The accompanying cut represents a method of ventilating rooms, counting-houses, etc. which has been adopted for some length of time, and has given general satisfaction.

The ventilator consists of louvres, or strips of glass placed horizontally across the window-frame, at such an angle as to cause the current of air to enter in an upward direction, thus preventing draught. It is furnished with a glass slide, or shutter, by moving which, the ventilation can be increased, diminished, or altogether suspended at pleasure. This slide can be made with upward, downward, or side action, and is worked by a line passing over pulleys, and brought by that means to the most convenient part for handling.

Now this is a contrivance simple and efficacious, and of most easy adaptation to the ventilation of our garden glass structures. A thing so inexpensive, yet so useful, seems to address itself to the commonest understanding, and makes it almost unnecessary to add, that its introduction at either end of a greenhouse, stove, vinery, or what not, places at all times in the hands of the gardener a power of ventilation to a greater or less extent; but particularly in bad weather, high winds, or in a frosty season, when, after a night's firing, he may wish to admit a small amount of fresh air. A ventilator of this kind is fixed in each end of the Orchid-house at Worton Cottage, and answers the purpose admirably.

Mr. Dromgole, whose advertisement has frequently appeared in The Florist, would be glad to answer inquiries respecting it, and to furnish models to explain its working.

Ventilating Contrivance 18490016