Page:Popular Science Monthly Volume 41.djvu/257

Rh window should be in two or three divisions, according to the height, not in one large casement from top to bottom. Thus have we provided for my first requirement, the cleaning of the window. The hinged window must be so constructed that when closed the framework of the window locks into a double rebated fast frame, after the manner of a jeweler's show-case. Then, if well made, it would fit tight and keep out wind and dust. This provides for my second requirement.

Lastly, the panes should be doubled that is, a second pane must be placed inside the ordinary pane at a distance of about five eighths of an inch. The outer pane is fixed by putty in the usual way. The fixing of the inner pane is peculiar and all-important. The inside of the frame is cut to receive the glass exactly in the same manner as the outer side for the outer pane, but the inside pane must not be fixed by putty, but is held in place, "sprigged" firmly against its rim, "the rebate," by small nails, two in each side, very carefully put in. Why do I insist upon this mode of fixing the inner pane? For two reasons: one, to make it easy to remove the inner pane if ever it should be necessary to clean the inside of the two panes; the other reason is, to enable me to render cleaning of the inside unnecessary. How is this achieved? By facing the flange, against which the pane is pressed, with cotton velvet. The air that must perforce pass in and out of the space between the panes must pass the velvet, and be filtered. Two windows of my bedroom thus treated five years ago have never needed to be cleaned; and a pane, which was removed at the erjd of four years for inspection, was absolutely clean. Another advantage of the double panes is this: When my other windows with single panes are steamed all over, and even glazed by the frost, the outer panes of the double window show hardly a trace of unfrozen steam; the inner panes are never steamed. Again, a thermometer placed between the panes has never been below 30° all this severe weather, even though a thermometer outside the window has been several times below 20°.

Lastly, I would treat the cupboards and drawers after the manner already described. The result would be, not absolute freedom from dirt, nor absolute protection from London fog, but such a departure from what is commonly experienced as to make the experiment well worth all the trouble it costs.—Journal of the Society of Arts.

the three hundred and twenty-three asteroids known on February 1st, seventy were discovered by American astronomers—forty-eight by Peters and twenty-two by Watson. Peters stands second on the list of successful discoverers. Palissa, who is first on the list, is credited with the discovery of eighty asteroids.