Deals with vibration transmitted to the body as a whole through the supporting surface, i.e. the feet of a standing person, the buttocks of a seated person, or the supporting area of a reclining person. This kind of vibration is usual in vehicles, in vibrating buildings, and in the vicinity of working machinery. The accumulated data is presented as a set of vibration criteria curves for vertical and lateral vibration over the frequency range 1 Hz to 80 Hz. Vibration at frequencies below 1 Hz, which occurs in many forms of transport and produces effects, e.g. kinetosis (motion sickness), that are completely different in character from those produced at higher frequencies, is covered in an appendix.