A simple and convenient form of ventilating warehouses and premises—when it is not required to close shut off the ventilation—is to fix some of the above pattern Panels in lieu of lenses, generally along the top row of Stallboards, see pages 49 and 50.

Nos. 120, 123, 124, 151 and 153 can be put in without extra charge.

Nos. 121 and 122 are used when the view through is to be obstructed, and No. 122 so that matches cannot be passed through.

No. 152 is a Hit-and-miss Ventilator which can be opened and shut in series.

An extra charge is made for Nos. 122 and 152.

No. 122 is also made in glass so as to obstruct as little daylight as possible.—Prices on application.