw lime, 108, 112 Aggregates, 99, 123 American slate, 83 Analyses, 100 Artificial cements, 120 Artificial induration of stone, 8 Atmospheric influence, 5 Auckland lime, 115 Australian slate, 82 B. Bab sb, Mr., 1*8 Balfour, Mr., 146, 207, 210 Barr, Mr., 119 Basalts, 18 Beeches, 191 Beton agglomere, 68 Bickerton, Professor, 29 Birches, 191 Black band iron ore, 230, 235 Blackett, Mr., 175, 201 Black heart birch, 203, 217 Black pine, 175 Black, Professor — granite, 13 ; clays, 59 ; analyses, 100 ; lime, 101 ; iron, 231 j tin, 238 Bluestone, 18 Bog iron ore, 230, 235 Bolsover stone, 6 Brard's process, 8 Breccia, 22 Breccias and trachytes, 20 Bricks, 57 — locality and raw ma- terials, 57; manufacture, 60; pottery and tile works, 61 Broadleaf, 155 Brunton, Mr., 211 Buchanan, Mr., 165, 168, 175, 176, 195 Buchanan, Mr. J., 212 Building stones, 1 — classification, 1 ; properties, 1; composition, 2; decay, 4 ; tests, 7 ; absorbent properties, 8 ; artificial indura- tion, 8 ; geographical distribu- tion, 9; hardstones, 12; free- stones, 24; limestones, 30; sand- stones, 48 ; conclusion, 57 C. Cameron, Mr., 201 Campbell, M.L.C., Hon. R, 26 Campbell-Walker, Capt., 187, 206 Canterbury lime, 116 Calcareous stones, 4 Carpodetns serraius, 148 Castle Bock stone, 47 Caversham stone, 3, 55 Cedar, 164 Celery pine, 189 Cement stones, 99, 117 Cementing materials, 90 — definition of terms, 90 ; classification, 91 ; composition, 91 ; quality of lime- stones, 93 ; properties, 95 ; use of aggregates, 97; strength, 97 Cippollino, 28 Clays, 57, 99, 121 Clay ironstones, 230 Cleavage, 86 Coignet, M., 68, 74 index. Conifers, 164 Comparison of materials, 72 Concrete, 62 — general, 62; proper- ties, 64 ; nses, 65 ; making con- crete, 66 ; experiments, 70 Copper, 237 Cost of walls, 75 ; of slates, 88 ; of mortars, 124 Craigleith sandstone, 2 D. Dacrydium, 180 — Dacrydium en- pressimum, 181 ; D. Colensoi, 186; D. westlandicum, 187 ; D. intermedium, 187 Dimensions of trees, 207, 223 Dolerite, 19 Dowling Bay limestones, 103, 110, 114 E. Eleocaepus, 160 — Fleocarpus hoo- Jcerianus, 160; ~E. dentatus, 161 E. FaguS, 191. Fagus menziesii, 194 ; F. fusca, 197 ; F. solandri, 203 ; F. cliffortioides, 203 Eelling timber, 133, 207 Eraser, M.L.C., Hon. Capt., 26 Freestones, 24— classification, 24; marbles, 25 ; limestones, 30 ; sandstones, 48 Fuschia, 155 — Fuschia excorticata, 155 G. Gilmobe, General, 68 Godfrey, Mr., 41 Gordon, Mr. H., 184, 188, 191. 201 Granites, 13— true granite, 13 ; sye- nite, 14 ; pegmatite, 15 ; con- stituents, 15 Gvanulite, 7 Grass tree, 162 Greenstone, 19 Griselinia Uttoralis, 155 Guthrie and Larnach, Messrs., 154, 158 G. Haast, Dr., 99, 194 Hardstones, 12— granites, 13; me- tamorpbic rocks, 16; volcanic and trap rocks, 17 Hardwoods, 146— mapaus, 146,147, 148; turpentine, 147 ; manuka, 148 ; rata, 151 ; kowhai, 153 ; fuscbia, 155; broadleaf, 155; kamai, 156; pokako, 160; rib- bon woods, 161 ; grass tree, 162 Hay, M.A., Mr., 83, 100 Hector, Dr.,— granite, 13; marble, 26 ; Oamaru stone, 35 ; sand- stones, 51 ; kamai, 157 ; cedar, 168; black heart birch, 205; iron, 232; lead, 238 Hematite, 230, 235 Higginson, Mr., 116 Hoffman brick kiln, 60 Holywell stone, 108, 114 Hooker, Dr., 163, 165, 198, 203 Horman, Mr., 176, 208 Horse Eange limestone, 105 Houses of Parliament, 5 Hull, Professor, 16, 83 Hutton, Professor — Geology of Otago,9; granites, 13; marbles, 25 ; Oamaru stone, 35 ; slates, 82, 84, 86 ; Walcatipu, 104 ; ma- rine worms, 141 ; iron, 231 Hydraulic cements, 91, 117 Hydraulic limes, 91— general, 107; types, 1G8 ; Oamaru, 109 ; Pe- ninsula and Lower Harbour, 109; Auckland, 115 ; Taranaki, 115; Canterbury, 116 Index. I. Ingram, Mr., 197 Innes, Mr., 217 Iron, 230 Iron sand, 231, 231 K. Kahikatea, 177 Kakanui limestone, 1C1 Kamai, 156 Kirk, Professor — marine worms, 141, 151 ; kamai, 157, 159 ; po- kako, 161; pines, 163; cedar, 165 ; miro, 172 ; totara, 174 ; white pine, 180; westland and silver pine, 187; celery pine, 190; birches, 193; red birch, 199 ; felling timbers, 207 L. Laslett, Mr., 132, 137, 215 Lawson, Mr., 78 Lead, 238 Leptospermum scoparmm, 148 ; L. ericoides, 149 Libocedrus, 164 ; L. bidiuilU, 164 ; L. doniana, 164 Lithographic stone, 102 Limestones (building stones) — clas- sification, 30; Wakatipu, 30; Horse Eange, 31 ; Peninsula, 31 ; Kakanui, 31 ; Waiareka, 32 ; Waihola, 32 ; Pleasant Yal- ley, 33 ; Oamaru stone, 33 ; Upper Waihemo Valley, 44 ; Southland, 46 ; Canterbury, 48 Limestones (lime), 93, 98 Localities, 9 Lyme Eegis, 108, 114 M. Macdonald, Mr., 94, 110 Macfarlane, Mr., 27, 52 Macgregor, Mr., 119 Macpherson, Mr., 82 Magnetite, 232 Manuka, 148 Mapaus, 146, 147, 148 Marbles, 25 — Horse Eange, 25 ; To- komairiro, 25 ; Otekaike, 26 ; Clyde, 26; West Coast, 26; Canterbury, 28 Marine worms, 141, 148, 162, 172, 177, 180 Matai, 175 McArthur, Mr., 177, 197 Mclnnes, Mr., 81 McQueen, Mr., 152 Metals, 230— General, 230; Iron, 230 ; Copper, 237 ; Lead and Tin, 238 Metamorphic rocks, 16 Miro, 169 Moeraki boulders, 99, 117 Munro, Mr., 28, 43 Myrsine urvillei, 147 ; M. lucida, 151 Myrtles, 148 N. Nomenclature of trees, 142, 218 O. Oamaru stone, 33 ; experiments, 36 ; lime, 105 Otepopo slate, 80 P. Paint hematite. 237 Panax crassifolium, 162 Para Para iron, 235 Pegmatite, 15 Peninsula lime, 110, 112, 113, 114 Petre, Mr., 77 Index. 243 Phonolite, 19 Phyllocladns alpina, 189; P. tricho- manoides, 190 Pines, 163 Pittosporum tenufolium, 146 ; P. co- lensoi, 146 ; P. eugeniodes, 147 Podocarpus, 169 ; P.ferruginea, 169 ; P. totara, 172; P. spieata, 175; P. daorydioldes, 177 Pokako, 160 Poor limes, 91, 106 Port Chalmers stone, 20 Pozzuolanas, 122 Products of geological formations, 11 Purdie, Mr., 159, 175 Pvke, M.H.R., Mr. Vincent, 26 R. Rata, 151 Red Birch, 197 Red pine, 181 Ribbon woods, 161 Richardson, Hon. E., 217 Rich limes, 91 ; types, 100; Otago stone, 101 Rimu, 181 Roofing slates, 80 — locality, 80 ; ex- tent, 82 ; quality, 82 ; products, 87 ; cost, 88 : general, 89 S. Sandstones, 48— general, 48 ; grits, 49 ; silicious sandstones, 49 ; hard sandstones, 50 ; ordinary sandstones, 53 ; soft sandstones, 55. Seasoning timbers, 137, 208, 224 Septaria, 99, 117 Short, Mr., 80 Silver birch, 194 Silver pine, 187 Skey, Mr., 16, 35, 158 Soft woods, 163— pinos, 163 ; cedar, 164; miro, 169; totara, 172; black pine, 1 75 ; white pine, 177 ; red pine, 181; yellow pine, 186; westland pine, 187 ; silver pine, 187 ; celery pine, 189 ; birches, 191 ; silver birch, 194 ; red birch, 197 ; black heart birch, 203, 217; general, 206 Sophora tetmptera, 153 Southland stone, 46, 104, 105 Sparrow, Mr., 154 Spathic iron ores, 234 Strength of timbers, 210, 225, 226 Syenite, 14 Syenite gneiss, 17 T. Tables— Nos. I. to V., at end of volume; No. VL, 218 ; No. VII., 223; No. VIII., 224; No. IX., 225 ; No. X., 226 ; No. XL, 228 Taranaki lime, 115 Tatlock, Mr., 236 Tests, 7, 208, 211, 224, 225 Theil lime, 108, 113 Thomson, Mr. J. T., 118 Thomson, Mr. P., 169 Tiinarzite, 20 Timbers, 129 — properties, 129 ; structure, 129; growth, 130; felling, 133 ; qualities, 136 ; seasoning, 137; decay and pre- servation, 139; nomenclature, 142; distribution and classifi- cation, 143 ; hard woods, 146 j soft woods, 163 ; general, 206 ; recapitulation, 206 ; conclusion, 216; Tables, 218 Tin, 238 Totara, 172 Trachytes, 23 Travertine, 102 Turpentine, 147 244 Index. IT. ITlrich, Professor, 42 Uses of Timber, 216, 228 V. Vicat, M., 8 Volcanic and trap rocks, 17— varie- ties, 17 ; basalts, 18 ; blue- stones, 18 ; greenstone, 19 ; do- lerite, 19 ; phonolite, 19 ; ti- marzite, 20 ; breccias and tra- chytes, 20; breccia, 22; tra- chytes, 23 W. Waihola limestone, 102 Wakatipu stone, 80, 104 TPeinmannia racemosa, 156 Welsh, slate, 83 Westland pine, 187 White pine, 177 Winton limestones, 101 Yellow pine, 186 DUNEDLN: PRINTED BY COULLS AND CULLING, RATTRAY STREET. TABLE II. ANALYSES OF OTAGO LIMESTONES THAT FURNISH POOR LIMES, WITH ENGLISH AND FOREIGN TYPES. Number. Description. Locality. Lime and Carbonate of Lime. Carbonate of Magnesia. Silica Soluble. Silica Insoluble. Alumina Soluble. Alumina Insoluble. Sand Insoluble. Clay partly Soluble. Sesqui-oxide of Iron Insoluble. Oxide of Iron Soluble. Carbonate of Iron soluble. Iron Alumina. Insoluble Matter not determined. Alkalies, Water, and Loss. Analyst or Authority. Remarks. Number. English § Foreign Types. 1 Sandy stone of Calraic France 70-00 2-00 1-25 24-75 M. Vicat 1 2 Coarse stone of Dessin 61-89 7-44 Q.in 757 26-00 2 )» ... ... ... Of ago Limestones 3 Grey Caversham 68-51 Trace 0-72 1-79 0-79 27*65 0-54 Dr Hector Jurors' Reports, N.Z. Exhibition Q O 4 5 6 Greyish yellow Dark grey n ii ••• ••• Kaikorai Waikouaiti Upper Har- bour West ~6S 65-77 64-60 •50 Trace 1-16 1-00 3-00 27-60 2-40 0-80 Trace 2-83 31-40 30-01 0-42 6-22 » >) » » » ii ii ii ii V » » )l 4 5 6 7 8 Grey Bluish grey Pleasant River ii ii 64-10 63-08 1-10 6*63 6.60 29-50 1-20 0-80 0-83 29-53 4-22 )> II II II II II II II II 7 8 9 10 11 12 Greyish yellow Light j ellow Dark grey Moeraki boulder Kaikorai Waihemo Kaikorai Moeraki (if 61-60 60-86 60-50 !-80 0- 28 1- 99 2.50 1*67 1-80 2.90 28-00 21-00 5-50 14-00 1-80 1-20 1-78 34-80 30-19 0-60 0.32 0-71 2-30 it ii !t Dr Black )) >J l> » II II II II » » ») >> Laboratory Report, 1875-6 9 10 11 12 13 14 Bluish grey Greenish grey Caversham ii 53-00 51-22 1-56 24-40 19-10 1-40 2-92 43-64 2-20 2-66 Dr Hector n Jurors' Reports, N.Z. Exhibition ii ii *ii ii 13 14 15 16 17 18 Bluish grey Compact dark blue Dark grey Fine grey, soft Hawksbury Wakatipu Hawksbury Waihola 5 50-79 50-05 43-30 L-17 2-80 1-70 Trace 6-23 0-70 23-58 27-60 8-84 2-94 7-49 25-00 21-50 19-00 1- 56 2- 40 0-80 2-80 0-90 42-94 1-90 1-91 0.77 0-70 Dr Black Dr Hector Dr Black » i» » » 12-46 per cent, of silica in form of sand Jurors' Reports, N.Z. Exhibition 21-98 per cent, of silica in form of sand 15 16 17 18 19 20 21 Buff yellow Dark grey Pale yellow Kaikorai Tokomairiro Kaikorai H 41-20 40-45 2-10 Trace 1-70 340 1-75 21-00 29-30 1-70 Trace 5-2C 52-20 46-80 5-90 1-40 5-90 Dr Hector ii it Jurors' Reports, N.Z. Exhibition ii it ii ii ii ii ii ii 19 20 21 Back of Foldout Not Imaged TABLE III. ANALYSES OF OTAGO LIMESTONES THAT FURNISH HYDRAULIC LIMES WITH ENGLISH AND FOREIGN TYPES- Number. Description. Locality. Lime and Carbonate of Lime. Carbonate of Magnesia. Silica Soluble. Silica Insoluble. Alumina Soluble. Alumina Insoluble. Sand Insoluble. Clay partly Soluble. Sesqui-oxide of Iron Insoluble. Oxide of Iron Soluble. Carbonate of Iron Soluble. Iron Alumina. Insoluble Matter not determined. Alkalies, Water, and Loss. Analyst or Authority. Remarks. Number. 1 2 Aberthaw Fro T1 r> O England 88-00 86-20 6 85 4-00 11-20 M5 2-60 m. v icau Hy. Reid M. Vicat Gen. Gilmore Hy. Reid Feebly hydraulic ; sets under water in 15 days 1 2 3 4 5 Bituminous bluish grey Theil Limestone Blue Lias of Lime Regis England 82-25 81-36 79-20 1-00 10-50 5-50 14-90 17-30 peroxide 1-42 1-71 1-70 1-10 3-50 Set under water in five days Used in Port Said breakwater Used at London Docks 3 4 5 8 America , , 79-04 11-10 9, 4-54 Prof. Boynton M. Vicat C. Tomlinson 6 7 8 Yellow Metz limestone 77-40 77-30 3-00 ic- 25 8-35 15-20 1-00 manganese 1-50 3-00 Eminently hydraulic ; sets under water in three days Eminently hydraulic 7 8 9 72-60 4-50 23-00 9 10 Blue Lias of Holywell 71-55 1-35 20-10 3-52 2-21 0-84 Dr. Muspratt (74-73 soluble ) . ., ] 25-27 insoluble} m acids / Used in the Liverpool Docks 10 Ota go Limestones — 11 12 13 14 15 16 White conglomerate Dark compact Dark fawn compact Drab granular, 5th lowest Yellowish do. Portobello Peninsula Dowling Bay Peninsula Portobello 87-08 86-80 86-05 84-03 82-03 81-10 Trace »> 2-22 0- 33 Trace 1- 70 not estimated 0-20 0-36 not 7-00 10-93 9-10 2-85 0-80 0- 90 1- 23 2- 30 Trace 3-57 2-76 2-53 0- 55 1- 00 0-55 079 Trace 0-97 0-98 2-80 0-60 8'58 12-40 16-60 0- 78 1- 46 1-26 0-33 Dr Hector Dr Black n >> Dr Hector Jurors' Reports, N.Z. Exhibition 3-17 per ct. silica in form of sand Trace of sand and mica 2-67 per ct. silica in form of sand 11 12 13 14 15 16 17 18 19 20 17 18 19 20 Fawn top seam Drab granular. 2nd highest seam Do. do. lowest seam Peninsula Dowling Bay Peninsula 77- 07 78- 87 69-70 69-46 1-98 0- 80 1- 50 2- 26 estimated 0-22 0-62 0-31 0*16 10-51 12-70 18-87 18-69 1-61 1- 52 0-80 2- 10 4-21 4-05 3-74 3-16 0-85 oxide 0-70 0-69 0-95 1-53 0- 35 1- 30 2- 34 1- 12 0-39 2- 09 0-97 Dr Black ft If M 3*60 per ct. silica in form of sand 3-80 per ct. „ „ „ 7-60 per ct. „ „ „ 7*03 per ct. of sand, but mixed with some clay Back of Foldout Not Imaged 9 K) n 12 18 Description. English Sf Foreign Types. Raw materials Portland cement Portland cement, artifi- cial Boulogne cement stone Portland cement, natural Calderwood cement stone Vassy „ „ Rosendale „ Yorkshire „ „ Sheppy Harwich Otago Cement Stones. Septarian boulder Locality. England Germany France Boulogne Scotland France America England Moeraki TABLE IV. ANALYSES OF OTAGO CEMENT STONES WITH ENGLISH AND FOREIGN TYPES. -a ° II o » . s ■a a § o 69-87 61-40 52-00 .. 72-40 0-30 .2 3 20-54 20-67 23-00 23-86 20-42 8- 80 14-00 27-70 24-00 18-00 9- 37 0-80 II d -J •S3 3-49 10-43 8- 00 9- 20 13-88 3-40 5-70 2-34 « ,3 1 23-80 17-80 o o 02 O 02 peroxide 5-12 protoxide 10-20 peroxide 1-26 •a 00 o 4-44 0-87 4-00 1-31 5-25 17-75 -2 d • * °02 6-00 11-60 manganese 6-75 J 03 "S -12 d .a 2 .s x n H'rj lj 0) 8-70 CO m O Analyst 1-66 1-92 6-60 630 3-40 4-94 11-37 0-60 or Authority. Various Hy. Reid Herr Feich- tenge C. Tomlinson Various Prof. Penny C. Tomlinson Gen. Gilmore Various Dr Hector Remarks. Manufactured by White Bros. Average quality Quick setting Quick setting 7-50 per cent, sulphate of soda, &c. Colonial Museum Report, 1870-1 Back of Foldout Not Imaged TABLE V. TENSILE STRENGTH OF WAIHOLA LIME MORTARS WITH DIFFERENT SANDS. No. Description. Locality. Weight in lbs. required to tear asunder Bricks. , — | Remarks. No. 1 Grey, with faint yellow tinge ; fine, but sharp. Mr Knox's pit, Anderson Bay. 226 218 f 11 sq. inches in middle not quite \ hard. 2 „ » » 15 2 Grey ; fine and sharp ; small quantity of clay. Railway cutting at Eng- lish Church, Cavershaui 212 nil. Good bed, uniformly hard. Broke in fixing; flaw in bed. 16 3 White ; very soft, clean, and fine. Railway cutting at Ab- bott's Creek 150 136 Uniformly hard throughout. « » »> 17 4 Round quartz gravel. Mr Cutten's pit, Ander- son Bay 158 109 Uniformly hard throughout. „ „ but not all adhering. 18 5 Dark grey ; irregular and soft. Mr Casey's pit, Ander- son Bay 143 122 1 2} sq. inches in middle not quite I hard. Thickish bed ; soft in centre. 19 6 Yellowish grey ; fine, very sharp. Mr Knox's pit, Anderson Bay 143 67 ( 2^ sq. inches in middle not quite 1 hard. 21 „ » » 20 7 Quartz gravel. Railway cutting at Ab- bott's Creek 140 82 Uniformly hard. Not adhering properly. 21 8 Reddish yellow, irregu- lar ; clay and quartz. Railway Cutting at Ab- bott's Creek 138 88 j Very thin good bed; uniformly | hard. Bed not good. 22 9 Deep red ; coarse ; ir- regular. Railway cutting at Ab- bott's Creek. l 138 nil. Uniformly hard. Broken on shelf. 23 10 Deep reddish yellow ; fine and sharp. Mr Cutten's pit, Ander- son Bay 122 122 (Piece in middle like a small '( oyster not quite hard 24 11 Orange ; very soft and fine. Railway cutting at Ab- bott's Creek 106 97 Not well set. 25 12 Whitish grey ; soft. Mr Casey's pit, Anderson Bay 102 nil. ]21 sq. inches in middle not quite | hard. Broken on shelf. 13 Yellowish grey ; soft. Mr Casey's pit, Anderson Bay 102 nil. Not well bedded. 1 Did not carry 281bs. ; seems to ( have been broken. 27 14 Greyish white ; fine ; very sharp. Mr Knox's pit, Anderson Bay 96 nil. Uniformly hard. f Broke in handling; not adhering [ properly to bricks. Description. Locality. Weight in lbs. required to tear asunder Bricks. Remarks. Reddish yellow ; fine Mr Casey's pit, Anderson Bay 88 nil. ( 21 sq. inches in middle not quite ( hard. (Did not lift 21 lbs.; not quite \ hard ; not adhering well. Grey ; fine Railway Cutting at Car- gill Hill 82 68 Good bed ; uniformly soft. Grey and yellow ; fine Railway cutting at Car- gill Hill 82 nil. Good bed ; uniformly soft- Did not carry 28 lbs. Greyish yellow ; very sharp Mr Harris's pit, Anderson Bay 81 70 Good bed ; 3 sq. inches not hard. 5 Yellowish grey Railway cutting at Eng- lish Church, Caversham 75 nil. Uniform consistency throughout. Broke in handling ; not bedded. Yellow ; fine and sharp Mr Harris's pit, Anderson Bnv jjciy 67 nil. 2 sq. inches not quite hard. W ould not stand handling. Deep reddish yellow ; fine and sharp Mr Cutten's pit, Ander- son Bay 65 nil. Bad bed ; soft in heart. ( Did not lift 28 lbs ; piece like a \ small oyster not quite hard. Deep orange ; very sharp Mr Cutten's pit, Ander- son Bay 61 nil. ( Very good bed ; 4 sq. inches ; not ( quite hard. Broke in handling. Light orange ; very sharp Mr Cutten's pit, Ander- son Bay 61 nil. Good bed. Did not carry 28 lbs. Yellow ; sharp and fine Railway cutting at Car- gill Hill 54 nil. Good bed ; soft throughout. Did not carry 14 lbs. ; bad bed. Yellow ; sharp and fine Railway cutting at Car- gill Hill 47 nil. Pretty well set. Broke with about 10 lbs. Yellow ; mixed with pebbles as large as peas Railway cutting at Ab- bott's Creek nil. nil. Broke in handling. ( Did not carry its own we'ght ; ( soft throughout. Yellow ; fine and sharp Railway cutting at Ab- bott's Creek nil. nil. Broke with its own weight. Do. do.; had not set. /& -22 GETTY CENTER LIBRARY 3 3125 00778 1061