Primary tabs
Transcription
[Page 11]
specific gravity, but much depends upon the dexterity with which this operation is conducted & on the implements that are made use of for this purpose.
If the Gentlemen who are employd [employed] in this expedition had been more in the habit of pursuing these enquiries, a much greater variety of important matter might be pointed out to their attention & many more usefull [useful] hints might be given for directing their observations.
It remains now for the Writer to give a few instructions for collecting specimens of the Mineral productions of these new Countries, a point of the utmost importance in respect to the verification of the discoveries which will be made in this line.
In the composition of the sand or the shingle of the sea beach will be found the more indurated contents of the neighboring strata, which although worn smooth by attrition are not to be rejected unless better specimens can be obtaind [obtained] from their native beds.
The substances more commonly found in such situations are Agates Jaspers Calcedonys [Chalcedonys] & Quarz [Quartz].
From the inspection of the Sea Beach some judgment may be formd [formed] of the contents of the neighboring Cliffs & Hills.
The Cliffs present the most Striking & instructive phoenomena. The Metallic substances are often exposed there to view in their native beds or veins.
In the choice of Specimens both of the Rock & of the substances which it encloses, care must be taken to select such as shew the characters by which they are distinguishd [distinguished], in their most perfect State. They must be taken therefore from the more Solid & undecayd [undecayed] parts of the Mass & must be sufficiently numerous to exhibit