270 SEC. 8. HEAT. 



feeble. All these boxes are contained in a cylindrical vessel made of brass, 

 into which a determined volume of water, at a known temperature, is poured. 

 In this first envelope is a thermometer and an agitator. To preserve the 

 calorimeter from irregular currents of air it is enclosed in a second vessel, 

 the bottom of which is provided with three small cones made of wood or 

 cork, on which is placed the calorimeter. This vessel has a hole in the side 

 to allow the tube of the calorimeter to pass through, and a cover in which are 

 two holes, one of which affords a passage for the discharge tube, and the 

 other for the stem of the agitator. It has, moreover, a third opening through 

 which the thermometer is introduced. Finally the calorimeter and its enve- 

 lopes are supported and fixed at their proper height by means of an adjustable 

 foot. 



The details of the experiments made, and the latest information published 

 by M. Eegnault, will be found in the " Meinoires de 1' Academic des Sciences," 

 vol. 26, p. 41. 



1058bb. Regnault's Apparatus for determining the 

 Specific Heat of Solids. L. Golaz, Paris. 



This apparatus, made by the exhibitor for M. llegnault on a new pattern, 

 enables experiments to be made with great ease and rapidity. It is com- 

 posed of three distinct parts : 1. The stove for heating the body which is 

 to be investigated. 2. The apparatus for the production of steam. 3. The 

 calorimeter. 



1. This consists of three concentric tubes closed at their upper ends by a 

 copper plate attached by bolts to the circumference of the outside tube, at the 

 centre there is an opening of the size of the central tube and closed by a 

 metallic plug with double sides, in the centre of which there is another 

 opening in which a thermometer is fixed. At the lower end of the tubes 

 there is bolted a metallic plate similar to the one above, and terminating 

 in a cone ; the central tube also has an outlet at the base of this piece, the 

 second enclosure descends near the sides of the cone, the third enclosure 

 is attached to this piece. The vapour issuing from an apparatus to be 

 described further on reaches the lower part or base of the cone, between the 

 first and second enclosure, circulates all round and warms the centre, leaves 

 this chamber by holes made at the top of this tube and passes once more into 

 the third enclosure, whence it goes into the neighbouring condenser. 



2. The apparatus for producing the steam is a copper boiler furnished 

 with three .tubes, the first of which, placed in the centre, receives an 

 apparatus of copper in which the steam on its way back is condensed 5 above 

 the condenser is a funnel fed by a current of water which accelerates con- 

 densation ; a return tube reaches to the bottom of the boiler and serves as a 

 passage for the condensed vapour. The second tube, which is the largest, is 

 used as a conductor for the vapour to the stove. The third one, which is 

 small in diameter, brings the vapour which can be condensed in the stove 

 directly into the boiler. The condenser is bound to the enclosures by tubes 

 provided with junctions. 



3. The calorimeter is composed of two concentric vessels supported on a 

 wooden stand with square columns, and on one of them is placed a copper 

 block, which serves to fix the thermometer. Under this support there is 

 screwed a copper carrier, which slides on a guide of the same metal fixed to 

 the table of the apparatus. A sliding wooden screen intercepts the radiation 

 of the rest of the apparatus from the calorimeter. A chair suitably placed 

 supports the stoves, and a support connected with the table serves to fix at a 

 convenient height the apparatus for producing the vapour. 



