Preparing the Rungs.—­Lay a piece of rung batten across the lowest notches, the end overhanging the side by a quarter of an inch or so to allow for the taper of the ladder, and draw your pencil along the angles which it makes with the sides.  Mark the positions of the nail holes.  Cut off the rung at the cross lines; drill the four nail holes on the skew, as shown in Fig. 10; and round off all the corners.  The other rungs are treated in the same manner, and the sides are then separated, for the inside top corner and both back corners, which will be handled most, to be well rounded off and rubbed smooth with glass paper.

Assembling.—­Before putting the parts together give them a coating of paint, as the contact surfaces will not be accessible to the brush afterwards.  When the paint has dried, lay the sides out as before, and nail on the rungs with 3-inch nails.  To counteract any tendency of the sides to draw apart, a light cross bar should be fixed on the back of the ladder behind the top and bottom rungs.

Round off the end angles of the rungs, and apply a second coating of paint.

Note.—­A ladder of this kind is given a more presentable appearance if the rungs are let in square to the sides and flush, but at the sacrifice either of strength or lightness, unless narrow rungs of a hard wood, such as oak, be used.  Moreover, square notches are not so easy to cut out as triangular.

For a short ladder, not more than 9 feet long, the section of the sides may safely be reduced to 2-3/4 by 1 inch (actual), if good material is selected.

V. A DEVELOPING SINK.

Many amateur photographers are obliged to do their developing in odd corners and under conditions which render the hobby somewhat irksome if a large number of plates have to be treated.  The main difficulty is to secure an adequate water supply and to dispose of the waste water.  At a small expenditure of money and energy it is easy, however, to rig up a contrivance which, if it does not afford the conveniences of a properly equipped dark room, is in advance of the jug-and-basin arrangement with which one might otherwise have to be content.  A strong point in favour of the subject of this chapter is that it can be moved without any trouble if the photographer has to change his quarters.

The foundation, so to speak, of the developing sink is a common wooden washstand of the kind which has a circular hole in the top to hold the basin.  A secondhand article of this sort can be purchased for a shilling or two.  A thoroughly sound specimen should be selected, even if it is not the cheapest offered, especial attention being paid to its general rigidity and the good condition of the boards surrounding the basin shelf.

[Illustration:  Fig. 11.—­A home-made developing sink for the darkroom.]

The area of the top is generally about 20 by 15 inches; but if a stand of larger dimensions can be found, choose it by preference.