A GREAT BUILDING STONE.

Dominion, Volume 6, Issue 1608, 27 November 1912, Page 5

A GREAT BUILDING STONE.

THE PRODUCT OF TONGA BAY, EXPERTS SAT TVILI, ENDURE FOR AGES. After all is said about the stately edifice in Peatherston Street, one of the chief features as far as Wellington, indeed, the whole Dominion, is concerned, is that the new General Post Office is erected in a magnificent building granite, - obtainable at our very doors—in Tonga Bay (near Nelson), about eight hours' steam from Wellington. In the past this city 'has been sadly handicapped for the lack •of a good building stone,' and , whilst Dunedin and other southern cities have in a measure been able to utilise certain stones, mostly of the soft limestone order,' Wellington has had to depend almost entirely on bricks and mortar. Tonga Bay. stono was first used in Wellington in ■the Public Trust building, one of the handsomest structures in the whole of the Dominion, and noting what a very fine effect visualfy the stone from across the strait had, apart from its unquestioned utility, it was decided by the Government Architect to provide for the building of the new post, office; in the, same material, with what result anyone' passing down Featherston Street may now judge for themselves. It 6hould be stated at the outset that ■Tonga Bay stono. is really a granite, the most enduring of all forms of rock, and to build in granite'means tp build for all time, i The' existence of the Tonga Bay deposits have been known for some thirty years at least, but those on the. mainland have never , been greatly disturbed for a'.£reat..many- years, and; liave.;ne.ver • really teen systematically worked at all until the ■ quarries were acquired by Messrs. J. and A. Wilson, Ltd., about six years ago. Before then the Government used to obtain limited supplies of 'the-"granite', for special .'purposes from Tonga';lsland,! which lies off the bay, but that has long ago been declared a scenic Teserve, and consequently the deposits there are not ;again to W disturbed, the island being a very attractive spot scenically. s Tonga Bay granite is medium coarse in texture, and'is pepper and salt , in- colour; —perhaps the most valuable > colour -for city wear, as it cleans-nicely-after every • downpour of . rain. ' Being absolutely holocrystalliiie in ' character, ;like '"all -: true. granites,. it is capable of taking a very high polish;' and should be;largely used" ill that direction in the finer ornamental I work in years to come. A ..GOOD 'FEATURE. One of the most cantankerous features, of most gi-anites is the difficulty experienced in working it, but here the .TongaBay granite;- : lias a, distinct .JTdyantnge over many. '/' That 19 to say, -that/-when first quarried the granite is quite amenable to.the ; saw, and can be worked with.- -j out any trouble, but as the blocks become' exposed to the air, tho stone, gradually hardens, aiid after a few months' exposure the stone is as hard as Aberdeen granite and as - difficult to work. This was graphically /illustrated not so long ago id connection-with the Public Trust Office. The Government-Architect wished to deepen the ornamental design in one part of the building. It was. only a little job, lie-thought, that would take a skilled mason a few, hours, but' after a hard try the mason'complained'that the. stone was most recalcitrant, "and- that the work-■ w : o'uld 'take- weeks instead'taf hours. On this Sir. John Campbell went out on the scaffolding himself and tried

his' Laud'" with' mallet and chisel, only to J ■■■] find that "the mason had' spoken' the bate" •:

truth, and so-the contemplated work was* s abandoned. This,speaks wonders for tha- 1 durability of the' stone, which ilr.-UamjM; :j bell vouches will last for centuries, : • •,< A VALUABLE PROPERTI". : The property known as the, Tonga Baj;' quarries, owned /by' Messrs. J. ani c A..;. ) Wilson,' Ltd., the builders of the. General *' ' j Post Office and Public.Trust Office, is situ-|':. ated opposite Tonga Island, on the coast,', . j a, 'few miles north (on the Wellington - side) of Nelson, and-every steamer tra-\ -J veiling between . Wellington and t Nelson >. I passes within two or three miles'of' the'. j spot. It consists of some" 460 acres of' ' i hilly ground, composed of huge boulders? l ; or bosses of; the granite, packed... pretty. [ j closely together, : .as-is often the : case with' : .' .: such granitous deposits. As a matter of fact,, it is well known that granite would ' : be much harder to displace were it 'not ; i for the interstices of earth, between the -i bosses, which are distinctly helpful in, the / ' j blasting operations. The supply of gran- i -i ite on. the block has. never really 'been ; I estimated, but it,is said to .be practically \ illimitable, and there is the sanie.-even quality;of stone wherever' on the'-'blocli : samples have been hewn. •'■■ ■ ! ITS 'AMAZING STRENGTH. " . i Proof of this is best illustrated in the ' amazing textile. strength of' the." Tonga ! * j Bay granite. | Professor R. .A.'.Scott, • ! M. Inst., C.E., of the Canterbury Coliega ! faculty, who tested" the stone, ; j ed .that, it will stand a pressure of. 1033 . tons to the square-,foot. A practicable» building stone of such strength is'not'to >■', i be found readily in every country, and for J i an almost limitless supply. of ; such .ma-v terial to be within a few hours steam of I Wellinßtpn'. should be,*, an asset to the• Empire Gity that should not be valued too ' ! lightly. Wellington is not always to be. j a city of brick and stucco, however well; i those materials may have served the town ; 1 i in its youth. There is a dignity ; and ii ! solidity in a stone building—and a stone- j b,uilt city—that is not to be denied,' and j which conveys with impressive finality j that sense of permanence'that' is usually • absent in a colonial town. .... J QUARRIES • PORTUNATELX SITUw ' W s.ATED.' '.' ' " 'i The Tonga Bay quarries' are fortunately. siutated. The ..stone which, has gone., .to build the-General Post Office has been ob-. • tained from. a face : ;,only a few "fyards diSSj' ■fcant from' the sea-frt>'nt, ; and there':is.,deep? ! water right up to the shore. . Therr'is^a' t j stoutly-built : ;wharf.iTi existence, ) which steamers of.-moderate'tonnage may:;' berth with-safety;;.y-TheJvharf, .which is. •: only a quarter, ofi-a mile away from,;,that'' portion of the quarry now being worked;;! 1 is-connected therewith by '-.a* tramway (of ' -3ft. ghagej. Messrs. J.and.A. Wilson, Ltd:/■ , '..have a'.'first-class:, sawing-plant on thai- •! .spot, worked.by a 35-liorse power :'MarshaU-; > ■! steam-ehgine.' As the resulfc'.'otftlie big supply of granite needed for tlie'iew General Post Office and other jobs, the quar< ! ries'. are-now in-fine order,, and a splenVTv. ! did and.econbmical system of 'working, has'! i beeri devised. " As. a/monument !' : own," the post-office ',would be difficult to ' i ■ excel; >and several 'builders and'architects;. . from Australia and England have already,. j spoken in the highest-terms of the stoned I