SECTIONAL TRANSACTIONS.— E. 571 



Friday, September 7. 



Col. H. S. L. WiNTERBOTHAM. — Recent Expansion in bur Colonial Surveys. 

 Col. M. N. MacLeod. — Methods of Revision of Ordnance Survey Maps. 



Capt. M. HoTiNE. — Air Surveys. 



Aftebnoon. 

 Excursion to Drymen, Aberfoyle, and the Blane Valley. 



Saturday, September 8. 



Excursion to Arrochar, Crianlarich, and Callander. 



Monday, September 10. 



Mr. J. Holmes. — The Clyde Estuary. 



The Clyde Estuary is a region of ships, holiday villages and busy industrial towns. 

 A detailed" analysis will be found in a recent article in the Scottish Geographic Magazine 



(vol. xiv. 1927). • .> a ^ 1,- u 



In this region there is an excellent opportunity to examine the ettect wmch 

 inorganic causes have on organic results. 



The water body of the estuary unites three different and distinct physiographic 

 regions, and brings into close contact three contrasting environments. The Highland 

 desert with its valley and lochhead oases forms abrupt contact with the prosperous 

 industrial lowland. 



There is an indigenous development in each area of the region, and also a super- 

 imposed activity which latter bears no direct relation to the localised natural resources 

 of the areas themselves. . 



The superimposed development has come from the eastern industrial area. When 

 this activation reached the estuarine region it took three distinct aspects in direct 

 coincidence with the three distinct physiographic areas which compose the region. 



Thus there is an industrial zone in the southern area bordering the deep channel 

 in the river, a residential and dormitory zone in the northern area and holiday villages 

 in the oases of the highland area. , ,-, 



The impulse to increased development in the estuarine region may be likened to 

 a series of economic waves. These have, from time to time within the last fifty years, 

 swept down the river. To-day it is evidenced in the migration of Glasgow bridges 

 down stream, the various schemes for dock construction near Greenock, suggested 

 ferries across the estuary, and, in a recent case, the supply of electricity from Greenock 

 on the south side to Dunoon on the north. The rebound of these waves has taken 

 place at the estuary since the highland zone offered resistance to the changes. Is it 

 Sot a likely phenomena that the highland zone will supply hydro-electric power to 

 its southern neighbour ? The return wave, however, does not make itself felt as far 

 up-stream as the starting point of the original. The locus of greatest activity, then, 



is the estuary. .,..,,■. ^ x * 



Thus we are led to the conclusion that the estuary is destmed to be a great outport 



for the Midland Valley of Scotland. 



Mr. J. S. Thoms. — The Site of Glasgoiv. 



A map on a scale of G'Vmile, contoured at intervals of 20 ft., the contours having 

 been plotted from all available spot height and bench mark data, was used as a base 

 for his investigation by the writer. The contours were reinforced at fixed mtervals 

 of 100 ft. in order to emphasise the structural alignment of the area. 



The map revealed considerable diversification of elevation and contour mtlun 

 the urban area. Elevation was shown to fall off from heights of 350 ft. in the N.Ji., 



