loi YEAR-BOOK OP FACTS. 



this pump. Mr. Yeates, of Dublin, explained a simple pump nearly 

 similar in construction to that now shown by Mr. Ladd, which he 

 had executed several years ago. 



CURRENTS OF THE AIR AND THE OCEAN. 



Mr. Thomas Hopkins has read to the Royal Society a paper " On 

 the Forces that produce the great Currents of the Air and of the 

 Ocean." In this paper the writer pointed out the fact that we have at 

 present no satisfactory evidence in books of what are the- immediate 

 causes of the great currents of the air and of the ocean ; and he 

 maintained that the liberated heat of condensing vapour is the cause 

 of these currents. He then proceeded to show that all the great 

 winds terminate in comparative vacua created in particular localities 

 where much vapour has been condensed ; and contended that such 

 vacua enable and cause heavier air to press and flow towards the 

 parts which have been rendered light, — to re-establish the equili- 

 brium of atmospheric pressure, — thus making beat the disturbing 

 power in the aerial ocean, and leaving gravitation to act to restore an 

 equilibrium. The great primary currents of the ocean were also 

 described, and they were shown to be so situated as to be under the 

 influence of the principal winds, which, in their passage over the 

 waters, press on them, and force them forward as currents. These 

 currents were maintained to be of a velocity, extent, and depth 

 proportioned to the strength and continuity of the wind, showing 

 that the pressure of the air on the water, whilst moving over it, is 

 capable of producing the movement which takes place. When, how- 

 ever, water is put into motion, it may be obstructed by land, and 

 turned from its direct course, and in that way be made to form 

 secondary currents. But it was contended that heat of vapour, set 

 free in the atmosphere, is the force which disturbs the equilibrium 

 of pressure, and either directly or indirectly produces all the great 

 continuous movements that take place both in the atmosphere and 

 the ocean. 



VERTICAL AND OBLIQUE CURRENTS OF THE ATMOSPHERE. 



Professor Henm.ssy, in the Atlantis, No. 5, remarks: "The- 

 influence of Vertical and Oblique Currents in the Atmosphere 

 is not only manifest in the comparative limited and local phe- 

 nomena of sea.- and land-breezes, mountain-wind.-:, and whirlwinds, 

 but it has also been appealed to in order to explain the circulation of 

 the great winds of t lie i aitli. Thus Maury, in his attempt to exhibit 



the general laws of the great winds, presents a diagram in which 

 ascending and descending currents are distinctly indicated over 

 different regions of the globe. Their agency is also appealed to 

 by other inquirers; and their principal seats of action seem to be 

 indicated as the ealm regions, that is to say. the regions where hori- 

 zontal winds blow with least intensity. Observation! with the aid of 

 the anemoscope in the regions of equatorial and tropical oalms would 

 therefore probably serve to ■ ouraoj of the general views 



hero alluded to. The systematic study of the non-horizontal move- 



