482 



EXPEDITION TO JAPAN. 



board the steamers, the engineers reported that it was of a qualitj^ so inferior that they were 

 unable to keep up steam witli it. They have, however, very good coal, and the experiments 

 practically made on specimens brought home by the squadron give the following results. A 

 careful chemical analysis made at the navy yard laboratory, Brooklyn, will be found in the 

 Appendix. 



" Navy Yard, New York, January 8, 1856. 



"Sir: In compliance with your order of November 5, to subject to suitable tests samples of 

 Japan and Formosa coals, with a view to ascertain their respective qualities as fuel, we 

 respectfully report, as follows, viz : 



" As both the Japan and Formosa coals are of bituminous character, we have used, as a 

 standard of comparison, the best quality of Cumberland coal, and conducted the test upon a 

 scale sufHciently large, that incidental causes, of a minor character, always attending experi- 

 ments, would not be likely to materially affect the correctness of the results obtained. 



" The test was made in a boiler of the drop-flue form, having thirty-nine square feet of grate 

 surface. The engine worked from this boiler has a cylinder of thirty-six inches diameter, with 

 foxir feet length of stroke, and operates the machinery in the machine shop of this yard ; the 

 work is so nearly equal, at each moment of time, that the resistance may be considered constant. 



"The experiments were conducted for consecutive days with the different kinds of coal, and 

 the quantity consumed at the expiration of each day's work accurately noted, which was 

 required to maintain as nearly an equal pressure of steam as possible. 



"The following table embraces the results obtained of the comparative evaporative effect of 

 the two coals, and also the comparative stowage : 



CUMBERLAND COAL. 



