Page:Popular Science Monthly Volume 7.djvu/784

764 How this is accounted for by Secchi was stated in the September number.

Prof. Mayer, of the Stevens Technological Institute, adopts a different method of observation, and his results differ considerably from those both of Langley and of Secchi. He causes the image of the sun to fall on the smoked surface of a thin sheet of paper, while the other side of the paper is coated with a film of Meusel's double iodide of copper and mercury. He begins with an aperture of object-glass, which does not give sufficient heat in any part of the solar image to blacken the iodide, gradually increasing the aperture till he gets a well-defined blackened area. This is the area of maximum temperature. The aperture being further increased, the blackened surface extends, and a new area is formed bounded by a well-defined isothermal line. This process is continued till the isothermals of the entire image are mapped out.

Prof. Mayer finds that—1. There exists in the solar image an area of sensibly uniform temperature and of maximum intensity. 2. That this area is of variable size. 3. That it has a motion on the solar image. 4. That it is surrounded by well-defined isothermals. 5. That the general motions of translation and of rotation of these isothermals appear to follow the motions of the area of maximum temperature, but that both central area and isothermals have independent actions of their own.

One-sided Development.—In an article entitled "Lop-sided Generations," published in the Journal of Anatomy and Physiology, Dr. Hollis points out the existence of the habit of using the right hand in preference to the left among those peoples whose monuments date from the remotest antiquity. What is the reason of this almost universal fact? The author turns to the anatomical mechanism of the human body for an answer. It is known that the right lung, liver-lobe, and limbs, exceed in size those of the left side, involving, of course, a greater amount of tissue-structure, and a larger supply of nerves and blood-vessels for their nutrition. A person walking in a dense fog figures with his feet the segment of a circle; and, if he is right-handed, he takes a direction to the left, because the right leg naturally takes a longer stride. The left side of the brain is larger than the right; it has been shown that the power of verbal articulation in the right-handed is confined to a certain convolution on the left side; and hence we arrive at the fact that in speaking and thinking we use the left side of our brain, this being the result of dextral education. Amnesia and aphasia in right-handed men indicate disease of the left brain. Hammer-palsy and writer's cramp show the results of excessive working of the left brain. Dr. Hollis insists on the necessity of adopting a system of education which will give an equal prominence to both sides of the brain in all intellectual operations.

The Tribes of Western Australia.—Mr. John Forrest, of the British Anthropological Institute, in giving an account of the natives of Western Australia, states that they are divided into two great tribes, Jornderuss and Ballavook, which are again divided into innumerable sub-tribes. These great tribes are exogamous: a Jornderuss may not marry a Jornderuss, but must take a Ballavook. Wife-stealing is a constant source of quarreling among them, and the women are frequently speared or killed. The children belong to the mother's tribe. Tattooing and marking on the shoulder and breast are almost universal among these tribes. The rite of circumcision is practised by all the tribes that Mr. Forrest met with, except those of the southwest corner of Australia. It is a religious ceremony, and the men and women part for a fortnight upon the occasion of it. The natives of the interior are entirely without clothing, and suffer much from the cold. They sleep in the open air, except in wet weather, when they build small huts. Cannibalism is common in the interior.

Science allaying National Antipathies.—The Edinburgh Review expresses the opinion that the study of two sciences, namely, comparative philology and ancient law, has already done much, and is destined to do still more, to bring about an understanding between the people of Ireland and of England. Comparative philology proves, beyond doubt, the connection of the Saxon and Celtic people; and indicates, in a