HUXLEY ON SCIENCE.
[1.] “Aliases.” The plural of alias (āˈle-as). Meaning another name, an assumed name.
THE CIRCLE OF THE SCIENCES.
[1.] “Napier,” naˈpe-er, John. (1550-1617.) An English mathematician. “Logarithms” are numbers so related to natural numbers that the multiplication and division of the latter may be performed by addition and subtraction, and the raising to powers and the extraction of roots by the multiplication and division of the former. They are arranged in tables which can be readily understood and used, and they save enormous calculations and labor.
[2.] “Kepler,” Johann. A German astronomer.
[3.] “Mercator’s Chart.” In all the charts in use before Mercator’s, curved lines were drawn representing the meridians and parallels. A vessel which followed these lines always receded too far from the equator, and, if land did not intervene, would describe a spiral course and finally reach the pole. Mercator constructed a map as follows: A line, AB, was drawn representing the equator, and was divided into 36, 24 or 18 equal parts for meridians at 10°, 15°, or 20° apart, and the meridians were then drawn through them perpendicular to AB. The distance of the parallels and the tropics, and the arctic circles were marked from the equator on the sides, and these points joined by straight lines. The map does not give a natural representation, as the polar regions are immensely exaggerated. The distortions in the form of the countries and the relative distances of places are rectified by making the degrees of latitude increase proportionably to those of longitude.
[4.] “Quadrant.” Quadrants were used for surveying, making astronomical observations, and, in navigation, for determining the meridian altitude of the sun, and from that the latitude of the observer. They were made of a great variety of form and size to suit their several uses. The interest attaching to them at the present time is chiefly historical, as they have been superseded by the sextant and the full circle.
“Davis.” An eminent English navigator of the latter part of the sixteenth century.
“Hadley,” John. An English mathematician of the early part of the eighteenth century. An intimate friend of Newton.