488 



Queries and Answers, 



TJie Dadiey*s Spring. — Sir, The corn spring in this parish, which I 

 gave a short notice of, p. 297. of your Magazine, I visited on the 21st of 

 August, and found that it had entirely ceased to flow. The exact period of 

 its cessation I am unable to state ; but I know that it was flowing about the 

 middle of June or later, though with a somewhat diminished stream. From 

 the appearance which the channel presented on the 21st of August, I should 

 suppose the spring must have ceased to flow for at least a fortnight or more. 

 Is it not fair to infer that its operations may have been stopped by the long 

 continued drought in the early part of the summer ? The late heavy rains 

 have probably not yet had time to produce a counter effect. Allow me to 

 remark, that your printer has committed a slight mistake in the orthography 

 of the name of the above-mentioned spring : it should be Dudley's spring, 

 not Dudley's^ as printed at p. 297. Yours, &c. — W. T. Bree, Alledey 

 Rectory., August 26. 1829. 



The Corn Spring (p. 297. 408). — May not this be accounted for on 

 the principle of the intermitting springs explained in the Library of Useful 

 Knowledge.^ under Hydrostatics ? — John Meaims, Shobden Courty near Leo- 

 minster., Sept. 27. 1829. 



Muphatamefs Optical Phenomenon (p. 108.) is perfectly easy of solution, 

 without having recourse to any supposition about the effect of refraction. 

 No shadows can be visible unless produced by bodies obstructing the rays or 

 stream of light, whether from the body or from the reflected image of the 

 sun. The first and darkest shadow was that of the passenger on the wall, 

 produced in the ordinary way {fig. 119. a). The second was the shadow of 



119 



the same passenger {b\ produced by the obstruction of the stream of re- 

 flected light from the sun's image presented on the watery surface of the 

 street, as shown in the diagram annexed. As proof of this, let any one 

 stand between a wall and a piece of water (or looking-glass laid on the ground 

 in the Hue of the sun), so as the spectator can see both the sun and the 

 sun's image at the same time ; he will have a double shadow on the walls 

 quite visible to himself or others. This effect is often seen, or may be seen, 

 in well-lighted rooms where there are plate looking-glasses or mirrors. 

 — J, M, 



