TRANSACTIONS OP THE SECTIONS. 53 



long barrels (length 5 feet), whicli were proTided in order to give the tidal curves 

 on the diagi'am on a very large scale. Six of these instruments had been sent out 

 to India some years before ; they were modified in Bombay, so as to be similar to 

 the new one which was tested at Chatham, and had scales of wheels put on for 

 adaptation to particular tides, friction-rollers for the barrel, zero-hnea for time and 

 height cut, &c. As the rise and fall of the tide is materially influenced by direction 

 and force of the wind, and also hj clianges in the barometer, self-registering anemo- 

 meters and barometers were procured for each tidal station. On my return to 

 India I was ordered to make a reconnaissance of the Gulf of Cutch, to select sites 

 for tidal stations. I cruised about for a month in a common native sailing-boat, 

 and after long searching along the muddy foreshores of the Gulf I found three 

 places well adapted for tidal observations — one right at the head of the Gulf, just 

 in the Runn of Cutch, called Haustal Tidal Station ; another midwaj^ up the Gulf 

 of the Cutch coast, called Nowanar ; and the third, Okha, just at the mouth of the 

 Gulf, opposite the island of Beyt. They were well situated for the purposes required, 

 as far as their geogi'aphical position ; but as one was at a point twenty miles from the 

 nearest village (from which drinking-water had to be brought by boat as well as 

 food for the men in charge), another station nine miles, and the third two miles 

 from the villages, the arrangements for the continuous working of the stations for 

 about a year and a half had to be most carefully made. I returned to Bombay and 

 got all the apparatus ready, such as iron cylinders in length (so as to be portable), 

 iron piping, suction-piping, anchors, and buoys, &e. for the deep-sea connexion, 

 temporary tide-gauges for comparison, portable observatories — in fact every thing, 

 even to bricks and lime for sinking the masonry well for holding the cylinders, for 

 nothing could be procured in the places selected for the stations. While in Bom- 

 bay I tested the working of the whole apparatus for each observatory, and made 

 many modifications fi'om time to time. I found that air would collect in the pipes, 

 which were in the shape of a long siphon, and thus cause differences of level in 

 the cylinder and the sea. I overcame this difiicult}' by inserting stopcocks at the 

 top bends, which were to be always below the lowest high-water ; and in this way 

 I was able to get the same level of the water inside the cylinder as in the open 

 sea. By frequent comparison with the temporary tide-gauges, the identity of level 

 was determined ; the size of the pipe connecting the cylinder had been calculated, 

 so that practically there would be no retardation in the flow of the water. The 

 native sub-surveyors, who were to be in charge of the stations, were also trained 

 in Bombay. 



The observations and apparatus were then described at length, and several illus- 

 trations and diagrams showed the method of their working. In addition to the 

 self-registering anemometer and self-registering aneroid barometer, each observatory 

 was fitted out with a standard mercurial barometer (for comparisons) and a rain- 

 gauge. Three bench mark-stones in masonry platforms, at different distances from 

 the observatory, were built as standard points for the levels, and each carefully 

 connected with the zero of the self-registering tide-gauge. The whole of the appa- 

 ratus and instruments were sent ofl^ in a large native sailing-vessel direct to Okha, 

 the natives who were to be employed also going. I marched across Kattyanon to 

 Okha, having made some arrangements with the Political Agent at Rajkot as to the 

 help we should get from the native states. The construction of Okha tidal station 

 was then described, and many of the difficulties which were successfully overcome; 

 also the different methods of comparing position of pencil on diagram with the 

 height of water ; checks on the working of the instruments for insertion in the daily 

 reports submitted by the sub-surveyors. 1 detected a serious fault in the self- 

 registering tide-gauge, viz. that the instrument was by no means correct in the 

 time registration. I eventually devised a simple, plan which I called " back-lash 

 weight," which completely removed this cause of error : I am of opinion this plan 

 ought to be carried out in its entiretj^, and the barrel made to drive the clock in- 

 stead of the clock the barrel. 



Just after all was ready, and the instruments being started at Okha, a great dis- 

 aster happened early one morning. A boat drifted dovm past the station, her anchor 

 dragged across the flexible pipe, smashed it, and carried oft" a large portion of it, as 

 well as buoys, anchoi-, &c. Here we had to land and to have the repairs quickly 



