Hardly any theory is all true, and many theories are not all false. A theory may be essentially at fault and yet point the way to truth, and so justify its temporary existence. We should not, therefore, totally reject one or other of two rival theories on the ground that they seem, with our present knowledge, mutually inconsistent, for it is likely that both may contain important elements of truth. A new industry, the making of mattresses, pillows, etc., of sponge, has been started in Florida. The sponge material is cleansed of all foreign matter by a scrubbing process in large tanks of water, then run ' through wringers, and the drying continued by subjecting it to a cold-air blast. It is then shredded by machinery, sterilized, and rendered odorless by chemical treatment, and subjected again to cold-air drying, when it is ready for use. It is claimed that the sponge mattresses are only about one-third of the weight, and cost only about two-thirds as much as those of the same size made of hair, that they are thoroughly springy, yet firm and durable, and that they are especially sanitary, the material being non-absorbent of moisture and emanations from the body. A pillow is made measuring 19 by 26 inches which weighs only one pound, feather pillows of the same size weighing three pounds. Other articles are a sponge cushion and a toy sponge ball as light as an inflated rubber ball. The berries of different species of coffee generally contain from 10 to 15 grammes of caffein per kilogramme. M. Bertrand, in a recent communication to the Academie des Sciences, shows that there are exceptions to the rule. The coffee of the Great Cornaro, to which Baillon has given the name of Coffea Hwmblo-tiana, does not contain the slightest trace of the alkaloid. This exception is the more curious, as this species much resembles the ordinary kind, the Coffea ambica. The absence of caffein in the coffee of the Great Cornaro is not due to the influence, either of the soil or of the climate of the African island. Analysis of the Coffea arabica, cultivated in the same island, has yielded a normal percentage of caffein, 13.4 grammes per kilogramme of the berries. Other coffees gathered near Diego-Suarez in Madagascar, and quite distinct species, exhibit the same peculiarity, the absence of caffein. This fact is not accidental, but a distinct characteristic of certain species, previously found only in Madagascar. Prof. Moreaux describes in a paper, read at a session of the Academie des Sciences, observations on a waterspout which passed through the communes of Saint-Maul' and Champigny on the 28th of August. The direction was from west-southwest to east-northeast. It seems to have been formed to the south of Saint-Maur-lce, and passed over a space of about five kilometers in twenty-five minutes, from 10 minutes after 3 o'clock to 35 minutes after 3 o'clock in the afternoon. It was noticed at the observatory of Saint-Maur when it had completed about half of its course. Its passage was accompanied with a sound which is described as resembling that of a battery of artillery drawn on the gallop over a paved street. At the base of an extended nimbus hung the reversed cone characteristic of phenomena of this kind. The barometer, 11 millimeters lower than the day before, stood at 745 millimeters at an altitude of 50.3 meters, at 5 minutes after 3 o'clock, when the fall was increased. ' A strong wind was then blowing from the south-southwest. The temperature was 15 deg. C. These two conditions did not change. The waterspout passed to the north of the observatory within a distance of about one kilometer. It was preceded by a storm, and followed by a shower. The ordinary methods for the determination of refraction, of which the 'influence is so considerable in all astronomical measurements, are 'attended with great difficulties. Observations must be accumulated during a course of years, and at the same time estimates must be made of the multiple effects of the numerous causes that may intervene in measurements taken by means of meridian and other similar instruments. M. Loewy, who has studied this subject closely, pointed out several years ago two methods by which the inconveniences might in great part be 'Avoided. They were based on the comparison of the stellar distances by the use of a special compass, of which'the"'opening remains constant; this consists of two mirrors cut from the same block of glass in prismatic form. ' With the aid of this optical apparatus before the objective of an equatorial. the distance between two' stars may be determined , whatever the size, with . much precision. The constant of refraction may be deduced under certain conditions. In a new communication to the Academie des Sciences, he has recently made known .an improved method free from the practical imperfections of the previous theoretical solutions. By means of a single prism the refractions can be exactly measured at all zenithal distances, by taking advantage of the fact that the apparent distance between two stars is not diminished by the effect of refraction, provided the vertical circle of one of the stars is perpendicular to the arc of the great circle which joins them.