THE NATIONAL INSTITUTION. 167 



Philadelphia pea coal |, Sydney slack i, 11.48, 100 pounds burned per hour. 

 Lackawanna egg anthracite, 11.55, 109 pounds burned per hour. 

 Anthracite dust i, Sydney slack i, 12.52, 87i pounds burned per hour. 



5. In a tubular Boiler, thirty-six feet long, twelve tubes, each three inches in 



diameter. 

 Coarse Lackawanna anthracite, 11.96, 85.8 pounds burned per hour. 



6. In a Cornish Boiler of the usual construction, thirty-six feet long, six feet 



exterior, and three feet ten inches interior diameter. 



Coarse Sydney bituminous coal, 6.32, 233J pounds burned per hour. 

 Coarse Lackawanna anthracite, 7.75, 155.4 pounds burned per hour. 



7. In an improved Cornish Boiler, with three interior boilers inserted in the 



interior Flue. 



Coarse anthracite, kind uncertain, 10.90, 171.6 pounds burned per hour. 



Pea anthracite 3 parts, bituminous slack 1 part, 12.08, 136. G pounds burned per 



hour. 

 Lackawanna anthracite, ordinary size, 12.98, 145 pounds burned per hour. 

 Beaver meadow anthracite, ordinary size, 13.41, 122 pounds burned per hour. 



The following results have been obtained in this country, in a Locomotive boiler 

 of the common form : ■ 



Schuylkill anthracite, 9.51, 57.3 pounds burned per hour. 



Wood, 4.71, 112.6 pounds burned per hour. 



Mr. Thomas Wicksteed has published a set of results obtained in Cornish boilers, 

 using various sorts of fuel, which I have reduced to the standard of 212°, to render 

 them comparable with the preceding and following sets. Unfortunately they have 

 not come to hand with the rates of combustion annexed ; but they may be arranged 

 in the following order : 



Blythe Maine Northumberland bituminous coal, 7.44. 



Derbyshire bituminous coal, 7.64. 



Large New-Castle coal, average 8.64. 



Derbyshire i, small New-Castle J, 8.69. 



Welsh i, New-Castle i, 8.86. 



Gas coke i, small New-Castle J, 8.91. 



Gas coke alone, 8.92. 



Average Welsh, 8.98. 



Average small New-Castle, 9.01. 



Best small New-Castle, 9.38. 



Anthracite, 10.17. 



Best Welsh coal, 10.71. 



In tho work on Anthracite Iron, above mentioned, will be found at page 149, the 

 following table of tho evaporative powers of different kinds of fuel, as given by ex. 

 periencc in different forms of boilers. 



1. In a Locomotive Boiler. 



Bituminous coal, by N. Wood's experiments, 5.12. 



Coko, by Pambour's trial, 7.12. 



