Inferior, third-rate. The phrase probably originated from the size of common window-glass. In R. Cumberlands The West Indian, i. 2, the same combination of figures has an opposite meaning. The house-keeper says, See what a bill of fare Ive been forced to draw out; seven and nine, Ill assure you, and only a family dinner, as he calls it. (1771.) This is unexplained.
1794. 7 by 9 and 6 by 8 Window Glass advertised by Daniel Waldo at the Brick Store in Worcester.Mass. Spy, May 22.
1800. Nine windows, with 20 pains of glass, each of the size of 7 by 9, were beaten in.The Aurora, Phila., July 18.
1840. What was the state of the [White House] receiving-room? There was not a mirror, even a common seven-by-nine mirror, in it.Mr. Lincoln of Mass., House of Repr., April 16: Cong. Globe, p. 334.
1843. He intended to buy four panes of glass, 8 by 10s.See B. R. Hall (Robert Carlton), The New Purchase, i. 254.
1846. [The charge was] re-echoed by every little paltry seven by nine Locofoco print, and every brawling bar-room politician.Mr. Root of Ohio, House of Repr., Dec. 24: Cong. Globe, p. 86.
1854. I was led to believe that he was some great 7 by 9 politician or lawyer.Weekly Oregonian, July 22.
1855. A series of diminutive windows, consisting of four panes of seven-by-nine.S. A. Hammett (Philip Paxton), Captain Priest, p. 47.
1862. [This attempt to abolish the franking privilege] is a seven by nine measure of reform. It is a measure of reform that is not demanded.Mr. Hendrick B. Wright of Pa., House of Repr., Jan. 9: Cong. Globe, p. 260/1.
*** See a note by Mr. Forrest Morgan in Notes and Queries, 10 S. xii. 38.