July 3, 1896.] 



SGIENGE. 



15 



saves handsomely "when operated under 

 favorable conditions on a large scale. 



Prof. Carpenter described a new form of 

 steam ' calorimeter ' employed at Sibley 

 College, Cornell University, in the de- 

 termination of the ' quality ' of steam. It 

 consists simply of a small chamber, jacketed 

 with steam, a water-glass gauge and a 

 specially graduated pressure gauge. Dis- 

 charge takes place through a ' standard ori- 

 fice," and the gauge indicates the flow in 

 the unit of time. The separated moisture 

 is collected in the reservoir, and its weight 

 is compared with that of the indicated 

 volume of dry steam discharged, to give a 

 measure of the original quality of the 

 vapor. The instrument had been in use 

 about a year, in the form described, and 

 found very accurate and satisfactory after 

 prolonged comparison with the familiar 

 forms of apparatus employed for the same 

 purpose. 



Mr. Alberger presented an account of a 

 ' self-cooling condenser ' for use where con- 

 densing water for the steam engine is diffi- 

 cult to obtain or costly. These systems of 

 cooling the water of condensation for re- 

 peated use in a circulation comprehending 

 the condenser and a cooling tower or other 

 device for the removal of the heat taken up 

 from the steam, are coming rapidly into use 

 in many localities. That described consists 

 of a tower in which is installed a large 

 mass of tiling, over which the water circu- 

 lates and in the midst of which large 

 volumes of air are circulated by the action 

 of a fan blast. A steam-pump circulates 

 the water from condenser to the top of the 

 tower and back in a continually moving 

 stream flooding the tiling ; drawing water 

 from a well or tank at the foot of the tower, 

 and passing it through the condenser and 

 then through the masses of tile in the cool- 

 ing tower, the water finally falling into the 

 well after its temperature has again been 

 reduced to the minimum. The fan requires 



less than two per cent, of the power of the 

 main engine ; it may not exceed one per 

 cent. The heat is carried away mainly by 

 evaporation into the rising current of air 

 from the fan. The cost is stated at about 

 that of one pound of water per horse power 

 per hour as used in the engines, including 

 all expenses of steam-making. 



Mr. Kent discussed the definition of 

 steam-boiler 'efficiency,' as that term is now 

 applied in connection with the boiler-trials 

 made under the now usual forms of stand- 

 ard tests. The paper indicated the nature 

 and extent of the difficulties arising in the 

 endeavor to obtain the unit of measure- 

 ment, and in its application to the numeri- 

 cal rating of boiler efficiencies; showing 

 that the uncertainties introduced through 

 the inaccuracy of existing methods of meas- 

 uring the total heating power of a fuel, and 

 in thus obtaining a basis of comparison, 

 might be so great as to preclude any pos- 

 sible uniformity or accuracy of measure- 

 ment of the true efficiency of the boiler. 

 Two illustrative cases were presented in 

 the paper. The heating power of a coal 

 was reported by two difiierent systems of 

 calorimetric measurement, as respectively, 

 13, 302 and 14, 620 from different calori- 

 meters, and, in the other case, 13,799 and 

 16,212 B. T. U. per pound. The boiler thus 

 received credits for efficiency, ranging from 

 56.66 to 66.37 in the one case, and from 

 73.12 to 85.83 in the other, accordingly as 

 one or another calorimeter was employed 

 to do the work of measuring the ' actual ' 

 heating power of the fuel. 



Prof. Thurston presented a paper on ' Su- 

 perheated Steam ; Facts, Data and Princi- 

 ples Eelating to the Problem of its Use.' 

 The nature of superheated steam, its ther- 

 jnal and thermodynamic properties and 

 its value in the steam-engine were studied. 

 Its only use to-day is that of reducing in- 

 ternal wastes by 'cylinder condensation,' 

 through the process of supplying sufficient 



