IN THE SYSTEMATIC STUDY OF THE HIGHER PLANTS. 355 



on the nature of the past flora of a region may be gained in this 

 way, from the examination of long-buried fragments of wood. 

 The antiquarian or ethnologist frequently wishes to know the 

 nature of the wood of which some article of interest to himself 

 is made. And the bore will invite you to diagnose the botanical 

 nature of his walking-stick. If time is precious the last-named 

 may generally be choked-off by suggesting the necessity of 

 cutting a cross-section. 



A case which frequently recurs is the discrimination between 

 oak and chestnut in connection with the timber-work of old 

 buildings. The trees themselves are so distinct in habit, and in 

 character of leaf, flower and fruit, that it maybe a little surprising 

 that there should be a difficulty in distinguishing the two timbers. 

 The component parts of the wood are, however, similar in the two 

 species ; and though what we call a typical piece of oak is distin- 

 guished without difficulty from a typical piece of chestnut, there 

 are certain varieties of oak which so closely approach chestnut 

 as to give rise to considerable difference of opinion among experts 

 as to the nature of the wood. 



You may remember a controversy a few years ago, when the 

 roof of Westminster Hall was undergoing repair, as to whether the 

 original structure was oak or chestnut. There was difference of 

 opinion among experts, but the view which was ultimately 

 accepted, I think rightly, was that the structure is oak. I have 

 recently been asked to give an opinion as to the nature of the 

 wood used for the roof of the hall at Winchester School. Tradi- 

 tion calls it chestnut, but microscopic examination leads to the 

 conclusion that it is oak. The nature of the thin layers of wood 

 used in the construction of the propellers of the Zeppelins which 

 were brought down near London supplied problems which were 

 of interest to us at the Museum, and were also, I believe, of some 

 importance to those in authority. 



The microscopic study of timber-structure is of considerable 

 importance commercially. Timber is put on the market under 

 some name known in the trade, and the assumption is that the 

 sample will have the properties of tensility, rigidity, durability, 

 etc., which are associated with that name. These properties, or 

 their proper combination, may be of vital importance in connec- 

 tion with the use to which the timber is to be put. For instance 

 in the manufacture of an aeroplane an insufficiency in one respect 



