When one end is fixed, and the other projecting, the strength is inversely as the distance of the weight from the section acted upon; and the strain upon any section is directly as the distance of the weight from that section.

When both ends are supported only, the strength is 4 times greater for an equal length, when the weight is applied in the middle between the supports, than if one end only is fixed.

When both ends are fixed, the strength is 6 times greater for an equal length, when the weight is applied in the middle, than if one end only is fixed, or one-half stronger than if both ends were merely supported. +

When the weight or strain is uniformly distributed, a beam will sustain double the weight that it would bear if the load was all at the centre.

* From one-fourth to one-seventh of the breaking-weight is a safe-load.

+ If a beam is supported two or three feet from each end, a weight applied in the centre would cause the ends to tip up as the middle went down; but if the ends were flxeri, - say, for example, built into a brick wall, - the beam would sustain one-half more weight than if the ends were merely supported.

Reduced to the Uniform Measure of One Inch Square, and One Foot in Length, extending horizontally, fixed at One End. Weight suspended from the Other.

* The safe-load of any material is from one-fourth to one-seventh of its breaking-weight.