This is one of the nicest things Hazlitt says about Coleridge in The Spirit of the Age:
"Hardly a speculation has been left on record from the earliest time, but it is loosely folded up in Mr Coleridge’s memory ... Mr Coleridge ... has only to draw the sliders of his imagination, and a thousand subjects expand before him, startling him with their brilliancy, or losing themselves in endless obscurity."
Although it's not all that nice, because it ends up with STC either startled or plunged in obscurity. However, my empirically-minded question is this: what are we supposed to imagine when Hazlitt talks about drawing the 'sliders'? Is it something to do with stargazing? The OED very nearly answers this question, but not quite. This is what you get in the 'slider' entry under 4b:
1681 GREW Musæum IV. ii. 366 A Slider, with a thin Plate-Spring, which plays against the said Teeth. 1692 Capt. Smith's Seaman's Gram. II. xxiv. 130 A small Line must be drawn quite thro' the Slider. 1733 TULL Horse-Hoeing Husb. xxii. 339 (Dubl.), To fix in this Wreath from coming off, we make use of the Slider. 1763 Museum Rust. I. 78 The aperture in the floor of the third cell is shut by means of the slider. 1790 Phil. Trans. LXXXI. 27 The front of this vessel is a plate of glass, and the back a tin~plate slider. 1834-6 Encycl. Metrop. (1845) VIII. 751/1 In a groove under the dovetail is a slider L, moved by a wire K. 1839 URE Dict. Arts 983 Betwixt these guides, friction-roller sliders are placed,..to which sliders the corves are suspended. 1884 Law Times LXXVIII. 8/1 An upright rod, up and down which worked a slider which contained the cartridge.
fig. 1825 HAZLITT Spirit of Age 64 He has only to draw the sliders of his imagination, and a thousand subjects expand before him.