Abstract: A sandglass-type timing device which can be reset to commence a new timing operation without first completing a pre-existing timing function. The timing device is formed from a transparent plastics material and it comprises a first chamber (18), a second chamber (19) and a narrow neck (20) interconnecting the two chambers. A particular material (21) is located within the device and it is flowable, under the influence of gravity, to pass from the first to the second chamber and vice versa by way of the neck (20). A passageway (24) interconnects the first and second chambers (18 and 19) and provides an unimpeded passage through which the material (21) can be directed, by appropriately orientating the device, as an alternative to trickling it through the neck (20).