50 Years Ago
The distance travelled by grazing sheep and the energy cost of locomotion have been measured ... This leaves the energy cost of grazing per se and of the animal's reactions to its environment to be accounted for; the first measurements of the former can now be reported. Two sheep were allowed to graze normally for a week. A patch of turf 1.0 × 1.5 m was then dug up and relaid on the floor of a respiration chamber. The sheep, which had both been trained for such work, were then, one at a time, placed in the respiration chamber ... The energy expenditure of the sheep always increased during grazing and fell again during the subsequent rest period, but there was no significant change when pre-cut grass was given to the sheep. The grazing increment did not vary significantly from sward to sward, and had a mean value of 0.62 ± 0.04 kcal/h/kg body-weight for a 29-kg Merino ewe and of 0.84 ± 0.12 for a 53-kg Merino wether.
From Nature 20 October 1962
100 Years Ago
The accompanying photograph shows a pearl ... alleged to have been found in Nautilus pompilus, from the Sulu archipelago.
The pearl ... weighs 18 carats (72 grains), and is composed of the porcellanous (not the nacreous) constituent of the shell. It is somewhat translucent, white, with a slight creamy tinge, rather suggesting fine Beleek china
From Nature 17 October 1912