50 Years Ago

“A cæsium clock” — In the issue of Atoms for Peace Digest for February 23, the fortnightly periodical of the United States Information Service, brief details are given of the 'Atomichron', the first cæsium atom-beam clock to be available commercially in the United States, and probably in the world... The model costs 50,000 dollars, weighs 500 lb. and measures 84 in. ×22 in. ×18 in. It is capable of keeping time to an accuracy of five seconds over a period of 300 years... The Atomichron has already been used by the U.S. Armed Forces in navigation systems. It should find application in the improvement of astronomical observations, long-range navigation, radio communications, surveying and map-making, and in the study of basic physics, particularly the accurate determination of the velocity of light.

From Nature 6 April 1957.

100 YEARS AGO

The following account of a toad attacking a golden carp may be of interest to some of your readers from its bearing on the ancient belief that frogs and toads are at enmity with carp, and kill them by destroying their eyes... On March 29 my son directed my attention to a large golden carp (C. auratus) lying in shallow water near the edge of a pond in my garden with a frog or toad apparently resting on its head. The fish appeared to be very sluggish... On examination it was found that the head of the fish was held tightly by a medium-sized common toad (Bufo vulgaris), which had obtained a very firm grasp by inserting its fore-limbs as far as the second, or elbow, joint into the sockets of the eyes of the unfortunate fish... A few years ago in the same pond... I found a toad embracing a water-logged puffball so firmly that it required considerable force to release the fungus from the amphibian's grasp.

From Nature 4 April 1907.