OF all the metals for covering roofs there is none so yielding, so accommodating to the skilful worker, as lead. With it he can cover almost any form of woodwork on roof, spire, or turret. Turned, moulded, or carved wood finials and pinnacles, as well as balustrades, carved wood crockets, and moulded cornices, only require time for the manipulator of lead to so cover them that they shall stand the weather and last for centuries. The plumber can cover with lead a wood ball of any size, if not as quickly, yet as dexterously, as a cook covers an apple with dough.

2. Then as to the durability of lead. Iron rusts away, cement cracks and falls down, zinc perishes and vanishes, and tiles and slates break here and there about the roof, and so come and go, but the well-laid lead goes on for ever. Upon its surfaces on the roofs of old abbeys and cathedrals, Crows that live a century rub their beaks when hatched, and clean their bills when they go to the place where they caw no more. And when the time comes for its renewal, its sale as old lead often realizes 40 per cent. of its original cost, including the cost of the labour both of laying it and removing it. Of what other roof-covering can the like be said?

3. The durability of leadwork on the roofs of houses, churches, and abbeys, is often diminished as much from want of a knowledge of the principles on which it should be executed as from a want of skill in the art of executing it.

Like the members of many a poor family, many a nail, many a tack, is often left to bear a weight that can only be borne for a short period, when nail and tack let go their hold, and the lead and its insufficient supports slip away together.

Elevated though the pieces of lead often are to the very highest positions, their tendency is ever downwards; and unless they are well secured to their places by the plumber, no matter how clever the bossing may be, they will soon begin to drop away; until, finally, losing all hold upon their surroundings, they sink right down, and give place to other pieces.

If it were not the tendency of human nature to forget, it would hardly be necessary to remind a plumber of the specific gravity of lead. He knows its weight well enough when he is tugging up a ladder with a roll on his shoulder; and, also, when he is lifting a large piece into its position; but when it is there he often becomes forgetful, and insufficiently secures the lead in its place.

4. To succeed in laying lead well and efficiently, it is not only necessary to secure it properly, but it must also be rightly bossed and equally distributed; and not left thick in one place and thin in another, as is too often the case.

Happy would be that monarch who could so regulate the affairs of his nation that there should be no want or complaining in his streets. And though this might mean neither poverty nor riches to any of his subjects, it would mean some comfort to them all. The skilful plumber can so manipulate his lead, that in his efforts to benefit the poverty-stricken places he need not beggar the richer parts; and when his work is done, he can rejoice that he has left his breaks and corners - his bossings - of an even thickness right throughout.

5. Every schoolboy knows that from nothing you can take nothing. It is, therefore, useless to attempt to work a piece of lead of a certain superficial area into a place of much larger area, and expect to leave it the same thickness in the latter as it was in the former. And yet some men often try this, with the result that lead 1/8 in. at starting is thinned down at the finishing to 1/36 in., with, perhaps, a "bird's-eye" (a little hole) here and there, - often screened from sight by a bit of " touch." "The last tap did it, sir," used to be the croaking cry of a plumber who was fairly good at internal work, but who, off and on, for twenty years had been trying to learn the art of bossing.

6. In leadwork, wherever the need may be, the worker rejoices in the use of a metal that, presto like, can be passed from one place to another; that can be worked by the skilled from the place of plenty to the place of poverty. To do this without causing distress on any part of the lead operated upon is the plumber's privilege, as it is his duty.

7. There is no difficulty in bossing up a corner, or in working up a break, to any height required; though a height of 6 in. is generally sufficient for flats and gutters. For cesspools, where the angles are not allowed to be soldered, the corners and breaks may have to be bossed up to a height of 15 in., or even higher. Nor is there any difficulty in doing this or in bossing up out of a piece of flat sheet lead a lead jar or lead vase 3 ft. high.

8. The difficulty in working lead is when it can only be bossed on one of its sides, when the tools cannot be used on both faces to keep the lead smooth and free from buckling and creasing, when bossing it into recesses, and into the internal angles of deep moulded cornices, etc.

9. In breaks, hollows, drips, and recesses, and such-like places, where the parts to be covered are of much greater area than the surface of the lead standing directly over or round about such parts, the plumber should take some pains to compute the extra lead required, and then see where he can best draw it from.

10. It has been said that an artist has more than two eyes; the plumber must often wish for a greater sight than he is blessed with, to see where he can get a supply to meet his wants. He can leave on lobes and extra widths, here and there, in his piece of lead, when cutting it out; and he can generally manage to work up feeders from the margins; but, like Oliver Twist, he ever cries for "more."

11. In robbing Peter to pay Paul - in drawing lead from one part to drive it into another - care must be taken not to thin the roadway along which the extra lead has to travel, for it is easier to work up contingents - supplies of lead - through lead 1/8 in. thick than through lead half that thickness. It is also easier and quicker to work up supplies of lead in the form of wavelets than in the form of driblets; for the lead particles travel better in masses, and in rounded forms, than in detachments or thin lines - better in the shape of a walnut than a wafer.

12. It is no mark of competency to polish up or overdress a piece of work. The skill of the worker is shown at a much earlier stage. Finish off the work without tool-marks, but leave burnishings to the incompetent.

13. The great absence of that noisy music that ever denotes the whereabouts of the plumber when he is on a building, rather proves that he had "no part or lot " in that house which was put together without sound of tool or hammer; but though the plumber can do but little on a roof without making himself heard, he can, when he possesses the skill, so complete his work that no mark of the hammer or any such tool shall be left upon it, and this is the " Hall mark " of a master of his craft.

Table showing relative strengths of Lead in so many pounds per superficial foot for various purposes, and in three gradations.