l«J(i 



VIII. 



TTDAL AND LEVELLING OBSERVATIONS. 



The systematic record of tidal observations in India may be said 

 to date from the 4th July 1877, when an important Resolution on 

 the subject was passed by the Government of India. The advan- 

 tages of such observations were pointed out in the Resolution to be 

 mainly the following : — 



(1.) They enable standards to be fixed for the purposes of survey. 



(2.) They afford data for the calculation of the rise and fall of 

 the tides, and thus subserve the purposes of navigation. 



(3.) They are of scientific interest apart from their practical 

 usefulness. 



The first two of the above were considered by the Government 

 of India to be of strictly local bearing, an accurate survey of a port 

 being essential to the safety of the shipping frequenting it, and 

 correct tide-tables necessary for the convenience of navigators and 

 engineering purposes within the port itself. It was therefore laid 

 down that every port where a tidal gauge was set up should pay 

 for its establishment and maintenance from port funds. The third 

 objectj the scientific results to be expected from the record, would 

 be sufficiently provided for by the appointment by the Government 

 of India of one of its own officers to supervise and control the local 

 observations, and to arrange for their utilisation. 



The general superintendence and control of the tidal observations 

 (which included a continuous registration of the barometric pressure 

 and of the velocity and direction of the wind taken by self-recording 

 instruments) were entrusted to Captain A. W. Baird, R.E., Deputy 

 Superintendent. Great Trigonometrical Survey of India, who had 



