The ash pits must be big enough to hold ashes away from the grates. 6. Sectional construction desirable.-- These sections make it possible to enlarge a boiler; (2) to move it into a house built completely without tearing down the house, and obviates its sitting around in a house which is being built, a prey to all sorts of bad treatment; (3) can be taken through any cellar door; (4) can easily be taken apart. 7. Must be easily cleaned.-- All surfaces must be available, fire and flue parts largely self cleaning. The surfaces can be so made that soot peels off. Flat surfaces must be easily reached for quick cleaning, ¹⁄₄ inch soot deposit will demand 50% more coal. So get an easily cleaned boiler or no one will clean it at all! Boilers should have conveniently placed doors into which cleaners can have access. If cleaning is easy it will be done, otherwise it will not. We made this point too, with refrigerators, etc. 8. All connections must be water tight, steam tight, gas tight. There should be no packed or gasket joints made of rubber, asbestos, paper or other washers in connecting joints, etc. This is very important. Re-packing should never be necessary with _your_ boiler--the longer it is used the tighter the sections, etc., and yet they are easily taken apart at any moment. The nipples or valves must be easily closed and everlastingly tight, yet easily opened. 9. The steam boiler for steam heat; the water boiler for water heating. No straddlers must be used. 10. The best boiler is of cast-iron. It will outlast the building; will not rust or pit. It is so built as never to need repair and it doesn’t ever seem to wear out. This is an investment--other kinds of boilers are finally permitted to add a value to the junk pile by rusting, pitting, and other useless decadences. 11. No danger in a boiler where the fire chamber is entirely surrounded by water and steam surfaces; and when the boiler stands low and therefore well away from the joists and woodwork. Boilers are generally tested for 80 pounds pressure, but to operate them 2 pounds ought to be enough, though 1 to 5 is the usual bill-of-fare. Steam boilers should have a relief valve--when pressure builds up to 10 or 11 pounds. 12. Should be few outside fixings--should be able to be installed without digging a pit. This, by the way, would be a good way of starting your chat with the regal contractor, “I want a simple, fine boiler, for which no pits must be dug, or brick enclosures.” The best boilers only require a brick base, for obvious reasons. There should be no alterations of building necessary, because the sectional boiler like the sectional bookcase is made to fit in anywhere. Asbestos covering of boiler often prevents waste of heat in the cellar.