INDIAN MARINE SURVEYS. 27 



island, where the survey of the previous season had ended, 

 down to Forrest strait near Pakckan. The track is useful to 

 local trade and gives protection to vessels trading to Singapore, 

 but until thoroughly surveyed on a large scale, which the trade 

 does not at present seem to require, it is not recommended for 

 large and deep draught vessels. In fact, large ships able to steam 

 against the ordinary monsoon would not use it. 



On Christmas day a visit was paid to the Elephant islands, close 

 to the south-east side of Domel island. The former are composed 

 of a marble of medium quality, and are very remarkable, both for 

 their abrupt shapes and the beautiful grottoes they contain. The 

 grottoes are mostly accessible at low water through tunnels below 

 high-water mark opening into lofty caves. At the south end of 

 the largest islet, which is 1,000 feet, a low- water tunnel admits 

 a boat into a lagoon, entirely closed by high precipitous cliffs and 

 open only to the sky. Into this lagoon, which seems to be 

 purposely created for smugglers, several cave grottoes open from 

 under the cliffs. An interesting description of these islands will be 

 found in the Records of the Geological Survey. 



"With the object of examining the banks extending off the 

 Sundarbans between Chittagong and the " Swatch," a survey was 

 made of the Meghna flats. No less than 1,750 square miles were 

 sounded, the result being to show more water in nearly every 

 direction than on the published charts, and no extension of the 

 prominent shoals. No. 1 Boat party completed their survey of 

 the channel between the Narbada river and Perim island in the 

 Gulf of Cambay (Narbada river to Perim island), the triangulation 

 being carried across the gulf from the Kathiawar side to Broach 

 point by means of mirrors which were extemporised as heliostats. 

 Mandwa bay, Diu head, was also surveyed, the area sounded being 

 10 square miles, while in the case of the Gulf of Cambay it was 

 65 square miles. Between October and February the " Investigator " 

 was at work in surveying the entrance to the Bey pur river, and 

 here, and at Calicut, and off Cotta point, an aggregate area of 

 139 square miles were sounded and plotted on various scales. Boat 

 party No. 2, surveyed the approaches to the Ye river on the 

 Tenasserim coast on the scale of four inches to the mile, but the 

 work was much impeded and interrupted by the ill-health of the 

 party, until on the 18th November no fewer than 23 were on the 



