Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-23T22:16:26.551Z Has data issue: false hasContentIssue false

The factors determining soil temperature

Published online by Cambridge University Press:  27 March 2009

B. A. Keen
Affiliation:
Rothamsted Experimental Station, Harpenden, Herts.
E. J. Russell
Affiliation:
Rothamsted Experimental Station, Harpenden, Herts.

Extract

The general principles regulating soil temperature are well known.

Measurements in deep mines and wells indicate the existence of a temperature gradient in the earth's crust from the interior outwards, which causes a flow of heat to the surface at a sensibly constant rate. Extensive measurements were carried out by Forbes1 and by William Thomson (afterwards Lord Kelvin) who worked up the former's experimental values, and later by a Committee of the British Association, which concluded that an average of “41·4 gramme-degrees of heat escape annually through a sq. cm. of a horizontal section of the earth's substance.” For our present purpose this source of heat is negligible.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1921

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

page 211 note 1 Trans. Roy. Soc. (Bdin.), 16 (1846), pt. 2, p. 189.Google Scholar

page 211 note 2 Ibid. 23 (1862), p. 157.

page 211 note 3 Brit. Assoc. Rept. (1882), p. 72Google Scholar

page 213 note 1 All times throughout this paper are Greenwich mean time.

page 215 note 1 Trans. Roy. Soc. Canada, 1895 (2nd Series), 1, p. 1.Google Scholar

page 216 note 1 Michigan Expt. Station, Technical Bull. No. 22 (1915).Google Scholar

page 220 note 1 Russell, E. J. and Appleyard, A., This Journal, 1915, 7, p. 1Google Scholar

page 224 note 1 U. S. Bureau of Soils, Bull. 59 (1909).Google Scholar

page 224 note 2 Trans. Roy. Soc. Canada, 1896 (2nd Series), p. 109.Google Scholar

page 225 note 1 Amplitude of rise: maximum temperature of one day, minus minimum temperature of same day. Amplitude of fall: maximum temperature of one day, minus minimum temperature of next day.

page 234 note 1 The precise length cannot now be determined without digging up the instrument which, for obvious reasons, we do not wish to do.

page 236 note 1 It was found very convenient to record the 9 a.m. reading of the soil thermometer by moving the pointer sideways very slightly with the finger, so as to leave a small mark on the paper. The chart could then be examined at leisure, and the mark, being made at a known time, also afforded a check on the accuracy of the clockwork mechanism.