TOPOGRAPHICAL SURVEYS. 81 



contour lines represent vertical intervals of 250 feet between which 

 were drawn nine eye contours at about 25 feet apart, while in the 

 cantonment maps on the 24-inch scale the true contour lines ran 

 at vertical intervals of 50 feet between which there were four eye 

 contours. This method of contouring proved valuable, enabling, 

 as it did, native surveyors with no aptitude for hill sketching to 

 produce accurate maps of difficult hill country, and reducing the 

 delineation thereof to a comparatively mechanical operation. 



Operations in 1878-79 were resumed in the Bikanir desert, where 

 the ground was characterised by the regular sand waves formed 

 by the prevalent south-west wind, and a general paucity of 

 vegetation. The country, however, may be said to be culturable, 

 for it only requires for the saud to be snatched up, seed to be 

 sown, and the rainfall does the rest. It is said that when the rain- 

 fall has been good and the locusts do not destroy the standing 

 crops one year's harvest will feed the people for three years. By 

 December the crops are all off the ground, and after that, till the 

 next rains, the Bikanir cultivators remain idle in their houses. The 

 ground traversed during the following season was of the same rather 

 uninteresting description, being varied only by the salt works at 

 Sar and the sandstone quarries at Khari. In the former a coarse 

 salt is produced by solar evaporation, and in the latter a stone 

 of good colour and of compact texture, of which the stratum is 

 horizontal and close to the surface. 



During the following year, as the work moved gradually to the 

 north and west, the country became even more desert-like than 

 before ; but in the Jodhpur State a welcome change ensued, the 

 usual rolling sand hills and ridges of the desert being replaced by 

 extensive plains composed of sandy clay, all more or less fertile, 

 varied by clumps of rocky hills. The wells in this part of the 

 country are of great depth, one measured by Mr. McGrill, who was 

 in charge of the party in 1881-82, being 480 feet deep, and the 

 average depth being 270 feet. 



At the close of the season the Bajputana party was transferred 

 to Burma and merged into the Burma Topographical party, the 

 Bajputana work being handed over to No. 1 topographical party, 

 as mentioned above (see page 70). 



Mysore. — The important survey of the Native State of Mysore* had 

 been commenced in 1874-75, and good progress had been made during 



* See Memoirs on the Indian Surveys, 2nd ed., p. 175. 



I Y 20321. -C 



