WATER-CONTENT 35 
research, the chresard must of course be ascertained for each formation with 
respect to its peculiar plants and soil. .The influence of the ecad in more or 
less determining the echard is also shown by Hedgcock, who found that 
floating plants wilt at 25 per cent, amphibious ones at 15-20 per cent, 
mesophytes at 6-12 per cent, and mesophytic xerophytes at 3-6 per cent. 
The echard is also somewhat higher for shade plants than for heliophytes. 
Records and Results 
55. The field record. It is superfluous to point out that a definite form 
for field records saves much time and prevents many mistakes. The exact 
form may be left to personal taste, but there are certain features which are 
essential. Many of these are evident, while others may seem unnecessary ; 
all, however, have heen proved by experience to have some value in saving 
time or in preventing confusion. The two fundamental maxims of field work 
are that nothing is too trivial to be of importance, and that no detail should 
be entrusted to the memory. The field record should contain in unmis- 
takable terms all that the field has yielded. These statements apply with 
especial force to water-content, in many senses the most important of 
physical factors. The precise character of the record depends upon the way 
in which the readings are made, whether scattered or in series. As the 
day-station series is of the greatest importance, the record is adapted’ for it 
especially, but it will also serve for all readings. The record is chronolog- 
ical, since this is the only convenient method for the field. A proper form 
for a field record of water-content is the following: 
HOLARD ECHARD |x| NOTES 
& 3 2 4 Fi 
ei gq 2 8 @ | Weighings Weighings a ' 
< ES 3 Be sr EI |e] p }es 
A eel br ga 8 & | 1st | 24 |can}4¢} ist] 2d |canl4/6| gf [gs 
2/8/04|Spruce forest|Jack Brook| Mertensiare] Loam 10 [58.7 | 50.1 |25.52/2 |58.7 /53.41/25.52/10/16) Cloudy 
«  |Spruce forest|Milky Way| Gentianare Poca 10:2|64.25] 57.5 |21.35|16/64.25/59.6 |21.35| 5/11] Cloudy 
“ /Gravel slide.|Hiawatha | Asterare Gravel | 2:10)78.55] 74.3 |22 85] 8]78.55/74.&5/22.85/ 1] 7) Cloudy 
A general designation of the soil-composition is a material aid, especially 
where there is a difference in the core. For example, in a mountain forest 
or meadow, the upper layer will usually be mold, the lower sand or gravel. 
A careful estimate of the relation between the two throws much light upon 
the chresard. Under “sample” the number taken to reach the desired depth, 
if more than one, is indicated by placing the number before the depth, thus 
2:10. When two or more full cores are included in the same sample for a 
