Cheeseman. — Age and Growth of the Kauri. 11 



earliest of these is Mr. T. Laslett, author of the well-known book !i Timber 

 and Timber-trees." Mr. Laslett, in his capacity as timber inspector to the 

 Admiralty, made several visits to New Zealand during the years 1840^13, 

 being attached to certain expeditions sent by the British Government for 

 the purpose of procuring spars fit for the topmasts of line-of-battle ships. 

 During these expeditions he had good opportunities of studying the kauri, 

 and from his wide acquaintance with timber and timber-trees, as well as 

 from his scientific training and experience, was well qualified to speak with 

 authority. At pages 44^5 of his book he gives a tabular statement of the 

 number of concentric circles or woody layers found in various timber-trees 

 " within a radius of 3 in., 6 in., 9 in., 12 in., 15 in., 18 in., 21 in., and 24 in., 

 measured from the pith, or centre," representing, of course, trees with a 

 total diameter of double the radius. From an examination of four kauri 

 sections he arrives at the conclusion that the average number of woody 

 layers required to make 1 in. of wood for a full diameter of 24 in. would be 

 6-7 for each inch of the whole diameter, equivalent to 13-4 per inch of the 

 radius alone. It will be seen that this represents a somewhat slower rate 

 of growth than that which I have obtained from the examination of a much 

 greater number of sections ; but the difference is not very large. If Mr. 

 Laslett's estimates had received proper consideration from subsequent 

 writers many rash and unsupported statements would never have been 

 made. 



The next writer of note to deal with the age of the kauri was Dr. Hoch- 

 stetter. In his well-known book, " New Zealand, its Physical Geography, 

 Geology, and Natural History," he gives by far the best and most reliable 

 popular account of the kauri that has yet been published. At page 147 he 

 savs, " The oldest and largest trunks attain a diameter of 15 ft., and a 

 height of 100 ft. to the lowest branches, or from 150 ft. to 180 ft. to the 

 top of the crown. Such trees are probably seven hundred to eight hundred 

 years old. Having examined several trunk sections, I found, as the 

 mean result, from ten to twelve rings to 1 in., although in some cases the 

 rings attain a much greater thickness. In some few cases of rare occur- 

 rence I have even observed single rings of a thickness of 1 in. For the 

 sawmill the woodcutters generally pick out trees of 4 ft. diameter, with 

 trunks measuring from 60 ft. to 80 ft. to the crown. Such trees are pro- 

 bably two hundred and fifty to three hundred years old." 



Hochstetter's estimate of " ten to twelve annual rings to 1 in." is inter- 

 mediate between my own and Laslett's ; but, on the other hand, his state- 

 ment that trees with a diameter of 15 ft. "are probably from seven hundred 

 to eight hundred years old " is somewhat under the mark, as it would 

 imply only 8-0 rings for each inch of radius. 



We now arrive at the views entertained by the late Mr. T. Kirk, a 

 synopsis of which will be found on pages 144-45 of his " Forest Flora." 

 He says, " A cross-section of a kauri felled in a free-growing condition 

 usually exhibits from seven to thirteen concentric rings to each inch of 

 radius : if we take ten rings as a fair average for growing timber, it would 

 give three centuries as the age of a tree with a diameter of 5 ft. at the 

 base. This rate of increase is supported by the little we know of the rate 

 of growth of young trees. In the Auckland Domain trees planted twenty- 

 two years ago are now 25 ft. high, with a circumference of 26 in., which 

 shows greater rapidity of growth ; but the trees are growing under very 

 favourable conditions. Another tree planted twenty years ago is 20 ft. 

 high, with a diameter [? circumference] of only 20 in." Now, all this is 



