1885.] LESSONS ON TIMBER-PRESERVING. 155 



cannot be done twice a year, it must be performed once a year at 

 least. 



In the following table are shown (in the first column) the names 

 of different kinds of timber, in the second column the number of 

 years for which they may be preserved in the timber store, and in 

 the third column the period at which they are best adapted for 

 use : — 



I. 

 Hinokai {Thuya obtusd), 

 Matsou or Momi {Abies firma), 

 Sugi {Cryptomcria japonica), 

 Tsuga {Tsuga Sicboldii), 

 Hiba {Thuja dolahrata), 

 Tawara {Thuja 'pi&ifcrd), 

 Reyaki {Zelkoiva Keyahi), 

 Kashi, „ „ 



(The number of years is calculated from the day of felling, and 

 the time which is spent before timber comes to the store is reckoned 

 to be one year.) 



A pond of 15,000 tenbo in area can, on the average, store up 

 about 10,000 pieces of timber. They are of various lengths, as the 

 following table shows : — 



Lengths of timber (in kens), 2, 3, 2-5, 4, 3-5, 4*5 5, 6, 

 Percentage number, . 50, 20, 10, 5, 10, 5, per cent. 



Thus one-half of the whole timber in the pond is of 2 kens in 

 length, one-fifth is of 3 kens in length, etc. (1 ken= 2 yards.) 



At ordinary times, only three or four men are employed, whose 

 daily wage is 35 to 45 kus (?), but at the washing season 15 men 

 are employed daily for a period of about half a month. 



boulton's method. 

 Convinced by a series of elaborate analyses, that to call the 

 process generally introduced by Bethell for preserving railway 

 sleepers " creosoting " was a misnomer, much of the so-called creosote 

 being washed out by rain, snow, etc. ; also that the solid pro- 

 ducts in coal-tar were really powerful antiseptics, ]\Ir. Boulton has 

 invented his new process, now exhibited at the Inventories, by 

 which he has been able to remove the watery moisture in the timbe? 

 present at the time of injecting the coal-oil. Eailway sleepers 

 should and usually are stacked and seasoned several months before 

 being introduced into the cylinders ; but timber of irregular sizes 

 and large scantlings sawn from large logs previously kept in 

 timber ponds, and which from being used in sea-water may be sub- 



