IV.] 
HEAR T-SHAKE. 
27 
a veiy objectionable form. These species are among 
the hard and strong woods used for architectural pur¬ 
poses in this country, and by cabinet-makers for the 
manufacture of furniture, and for other domestic uses. 
As regards the white or softer woods, it is generally 
very small in the Dantzic, but extensive and open in 
Riga and Swedish Fir. In the Pines, the Canadian Red 
is perhaps the closest and least of all affected by it, the 
Canadian Yellow coming next in order; but in the 
Pitch Pine of the Southern States of North America it 
is often present in a more enlarged form, and the centre, 
or pith, of this species cannot well be approached if thin 
boards are required to be cut from it. 
This defect, as before mentioned, affects and pervades 
more or less nearly every description of timber ; it is 
common to all the exogenous trees, and neither age, 
soil, nor situation appears to have anything to do with 
its origin. It must consequently be accepted as an 
arrangement in the natural order of things for which 
there is no help, and our study should be to so utilise 
the trees possessing it in its most extensive and objec¬ 
tionable form, as to employ them for purposes which 
require their full growth, doing as little as possible to 
them if we wish to convert the logs profitably. The 
heart-shake is, nevertheless, so very insignificant in some 
timber, that many persons, not professionally educated 
to the work, might look at a log without suspecting its 
presence. Others, again, if they did discover it, would 
hardly consider it to be of any importance, as it is often 
so small that the blade of a penknife could scarcely be 
thrust into it. 
There are, however, several varieties of timber which 
have it, not in an insignificant form or shape, but 
extending from the pith to a distance of about two- 
