MEMORANDA IN RELATION TO FIELD SKETCHES. 7 



Thermometer. Take the 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 be 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/owr and T \ 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 each 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. Keptiles, 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 



