Centre of gravity of a stool or tripod
Sometimes the centre of gravity of a body is not situated in the actual material of the body, but may be at a point in the air near by. Examples are an iron tripod or a Laboratory stool. The plumbline method can still be employed, but requires more will and ingenuity to carry out than in the case of a lamina. It is necessary to suspend he stool or tripod in such a way that the plumbline positions can be located by lengths of cotton fixed with soft wax.