494 



NATURE 



[March 21, 1901 



PILOT CHARTS. 



Tip ROM the popular and astrological point of view, 

 ^ meteorology is as old as the oldest of the canonical 

 writings ; but as a scientific study it may truly be said to 

 belong wholly to the great Victorian era of scientific 

 development. It was only in the 'thirties of last century 

 that Redfield and Reid— the former in America, the latter 

 in the West Indies — set about the patient study of the 

 vagaries of storms, and discovered that these meteors 

 were, like everything else in Nature, subject to natural 

 laws. By the middle of the nineteenth century the pro- 

 gress made by the early pioneers was such that Maury 

 felt justified in utilising the results in the preparation of 

 his pilot charts for mariners all the world over. Maury's 

 charts were certainly not perfect ; fifty years afterwards 

 many would, no doubt, regard them as a confused mass of 

 information which would weaiy the most persistent 

 student in an endeavour to unravel them ; but useless as 

 they seemed to be at first sight, they have proved to be 

 the pioneers of the most useful works published in the 

 interest of navigators. It has long been recognised that 

 the sailor wants, in addition to ponderous tomes dealing 

 minutely with every phase of navigation, handy summaries 

 of the more essential features of everyday life on the 

 ocean, arranged in a simple manner for immediate refer- 

 ence. The Board of Trade published charts containing 

 varied information forty-five years ago, and the Hydro- 

 graphic Department issued its well-known quarterly pilot 

 charts more than thirty years ago. Other nations, France, 

 Holland, Denmark, &c., have devoted much attention to 

 the necessity of keeping mariners acquainted with all the 

 latest information relating to the meteorology of the 

 various oceans. For many years past the Hydrographic 

 Department at Washington has left no stone unturned to 

 popularise its Pilot Chart of the North Atlantic, and of 

 iate years it has been perfecting a similar work for the 

 North Pacific. In the meantime, Germany has not only 

 been increasing her naval strength, but her mercantile 

 fleet is daily becoming more and more important, and 

 the latest evidence of this is found in the January number 

 of the Annalen der Hydrographie und Marititnen 

 Meteorologie^ in which Dr. Neumayer announces the 

 issue, by the Deutsche Seewarte at Hamburg, of a monthly 

 chart for the Atlantic, mainly for the steamships engaged 

 in the Transatlantic trade. 



But the importance of the question of keeping the 

 mariner in touch with the progress of meteorology has 

 not escaped the attention of the English authorities, for 

 the Meteorological Council has just distributed a speci- 

 men monthly pilot chart of the North Atlantic and 

 Mediterranean for the month of January, it having been 

 decided to commence a series of such publications in 

 April. In the compilation of the charts,* advantage 

 is to be taken not only of information in the possession 

 of our own Hydrographic and Meteorological Offices, 

 but also of any suitable facts published by similar estab- 

 lishments in other countries. Just as we are certain that 

 the atmospheric conditions during winter are different in 

 various ways from those which obtain in summer, so we 

 may conclude that between the extremes there are, on the 

 average, more or less gradual changes in the controlling 

 features, and, therefore, we must expect that every month 

 in the year has its own individualities, which are not 

 exactly in agreement with even those of neighbouring 

 months. To be of real use to the navigator, then, infor- 

 mation should, as far as possible, be sorted out into its 

 principal monthly features, and this is to be the aim of 

 the Marine Department of the Meteorological Office 

 under Commander Hepwortb, R.N.R., the superin- 

 tendent. Each ocean area of 5° of latitude by 5° of 

 longitude contains a wind-rose showing the prevail- 

 ing winds, some of the less frequent wind^, and the 

 frequency of calms, a simple method being adopted 



NO. 1638, VOL. 63] 



to indicate the mean strength of the wind, whether 

 light, moderate, or gale. The normal limits of the 

 Trades ; the sailing routes recommended to and from the 

 Equator ; the steamship routes to and from America ; 

 the mean paths followed by cyclonic areas ; the region in 

 which gales exceed 10 per cent, of the wind observations ; 

 the localities affected by fog ; and the ice limits about 

 Newfoundland are laid down. A feature of as great 

 interest to the theoretical physicist as to the practical 

 sailor will be the ocean currents for each separate 

 month, based upon observations covering a period of 

 sixty-five years. Until the Admiralty and Meteorological 

 Office recently published a selection of the currents in 

 representative months, the scientific world had to be 

 content with studying the circulation of the waters from 

 a chart representing the annual results only. There will 

 now be an opportunity for a much closer study, as the 

 monthly winds and currents are given together in the 

 same sea-room, while the distribution of atmospheric 

 pressure for the same month is given, with that of the 

 air and of the sea temperature, in an inset chart, and all 

 three subjects must be considered as inseparable when 

 investigating ocean currents. Two other inset charts 

 represent south-westerly and westerly types of weather 

 over Western Europe. In addition to the foregoing pic- 

 torial method of displaying the facts, a considerable 

 amount of valuable information is conveyed in descrip- 

 tive letterpress on all available spaces, directing the 

 navigator's attention to the dangers associated with 

 making the Spanish coast, to the Harmattan winds of 

 West Africa, the Northers of the Gulf of Mexico, the 

 Mediterranean sirocco and other winds ; to treacherous 

 inshore currents ; to the difficulties arising from the low- 

 lying haze and the great refraction along the west coast 

 of Africa ; to the rollers breaking on the South American 

 coast, from Trinidad to Guiana ; and advice is given as 

 to the best routes for crossing the Equator. An interest- 

 ing article is devoted to Atlantic storm systems, showing 

 how the mariner must combine his wind and barometer 

 observations when he wants to ascertain the behaviour of 

 the disturbance which may be affecting his ship, the 

 problem being much more complicated than is generally 

 supposed, and more particularly in this age of swift 

 steamships, which may be travelling faster than a 

 cyclone, so that the experiences on a liner travelling east- 

 ward through a storm would be largely different from 

 those on another meeting it going westward. Every- 

 thing depends upon the particular circumstances, and 

 with the aid of these notes and an intelligent interpreta- 

 tion of them, officers should be able to have a much 

 better knowledge of the cyclonic areas through which 

 they so frequently have to steer. For many reasons, the 

 new pilot charts deserve to have a long and successful 

 career. 



MALARIA AND ITS PREVENTION. 



SINCE the work of Laveran (1880) proved malaria to 

 be a fever caused by the invasion of the blood by 

 minute animal organisms, steady progress has been made 

 in the work of probing and elucidating the etiology and 

 pathology of this dreadful scourge. 



The extent of its ravages was — and, unfortunately, still 

 is— appalling, and the recognition of this fact has impelled 

 many eminent scientific men to direct their best efforts 

 towards solving the problems which have been facing us 

 for the last twenty years, and which were the natural off- 

 spring of Laveran's discoveries. 



English, Italian and German workers have competed 

 with each other in the race and shown unprecedented 

 keenness and enthusiasm ; of their work an immense 

 bibliography remains as a monument to-day. In America, 

 too, has been done some of the very best work. 



