METHODS OF HARVESTING. 797 



cannot be utilized. Thus a loss of peat occurs, often 25 or 

 50 per cent, of its whole volume. If, however, this otherwise 

 wasted material can be moulded into turves, no loss need 

 accrue. 



2. Quality. 



The quality of the peat is ascertained in the above-men- 

 tioned manner, both as regards its efficiency as fuel, and the 

 possibility of thoroughly draining the bog. 



It has already been remarked that the quality of the peat 

 varies in the different strata of the bog, the best peat being, as 

 a rule, at the base of the bog and the inferior kind at its 

 surface. In order to ascertain the nature of the peat through- 

 out the bog, several experimental trenches are dug: the 

 refuse is set aside and the fibrous peat stacked apart from 

 the black peat, the relative proportion of each kind being 

 calculated ; the peat at the base is then dredged out and each 

 kind analysed. 



As the value of peat depends on the quantity of combustible 

 matter in it, which is greater the less water or ash the peat 

 contains, the analysis is directed chiefly to ascertaining the 

 quantity of water and ashes in the peat. The contents of the 

 peat in bituminous substance and uncombined carbon, which 

 is always a test of its value, may be found by extracting them 

 with sulphurous ether. 



The value of a peat-bog depends also on the possibility 

 of draining it. If a bog can be thoroughly drained within 

 a year from the commencement of working it, the admis- 

 sion of oxygen from the air will more or less quickly con- 

 vert the insufficiently decomposed and less valuable peat 

 into rich black peat which is the most valuable kind. Well- 

 drained peat also crumbles far less than when the bog is 

 undrained. 



It is evident that if a bog is to be properly utilised, it 

 should be worked in accordance with a fixed plan prepared 

 beforehand ; this plan specifies how much peat should be dug 

 yearly, when the digging is to be commenced, in what direc- 

 tion it is to be continued, according to what principles it is to 

 be drained and the best lines for transport. Wherever there 



