ForecastiiKi Weather. 1 99 



iiiieoiiiiuonly iu one position for many days togetluT. When 

 the forecaster sees upon the chart say a cyclone or depression 

 wiiieh has ai-rived from the Athmtic, his business is to deter- 

 mine in which direction it will move, and whether its progress 

 will lie fast or slow. The accompanying winds and weather 

 are subject to occasional modification, but are sufficiently con- 

 stant to enable a successful forecast to be made in the large 

 majority of cases in which the depression has obediently 

 foUowed the course anticipated. In cases of hopeless failure 

 it niay be at once assumed that this has not happened. Some- 

 times the travelling weather system goes off in a direction that 

 was not at all expected, and in other instances it moves much 

 faster or slower, the result in either case lieing seen in a partial, 

 and not infrequently, a total failure of the prediction issued. 



One or two of the chapters in Di*. Shaws work are likely 

 to appeal to the scientific student rather than to the general 

 reader, but there is very little matter presenting any real 

 difficulty to persons of Ordinary intelligence. The section on 

 types of weather explains why one particular class of conditions 

 will often prevail with slight variations for many days, or even 

 for weeks at a stretch. Another interesting chapter deals with 

 local variations in the weather, and shows that in very many 

 instances forecasts which are prepared, as at present, for large 

 districts are often justified by the conditions prevailing in one 

 part of the district, and entirely falsified by the weather 

 experienced a few miles away, i^nother chapter is devoted to 

 the system of storm warnings which prevails in this country, 

 and yet another to the difficulties existing in the way of 

 successfully forecasting fogs and thunderstorms. 



The sections of the work which are likely to appeal most 

 forcibl}' to the agriculturist are, however, those entitled " Agri- 

 cultural Weather Forecasts " and " The Practical Utility of 

 Weather Forecasts." In order that these portions of the subject 

 may be brought fully and fairly to the notice of the readers of 

 this Journal, we have received from the author generous 

 permission to quote freely from the pages of the book. 



One of the most serious difficulties with which the farmer 

 and the fruit grower have to contend is the occurrence of 

 severe spi-ing frosts, resulting at times in the complete destruc- 

 tion of many acres of })romising crops. In the section dealing 

 with tliis very important subject. Dr. Shaw remarks : — 



"The frosts which occur in spring are specially destructive on account of 

 tlie sensitiveness of young plants, and it is, therefore, desirable to recognise the 

 conditions under which they are likely to occur, and if possible, to take pre- 

 cautions for the protection of young growth. 



" As measured by instruments, the weather is not much more changeable 

 during spring than it is in winter or summer, but the changes are of greater 

 practical importance. The change of shade temperature, for example, from 



