The most expeditious method of determining altitudes ... with the ... barometer ; together with a description of the instrument, examples of its use ... To which is added a short description and use of T. Jones's patent sectograph / [Sir Henry Englefield].

  • Henry Englefield
Date:
1811
Catalogue details

Licence: Public Domain Mark

Credit: The most expeditious method of determining altitudes ... with the ... barometer ; together with a description of the instrument, examples of its use ... To which is added a short description and use of T. Jones's patent sectograph / [Sir Henry Englefield]. Source: Wellcome Collection.

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    EXPEDITIOUS METHOD OP DETERMINING ALTITU D E S. rF JL PIE experience of three years having ascertained the convenience and utility of the Mountain Barometers,, (made on the principles of which a description was drawn up by me and inserted in the Philosophical Journals,) I have, at the request of Mr. T. Jones, whom ! originally employed in making them, and who has continued to do so, very much to my satisfaction, made some additions to my former description, respecting improvements in their construction and use. The mensuration of heights by the Barometer has been, by the labours of Mr. De Luc, Sir George Shuckburgh, General Roy, and several other scientific men, brought to such perfection, and affords so much an easier mode of ascertaining the elevations of the different parts of the surface of the earth, to a considerable precision, than any other known process, that it might have been supposed that, in the course of thirty years, which have elapsed since this branch of science has been perfected, a very great number of observations would have been made, and the heights of almost the whole surface of our own coun- try ascertained by the numerous travellers who continually traverse it. The contrary is, however, the case ; and the small number of observations of this kind may be attri- buted to several causes. The instruments are of consi- derable expense, and, from their complicated construction, easily liable to be out of order in the course of a long journey. I he observations themselves, though each not taking up any very long time, yet, when multiplied on every hill and valley, as they ought to be, for the purpose of obtaining a, just idea of the face of the country surveyed, in the aggre- gate consume much of the traveller’s time ; and the cpn- stant unpacking and re-packing the instrument, becomes a greater
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