482 Mr. W. Baily on an 



the want of sphericity of the earth's form, and on account of 

 the centrifugal pressure towards the equator. Extra-terres- 

 trial influences, such as the conjunction and apposition of the 

 sun and moon and the variation in solar radiation, are asym- 

 metrical, so that the earth's crust heaves and cracks and allows 

 the eutectic melted alloy to break through, and as an intrusive 

 mass metamorphose and overlie the older formations. Once 

 rendered asymmetrical, the geographical features give rise to 

 climates and weathers, and determine the formation of the 

 sedimentary strata. 



LIU. On an Integrating Anemometer. 

 By Walter Baily, M.A* 



[Plates XIV. & XV.] 



ON June 10th, ]882, I communicated to the Society a 

 design for an integrating anemometer, and exhibited a 

 working model f- I have now to describe the instrument 

 itself, which I have had made by Messrs. Elliott, with the 

 assistance of a grant from the Royal Society. The mecha- 

 nical part of the instrument is seen in perspective in Plate XIV. 

 fig. 1. The base is of iron, and the rest of the instrument is 

 chiefly of brass. On the base stand four columns C, of which 

 only two are shown in fig. 1. These hold a table 0, of which 

 fig. 2 gives a view as seen from above. The tops of the 

 columns C are seen in fig. 2. The table supports four columns, 

 D, of which only two are shown in fig. 1, and of all of which 

 the positions are shown in fig. 2. The pillars D hold the sup- 

 ports of a spindle A, fig. J, which is to be connected with a 

 vane. There is another spindle, B, which is to be connected 

 with Robinson's cups, and which turns, by means of cogs, the 

 large horizontal disk X, so that X will revolve with a velocity 

 which may be taken as proportional to that of the wind. The 

 spindle A carries a horizontal bar G, which is to be kept by the 

 vane in the direction of the wind, and which, by means of a 

 forked end, holds a vertical pin rising from the centre of the 

 bar F. This bar is pivoted at E to the centres of two trucks H, 

 each of which runs by means of five wheels (U) between tram- 

 lines (M) placed so as to form a cross with the arms directed 

 towards the cardinal points (compare figs. 1 and 2). The 

 centre of the cross is vertically over the centre of the disk X. 

 Centrally between the tram-lines M are slits S through the 

 table 0. The object in having five wheels (U) placed as shown 

 in fig. 1 (see also fig. 3) is to enable each wheel of the truck H 



* Communicated by the Physical Society. Eead December 8, 1883. 

 t Phil. Mag. Sept. 1882 ; Phys. Soc. Proc. vol. v. p. 157. 



