Oct 20, 1850
F. R. DELANO

MESSRS. EDITORS--.As I have been for several years a constant reader of your valuable journal, I have of course received from a perusal of its columns much valuable information, and, I must also say, that I have formed strong prejudices in favor of or against machines of various kinds, prominent among those for and against which I had formed a very poor opinion, was the Rotary Engine, and from a careful examination of the various kinds which you laid before your readers, I had become a perfect skeptic, in all things relating to a rotary steam engine, which would ever be of real value, (by real value I mean an engine which with the same chance and with the same cost would earn as much or more money) and had placed rotary engines in the same class with perpetual motions and what I looked upon as grand humbugs.

Since December, 1849, I have had good reason to change my views and opinions in regard to the invention of rotary engines entirely. At that time, my attention was called in the course of my mechanical duty, to an engine, the invention of Mr. James A. Stewart, of Tennessee. So little faith had I in the good qualities of this engine, as set forth to me by persons who had seen the engines in operation, that to fully satisfy myself in regard to the matter, I made a. trip from this city to Nashville, expressly to see and examine into the merits of said engine. In order to give it a thorough investigation I went to Tyrees Spring, Robertson County, Tennessee, where I found the first engine which was put into practical use, and which had then been in operation three years.

The engine consists simply in having two cog wheels running into each other and brought into contact with the caps and end plates as to render them, without any packing whatever, steam and air tight. The machine is made entirely of cast iron, no other metal of any kind or description being used except for the pillow blocks, which are lined with Babbitt metal in the usual manner. The Tyrees Spring engine has steam wheels 10 inches diameter, from pitch circle, and 10 inches face, and has 10 cogs to each wheel, and the position which they occupy to the caps is such that they have 20 square inches effective surface. The boiler is a cylinder 20 feet long 32 in. dia., carries steam at a pressure of 65lbs. per inch, and with what fuel the mill makes, (dust and slabs) cuts an average of 3,000 feet of oak lumber per day of 12 hours. This much for the Tyrees Springs mill, and I may say the same of the other mills which I visited while in Tennessee.

I will now give you my own experience with the Stewart Engine, one of which I put into the Carondelet mill to drive a single sash saw: the engine is the same size as the Tyree, the boiler is 22 feet long, 36 inches diameter, two 11 inch flues, pressure of steam 60 lbs. per inch, and with the saw dust and a half cord of green slabs, we saw 5,000 feet of inch square edge lumber per day of 12 hours. This engine has been in operation for three months, and had it not been necessary to have cleaned out our boiler or to have given due regard to the Sabbath, we might have run our engine every minute of the time. Not the least wear can be discovered except upon the Babbitt metal, and the arrangement for moving and adjusting the pillow blocks is such, that it is done while the engine is in operation. Since the Carondelet engine went into operation I should say that at least 5,000 persons have witnessed its performance. and I have heard but one person find fault with it, and at least one half of the visitors were practical millers, machinists, and engineers.

The great secret of this engine was to invent a pair of cog wheels which would work together steam tight. Mr. Stewart commenced his experiments at Hoe & Co.'s shops in New York, but did not succeed in getting the proper form of cog wheels. Mr. Hoe was so well pleased with the principle of the machine that he gave Mr. Stewart a certificate to the effect that if he succeeded in getting his wheels to work steam tight it would prove the most valuable engine in use.

After five years of hard work, hard thinking, and hard dollars, spent in making and throwing away wheels, the last finishing touch was given it, and everything went like a top, and now the thing is so simple it is the wonder of all who see it, that some Yankee didn't think of it years ago.

Columbus made the egg stand upon its end. Stewart makes a pair of cog wheels which will run steam tight without any packing or valves, and as a machinist and engineer, I challenge the whole mechanical and inventive talent of the world to bring forth an engine which will do the same amount of labor and earn the same amount of almighty dollars with, and at the same cost, every thing taken into consideration.

I have not, Messrs. Editors, the least idea of making you or any other person a convert to rotary engines merely upon my say-so, but if you could visit our mills and see with your own eyes the rotary in operation, with its single boiler, and then take a look at a piston engine along side, with its cylinder of four feet stroke and 13 inches diameter, together with its heavy shafts, ponderous balance wheels, &c., two boilers to supply the steam, and doing less work, I rather think you would let us have your hat. Arrangements have been made for their manufacture at this place, and as soon as the proprietors get their engraving up explanatory of the machine, I will forward you a copy, from which you can get an idea of its merits. Our engine is held in its place by four wood screws three inches long, by 5/8 diameter, the largest shaft about it is three inches diameter, and of cast iron, and although we have driven our saw into oak logs with sufficient force to twist off a heavy saw pitman crank, yet the engine has not moved from its position one iota, although it is screwed into pine timber.

I shall do all that I can to have an engine sent to your place so as to give you unbelieving Gothamites a chance to become converted before you are called away to kingdom come.

Until you hear from me again I remain your’s,

F. R. DELANO,

Sup’t Carondelet Mills.
St. Louis, Mo., Oct., 1850.