418 



Missouri Agricuiiural Report. 



The forms should remain undisturbed from 3 to 10 days, depend- 

 ing upon the weather conditions and the nature of the loading. A 

 wet mix will be longer in setting than a dry one, while concrete takes 

 longer to set or harden in cold or damp than in warm or dry weather. 



Foundation concrete may be put into excavations without the 

 use of forms, provided the sides of the excavation are reasonably true 

 and sufficiently firm to withstand the tamping of the concrete without 

 yielding. 



Figure 



Forms set for concrete curbing. 



Circular Forms — There are two sides — inner and outer — in a circu- 

 lar form. Both sides are made in the same way, but the radii of the 

 forms being different, they are not made by the same pattern. Make 

 a circular form by drawing a circle of the size of the form desired 

 and laying boards around the circumference of the circle. Nail the 

 boards lightly together and, with the same radius, mark out the circle 

 on them. Then knock them apart and saw them out along the lines 

 marked and again fasten them together, this time securely. After 

 enough forms are made for a section of the circular figure, set them 

 up, equally spaced, and put on the side boards or ("lagging.") See 

 Figs. Nos. 8 and 9. 



