30 DACRYDIUM CUPRESSINUM. 
The specific gravity of rimu varies from ‘550 to °644, and its weight from 
34°281b. to 4o'11lb. per cubic foot.* Mr. Blair states} that it requires a weight 
of 350°88lb. to break a piece 2ft. long and tin. square supported at both ends 
and loaded in the centre,{ so that it is equal to English oak in strength. 
The proportion of sapwood varies to a considerable extent. Fully matured 
trees 4ft. in diameter sometimes exhibit less than 4in. of sap, while in smaller 
trees the sapwood may form one-fourth or even one-third of the diameter: this, 
however, depends chiefly on the age of the tree. Well-ripened small trees may 
be found with a very small quantity of sapwood. The heart of old trees is often 
excessively resinous, and affords timber of great durability for certain purposes ; 
usually, however, it is not a durable timber when exposed, especially if in 
contact with the ground. 
During the period of growth the rimu is liable to a partial separation of the 
concentric rings of the trunk, the shakes or cavities thus formed being filled 
with a white resin; occasionally the shake is sufficiently extensive to cause a 
considerable percentage of waste in conversion. Specimens with a twisted and 
uneven grain are not uncommon, and afford timber of special value for orna- 
mental work, although not adapted to purposes where strength is required. 
Kimu is applied to a great variety of purposes, and a fairly unanimous 
opinion has been formed as to its merits and value. It is the chief timber 
employed for general building purposes over fully two-thirds of the colony, some- 
times conjointly with other timbers, but most frequently alone: it is used alike 
for framing, joists, flooring- and weather-boards, doors, sashes, mantelpieces, &c. 
Its handsome figure renders it very effective when worked up into doors and 
mantelpieces, as, if well grown, it takes a high finish when polished. It is also 
largely used for dadoing in public and private buildings, and for panel-work, 
office-fittings, &c. It has been extensively used in the construction of bridges, 
but for the most part with unsatisfactory results. In the Waikato, bridges built 
of this timber had to be re-erected within seven years: the same experience has 
been realised in various parts of the South Island. Decay speedily commences 
at the joints, owing to the retention of water, or rain may gain access to an 
unnoticed shake, when the affected timber speedily becomes a mass of corrup- 
tion. At Invercargill I examined some large hewn stringers, I6in. square, 
used in the construction of a railway bridge, without cross-beams or road- 
planking, so that the conditions were unusually favourable to durability ; but it 
had been found necessary to replace them within ten years, owing to their unsafe 
condition from decay, which appeared to have been caused primarily by rain- 
water which had been retained in the concavities of the upper hewn surface, 
and caused surface-cracks which allowed water to find its way to the heart. In 
Taranaki, however, it is frequently used in bridge-building, but exposed joints 
are carefully cemented and otherwise protected from the action of moisture: the 
life of a bridge thus constructed is estimated at fourteen years. The rimu of 
Taranaki is unusually straight-grained, even in old trees, and very resinous. 
Rimu has been used for the keels of ships of considerable tonnage, and for 
other purposes in ship-building. About eighteen years ago, a large brig was 
built at Port Pegasus, Stewart Island, entirely of rimu, with the exception of the 
framing, which was obtained from the southern rata (Metrosideros lucida). 
* See Balfour’s Table of Results of Experiments on New Zealand Woods for the Commissioners of the New 
Zealand Exhibition, Otago, 1865. Mr. Blair states the weight of rimu in the green state to be from 43'117Ib. to 
71'130lb. per cubic foot ; when seasoned, 34'204Ib. to 42°775]b, (Blair : Building’ Materials of Otago, p. 224.) 
} Blair: Building Materials of Otago, Pp. 225. : 
{ In Balfour's Table the weight required to break good s 
pecimens rft, long and rin. square, supported at one end 
and loaded at the other, is stated to be from roglb. to 178lb, 
