Scientific Intelligence — Geology. 375 



of Sheppey. By J. S. Bowerbank, F.R.S. — The specimen described 

 is a fragment of one of the bones of the extremities. It is 4 inches 

 long, and 1 inch in diameter at the longer end, and is somewhat 

 three-sided with rounded angles. The thickness of its walls is from 

 J of a line to 1 J line ; its microscopic structure exhibits the charac- 

 teristic bone-cells of animals of the bird tribe. The specimen indi- 

 cates the bird to have been at least the size of a full-grown albatross. 

 — (British Association Report for 1851.) 



13. Map of Switzerland. — In speaking of the progress which 

 has been made in the topographical survey of Switzerland, I would 

 specially direct your attention to four sheets of the cantons of Ap- 

 penzell and St Gallen, which M. Ziegler of Winterthur, who has 

 drawn and executed them, has just presented to us. They form part 

 of a survey on the same large scale of 2% inches to a mile, or I jL__ j 

 which is also in the course of application to the cantons of Zurich 

 and Schaffhausen. To give full effect to these four sheets only, M, 

 Ziegler passed six consecutive summers in the mountains and valleys 

 of St Gallen and Appenzell, the geometrical measurements of which 

 had been made under the direction of M. Eschmann. The inspec- 

 tion of the results will, I am sure, lead any of you who have studied 

 map-making to agree with me, that they are examples of a fidelity 

 to nature which has rarely been attained. M. Ziegler soon found 

 (M. Leopold von Buch and M. Escher von dcr Linth being his 

 counsellors) that every class of rock has a peculiar " facies," and 

 hence he became convinced, that no really good topography can be 

 made by surveyors who neglect geological data. Thus, in these 

 sheets, the eye of a geologist at once seizes the rugged escarpment of 

 slaty rocks, the undulations of limestone, or the bosses of conglomerate 

 or nagelflue ; whilst, from personal inspection of a portion of the 

 difficult region here represented, I can truly say, that I never yet 

 saw a map more completely ready to receive the colours of a field 

 geologist. The lights are all thrown in perpendicularly, so that the 

 defects of the maps of Geneva and Vaud, as proceeding from oblique 

 shading, are avoided, and the altitude of each terrace, valley, or mountain 

 top, is inserted in numbers on a most exquisitely finished lithographic 

 relief. I am authorised by M. Ziegler to say, that, if the large scale of 

 2 T 8 o inches to a mile had not been determined upon, he could have 

 delineated as effectually all the same features on a scale of about \\ 

 inch to a mile. In these works we perceive at a glance the value of 

 good hill-shading; and when the map of the magnificent mountain 

 of Sentis, which stands out to the low countries of Germany as the 

 great sentinel of the Swiss Alps, is forwarded to us, you will see in 

 it how perfectly such a work may supersede the want of any model 

 whatever. 



The largest part of the cantons of the Grisons and of Tessin has 

 been surveyed ; but detailed maps of this mountainous region are 

 still wanting, as well as those of large portions of Berne, which are 



