Tropical and Extra-tropical Cyclones. 11 



Fig. 4. 



/ 



Figs. 2 to 4 : Cyclone in the Bay of Bengal. May type. 



depression is very noticeable. The small scale of the charts does not 

 permit of the isobars being drawn at regular intervals, or this fact 

 would have been still more obvious. The numbers 760, 757, &c, are 

 the approximate equivalents of the isobars in millimetres. 



The path of the cyclone is given in fig. 2. The velocity of propa- 

 gation was — 



From 16th to 17th 4' 3 miles per hour. 



„ 17th „ 18th 87 „ „ .-i 



„ 18th „ 19th 17-5 



The rotation of the wind as an in-going spiral, counter-clockwise, is 

 very obvious, and calls for no remark. 



The following extracts from ships' logs will sufficiently illustrate 

 the sequence of weather in this cyclone : — 



The " Mistly Hall," on bhe west side of the cyclone, remarked a 

 fiery sunrise as early as the 14th May, before the barometer began to 

 fall. On the 15th and 16th she experienced rain, lightning, and 

 squalls from N.E. to N. On the 17th, two hours after the barometric 

 minimum, the wind went from N.W. to S.W., with lightning, tor- 

 rents of rain, and terrific gusts. Twelve hours later the storm mode- 

 rated. 



In this report we see little trace of trough phenomena. The appa- 

 rent non-coincidence of the wind sequence with the barometric 

 minimum cannot be fully discussed for want of sufficient observations. 

 There does not appear to have been any rapid filling up of the cyclone 

 this day, as, on the contrary, the lowest reading report on the 17th is 

 29*043 inches, and on the 18th rather less, viz., 28*95. But we may 



