PROCEEDINGS OF THE CANADIAN INSTITUTE. 63. 



As neither the ordinary mercurial nor aneroid barograph is sufficiently sen- 

 sitive to record the more rapid and smaller atmospheric waves, I have devised, by 

 Mr. Stupart's permission, a simple form of self-recording air barometer, which is 

 seventeen times more sensitive. Most interesting results are now being obtained 

 from this instrument, which may furnish material for a future paper. 



To form some idea how sensitive even the photographic barograph is, you will 

 notice two large and well-defined atmospheric undulations upon the trace before 

 us. These are due to a great atmospheric wave, which was formed over Krakatoa, 

 in the Indian Archipelago, during the tremendous eruption there, which caused such 

 fearful loss of life and property in its vicinity. This catastrophe is vividly recalled to 

 our memory by the brilliant red sunsets observed here for many months after- 

 wards, caused by the volcanic dust in the air. This wave reached Toronto in four- 

 teen hours, on its way to the antipodes of Krakatoa, from whence it was reflected 

 back, repassing Toronto on its return, 8 hours and 20 minutes later. It was reflected 

 back and forward, between its point of origin and antipodes, several times, leaving 

 in all seven traces upon our barograph record. 



Finally, permit me to draw a few conclusions in connection with what has 

 been brought before you to-night. Meteorologists are unanimous that further 

 advance or improvement in weather forecasting is not to be expected without a 

 better knowledge of the movements of the upper atmosphere. The foregoing investi- 

 gations seem likely to prove of service in this direction. In connection with the 

 international system of cloud observations, now being carried on throughout the 

 world, interesting and useful results might be obtained by careful observations of 

 the undulatory forms assumed by clouds, and probably due to atmospheric billows, 

 of the kind to which reference has been made to-night. 



Since these peculiar undulations almost certainly occur upon all waters and 

 lakes, large and small, if simple instruments, similar to that in use at the mouth of 

 the Humber, were placed at several points on the shores of our great lakes ; or, 

 still better, if it were possible to have them in different parts of the world, and 

 especially along a western seaboard, such as that of Great Britain, or our own 

 British Columbian coast, results of great interest might be expected, and our 

 knowledge of the extent, direction, and rate of movement of these atmospheric 

 waves very greatly increased. 



Fishermen also would find such instruments of great service, since their records 

 furnish approximate indications of the probable force and direction of an approach- 

 ing high 'wind. Already, those fishermen who live near the Humber have learned 

 the advantages of consulting the records before going out to set their nets. A rise 

 of the water level at the west end of the lake precedes, by many hours, the arrival of 

 an easterly storm ; as, on the other hand, a coming westerly wind is marked before- 

 hand by a fall. 



These phenomena are evidently due to differences of barometric pressure over 

 the extremities of the lake, although, of course, at a later stage, the change of level 

 is augmented by the direct action of the wind. 



