83 



Artificial support of Limbs,— Tlie bracing together of large 



Imibs IS done in two ways. The commonest method is hy placing 

 a collar of iron round each limb and joining them by a stout chain 

 or iron rod fitted with a screw arrangement for tightening up. 

 This planis quite efficacious, but the collars need watching. As 

 the hmb increases in girth the collar becomes too small, and, if 

 -left too long, becomes imbedded in it {sec Plate I, fig. ii). It is 

 best to make a collar with a hinge, so that it can be adjusted to the 

 increasing girth of the limb ; also to move it up or down every five 

 years or so. Another plan equally effective for all but res'inous 

 conifers, and practically permanent, has been employed at Kew 

 during the past fifteen years. In this the collar is dispensed with. 

 A hole is bored right through each limb with an auger large 

 enough to admit an iron rod | to 1^ ins. thick, " threaded "at 

 each end, which must be long enongh to reach from limb to limb 

 and protrude a little be^'ond the outside of eacli. It is necessary, 

 of course, that the holes should be on the same alignment. Any 

 slight error in this respect can, howc\er, be overcome by bending 

 the rod. A stout iron plate curved to fit the circumference of the 

 branch is now placed at each end of the iron rod and made to set 

 close to each limb by means of a screw-nut and the whole tlius 

 braced togetlier. The weiglit of each limb is thereby supported 

 by the iron plate instead of a collar [see Plate I, fig. i). If, in 

 course of time, the wood should close over the plate no harm 

 would be done, rather the reverse. Tlie iron rod should fit the 

 auger-hole as closely as possible, and it should be heavily smeared 

 with coal tar before it is thrust through the limb — the object being 

 to make the opening air- and water-tight. This plan has been 

 adopted for a- good number of insecure limbs of trees in Kew, 

 such as beeches, Soplioras, oaks and Crataegus; in no case hare 

 any evil effects been noticed. It has not been employed for 

 ^ resinous trees for fear of persist eut bleeding. Some people regard 

 the boring of the auger-lude right through the heart of the limb 

 as a barbarous proceeding. But anyone acquainted with the 

 elementary characteristics of tree-growth knows that it is not so. 

 The vital processes connected witli growth and the deposit of new 

 yood are located just beneath the bark. A tightly clasping collar 

 is much more lilvely to interfere with them than a cleanly bored 

 hole. Practically the only disadvantage the latter involves is 

 a slight reduction of the resisting power of the limb to external 

 strain at that particular part. 



Watering and Feeding the Roots.— Long spells of excessive 



drought undoubtedly hasten the end of many trees that have 

 reached their period of decline. This was very evident to dwellers 

 ill the lower Thames Valley by the great number of dead trees 

 that could bo seen in hedgerows and elsewhere during the suc- 

 cession of dry summers about twenty years ago. When an 

 artificial supply of water is available, rare''or valuable trees can be 

 greatly hol])e(l by employing one or other of the various 

 " sprinklers " which distribute the water in the form of rain. To 

 effect any real benefit the soil should be thoroughly moistened all 

 through, and, for a big tree, the water should run for at least 

 twenty-four hours, or, still better, two or three days. It is reniark- 

 able, nevertheless, how much less effective artificial watering is 



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