AND METEOROLOGY OF DUKHUN. 191 



Dews first appear towards the close of the monsoon, on the last mornings of Sep- 

 tember after cloudless nights. A precipitation of moisture takes place on similar 

 nights in October and November. In December dews usually become somewhat 

 constant and copious ; and they are seen in January and February ; but they occur 

 under very anomalous circumstances, the causes of which I cannot explain. In con- 

 secutive nights of similar temperature, and similarly cloudless, dew will be found to 

 have been deposited one night and not the following. In September 1827, the 

 journal records " Heavy dew" on the nights of the 23rd, 24th, 25th, 26th, 27th, 28th, 

 29th, and 30th ; they then cease until the 5th of October, on the morning of which 

 there was a little dew ; on the 6th there was not any, and on the 7th there was a little. 

 They do not occur again until the 26th ; hence to the 1st of November " Dew :" sub- 

 sequently none until the 1st of December; hence no dew until the 6th of January 

 1828, when dew was met with on garden land, but not on Jield land; such continued 

 to be the case during the whole of January. At Marheh, Pergunnah Mohol, garden 

 produce was covered with a copious dew every morning ; the lands bordering the 

 gardens for forty or fifty yards around were slightly sprinkled with it ; but there was 

 not a vestige of it on the fields constituting the rising ground north and south of the 

 tract of garden land. I had daily experience of these facts from my habits of quail 

 shooting. In the young wheats I observed that the quantity of dew on the plants was 

 in ratio to the proximity of the time at which they had been irrigated. Plants on 

 land, irrigated the day previously, wetted my shoes and cloth pantaloons thoroughly 

 in a few minutes. Plants on land watered two days previously were plentifully 

 covered with dew, but I could walk through two or three fields ere my clothes were 

 fully saturated. Wheat irrigated three or four days previously, and bordering the 

 fields above noticed, had dew on it, but not sufficient to wet me through. Such rela- 

 tive states of moisture in adjoining fields seem to establish the fact of the local charac- 

 ter of dews. Aqueous vapour would appear to have been taken up by the action of 

 the sun during the day, suspended over the spot, and deposited at night as dew on 

 the land in proportion to the supply yielded by day, or the diflferent lands radiated 

 their heat in a different manner. My tents were within 200 yards of the fields where 

 I observed these phenomena ; but from the 1 1th to the 30th of January there was not 

 any deposition of dew about them, excepting on the 13th of January only, and the 

 dewing-point was but once within 4°-5 of the point of saturation. In consequence of 

 these observations I was induced to remark particularly the localities of dew at Poona 

 and in its neighbourhood. In September and October I found that when there was 

 not a trace of dew in the cantonment, there would be a deposition on the fields of 

 standing grain half a mile distant ; and when there was not any dew either in the 

 cantonment or in the Jields, it would yet be found on the banks of running rivulets, 

 and on the banks of the Mota Mola river : but with respect to the rivulets, fifteen or 

 twenty feet from the water were the limits of the deposition. 



The local character of dew is further attested by the following facts. On the night 



