Of the light steel forms, the most important on the market are the Metaforms and the Morrill forms. The Metaforms, originally the Reichert forms, are composed of individual form units. All units are standardized and interchangeable, and equipped with the necessary clamps and locking devices. These units are built of sheet steel, strongly reinforced, and measure 2 feet square. A single course of Metaforms is composed of an inner and outer shell of plates. As the work progresses the bottom course is taken off and placed above for the next, there being usually three courses of forms in operation. The Morrill form is also a sheet-steel form, only it uses a hinged “swing-up” construction, by which the lower courses of the form can be swung up into position for the new course as the work progresses. The Van Guilder double-wall machines have been gradually increasing in use throughout the country. They are not for sale, but the company establishes a contracting organization in different centres. The machine is a steel mould which is moved along and upward as the concrete wall is tamped in it. It builds a double wall in tiers. Each tier is 9 inches high and 5 feet long. A complete circuit of one tier is made around the wall, and then the next tier is begun on top. [Illustration: 23. A double monolithic wall built by the Van Guilder machine.] VI SAFEGUARDS AGAINST FIRE IN DWELLINGS _The Necessity for Safeguards_ The majority of small houses will be built of either wood-frame construction or of wood-and-masonry construction for many years to come, in spite of the propaganda favoring fireproof dwellings, for the cost of materials and labor are so adjusted that houses of this better type cannot be built by the average citizen. In fact, 90 per cent of the houses erected to-day use wooden studs and floor beams. This method of building costs the fire insurance companies about $60,000,000 a year. The actual loss must be even greater than this, for not all houses are insured. We might as well face these facts frankly and accept the next best means of preventing this enormous annual loss of dwellings by establishing safeguards against this fire dragon at the most vulnerable parts of the building. We must place the armor of protection where it is needed most, and set up the safeguards against fire where the dangerous enemy attacks.