142 Dr. Crombie & A. Pedler — On the Dacca Tornado. [May, 



The following paper was read — 



An account of the Dacca Tornado of April 1th, 1888, hy Dii. A. 

 Crombie, Civil Surgeon, Dacca, luith a short description of the Meteorology 

 of Bengal at that period. — By A. Pedler, Esq , F. C. S. 



(Abstract.) 



The opening part of the paper by Mr. Pedler consists first of a short 

 explanation of the manner in which tornadoes differ in their phenomena 

 from the ordinary storms such as cyclones &c. which visit Bengal. The 

 second part gives a very short account of the few well-authenticated 

 cases of tornadoes which have previously occurred in Bengal. The 

 third section is devoted to a brief resume of the state of our knowledge 

 of tornadoes and their occurrence and of the conditions which are found 

 to precede them as ascertained by the scientific work done in America 

 by the Meteorological Department of the United States. This section 

 also gives very briefly the theories which are held to account for the 

 formation of the phenomena called nor'-westers and dust-storms, while 

 the fourth or concluding part of the meteorological section of the paper 

 gives a very brief outline of the meteorology of the period, April 6th to 

 the 8th, and the conclusion is come to that the conditions which pre- 

 ceded the formation of the storm are similar to those which precede 

 similar tornadoes in the United States. 



Incidentally also a description is given of three other tornadoes 

 which have recently occurred in Bengal, one in the Magura Sub-division 

 of the Jessore District on the 27th March 1888, a second in the Pubna 

 District on the same date, and the third of a tornado which occurred 

 at Bhadreswur, close to Serampore, on the 27th of April 1888. 



The second part of the paper is by Dr. Crombie who details the 

 phenomena of the actual storm, giving also certain explanations of the 

 path selected by the storm, and of the damage done. Dr. Crombie 

 first discusses the action which a storm with winds gyrating in direction 

 opposite to the hands of a watch would have on obstacles in its path 

 and proves that the storm in question was a tornado with winds rota- 

 ting from right to left,(^. e., against the hands of a watch) by taking up 

 its action in one part of its course on the Buckland Bund close to the 

 Nawab's palace, and shews also how by the position of the objects 

 thrown down, the precise track of the centre of the storm can be 

 proved. It appears the tornado began its destructive course at the ex- ■ 

 treme west end of the municij^al limits of Dacca. The first clear signs 

 of the rotatory nature of the tempest occur in an orchard to the north- 

 cast of Fakirinka Masjid, where there is a clump of plantain trees 

 thrown down, and twisted in all directions, and even in its first mani- 



