..ST TYPES IX CEXTiiAL ROCKY MOT N TAINS. 89 



Table 25. — Mean soil temperatures at the control station (F-l) — 1 foot. 



Year. 



1911 



1915 



1913. 



1914 



1915. 



i9i; 



191S. 



Average to 

 10, 1918.... 



Julv 



1 

 2 

 3 



Month. 



1 

 2 

 3 



Month. 



1 



2 

 3 



Month. 



1 

 2 

 3 



Month. 



1 

 2 

 3 



Month. 



1 

 2 

 3 



Month. 



1 



2 

 3 



.Month. 



2 



3 

 .Month. 



(O 



26.3 

 32. 12 

 33. 59 



30. 79 



23.29 

 27. OS 

 30. 05 



25. 61 



25. .53 

 20.46 



32.04 

 31.76 



32. 44 39. 12 



28. 01 34. 65 39. 04 

 29. 80 40. 25,43. 42 



28.90 35.93)40.53 



43. 02 55. 94 58. 48 56 

 44. 50 57. SS 60. 0156 

 1156 



9157. 



53 57. 



29 52. 



45. 00158.20 59. 9156. 57|5a 



34. 01 32. 35|38. 34 43. 75 56. 04 .56. 3359. 57 53. 43,50. 

 33. 68 34. 02i37. 42 49. 78 56. 87 56. 45 59. 88 55. 74 46. 

 30. 59,35. 0641. 09 49. 25 57. 77 .54. 88,52. 8355. 13 38. 



32. 92 33. 85,38. 95:47. 65,56. 89,35. 8557. 2854. 77 fe 



14 41. 29 34. 07 

 39,38.62 32.83 

 52 37.75 28.60 



.Eg 



si 



a ■ 



58. 16 



05 35.10 30.64 



78 35.67 28.04 



79 31.38 27.99 



00:34. 05,28. 86 43. 07 ( 56. 40 



27. 68 28. 90 35. 20 40. 23 49. 93 56. 23,55. 

 29. 0Si31. 55 35. 75j37. 33 45. 6s 57. 39 .56. 

 27. 48'32. 02,35. 11:51. 25,50. 25 .56. 79,58. 



28. 10,30. ,86 35. 3543. 20 48. 62 50. 80 56. 86:51. 16,42. 4934. 76,27. 82,40. 24 .54. 38 



26. SO, 29. 88 35. 7242. 91 50. 46 

 29. 20 31. 93 36. 83 45. 59J49. 91 

 29. 6932. 07 39. 76 51. 05 54. 6S 



2S. 48 31. 32 37. 44 46. 67 51. 68 



30.60 26.71 

 27.3li32.09 

 28. 43132. 87 



28 



36. 00.38. 72.53. OS 



35.02 42.8155.54 



32.69 38.74 48.S9J 61.10 

 j-36. 58i43. 65 56. 57 



27. 53 32. 83 37. 72:44. 35 

 29.45 37.27 45.20 52.22 

 31.5139.39 43.43,53.52 



29.50 



34.00 

 39.91 



39. 74 



7, 30. 48 , 37. 94 



27755 -27705 

 24. 92128. 37 

 24. 96 30. 47 



25.7828.50 



K. 50 



34. 65 

 36. 78 

 39.44 



2 124.29 



3 24.45 



27.33 

 28.50 

 34. 30 



[Month. 



r 1 

 212 

 3 2 



[Month. 27.92 



26. <2 



•28720 

 5' 



29. 58 



29.85 

 30.74 



29.54 



27. 53 33. 30 

 27. 18,34. 96 

 32. 39 38. 20 



29. 14,35. 49 



235.2936.72 

 37.3336.61 

 3V. 95137. 13 



36. 89136. 82 



28. 26 30. 99,35. 76 



33. 26 36. 63 



34. 85 39. 14 



33. 09 37. IS 



I 



42. 16 50. 03 



90,57. 

 42 ! 52. 

 15143. 



1144. 

 8142. 

 5640. 



79 35.77 30.97 ... 

 74,35.35 29.29!... 

 19133. 16 23.62 ... 



62. 4961. 12 56. 55 45. 41 37. 47,33. 51 1 . 



61. 61 58. 47,50. 19|42. 52 37. S3 32. 98 



55. 75 57. 36 44. 19 39. 15 34. 92,31. 98| 



59. 81:58. 93 50. 31142. 26,36. 74 32. 80 41. 86 56. 84 



56.35 56.96 58.2152, 

 57. 83 58. 94,56. 78 46, 



9 40.1132.62 



736.70 



42 55. 26|55. 27[41. 95 35. 24 1 



21,56. 99 56. 75:47. 00,37. 35 ' 



54. 93,53. 23|55. 65|43. 81 44. 33,33. 05 ! 



60.81|52.10 53.60|40.34|34.97 31.0S 



54. 70 52. 1951. 33 43. 15 36. 38 30. 33 | 



36. 75 52.50,53.55 42.45 



41. 01 53. 03 62. 19 50. 52,56. 05 50. 91 

 43. 13 54. 09 56. 67 56. 04 47. 63 42. 71 

 60. 24 52. 57 .50. 48,38. 72 



46. 64 57. 70 

 43. 69 54. 94 



35. 2742. 25 

 39. 42 53. 12 

 38. 84 58. 73 



54.94 51.39 43.94 



58.03 59.5753.7149.39 



59. 79 52. 93 50. 79|46. 71 

 62. 10 51. 57,47. 87 39. 91 



38. 56 31. 38 



39. 63 32.61; 



31.40j25.37 .... 



31. 051 20.681 ... . 



3T03 26. 04 41. 90 56. 51 



60. 04 54. 59 50. 79 



37.8851.3 



4XO6 .50770 59. 07 59. 18 54. 0: 

 46. 50 58. 24!57. 50 57. 09.50. 44 

 50.35 57.58'57.62 58.75 



47.08,55. 51:58.05 58. 35 ! . 



40. 74 50. 64 58. 23 57. 47 56. 06 

 43. 81 53. 73I5S. 73 56. 4153. 19 

 47. 44 56. 90 57. 87 54. 53 50. 09 



44. 11 53. 76j58. 26 56. 08,53. 11 



39.1731.64 



35.8030.96 



, 34.99 1 33.83 : ! 



45. 16 36. 65 32. 20 40.63 55.18 



48.66 39.11 



44. 74 35. 79 

 40.42 34.36 



44.4736.42 



32. 39 

 30. OS 

 28.15 



30. 14 



,56.98 



42. 01 56. ( 



January assumed to be normal. 



Began using wooden tube. 



average variation for eight years of only 1.34°. From this time on, 

 the variation is somewhat greater, owing to the uncertainty of the snow 

 cover; but the variation decreases somewhat at the end of the winter. 



(5) The eight growing seasons for which complete records at 1 foot 

 are available show a slightly greater variation — 1.24° — than the six 

 whole years; but the six growing seasons corresponding to the six 

 whole years show practically the same variation, 1.04°. 



(6) The annual oscillation of soil temperatures, as determined from 

 the decade means, is for 1 foot 31.4°, and for 4 feet 22.7°; but the 

 corresponding oscillation of air temperatures is 35.9°, this greater 

 oscillation of the air being due to winter depression when the soil is 

 more or less blanketed with snow. The lowest average soil tempera- 

 tures occur in the second decade of January, while the lowest mean 



