8 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 
were held by means of wedges in the dies of the testing machine. 
All the six specimens prepared in this manner broke fairly well 
in tension, except the fourth, the specimen of hickory; the 
results obtained are shown in Table I. Of course, I do not for a 
TABLE I. Zension Tests of Timber. 
Fiat Bars (Cross Section }” x 13”). 
Tensile 
| 2 of | Kind of Wood. Stress at 
Specimen. Fracture. 
Tons persq. in. 
6796 | Ash, : 5 ; 4°08 
6797 | Beech, . ; : Zim 
| Gros | Biren, 
| 6799 Higees +i {ian sl a eeneeel 
| 6800 | Mahogany, . : 5:9 
| 6801 Oak, : ; é 4°97 
moment wish to assert that the actual tensile stresses obtained in 
these few tests are a fair measure of the tensile strength of these 
different kinds of wood; my object, in these particular experi- 
ments, was more to bring out the extreme difficulty of carrying 
out satisfactorily tensile tests. 
FIG. 4. 
Two other sets of specimens were prepared, which were 
turned in the lathe into a cylindrical form (see Fig. 4), the ends 
being left enlarged, so that they could be held securely in the 
testing machine, and pulled from the shoulders thus formed. 
