Yes; to such a degree that inflammable matters may be ignited by it. If a cannon ball be made red hot, and then be placed in an iron stand between two bright reflectors, inflammable materials, placed in a proper position to catch the reflected rays, _will ignite from the heat_. There is a curious and an exceptional fact with reference to _reflected_ heat, for which we confess that we are unable to give "_The Reason Why_." It is found that snow, which lies near the trunks of trees or the base of upright stones, melts before that which is at a distance from them, though the sun may shine equally upon both. If a blackened card is placed upon ice or snow under the sun's rays, the frozen body underneath it will be thawed before that which surrounds it. But if we _reflect_ the sun's rays from a metal surface, the result is _directly contrary_--the exposed snow is the first to melt, leaving the card standing as upon a pyramid. Snow _melts_ under heat which is _reflected_ from the trees or stones while it withstands the effect of the _direct solar rays_. In passing through a cemetery this winter (1857), when the snow lay deep, we were struck with the circumstance that the snow in front of the head-stones facing the sun was completely dissolved, and, in nearly every instance, the space on which the snow had melted assumed a coffin-like shape. This forced itself so much upon our attention that we remained some time to endeavour to analyse the phenomena; and it was not until we remembered the curious effect of _reflected heat_ that we could account for it. It is obvious that the rays falling from the upper part of the head-stone on to the _foot_ of the grave would be less powerful than those that radiated from the _centre_ of the stone to the centre of the grave. Hence it was that the heat dissolved at the foot of the grave only a narrow piece of snow, which widened towards the centre, and narrowed again as it approached the foot of the head-stone, where the lines of radiation would naturally decrease. Such a phenomena would prove sufficient to raise superstition in untutored minds. [Verse: "The light of the righteous rejoiceth, but the lamp of the wicked shall be put out."--PROVERBS XIII.] 216. _Are good reflectors of heat also good absorbers?_ No; for reflectors at once _send back_ the heat which they receive, while absorbers _retain it_. It is obvious, therefore, that _reflectors_ cannot be good _absorbers_. 217. _How do fire-screens contribute to keep rooms cool?_ Because they turn away from the persons in the room rays of heat which would otherwise make the warmth excessive. 218. _Why are white and light articles of clothing cool?_ Because they _reflect_ the rays of heat. White, as a _colour_, is also a bad _absorber_ and _conductor_.