WITH reference to the article in NATURE, vol. xvi. p. 450, on the above subject, allow me to place on record the following facts. On the night of January 7, l874, in Lucknow, the temperature fell considerably below the usual. The minimum thermometer on the grass at the observatory registered 5° below freezing point. The destruction of plants in the Horticultural Gardens was great. Plantains, pine apples, sugar-cane, mango trees, casuarinas, pomsettias, colvilleas, bugainvilleas, c some killed outright. The remarkable fact which I observed on that occasion was, that the destruction of vegetation was only up to a certain height, viz., up to between seven and eight feet from the ground. Above that, not a leaf was touched by the frost. On the mango trees especially, which were planted close to each other, it was very remarkable to see a distinct line of destruction along the trees, of seven or eight feet from the ground. This, I think, distinctly showed that the temperature on that night, above eight feet from the ground, was decidedly warmer, and thus protected all vegetation, while all below it was more or less injured, or killed by frost. Other observations, I made lately, corroborate the result of the direct observations made by Mr. Glaisher. During the commencement of October there were several rainy days, with an easterly wind; the total rainfall was under 21/2 inches. When it ceased, and the clouds cleared away, I observed the following:—Before seven o'clock in the morning there were only a few low-lying clouds to be seen. As the sun rose, the wind still in the east and almost a calm, clouds began to form in all directions; about noon, and till about 3 P.M., the sky was thickly studded with cumuli of various sizes. After that hour, wider and wider gaps began to form between the clouds, and the dissolving of the cloud-masses continued as the sun approached setting. About two hours after sunset there was scarcely a cloud to be seen, and the twinkling stars came out in their full brilliancy. This melting of the clouds after a certain hour, and completely so after sunset, would, I think, indicate that the cloud region after sunset became decidedly warmer than it had been during the day.