The principles of colliery ventilation / [Alan Bagot].

  • Alan Charles Bagot
Date:
1882
Catalogue details

Licence: Public Domain Mark

Credit: The principles of colliery ventilation / [Alan Bagot]. Source: Wellcome Collection.

    24/226 (page 8)
    upcast shaft will vary, being affected by the tempera- ture. The weight W is thus calculated : — w_ 1-32529 x 30 459 + t w_ 39-7587 ~ 459 + t When t the temperature is 62° Fahrenheit the result is the weight of one cubic foot of air in decimals of 1 lb. avoirdupois. Then the head in feet must be multiplied by the weight of one cubic foot W, as obtained above. W x H = pressure in lbs. per square foot of air of motive column. The weight of one cubic foot of air at 75° Fahr. =' •0744544 lb. per square foot. Referring to the formula under head of water- gauge, we find that W the water-gauge reading is thus calculated:— 1-32529x 30 ,, X M w- 459 + t 5-196 M the motive column of air in feet is equal to the velocity in feet per second, squared and divided by 64-4. A millimetre being 0-039370 of an inch, this may easily be converted to the French reading. The calorific capacity of air was determined by M. Regnault, and is represented by 0-237. So that