A.horizontal shaft runs length-ways through the trough, and is provided with stirring blades, arranged in such a manner that they constantly scrape the bottom, so that the salts cannot burn fast upon it, and are at the same time moved forward towards one of the ends of the trough where they are automatically removed by means of a chain of buckets.
When, in the last decade of the 19th century, works of thorough architectural investigation and repair were undertaken in that building under the superintendence of Professor Luca Beltrami, a devoted foreign student, Dr Paul Muller-Walde, obtained leave to scrape for traces of Leonardo's handiwork beneath the replastered and whitewashed walls and ceilings of chambers that might be identified with these.
Pieces of paper punctured with small holes are placed over the trays in which the hatching goes on; and the worms, immediately they burst their shell, creep through these openings to the light, and thereby scrape off any fragments of shell which, adhering to the skin, would kill them by constriction.
" They looked like anatomies of death; they did eat the dead carrion and one another soon after, insomuch as the very carcasses they spared not to scrape out of their graves; ...
The royal pupils spent their lesson hours, as Nicholas afterwards confessed, " partly in dreaming, partly in drawing all sorts of nonsense," in the end " cramming " just enough to scrape through their examinations without discredit.
Their chief importance, however, is that in Lapland and other northern countries they supply the winter food of the reindeer and other animals, who scrape away the snow and eagerly feed upon them.
The salt-springs attracted the first permanent settlers to the site of Lincoln in 1856, and settlers and freighters came long distances to reduce the brine or to scrape up the dry-weather surface deposits.