Dr. Piggott proposes to replace the spider's web of telescopes by a star illuminated transit eye-piece. A sheet of glass, on which a thin film of silver is deposited, is placed in the focus of the eye lens; transparent lines are drawn on the film, instead of wires, and as the star passes across the lines it is seen to flash out brightly. The film of silver is made sufficiently thin to permit of the star being seen when it is between the lines, but it appears that the lines themselves are only visible, except in the case of very large stars, when the star disc is in transit across a line.
* * * * *
Singular results of strains existing in the granite rocks through which the St. Gothard tunnel is passing are recorded. When the shots are fired at the end of the gallery they are sometimes succeeded at unequal intervals by other explosions at points where there is no drill hole and no powder. Workmen have been injured by these spontaneous explosions, which are to be explained only on the theory that there are strains in the rock; and when this tension is increased by the shock of a heavy explosion, the rock flies in pieces with noise. Similar effects have been noticed in other granites.
* * * * *
It is said that aniline colors are now used to color wines, and that enough of them is taken into the Bordeaux district of France to color one-third of its whole product. Husson gives the following method for detecting it: Take a small quantity of the wine and add a little ammonia, when the mixture turns a dirty green. Steep a thread of white woollen yarn in the liquor and allow a drop of vinegar to flow along it. If the color of the wine is natural, as the drop advances the original whiteness of the wool is restored; but if the wine has been sophisticated with magenta, the wool will take a rose color. This test is simple, easily tried, and effective.
* * * * *
An inquiry into the results of systematic gymnastic exercises in a French military school shows that the strength is increased on the average 15 to 17 per cent., and is also equalized on both sides of the body. The capacity of the chest is increased at least 16 per cent. and the weight 6 to 7 per cent. Coincident with this increase is a decrease in the bulk of the body, showing that fat is changed to muscle. The improvement is confined to the first three months of the course unless the exercise is then moderated. If continued at too high a rate, weakness succeeds the increase of strength. It would be a good plan to place a dynamometer in every gymnasium as a measure of the changes which take place in the gymnast.
* * * * *
MOON MADNESS.
The popular belief that the moon's rays will cause madness in any person who sleeps exposed to them has long been felt to be absurd, and yet it has appeared to have its source in undoubted facts. Some deleterious influence is experienced by those who rashly court slumber in full moonshine, and probably there is no superstition to which the well-to-do pay more attention. Windows are often carefully covered to keep the moonbeams from entering sleeping rooms. A gentleman living in India furnishes "Nature" with an explanation of this phenomenon which is at least plausible. He says: "It has often been observed that when the moon is full, or near its full time, there are rarely any clouds about; and if there be clouds before the full moon rises, they are soon dissipated; and therefore a perfectly clear sky, with a bright full moon, is frequently observed. A clear sky admits of rapid radiation of heat from the surface of the earth, and any person exposed to such radiation is sure to be chilled by rapid loss of heat. There is reason to believe that, under the circumstances, paralysis of one side of the face is sometimes likely to occur from chill, as one side of the face is more likely to be exposed to rapid radiation, and consequent loss of its heat. This chill is more likely to occur when the sky is perfectly clear. I have often slept in the open in India on a clear summer night, when there was no moon; and although the first part of the night may have been hot, yet toward two or three o'clock in the morning, the chill has been so great that I have often been awakened by an ache in my forehead, which I as often have counteracted by wrapping a handkerchief round my head, and drawing the blanket over my face. As the chill is likely to be greatest on a very clear night, and the clearest nights are likely to be those on which there is a bright moonshine, it is very possible that neuralgia, paralysis, or other similar injury, caused by sleeping in the open, has been attributed to the moon, when the proximate cause may really have been the chill, and the moon only a remote cause acting by dissipating the clouds and haze (if it do so), and leaving a perfectly clear sky for the play of radiation into space."