Page:Oregon Historical Quarterly volume 25.djvu/227

 portion as it now exists and leave room for the engineer and a supply of wood. In the writer's opinion, the "Oregon Pony" was the counterpart on a slightly smaller scale, of the pair of locomotives already mentioned as built a few months later.


 * Diameter of cylinders—6"×l2" stroke.
 * Diameter of drivers over tires—34"
 * Driving wheel base—7'
 * Total wheel base—7'
 * Total length of engine and tender over couplers—14'–3½"
 * Total weight of engine and tender—9700 pounds
 * Tractor power at 10 miles per hour—810 pounds
 * Boiler—36" in diameter
 * Length of fire box—33"
 * Width of fire box—18"
 * Height of fire box—43¼"
 * Length of boiler over all—67"
 * 67×114×25" flues

Turning for contrast with the present day to a recent Union Pacific locomotive, No. 5512, of 2-10-2 type the following is found:


 * Diameter of cylinders 29%"x30" stroke
 * Diameter of drivers over tires—63"
 * Driving wheel base—22' 6"
 * Total wheel base, engine and tender—79' 4¼"
 * Total length of engine and tender—88' 4¾"
 * Total weight of engine and tender in working order—592,500 pounds.
 * Tractive force—70,450 pounds
 * Boiler—88" in diameter
 * Length of fire box—126"
 * Width of fire box—96"
 * 305 2¼" and 5½"x22' 0" flues

It may be questioned if, should an engine of this size have been placed upon the Oregon Portage Railroad in 1862 the track would have borne the strain for a single revolution of the wheels yet such locomotives are becoming common on the leading railroads of America.

That the owners of the Oregon Portage Railroad were