70 



OSMOTIC PRESSURE OF AQUEOUS SOLUTIONS. 



m= 



It will be seen (Figure 35) that the ar- 

 rangements in the lower part of the bath are 

 nearly identical with those of the bath de- 

 scribed under Type II. There is the same 

 system of brass pipes (3, 7, 8, etc.) for the 

 circulation of hydrant water, and the same 

 arrangement for pumping water out of the 

 bath (through 12 and 13) to be heated by a 

 gas stove and returned through the large 

 pipe (14) . There is also 

 in both baths the same 

 provision for the "heat- 

 ing surface/' except 

 that the copper cylin- 

 ders (9 and 10), in which 

 the lamps are located, are 

 somewhat differently placed 

 in the two cases. 



The copper-lined upper 

 part of the bath — the "air 

 space" — (Figure 36) is elec- 

 trically heated by means of 

 the lamps (3, 4, 5, and 6), 

 which are shaded for the pro- 

 tection of the various instru- 

 ments containing mercury. 

 There are two systems of 

 pipes in the air space. That 

 seen in the top (7) is for the 

 circulation of hydrant water. 

 It serves the same purpose 

 in the air space as the system 

 of pipes (3, 7, 8, etc.) in the 

 lower part of the bath. The 

 system of pipes situated at 

 the end of the bath (8) is for 



.•1 • i , • m , , (1), (2), and (3) Gas lamps (outside of bath) for heating 



tne Circulation 01 not Water. circulating water; (4) pump; (5) and (6) stopcocks which 

 It may also be USed for COld are use( ^ when hydrant water is to be circulated through 



water. The air in the upper e pipes- 



part of the bath is kept in circulation by means of the fan (9) . 



The heating and pumping arrangements for the hot water are situated 

 on the outside of the bath. Their relation to what is seen on the inside 

 is shown in Figure 37. The gas burners (1,2, and 3) heat the water on 

 its way to the pump (4), from which it is returned in the direction of the 

 arrows. When the system is used for the circulation of hydrant water, 

 the water enters through 5 and leaves through 6. In one of the baths 



Fig. 37. — Hot-water circulating system with end of 

 bath removed. 



