Page:Popular Science Monthly Volume 9.djvu/272

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252
THE POPULAR SCIENCE MONTHLY.

ment the enemy fires a shot, the action of the report upon the "telemeter" marks the distance to a fraction. The instrument is entirely self-acting, easily kept in order, and requires no particular experience or intricate calculations to use it aright. The experiments to which it has been subjected in Prussia and in some other countries are stated to have been completely successful as regards cannon. Experiments in the rifle-grounds are still going on. Even should the invention be confined to artillery, its effect must be tremendous, considering the present deadly efficiency of firearms. One of its principal advantages, it is supposed, will be to enable gunners in a coast-battery to determine the position of a hostile ship—a calculation hitherto fraught with special difficulty.

 

Sir John Lubbock on the Habits of Ants.—Sir John Lubbock still continues his observations of ants, and at a recent meeting of the Linnean Society of London read a paper in which he treated—1. Of the power of intercommunication among ants; 2. Their organs of sense; 3. Their affection or regard for one another. The results are chiefly negative, contradicting many generally-received opinions. To test the ants' power of communicating information to one another, the author had a glass box for the "nest," so that he could watch what was done inside. This was placed on a pole. On the other side of the pole was a board intended as a promenade for the ants. Near to this were three pieces of glass, connected with the board by strips of paper. On one of the pieces of glass was placed a collection of food, and on the other two there was nothing. Two ants were taken and marked with spots of color, as in former observations, so that they should be readily recognized. These were both taken, one after the other, to the store of food, and were guided and taught their way to the nest. They soon learned their way to and from the nest to the food-supply, coming out of the door along the outside to the pole, around that, across the board, along the paper bridge, and so to the glass that supported the food, and so back again to the nest. Sir John Lubbock's object was to watch whether the other ants in the nest would find out the food, and, if so, to teat as far as possible whether they found it from information given, or whether they tracked the scent. He devoted certain periods to watching the movements of the ants, counting the number of journeys made by his marked ants, and also recording how many untaught strangers made their way from the board along the right bridge to the food. At his first period of observation he found that, while his marked ants made forty journeys with food, nineteen strangers also came on to the bridges. Of these, two only turned to the food, eight turned to the wrong bridge, and the rest went, straight on. Modifications in the arrangements of the bridges were made in different ways, while the rest of the construction was left unaltered. The observations made on different days and during periods of different duration all showed the same result.

In referring to the organs of sense, Sir John had endeavored to ascertain whether the antennæ are organs of hearing or of smell. He had tried them with all sorts of noises he could contrive, and found no results. If ants have hearing, they must be sensible to those vibrations of the air which do not affect the human ear. But he had also tried the antennæ with smells, and he found that if he put a fine camel's-hair pencil with a scent on it near one of them it shrank away, and then, if applied to the other, that also turned away. The use of the antennas, however, still needs investigation, and Sir John hopes soon to make further observations. As regards their affection for one another, he does not doubt that an ant that dies laden with food will be cared for by its companions; but he brought forward a number of instances in which he had put ants that had suffered immersion in water for periods of from an hour to ten hours in the way of ants that were passing by, and he found almost invariably that they took no notice of their unfortunate brethren. Indeed, the exceptions in which any attention was paid were so few that Sir John said he was disposed to regard these as ants with individual feelings, which were by no means those common to the community. It, is understood that the results of Sir John Lubbock's long-continued researches into the habits of bees