DIACARPOMETER. 



DIACAEPOMETER, OR INSTRUMENT FOR MEASURING 

 THE DIAMETER OF FRUITS, ETC. 



This instrument resembles, to a certain- degree, that known in the mechanical arts 

 under the name of callipers, but it diflFers from it materially in other particulars, 

 which render it more adapt- 

 ed to the uses for which it 

 is designed. It is 0-18 in 

 height, and from 0-12 to 

 14 in breadth. It can 

 measure objects of the 

 smallest dimensions as well 

 as those of a diameter of 

 0*25, within one millimetre, 

 which is sufficiently exact 

 for all the practical purposes 

 of horticulture. It is com- 

 posed, like the ordinary 

 compasses, of two brass 

 legs, 0-10 in length, united 

 by a rule joint, and which 

 terminate in the curved 

 steel branches, the points of 

 woich meet accurately when 

 the instrument is closed. 

 A graduated quadrant is 

 fixed by a screw to the right 



brass leg, passing through a fenestrum in the left leg, which can thus slide over this 

 arc, until it is arrested at any point desired by means of a thumb-screw. The divi- 

 sions on the quadrant indicate correctly the separation of the legs of the instrument, 

 or rather the linear distance between their steel points. In order to measure a fruit, 

 the legs are to be separated until the opposite points rub on its greatest diameter, 

 the graduated scale then marks the extent of this separation, which is the diameter 

 of the fnait. In the same way its height can be measured. 



It will readily be seen that, in addition to measuring the diameter of fruits, the 

 diacarpometer may be applied to many other uses in horticultui^ : one of which, as 

 recommended by its ingenious inventor, M. Abel de la Faroe, member of the 

 agricultural committee of Saless, is the determination of annular incisions in trees. 



It will thus be perceived that the diacarpometer is not a fancy instrument, in- 

 tended only for amateurs and dilettanti, but is destined to a practical and daily use 

 in horticulture, to give more accuracy, grace, and elegance to the labours of the 

 gardener, and at the same time afford more exact results than have hitherto been 

 obtained in the exercise of this agreeable employment. — A. Remi/, in Revue Ilort 



