METKOKOLOCilCAL OlisEltVATIUNS O.N lil-.S NKVIS. 191 



published in the Transnclions of the Royal Society of Edinburgh and in 

 the Journal of the Scottish Meteorological Society. 



Much work has been done in the offices in Edinburgh and Fort 

 William in recopying, on separate daily sheets, the hourly observations 

 of the two Observatories, in connection with a strictly scientific examina- 

 tion of the two sets of observations in their bearings on the meteorology 

 of north-western Europe. 



This important research was begun by Dr. Buchan in spring last, and 

 it has since occupied any time that has been available after the discharge 

 of his official duties. The subject has been divided into several parts, 

 and each is treated separately by itself, in its relations with the other 

 observations more or less closely connected with it. The following are 

 the selected divisions of the research : Cyc^lones ; anticyclones ; differ- 

 ences of temperature between the top and bottom of the mountain, much 

 smaller than the normal difference, including inversions of temperature, 

 when the temperature at the top is higher than that at Fort William ; 

 large differences of temperatui-e, much exceeding the normal difference, 

 particularly in their close connections with coming storms ; great dryness 

 of air at top, which occurs with anticyclones, and their intimate bearing 

 on the movements of these important weather factors ; marked differences 

 of wind at top and bottom, both as regards direction and force, especially 

 in their close relationship to the extent of the ' droop ' of the barometric 

 pressure likely to occur with the coming cyclone ; relations of the obser- 

 vations above and below to the storms repoi'ted by the keepers of the 

 Scottish Northern Lighthouses ; conditions under which very diverse 

 readings of the two barometers occur, as regards time of phases, and 

 chai'acter of the fluctuations ; and an examination of the whole observa- 

 tions with the reported rainfall at about a hundred stations selected from 

 all parts of Scotland. 



In these inquiries the weather maps of this and other European 

 countries at the time are examined. The general method of treatment 

 may be best shown by an example. Thus in dealing with cyclones, the 

 following data are collected and entered in the respective columns of the 

 sheet for cyclones, viz., position in Europe of the cyclone ; position of the 

 nearest anticyclone at the time, with its highest recorded barometer and 

 place ; the direction in which Ben Nevis is situated from the cyclone, 

 whether N., N.E., E., kc. ; distance of Ben Nevis from the centre of the 

 cyclone in miles ; temperatures at the Observatories ; humidities at ditto, 

 sunshine and cloud at ditto ; barometer at Fort William, at sea level ; 

 lowest recorded barometer at centre of cyclone, and its position ; wind at 

 sea level from daily weather maps, and at top of mountain ; and the light- 

 houses at which storms occurred. 



It will be recognised that several of these points have been to some 

 extent already adverted to in our previous reports ; but what is now 

 attempted to be done is an inquiry into their relations to each other. The 

 unique character of the inquiry results from the fact that the High Level 

 Observatory on Ben Nevis is situated right in the general path of the 

 cyclones of north-western Europe, whereas the other high level observatories 

 and stations of Europe that have been used in similar investigations are 

 altogether outside that path. So far as it has gone, the inquiry already 

 points to the result that there can be no doubt most important modifica- 

 tions will require to be made as to the theories of the cyclone more gener- 

 ally held by meteorologists at the present time. 



