410 Sir Norman Lockyer ami Dr. \V. -1. S. Locky-r 



The Indian meteorologists have abundantly proved that the in- 

 creased radiation from the sun on the upper air currents at maximum 

 is accompanied by a lower temperature in the lower strata, and that 

 with this disturbance of the normal temperature we must expect 

 pressure changes. Chambers was the first to show that large spotted 

 area was accompanied by low pressures over the land surface of 

 India.* 



Passing, then, from the consideration of individual spots to the zones 

 of prominences, with which they are in all probability associated, it is 

 of the highest interest to note the solar latitudes occupied when the 

 crossings previously referred to took place, as we then learn the belts 

 of prominences which are really effective in producing the increased 

 radiation. The area of these is much larger, and therefore a consider- 

 able difference of radiation must be expected. 



The greater disturbance of certain zones of solar latitude seems to 

 be more influential in causing the + pulse than the amount of 

 spotted area determined from spots in various latitudes. 



It is all the more necessary to point this out localise the insignificance 

 of the area occupied by the spots has been used as an argument against 

 any easily recognised connection between solar and terrestrial meteoro- 

 logical changes.! 



Assuming two belts of prominences X. and S. 10 wide, with their 

 centres over lat. 16, the sixth of the sun's visible hemisphere would be 

 in a state of disturbance. 



Indian Rainfall. S.ir. Monsoon, 1877-1886. 



It will be clear from what has been stated that our object in studying 

 rainfall was to endeavour to ascertain if the + and - temperature 

 pulses in the sun were echoed by + and - pulses of rainfall. The 

 Indian rainfall was taken first, not only because in the tropics we may 

 expect the phenomena to be the simplest, but because the regularity of 

 the Indian rains had broken down precisely when the widened line 

 observations showed a most remarkable departure from the normal. 



It was also important for us to deal with the individual observations 

 as far as possible, because it was of the essence of the inquiry to trace 

 the individual pulses if they were found. Hence the S.W. monsoon 

 was, in the first instance, considered by itself, because although Eliot 

 holds that the winter rains (X.E. monsoon) are due to moisture brought 



* 'Abnormal Variations, ' p. 1. 



t " So far as can be judged from the magnitude of the sunspcts, the cjclicml 

 variation of the magnitude of the sun's face free from spots is very small compared 

 with the surface itself ; and consequently, according to mathematic principle, the 

 effect on the elements of meteorological observation for the whole earth ought 

 also to be small " (Eliot, ' Report on the Meteorology of India in 1877,' p. 2). 



