This firm was established in 1844 to manufacture Isaac Straub's buhrstone grist mill. It was variously known as Straub Mill Co. and Isaac Straub & Co. There is no doubt that the grist mill was the mainstay of their business, but in the 1850s they also made a portable sawmill.

Ad from 1853 "Williams' Cincinnati Directory"

In 1863 the company became Simpson & Gault after Robert Simpson and a Mr. Gault, with Isaac Straub staying on as designer. In 1870 Mr. Gault left the firm and Simpson's son, Orville, assumed control. Orville changed the company name to Straub Machinery Co.. In 1910 the name changed to the Orville Simpson Co., and in 1974 it changed to ROTEX, Inc., after the company's very successful line of sifters.

Information Sources

• Fifth Annual Report of the Ohio State Board of Agriculture", 1850. List of premiums awarded at the Ohio State Fair, Cincinnati, October 1850: "best portable saw-mill, Isaac Straub & Co., Cincinnati: Diploma & $10." Silver Medal awarded by the State Board.
• The 1853 Williams' Cincinnati Directory lists

  STRAUB ISAAC & CO. (I. S. & Robert Hazlett), portable saw and corn mill manfs. 19 w. Front.

• p. 26 of Montague's Illinois and Missouri state directory for 1854-5:

  Straub, B. Hazlet. / Isaac Straub & Co., / MILL FACTORY, / Corner of Front and John Streets, / Cincinnati, Ohio. / Warehouse No. 19 Front Street, between Main and Walnut.

  The illustration is of a single geared 'Queen of the South' Corn Mill and Crusher. We manufacture a cob breaker of great strength and ease of operation. We place this useful contrivance on all sizes of Mills, by which means we convert a Corn Mill into a Stock-Feed mill; but a few minutes work to put it on, or to take it off. We manufacture portable mills, single and double-geared—best quality of French burrs—to grind corn, wheat, and stock feeds, calculated for steam, water or horse power. These mills have been run by steam and horse power, in competition against other make of mills of our city, at our State Fairs, and have never failed to carry off the first premium—on one occasion was awarded a beautiful silver medal. Our mills also took two first premiums as the best mills, at two Annual Fairs of our Mechanics' Institute. Also, Portable Saw Mills, to be run by steam, water or horse power. This mill was exhibited in operation by horse power, at the Ohio State Fair in 1850, when it was awarded a premium and a splendid silver medal. Also, different kinds of portable horse power and steam engines. All our articles, for ease of operation, simplicity, usefulness and durability, are surpassed by none now in use. All our articles are warranted as represented, or no sale, at our cost of transportation, and the money refunded. For a full description and testimonials of merit and usefulness, we refer those interested to our pamphlet, to be had at our factory, where we take pleasure to explain each article. ISAAC STRAUB & Co.

  Note.—Mr. Kimball, the partner of J. H. Burrows, while exhibiting a Burrows' Mill at our State Fair last fall, was boisterous about his mill, and courageously entered into a verbal agreement with me to grind corn thus. Whoever grinds the most, regarding quality and quantity, was to be the owner of both mills at each and every trial. First trial—Straub to run an 18 inch mill. Burrows & Co. to run a 20 inch mill. Second trial—Straub to run 22 inch mill. Burrows & Co. to run a 24 inch mill. Third trial—Straub to run a 26 inch mill. Burrows & Co. to run a 30 inch mill. When the pinch came, that boisterous courage stepped out. To the above a append a challenge to grind cob feed out of whole ears of corn. I will run my 18 inch 'Queen of the South,' with a cob-breaker attachment, the same article that took the premium at the Ohio State Fair, last fall, against a 24 inch Burrows' Mill and Wm. Stewart's Ohio and Kentucky Stock Feed Mills, both to be run at once, and if you are apprehensive of a risky business, you have my entire approbation to run Mr. Pomeroy's Corn Crusher as an auxiliary, should my single article fail to grind equal in quality and quantity to the combined productions of the two or three mills—just as you please—that you can draw a few hundred dollars as stakes to put up. Come boys don't be cowardly, there is nothing like walking into the merits of the things. To J. H. Burrows & Co., Sept. 29, 1852. ISAAC STRAUB.

• A genealogy page for Isaac Straub says that he was born 1794-12-09 in Milton, PA, and died 1875-12-17 in Kentucky. His occupation is listed as "grist mill, lumber mill, inventor, engineer (bridge-builder), merchant, manufacturer, machinist".
• A history page on the website of Rotex Co. indicates that that firm is directly descended from Straub Mill Co., also known as (or closely related to) Isaac Straub & Co.