1888.] A, Mukliopjidhyay — On Mongers Differential Equation. 165 



" On siicli occasions no men are allowed to accompany tlie women, 

 who, for the time being, conduct themselves in a very masterful and 

 masculine fashion. 



" They are decked out with pagris, coats and all the finery they can 

 borrow from their husbands and sweethearts, and they flourish their 

 spears, axes and sticks, beat their ' nageras,' (iron drums) shout, sing 

 hunting songs, and dance the Sendra and Kharia just as the men do. 

 The ceremony commences in the west and each village that has been 

 visited goes out on a similar excursion to its neighbours, but always to 

 the east. By this means it is supposed that the evil spirit is safely 

 conducted out of the district, without oJffending its dignity. 



" There is one village near Ranchi which is a notable exception. 

 Its title is ' Mahadaiva,' i. e., devoted to Mahadev, and there the ama- 

 zonian huntresses are not allowed to enter, as it is supposed to be under 

 the special protection of its patron saint. Were cholera to appear in 

 the ' Mahadaiva ' village, it would be because Mahadev had been 

 offended, and he would have to be propitiated before it could disappear." 



Babu Asutosh Mukhopadhtat read the following extract from a 

 letter on Monge's Differential Equation to all Conies, written (20th June 

 1888) to him by G. H. Stuart, Esq., M. A., Principal and Professor of 

 Mathematics in the Madras Presidency College. 



" I have some recollection of seeing a paper on the general differ- 

 ential equation to a conic in one of the mathematical journals, and I 

 have postponed my reply until I could give you the reference, but I 

 cannot find it. The substance of the paper was that for the general 

 conic, if p be the radius of curvature, and i// its inclination to a fixed 

 line, the general differential equation can, by the relation 



b<ny 





^ 



d^y 



dx^ 







be transformed into 











^ d^^ 



dp d^p 

 ^ d^ d^^ 



40 /c?p\8 , , 



d^ 





andif pi, pg. PS' ' 



points of the 1st, 2nd, 



be the radii of curvature 

 3rd, evolutes, so that 



at the corresponding 





dPi 



p^-dr^' 



• ••• > 





this equation becomes 











pYo' 



- ^Pl P2 Ps 



4(0 



= 0, 





