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has furnished in this paper a large amount of information from the experience of business establishments in his own and other States. Conciliation is the arrival at a mutual understanding, in case of difficulties between employers and employed, either through their own discussions or the intervention of friendly parties, and is voluntary. It was first brought into effect in the iron-works at Pittsburg. in 1866, and has been continued, with only such interruptions as were provided for in the agreements and were consistent with their terms, till the present time. Thence it has been extended to establishments in West Virginia and Ohio, Arbitration is reference of the dispute to an umpire, whose decision is intended to be binding. It has been tried in the anthracite, Pittsburg, and Shenango coal-regions in Pennsylvania, and in the coal-mines of Ohio, and has always so far. failed. One instance of its successful operation in this country is in a large cigar-manufactory in this city, where the relations between the proprietors and their workmen appear to be established on the most agreeable basis. The full history of all these efforts is given in the pamphlet.

began in 1876 a series of observations on the planets, for the purpose of studying them at every point of their orbits. Five hundred and ninety-one observations were made on Jupiter during five years, and not quite as many drawings were taken. The planet showed signs of lively commotion in 1876, when a spot was recognized on a second observation only once. During the following years the planet was more quiet, the spots were more durable, and one, the "great red spot," was persistent for several months. The periods of rotation of the planet, as deduced from observations of the spots, exhibit variations which appear to be dependent upon their proper motion. The great spot gives a period of between 9h, 55m, 38·81s, and 9h. 55m. 43·96s. M. Trouvelot thinks this is as near to the actual period as we are ever likely to arrive.

the usual teaching of drawing, pupils learn to observe and copy from models, and to construct perspectives "by rule-of thumb," but not, the author believes, except in the case of patterns for tapestry, carvings, and similar applications, to invent designs from which constructions can be made. For this purpose the designer should be able, in order that the object he conceives may be constructed from the drawing, to dissect it and so to project its several parts on the plane of the paper, that the artisan shall know just where to find them, and what they represent. The present work is designed as an introduction to this branch of the study.

was the first who undertook (in 1806) to suggest the true theory of the so-called imaginary quantities of mathematics. He was followed, twenty-five years afterward, by Gauss, and later by other authors who have given the subject a fuller development. The translation of his essay is followed in the present volume by notes on the geometrical interpretation of imaginary quantities by Professor Hardy.

is a strong presentation of the proofs that science is economically profitable, and of the arguments in favor of its endowment with means to prosecute investigations.