The Journal of Horticulture says :

" An amateur, writing to us on paraffin lamps for excluding frost, states that he has employed one for three years in his small greenhouse with great satisfaction and he would not hesitate if required to place a smaller lamp in a frame. He describes the reservoir of the lamp, which is of block tin, as resembling an inverted soup plate. This forms the base and supports a moveable cylinder a little more than a foot high, and six inches in diameter, with an aperture at the bottom for the burner to pass through, and an ornamental lid at the top with apertures for the escape of heat. After the heat has been turned 'full on' for a quarter of an hour the cylinder becomes quite hot, and is afterwards kept sufficiently so by a very small flame. If he 'fires hard in severe weather' he places a shallow tin dish of water on the top in place of the lid. No injury whatever has resulted from the lamp, but on the contrary he has "two hundred Geraniums which have been preserved through the present Winter at the cost of one gallon of oil.'"