Miscellaneous Tables , Figures and Notes. 139 



Various Recipes and Rules, continued. 



or coarse saw-dust. 4. Put in with the feed water or other- 

 wise, a small quantity of good molasses (not a chemical 

 syrup), say ^ pt. to i pt. in a week, depending upon size of 

 the boiler. This will remove and prevent incrustation without 

 damage to the boiler. These vegetable substances prevent, in 

 a measure, by mechanical means, the union of the particles 

 of lime into incrustations. 



Cutting glass bottles. i. Pass 5 or 6 strands of coarse 

 packing twine round the bottle on each side of where you want 

 it divided, so as to form a groove ^ inch wide ; in this groove 

 pass one turn of a piece of hard-laid white line, and extend 

 the two ends ; fasten to some support. Saw the bottle back- 

 wards and forwards for a short time ; after a minute's friction, 

 by a side motion of the bottle, throw it out of the line in a tub 

 .of water, and then tap the side of the tub and the bottom will 

 fall off. 



2. Fill the bottle the exact height you wish it to be cut, with 

 oil of any kind ; dip, very gradually, a red-hot iron into the 

 oil. The glass suddenly chips and cracks all round, then the 

 upper surface may be lifted off at the surface of the oil. 



3. For cutting bottoms of bottles off make a slight nick with 

 a file, and then mark round with a streak of ink where you 

 want it to come off. Make an iron red-hot and lay it on the 

 nick. This will cause it to expand and crack, then by moving 

 the rod round, the crack will follow. 



To preserve wooden labels. Thoroughly soak the pieces 

 of wood in a strong solution of copperas (sulphate of iron) ; 

 then lay them, after they are .dry, in lime water. This causes 

 the formation of sulphate of lime, a very insoluble salt, in the 

 wood 



To prepare paper for hot-bed sash. Use a sash without 

 bars, and stretch wires or strings across it to secure as a rest 

 for the paper. Procure stout but thin manilla wrapping paper 

 and paste it firmly on the sash with fresh flour paste. Dry in 

 r, warm place and then wipe the paper with a damp sponge to 



