392 BATHYMETRICAL SURVEY OF 



deepest water in the loch is close off the promontory on the west shore 

 and nearly in the narrows. Here is a little area over 40 feet deep, with 

 the maximum of 54 feet. Rock was seen at a number of points on the 

 east and south. There are several small islands, and one of these, north 

 of Eilean na Faoileige, is of rock. 



The temperature on May 5, 1903, was almost uniform throughout 

 at the surface, 46-5 Fahr. ; at 40 feet, 46-5 Fahr. ; and at 50 feet, 

 46-6 Fahr. 



Loch Oich (see Plate XCVII.). An insignificant loch in point of 

 size, though of considerable length, Loch Oich is commercially im- 

 portant, as it forms the highest portion of the Caledonian canal. 

 As regards length, it comes fifth in the Ness basin, if we exclude the 

 artificial Loch Mhor. 



Loch Oich is an exceedingly narrow, straight loch, with its long axis 

 running nearly south-west and north-east. High hills rise on the east, 

 and the dense woods which clothe the west shore, with the islands 

 on its surface, render Loch Oich extremely beautiful (see Fig. 61). 



Loch Oich is 4 miles long, and has a maximum breadth of little 

 over a quarter of a mile, and a mean breadth of barely one-fifth of a 

 mile. The superficial area is about 489 acres, or three-quarters of a 

 square mile, and the contents amount to 890 million cubic feet of water. 

 This is about one-half the volume of Loch Clunie, a loch very little 

 longer, and only one-fourth the volume of Loch Garry. 



The drainage area of Loch Oich, including as it does Lochs Quoich 

 and Garry, is very large, amounting to 170 square miles. The drainage 

 is brought chiefly by the river Garry, which enters the loch about the 

 middle of the west shore. Only little hill torrents come in on the east. 

 The out-flowing river Oich runs 4 miles north-east to Loch Ness. The 

 level of the loch on May 1, 1903, was found to be 106*0 feet above sea- 

 level; on the Ordnance Survey map the level is given as 104-8 feet 

 above the sea, but the date on which the observation was made is not 

 indicated. 



The outline of Loch Oich is constricted at several points, first at 

 Ardrishaig, half a mile from the south end, again a mile further down 

 the loch, and again at the mouth of the Garry, where a great peninsula 

 has been made by the river, and opposite to it long narrow islands. 

 From the mouth of the Garry the width increases to near the overflow. 

 A great part of the loch, equal to 68 per cent, of the entire area, is less 

 than 50 feet in depth. The central part of the loch is shallowest. 

 Opposite the mouth of the Garry the greatest depth is 20 feet, close to 

 the island. There are four areas of over 50 feet. The first of these is 

 close to the north-east end of the loch. It is three-quarters of a mile 

 long, and encloses an area half a mile long over 100 feet in depth. Near 

 the south-west end of this 100-feet area is the maximum depth of the 



