DUST AND FRESH AIR. 245 







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-im- 

 portant. The inside of the frame is cut to receive the glass ex- 

 actly 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 neces- 

 sary 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 re- 

 moved 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 ther- 

 mometer 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. 



Of 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. 



