The Pamphlet Collection of Sir Robert Stout: Volume 66
Strength of New Zealand Timbers
Strength of New Zealand Timbers.
No. | Native Names in Alphabetical Order. | Specific Gravity. | Weight of a Cubic Foot. | Greatest Weight carried with Unimpaired Elasticity. | Transverse Strength. |
---|---|---|---|---|---|
lb. | lb. | lb. | |||
1 | Hinau, or Pokaka (Elœocarpus dentatus) | .562 | 33.03 | 94.0 | 125.0 |
2 | Kahika, supposed white-pine | .502 | 31.28 | 57.3 | 77.5 |
3 | Kahikatea, white-pine (Podocarpus dacrydioides) | .488 | 30.43 | 57.9 | 106.0 |
4 | Kauri (Dammara australis) | .623 | 38.96 | 97.0 | 165.5 |
5 | Kawaka (Libocedrus doniana) | .637 | 39.69 | 75.0 | 120.0 |
6 | Kohekohe (Dysoxylum spectabile) | .678 | 42.25 | 92.0 | 117.4 |
7 | Kowhai (Sophora tetraptera var. grandiflora) | .884 | 55.11 | 98.0 | 207.5 |
8 | Maire, black maire (Olea cunninghamii | 1.159 | 72.29 | 193.0 | 314.2 |
9 | Maire-tawhake (Eugenia maire) | .790 | 49.24 | 106.0 | 179.7 |
10 | Mako (Aristotelia racemosa) | .593 | 33.62 | 62.0 | 122.0 |
11 | Manoao (Dacrydium colensoi) | .788 | 49.10 | 200.0 | 230.0 |
12 | Mangi, or mangeao (Tetranthera calicaris) | .621 | 38.70 | 109.0 | 137.8 |
13 | Manuka (Leptospermum ericoides) | .943 | 59.00 | 115.0 | 239.0 |
14 | Mapau, red mapau, or red-birch (Myrsine urvillei) | .991 | 61.82 | 92.0 | 192.4 |
15 | Matipo-tarata (Pittosporum tenuifolium) | .955 | 60.14 | 125.0 | 243.0 |
16 | Matai (Podocarpus spicata) | .787 | 49.07 | 133.0 | 197.2 |
17 | Miro (Podocarpus ferruginea) | .658 | 40.79 | 103.0 | 190.0 |
18 | Puriri (Vitex littoralis) | .959 | 59.50 | 175.0 | 223.0 |
19 | Rata, ironwood (Metrosideros lucida) | 1.045 | 65.13 | 93.0 | 196.0 |
20 | Rewarewa (Knightia excelsa) | .785 | 48.92 | 93.0 | 161.0 |
21 | Rimu, red pine (Dacrydium cupressinum) | .563 | 36.94 | 92.8 | 140.2 |
22 | Taraire (Nesodaphne taraire) | .888 | 55.34 | 99.6 | 112.3 |
23 | Tawa (Nesodaphne tawa) | .761 | 47.45 | 142.4 | 205.5 |
24 | Tawiri-kohukohu, white mapau (Carpodotus scrratus) | .822 | 51.24 | 80.0 | 177.6 |
25 | Titoki (Alectryon excelsum) | .916 | 57.10 | 116.0 | 248.0 |
26 | Totara (Podocarpus totara) | .559 | 35.17 | 77.0 | 133.6. |
27 | Tawai, red-birch (Fagus menziesii) | .626 | 38.99 | 73.6 | 158.2 |
28 | Tawai, black-birch (Fagus fusca) | .780 | 48.62 | 108.8 | 202.5 |
29 | Whawhako (see also Maire) (Eugenia maire) | .637 | 39.63 | 75.0 | 120.0 |
30 | Whau (Entelea arborescens) | .187 | 11.76 | 13.0 | 32.0 |
The experiments were conducted in the following manner: A pressure of 50lb. was applied for two minutes (as measured by a sand-glass), and the sample was then released; 75lb. was then applied for the same time, and then 100lb., and so on, increasing by 25lb. each time. Each time the sample was released the point on the deflection scale to which, it returned was read, and when it came to be notably under the original reading it was allowed to remain unloaded for two minutes, to see whether it would in time recover itself. Then the pressure was gradually increased, without being removed, until the specimen broke.
A particular description of forty-four of the principal forest-trees will be found in the appendix.