40 



Experiments on the Adhesion of Iron Spikes, 



A comparison of the results given in the following table, will show 

 what order those forms would possess among themselves, in point of 

 retentiveness, as well as the advantages of the respective species of 

 timber into which they were severally driven. 



TABLE III. 



Spikes of various forms — timber of different kinds. 



REMARKS. 



Experiment No. 10. — The measures in this and the two following cases were 

 taken outside the flanches. 



Experiment No. 12. — The weight of the part inserted is given by estimation in 

 this experiment. 



Experiment No. 16. — In this and the two following experiments, the spikes 

 were driven into the timber in the direction of the length of the fibres. 



The above table furnishes three sets of comparisons for deducing 

 the relative retaining powers of green chestnut, thoroughly seasoned 



