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XXI. Description of a Gauge for measuring Standing 

 Timber. By Mr. James Broad, of Downing Street*. 



J- HE instrument I send herewith, is for finding the girth 

 . of standing limber, and will, T flatter myself, be found ex- 

 ceedingly useful to all gentlemen and others having timber 

 to dispose of, and likewise to such purchasers as wish to 

 pay for the true quantity, at present a gentleman having 

 timber to dispose of, is liable to be imposed on to a very 

 large amount ; for though some surveyors may be found 

 whose eye is pretty accurate, yet that is far from being ge- 

 nerally the case. When an estate is sold on which the 

 timber is to be valued, I believe there is no other way in 

 general use of finding the girth of a tree (which being squared 

 and multiplied by its length, gives the contents), than by 

 actually getting up to the middle, where the girth is usually 

 taken, with a ladder or otherwise: a method which is very 

 troublesome and expensive where the quantity is laro-e. The 

 seller has, therefore, no way, but at an enormous expense, 

 of finding the real contents of what he has to offer j and as 

 the buyer, if a dealer, from his knowledge, is able to form a 

 more accurate judgment, it often happens that the seller sus- 

 tains much loss. I haue known it exceed 50 per cent. Having 

 some time ago a large quantity to survey, I thought it pos- 

 sible to invent an instrument which would obviate this in- 

 con*'enience, and which might be sold at a low price, be 

 correct in its work, quick in execution, and such as any 

 capacity might use. I likewise thought it might be so con- 

 trived as to make such an allowance for bark .as should be 

 agreed on. The instrument I send you possesses all these 

 *lualifications, and is susceptible of several improvements, 

 of which I was not aware when I made it, which I will point 

 out at the end of my letter. 



It is well known thai the diameter and circumference of 

 circles, are in a certain proportion to each other, and that 



• From Transactions of the Society for the Encouragement of Arts, Ma- 



nufactirci, and Commerce, lor lh07. 'I'lie silver medal of the Society was 



awarded to Mr. Broad for this communication. 



H 3 double 



