1851 Great Exhibition: Official Catalogue: Class X.: W. and A. K. Johnston
198. JOHNSTON, W. and A. K., Edinburgh — Manufacturers.
A terrestrial globe, 30 inches in diameter, showing the geological structure of the earth, the currents of the air and of the ocean, the trade winds, trade routes, monsoons, and isothermal lines, or lines of equal temperature. The stand is carved in walnut, and was designed and manufactured by W. Davidson. It has, at the four corners of the base, heads emblematical of the four seasons. Surrounding the compass-box, are figures which represent the four quarters of the globe, with their appropriate emblems; and the circular supports of the horizon are composed of clusters of fruit, indigenous to the quarters of the world over which they are suspended.
[The temperature of any particular month, or any place, varies very much in different years, and its true value can only be determined from observations made during a long series of years. Professor Dove, of Berlin, has collected the observations made at nearly 900 stations on the globe, and from them he has constructed maps of the isothermal lines, by joining those places, by lines, whose temperature was found to be the same.—J. G.]