52 CHAP. V. On the general Outlines, or the picturesque Characters of Rocks. As it lias been frequently asserted that the geologist may derive essential assistance in his investigations, from the general features or picturesque characters of rocks, and as some rapid and superficial travellers have even ventured to describe tracts of country from distant observations, made, often, in haste, and some times by means of a telescope, it will not be here misplaced to inquire what value is due to such ob servations. After reading the few remarks that follow, the student may determine bow far he may avail him self of this assistance, and where a reliance on it will mislead himself and deceive bis readers. That it may serve many useful accessary purposes, or occasionally convey valuable hints, is unquestionable; but it will be seen, that without great precautions, it will more frequently contribute to deceive than to instruct the observer. To profit by this class of observations, it is, in the first place, requisite that the geologist should possess the eye of an artist and the practice of a landscape painter; without which he will be a very imperfect judge of those minute variations in the picturesque characters of rocks, or of the tracts of land which they may form, that often indicate essential variations in their nature and disposition. It is next necessary