MEMORANDA IN RELATION TO FIELD SKETCHES. 
7 
Thermometer. —Take tlie air temperature in the shade, and where the air circulates freely. 
Suspend the thermometer, and leave it a sufficient time for the purpose. 
Wet-bulb thermometer, or hygrometer. —Coat the bulb with very thin cotton or linen. If it is 
kept constantly wet, the observation may he instantly made; if not, wait five or ten minutes 
after wetting it. If the air is very still, fan it, or swing it until it falls as low as it will. Eight 
degrees of difference shows a dry atmosphere; twelve degrees, very dry; no difference is com¬ 
plete saturation. 
Rain gauge. —Place the gauge in an open space, and sink it in the earth nearly to the level 
of the surface when practicable, at the beginning of every rain, and measure the amount when 
it ceases. 
One inch on the surface will measure four in the small part of the gauge. A foot-rule will 
give the amount, one inch deep being one-fourth or .25 on the surface; one-tenth of an inch 
being (.025) twenty-five thousandths. The small part of the gauge full gives three inches; the 
whole gauge four and inches. (The gauge is 6 inches across the top, 3 inches in the tube; 
the tube is 12 inches high; the whole 15 inches high; the two inner capacities as one to four.) 
Measure snow as snow, and melted as water. Soft snow will measure in the gauge; dry snow 
should be caught in a box; melting as many superficial inches as the gauge contains. 
The general purpose of these observations should be kept in view by eacli observer as a guide 
beyond specific directions. That purpose is to make the best possible determination of heights 
and of the profile of the country; secondly, to get the utmost possible amount of definite know 
ledge relative to its climate. 
The mean and extreme temperature of each particular district for each month of the year ; 
the amount of rain and snow, and sum of rain and melted snow, for each month and each dis¬ 
trict ; the contrast afforded in different districts and by the different mountain ranges ; the 
comparison of the Pacific climates with those of the mountain valleys and the plains, and the 
comparison of both with those of the eastern United States. 
The determination of every fact which may bear upon its topography ; upon engineering in 
every district; upon adaptation to settlement and cultivation ; and upon its general salubrity. 
MEMORANDA IN RELATION TO SKETCHES IN NATURAL HISTORY, GEOLOGY, BOTANY, AND TO VIEWS 
OF SCENERY AND NATURAL OBJECTS. 
BY J. M. STANLEY, ARTIST OF THE EXPEDITION. 
1. As a general rule, all that is necessary in regard to the delineation of animals, birds, 
and reptiles, while on a journey, will be to make sketches of their attitudes and outlines, with¬ 
out going into any minute detail. This is less necessary for birds than for other mentioned 
reptiles, as frogs, toads, and salamanders, which ought always to be sketched while alive. 
Details can always best be supplied in the office. Neither is it necessary to make colored 
sketches, excepting of such species as are likely to fade after preservation. Birds, quadrupeds, 
insects, and shells will usually retain their color sufficiently. Eeptiles, fishes, Crustacea, and 
soft animals generally, and nearly all alcoholic specimens, fade more or less, and should 
have sketches of color made while alive, or immediately after death. These can be made on the 
outlines of the natural attitude, but no care need be bestowed in details of drawings, as these 
will be made anew. Sometimes it will be sufficient to write on the sketch of outline the names 
of colors corresponding to different areas of the body. 
Similar sketches of colors may be made for flowers of evanescent tints. Sketches of entire 
trees of the different species will be highly interesting, as communicating information otherwise 
indescribable. 
Fossils, of course, need not be drawn, except when of such size as to prevent their being 
