[19] 



U S. FISH COMMISSIOX STEAMER ALBATROSS. 21 



The principal dimensions of the engines are as follow : 



Number of cylinders to each engine 2 



Diameter of the higli-pressure cylinders inches.. 18 



Diameter of the high-pressure piston-rods do ;? 



Net area of the high-pressure cylinders do 250.93 



Clearance of the high-pressure piston do .5 



Length of the steam-port of the high-pressure cylinder do 13.5 



Breadth of the steam-port of the high-pressure cylinder do 1.75 



Area of the steam-port of the high-pressure cylinder do 23.625 



Length of the exhaust-port of the high-pressure cylinder do 13.5 



Breadth of the exhaust-port of the high-pressure cylinder do 3.5 



Area of the exhaust-port of the high-pressure cylinder do 47.25 



Number of ports in the cut-off valve 3 



Length of the i)orts in the cut-off valve inches.. 13.5 



Breadth of the ports in the cut-off valve do .875 



Aggregate area of the cut-off valve ports square inches . . 35.4375 



Diameter of the low-pressiire cylinders inches . . 34 



Diameter of the low-pressure piston-rod do 3.5 



Net area of each low-pressure cylinder do 903.11 



Stroke of all the pistons do 30 



Clearance of the low-pressure pistons do .5 



Length of the steam-ports of the low-pressure cylinders do 20 



Breadth of the two steam-ports of the low-pressure cylinders do 3 



Area of the double steam-port of the low-pressure cylinders do 60 



Ratio of the volume of displacement of low-jiressure piston to that of the 



high-pressure piston, per stroke 3.599 



Length of pistons, on line of axis, at the circumference inches.. 6 



Thickness of metal in all the cylinders do 1 



Length of packing-rings on the high-pressure pistons do 4.5 



Length of packing-rings on the low-pressure pistons do 3.75 



Diameter of each (single-acting) air-pump plunger do 16 



Stroke of air-pump plungers do 13.5 



Displacement of each air-pump plunger per stroke cubic inches.. 2,814.84 



Diameter of each feed-pump plunger ^ . . . inches. . 4.5 



Stroke of each feed-pump plunger do 13.5 



Displacement of each feed-pump plunger per stroke cubic inches .. 214.7 



Diameter of the steam cylinder o f the circulating-pump inches . . 14 



Diameter of the steam piston-rod of the circulating-pump do 2 



Net area of the steam piston of the circulating-pumj) cubic inches.. 152.3 



Diameter of the water piston of the circulating-pump inches. . 16 



Diameter of the water piston-rod of the circulating-pump do 2 



Net area of the water piston of the circulating-pump square inches. . 199.49 



Stroke of the pistons of the circulating- pump inches - . 14 



Ratio of the area of steam piston to that of the water piston 1:1.308 



Number of brass tubes in the condenser 2, 394 



Outside diameter of the condenser-tubes inch.. .625 



Exposed length of the condenser-tubes inches . . GG 



Condensing surface of the tubes square feet . . 2, 142 



Number of crank-shaft journals to each engine ■ 3 



Diameter of the forward journal inches.. 7 



Diameter of the middle journal do 8.5 



Diameter of the after journal do 8.5 



Length of the forward journal do 8.5 



Length of the middle journal do 16 



Length of the after journal do 13.5 



