Portable Agricultural Steam Engines at Neiccastle. 121 
Table VI. — Compaeison between the Theoketical and Aotual 
EcoxoMT derived from an I^"CBEASE of Steasi Pressuhe. 
Cardiff. 
Newcastle-on-Tyne. 
Reading 
IroD works. 
Simple. 
Davey Pax- 
man k Co. 
Simple. 
Davey Pas- 
man & Co. 
Compound. 
Edward 
Foden. 
Compound. 
Catalogne Numbers (see page 720) 
1. Steam pressures above atmos-'l 
2. Temperature of steam . . .. F.° 
3. Corresponding absolute tempe-l 
4. Falls of temperature to 215' ot\ 
675° absolute F.^j 
5. Proportions which the falls bear to j 
the original absolute tempera- 1 
6. The reciprocals of the above ratios, , 
to which reciprocals the fuel! 
actually consumed should cor- > 
respond, reduced to the Read- 
7. Water actually consumed perl 
brake horse-power per hour (not > 
including jacket-water) lbs. ) 
8. Eelative proportion of water used 
2927 
3125 
3124 
3113 
80 
324 
784 
109 
•139 
1- 
30-22 
1- 
95 
334 
794 
119 
•150 
•9-27 
26-40 
-873 
150 
365 
825 
150 
•182 
•763 
21-33 
•706 
250 
406 
866 
191 
•220 
•632 
21-38 
1 
•707 
Table VII. — Ajjaltsis by Messrs. Pattinson and Stead, Middles- 
brough, of Powell-Dctffkyn's Coal used at the Newcastle 
TfiLiLS. 
Samples were collected at intervals during the trials, and the coal analysed 
was an average of these : — 
Carbon 88^40 .. available 
Hydrogen 3^65 - 0-32 = 3-33 H 
Oxygen 2 55 = 0-32 H = 2 87 H„0 (water) 
Nitrogen 0-64 
Sulphur 0-76 = 1-36% pyrites 
Ash 3-17 
Water 0 83 
100-00 
Sulphur in ash "... 0-04 
Calorific Value in British Thermal Units. 
Carbon.. .. -884 x 14,544 units = 12,856 units 
Hydrogen .. -0333 x 61,200 „ = 2,0.37 „ 
Pyrites estimated at 47 „ 
Total per one pound of coal 14,940 „ 
Weight of air required to bum one pound of coal, 11-38 lbs. 
