An hour-glass,a modern reproduction of an ancient device used to measure time. This technique of telling the time depended on the flow of a known volume of material (such as a fine sand) through a small opening. Hour-glass vertical: pink & blue starry background | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Craddock, Tony |
Taille de l’image : | 3383 px × 4299 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |