August 25, 1887] 



NATURE 



195 



the snail, it is so arranged that the snail shall give a 

 little. The small play the snail has, the distance it can 

 move under pressure, is sufficient to discharge the quarter 

 rack on to its snail. In repeating work the quarter rack 



is also an " all or nothing piece," for this reason, that 

 until it is discharged the hammer which strikes the hours 

 is hung up, and should you not press down the slide 

 sufficiently to reach the bottom of the depression in the 



Fig. 7. — Repeating mechanism. 



snail no blows are struck, so it is not possible for the 

 repeating work to give you a false answer. Fig. 7 

 illustrates repeating action. Clock-watches are watches 

 which strike the hours and quarters spontaneously ; their 



action is exceedingly complicated, and, unless their 

 mechanism is seen, is almost incapable of explanation. 



Henry Dent Gardner. 

 ( To be continued.) 



THE RECENT DROUGHT. 



'T'HE spell of dry weather recently experienced over 

 ■■■ the United Kingdom has been so unusually pro- 

 longed, and its effects have in many instances been so 

 disastrous, that a brief inquiry into its history and general 

 results may not be without interest. In the present 

 article it is therefore proposed to take into consideration, 

 — firstly, the conditions of barometrical pressure under 

 which the drought occurred ; and secondly, the actual 

 deficiency of rainfall experienced in various parts of the 

 country. 



With respect to the first point it will readily be sur- 

 mised by those who are in any way acquainted with the 

 subject of our meteorological changes that the general 

 distribution of pressure during the recent dry spell was 

 anticyclonic. At times, and notably during the second 

 half of June, the middle of July, and the early part of 

 August, the anticyclonic conditions ruled supreme over 

 the entire Kingdom. On other occasions, however, the 

 influence of the high pressure areas was confined to a 

 portion of our islands, the favoured localities being 

 usually those included within the eastern or the southern 

 half of Great Britain. With these latter conditions the 

 extreme western and northern districts were influenced to 



a very partial extent by the anticyclone, and to a much 

 greater extent by areas of low pressure, the centres of 

 which were, however, in nearly all cases at a considerable 

 distance from our shores. On a few rare occasions the 

 main disturbances were accompanied by shallow subsi- 

 diary depressions, which advanced directly over us, and 

 occasioned the temporary bursts of showery weather 

 which occurred from time to time. The most important 

 and general instances of this kind were observed during 

 the second week of July and towards the end of the same 

 month ; but in the former case there were isolated portions 

 of our southern and south-eastern counties which re- 

 mained altogether unaffected by the disturbed weather, 

 while in the latter instance the showers were in many 

 districts far too insignificant to be of any real value. 



Although an endeavour has thus been made briefly to 

 account for the unusual drought which occurred, one 

 cannot but feel that beyond and irrespective of the various 

 pressure movements which were reported from time to 

 time there wa= a distinct tendency for the weather to 

 remain dry and warm. Instances were not wanting of the 

 prevalence of very disturbed conditions of pressure without 

 any corresponding break up in the atmospherical appear- 

 ance. Of this, two recent examples maybe cited. On the 

 afternoon and evening of August 12, a depression formed 



