Fig. 72.—Rest of Donkey's-ear Block.
Fig. 73.—Mitre Template.
Fig. 74.—Moulding with Mitred Joint.
SPIRIT LEVEL.
The spirit level is used for determining the plane of the horizon, that is the plane forming a right angle to the vertical plane. A frame firmly holds a closed glass tube nearly filled with anhydrous ether, or with a mixture of ether and alcohol. Good spirit levels are provided with a graduated scale engraved on the glass tube or on a brass or steel rule fastened to the frame beside it, so as to mark the position of the bubble, the tube being so shaped that when the level is lying on a flat and horizontal surface the bubble occupies the centre of the tube. Many levels have provision for altering the length of the bubble. Fig. 77 is a view of an ordinary spirit level, and its construction is made quite clear by the sectional view, Fig. 78. In use the level is applied to the work twice, it being reversed at the second application, and the mean of the two indications then is adopted. Spirit levels are made in many sizes and shapes, but the method of construction always is the same. A serviceable tool is of the narrow shape, about 10 in. long, its greatest breadth being 11/16., and diminishing to 1/2 in. at the ends. The frame is of any hard, tough wood, such as box, ebony, lignum-vitæ, birch, beech, walnut, or oak. At the back of the tube should be silvering, which shows up the bubble and enables side lights to be dispensed with. The tube is set in plaster-of-paris, and has a brass cover. Shop-bought spirit levels are constructed generally in ebony or rosewood, better qualities having a metal protection for the edges and faces. This protection preserves the truth of the instruments for a long time, and is very desirable. A serviceable American level has a mount entirely of steel, which is hexagonal in section, and has rounded ends. Another handy form is the one mounted wholly in brass; this has a revolving protector over the bulb opening, and there is provision for adjustment should the level after a time wear out of truth. A very convenient form of level is the one with a graduated screw slide, by means of which the fall per foot is shown at a glance.
Fig. 75.—Application of Mitre Template.
Fig. 76.—Using Chisel with Mitre Template.
Fig. 77.—Spirit Level.
Fig. 78.—Section of Spirit Level.
HOLDING TOOLS.
BENCHES.
BEFORE any definite work can be done, a bench, or its substitute, must be obtained. For general manual work the ordinary bench in use by the joiner is, all things considered, the most serviceable; it should not be less than 6 ft. long, 2 ft. 6 in. high, and, say, 2 ft. 6 in. wide. It should be fitted with two wood bench screws and wood vice cheeks, one at each left-hand corner of the bench, to accommodate two workers. If possible, the bench should be so placed that light may fall directly upon both the ends—that is to say, the workers must, face the windows. There are many good and suitable benches on the market, but the worker must not get one that is too low, and the height should be influenced by the kind of work it is intended to perform upon it. The smaller benches sold at the tool-shops are not high enough for an adult—from 33 to 34 in. for a man is excellent, 26 to 30 in. for boys. The worker will become accustomed to work at the ordinary bench height, but it is absurd to suppose that one height suits tall and short people equally. The worker should choose a bench of the height at which he has the most command over his tools. He should be able to do his work conveniently without much necessity for stooping; but the height of the bench should not prevent his standing well over his work (see Fig. 79). It will thus be seen that some latitude is allowable, although no doubt something near ordinary bench height, somewhere about 2 ft. 6 in., is about the best. The height of an ordinary bench can be altered easily by cutting the legs shorter or putting something under them. A height of 2 ft. 6 in. may be found just right for mere occasional use, but too low to work at for any length of time. A simple method of raising it slightly from the floor is to put a piece of quartering under each pair of legs. For heavy work the bench may have to be fixed to the quartering, and the quartering to the floor, for which purpose stout screws or screw bolts will answer. Fig. 79 shows the relative heights of worker and bench.
Fig. 79.—Workman and Bench.
Fig. 80.—Bench with Side and Tail Vices.
Fig. 81.—Double Bench with Vices at each end.
VARIOUS KINDS OF BENCHES DESCRIBED.
Fig. 80 is a general view of a simple bench with side and tail vices. This form is extremely useful for cabinet making and similar work, where it is desirable to hold pieces of material that may have to be planed, moulded, chamfered, mortised, grooved, etc., without using a bench knife or similar method of fixing. The material could be held between stops, one being inserted in one of the holes in the top of the bench and another in the hole made in the cheek of the tail vice. The following dimensions are, of course, only suggestive, and the bench may be made longer or shorter, narrower or wider, to meet requirements: Top, 5 ft. by 1 ft. 9 in., and 2 in. thick. Height, 2 ft. 7 in. Distance between legs, 3 ft. 2 in. lengthwise, and 1 ft. 3 in. sideways. Legs, 3 in. by 3 in. The whole may be constructed of hard wood, such as beech or birch, and in any case it will be best to have hard wood for all the parts forming the top, side cheeks, and cheeks of vices, these being the main parts of the bench; the framing of the legs, rails, etc., might be of red deal. A simple bench is illustrated by Fig. 81; this is suitable for general carpentry and joinery. The framework is of thoroughly seasoned dry spruce fir or red pine, and the top of birch or yellow pine. This is a very serviceable bench for general utility. The folding bench illustrated by Fig. 82 will be found very suitable where a portable bench is required for occasional use only. It will be seen that when the bench is not in use, the screw, screw cheek, and runner can be taken out, the legs folded on to the wall, and the top and side folded and let down as indicated in Fig. 83. A more elaborate bench for cabinet work is shown