V. MASS. 71 



355. Hydrostatic Balance, by Ramsden ; with Weights, 

 by Robinson, presented to the Royal Society by Lady Banks. 



Royal Society. 



368. Xylometer (cylindrical form), with brass cylinder. 



Zimmer Brothers, Stuttgart. 



369. Xylometer of Glass, prismatic form. 



Zimmer Brothers, Stuttgart. 



These instruments are chiefly used in the management of forests, and for 

 agricultural purposes. 



The xylometer with brass cylinder (No. 1368), as well as the prism-shaped 

 glass xylometer (No. 6369), are employed for exact scientific examinations, 

 especially for the cubature of irregularly-shaped pieces of wood, and for 

 determining the specific weight of wood. 



With apparatus, No. 1369, cuneiform pieces of wood which have been split 

 out from the heart in the direction of the pith rays, and therefore contain pro- 

 portionate parts of all veins of wood, can be quickly and exactly examined. 



With both apparatus it is possible to read on the scale accurately down to 

 5 cub. centimeter (5 grammes water). 



(See " Holzmessekunst," by Prof. Dr. Baur, Hohenheim.) 



371. Hydrostatic Indicator Balance for determining the 

 specific gravity of liquids, constructed, according to the directions 

 of the exhibitor by Bohm, and Wiedemann, at Munich. 



Prof. Dr. W. von Bezold, Munich. 



1 This balance enables to be read at ones the specific weight of the liquid con- 

 tained in the small cylinder. Care, however, must be taken that the floating 

 oody is always entirely immersed in the fluid, and that on the other hand the 

 pointer does not move beyond the division on the arc in the direction towards 

 the negative side. This is the case with liquids whose specific weight is 

 smaller than 1, and only then when the free arm of the scales has been 

 loaded with the heavier counter-weight, in which case the number on the arc 

 indicated by the pointer gives at once the specific weight. 



With liquids which are heavier than water the lighter counter-weight II. 

 must be used, and 1 to be added to the number read on the graduated arc. 



372. Densimeter of Major Bode's construction, for determin- 

 ing the specific gravity of all sorts of powder. 



A. and R. Hahn, Cassel. 



The densimeter is the only existing instrument with which the specific 

 weight of all sorts of gunpowder (prismatic powder, powder-cakes, fine and 

 coarse grained powder, &c.), can be easily determined, in quantities of 50 to 

 250 grammes, with the most perfect accuracy. 



It is constructed by Major Bode. 



This apparatus consists of a reservoir with bolt, two gutta-percha tubes, and 

 a clamp. 



1. The reservoir is formed by a steel capsule, -with air tight fitting lid. 



By means of the bolt the lid of the steel capsule will be screwed fast on 

 this. 



The contents of the reservoir are measured so in the clear that a prismatic 

 powder grain can be easily placed in it. 



Lid -and steel capsule are vaulted, in order to accelerate the evacuation of 

 the air by pumping. 



