Since Blaker's article on valve gears and his attack on the Advance Engine and the Marsh Valve Gear in particular -- appearing in the ALBUM over a year ago, I've received a number of critical letters from past and present owners of Advance Engines and all agree the article is at variance to facts.
There goes an old saying, 'The tree with the best apples has the most clubs hanging in it.' As most everyone knows, the Advance was never a controversial Engine. It was favorably known throughout the U.S.A., Canada, the Pampas of Argentine to the Steppes of Russia for exceptional power, economy and symmetrical design. To quote Mr. O. C. Fry, Flint, Michigan, and raised at Battle Creek, Meinard Leafever, - 'his was a master mind.' He designed three engines, the Upton, Port Huron and Advance with similarity of design.
For several years following 1900, the writer at different times operated Advance Engines in Kansas and Oklahoma, both simple and compound, and owned one for ten years. All who have seen them perform in the belt will agree they TALK for themselves. Blaker writes the sharp exhaust is the result of bushing in exhaust pipe, which is not true. Advance Thresher Company furnished NO bushings for either simple or compound engines and made no provision for same. On another occasion, he has been quoted as saying it is not possible to set their valve with equal ports for both motions. This also is false, as Advance Engineers will testify.
It's reasonable to suppose Leaf ever selected to equip the advance Engine with the Marsh Valve Gear as best suited to operate the ALLEN DOUBLE PORTED VALVE which gives the same opening to live steam as a single ported valve with half the movement. With this short travel and quick release, Advance operates with up to half less back pressure than other engines. I saw this test run at Kansas State College the winter of 1903-04. It's true you can't vary the 'cut-off with the Marsh reverse, which in my humble opinion is mostly theory and 'eye wash' on an engine controlled by governor.
For many years I owned a 9 x 10 Prick. I appreciated its many fine and exclusive patented engineering features, together with its rugged construction, Its reverse gear (Landis Shifting Eccentric) had a half dozen notches on its quadrant we rarely used.
All Advance Engines tested up to three times their rated horsepower at the factory, due to internal steam pipe through boiler and smoke box and partway up the stack directly into steam chest. Having advantage of 'super heated' steam, accounted in part for their economical performance and to pull heavier load without excessive working pressure. This was proven at Montpelier, Ohio, last year when a 20 hp Advance pulled 82 hp on the 'brake' with working pressure of 150 lbs. After all, it's performance that counts!
I also note Blaker's appraisal of the Baker valve gear as the most efficient of ALL valve gears. I have no reason to detract from the good qualities this valve motion possesses. However, quoting the late Al Smith, 'Let's look at the record'. I'll take you back to 1907 and the Baker fan tests at Wichita when several engines other than Huber outperformed the Baker Engine. I believe the Baker valve gear reached its height of perfection in Locomotive practice, rather than on a traction engine. The Marsh valve gear was used on the Advance for the entire lifetime of this popular engine. Again I repeat, 'It's performance that counts - not theory.'