Heating and ventilating buildings : a manual for heating engineers and architects . r manner is used, as thespirits in contracting draw theindex with the alcohol becauseof the capillary adhesion be-tween the alcohol and theglass; but when the alcoholexpands it passes by the index,without displacing it, so thatits position shows the lowesttemperature to which the in-strument has been subjected. 11. Use of Thermom-eters.—In the use of ther-mometers for determining thetemperature of the air, theyshould be exposed to unob-structed circulation in a dryplace and in the shade. Anydrops of moisture on
Heating and ventilating buildings : a manual for heating engineers and architects . r manner is used, as thespirits in contracting draw theindex with the alcohol becauseof the capillary adhesion be-tween the alcohol and theglass; but when the alcoholexpands it passes by the index,without displacing it, so thatits position shows the lowesttemperature to which the in-strument has been subjected. 11. Use of Thermom-eters.—In the use of ther-mometers for determining thetemperature of the air, theyshould be exposed to unob-structed circulation in a dryplace and in the shade. Anydrops of moisture on the bulbof the thermometer tend to evaporate and lower the tem-perature. For determining the temperature of steam or waterunder pressure thermometers are set into a brass frame so thatthey will screw directly into the liquid (Fig. 5) without per-mitting leakage. In other cases the thermometer can be in-serted into a cup made as shown in Fig. 6. Cylinder-oil ormercury is put into the cup, and the reading of the thermom-eter will then indicate the temperature of the surrounding. Fig. 5.—Steam-thermometer. Fig. 6.—Ther-mometer-cup. 14 HEATING AND VENTILATING BUILDINGS. fluid. When the thermometer is inserted into a cup sometime will be required to obtain the correct temperature of steam-pipes or hot-water pipes cannotbe obtained accurately by any system of applying thethermometers externally to the pipes, and in case ther-mometers are used they should be set deep into the currentof flowing steam or water, not placed in a pocket where aircan gather. 12. Specific Heat.—The capacity which bodies have ofabsorbing heat when changing temperature varies greatly;for instance, the same amount of heat which would raise onepound of water one degree in temperature would raise about8 pounds of iron I degree in temperature or would raise Ipound 8 degrees in temperature. The term used to expressthis property of bodies is specific heat, which is defined asfollows: Specifi
Size: 885px × 2823px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublishernewyo, bookyear1910
