60 APPENDIX. 



10. The erection of a branch railway line to connect the 

 great timber and other works with the main trunk 

 Hne. 



1.— The great Dam and Sluice Work. Figs. 2 & 3. 



The starting point or pivot of the whole operation is in the 

 dam on the Saane. This is a truly grand structure, entirely 

 constituted of cement concrete, and made for the express purpose 

 of stopping and of backing up the waters a little above the 

 town, south, and to dam up the waters of the river to a suflB.cient 

 height to give the required power. 



This gigantic monolith is built entirely of cement concrete, 

 is erected sideways across the river for 509^ feet ; over the 

 surface of the water it is 39|- feet high, and from the foundation 

 of the dam upwards it is 72 feet ; the ground floor foundation is 

 98 feet broad, and the top of the dam is 19 feet SJ inches broad 

 or thick ; and it has a cubic measurement of 64,000 cubic 

 metres — equal to 83,714 cubic yards." This work was com- 

 menced in the year 1870, and was finished in 1872. By these 

 colossal dimensions and by this gigantic dam we are reminded 

 of the Eoman works. Neither expense nor trouble was spared 

 to complete the same ; and to hold it harmless against all 

 natural influences of water-pressure on the foundation, or of 

 atmospheric action and changes from heat to cold, which might 

 favour the decrepitation of the side wall rocks on either side 

 of the dam or shores of the river ; and no expense was spared 

 to insure its withstanding the action of possible earthquakes 

 over a long series of years. The geological formation of the 

 Saane, in the neighbourhood of the dam, is similar to that 

 of our own neighbourhood here at St. Grallou, on the Sitter. 

 Underneath the sandstone, near the surface, signs of atmo- 

 spheric action are seen ; but below the waterbed there is a very 

 durable and hard sandstone molasse ; over this is a tolerably 

 hard conglomerate, and on the top a loose swampy alluvium. 

 Luckily, and exactly at the required spot for the dam on the 

 river's bed, there was a cropping out of rocks and of hard stones 

 for a height of 19 feet 8^ inches on the most waterwearing side 

 of the river, which gave a most excellent foundation for the work 

 (as may be seen by looking at sectional plan, figures 2 and 3), so 

 much so that it may be hoped that the dam may be everlasting. 



A further foresight was availed of, that the surface of the 

 rocks, upon which the foundation of the dam had to come, after 

 the floor of the river was laid dry by pumping, was so hewn or 

 picked as to present a succession of steps, upon which the cement 

 work of the dam would be raised and united with the foundation 

 rocks, so as not only to secure the greatest possible strength to 

 the structure, but also to insure its impermeability from water 



