W. B. No. 443. Issued Dee. 31, 1910.

te > een eMENT OF AGRICULTURE,
WEATHER BUREAU.

BULLETIN T.

FROST AND TEMPERATURE CONDITIONS
IN THE CRANBERRY MARSHES
OF WISCONSIN.

Prepared under the direction of WILLIS L. MOORE, Chief of Weather Bureau.
By

HENRY J.°COX, Professor of Meteorology.

WASHINGTON:

GOVERNMENT PRINTING OFFICE.
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Oceurrenceot low temperaturesiand trost insmoorlands. - <= 25. - se 2 ew ee we ee 7
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Bie maTesiuOlL Me; Gram Dern yxClO Dee pee eee seem ie ee a ele he ee a erate enyai een epse ee ee mae a 9
Comparison of temperatures in Maszachusetts, New Jersey, and Wisconsin........----.----------------- 10
Flooding to w ard OlfpiroSi@en epee oases ae e Ans BS fe ie ar eens ee She SEN OAT ae es Se = 11
Previous knowledge of low temperatures in the Wisconsin fee Se ee Ree ene eos ee case 2
(lacirayerbayes Ohi [INT AN TSS NSO oe c em soa e noe en Soe et en edo sae on Cea aa eee saenaan eae eee See os saa es eae 14
@haracteristics of stationsiat Cranmoor, Berlin; and! Mathers. 2-5... -..- 2. = 22 2. 2 = sees == 7
BSN ER STAM Ot WAVES WENO SICK So ee Boao ateagee ane emneee ss ssce pores code ceaseee ooaecenenee ase oe— sac 18
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IDTEGUSSTONTORVDELESPRO DURAN pease Ae sae sae eee ere ee nee masa ae eecinh ce Serene Se a2 oe See se eee 26
Minimum temperatures in shelters and in the open, both at 5 inches above the surface. -_---- Se 26
Readings of exposed minimum thermometers at the surface and at the 5-inch height .-.--....----------- 35
Observations of temperatures in soil and at the surface in different locations, Mather, Wis., 1906 and 1907 - 37
Air temperatures and soil temperatures at Station 7 and Station 7a, Mather, Wis., September, 1906______- 3
Minimum temperatures at the coldest and at the warmest points on the bog, Mather, Wis-....---.------ 46
Comparison of minimum temperatures at Station 1, in shelter, and on bog at Stations 3 and 5, Mather, Wis- - 52
Curves of air and soil temperatures at Stations 1, 3, and 5, Mather, Wis., 1907....-....-----.------------ 56
Minimum temperatures at the coldest and at the warmest points on the bog at Berlin, Wis 58
Minimum temperatures over dry and moist sand, Stations 3 and 4, Berlin, Wi 6]
Minimum temperatures over peat bogs, heavily vined and thinly vined, Berlin, Wis., September, 1906_- 62
Minimum temperatures over peat bogs and sanded bogs, thermometers exposed at 5 inches above the

Slintacewah Oranmoon Mather and tBenlin s. 2422 eon. 26 5= sose Seine ona Saeco meee ni 63
Readings of exposed minimums at various elevations over bog and upland, Stations 2 and 9, Mather, Wis- - 65
Comparison of wind moyement over upland and marsh, and effect on temperature, Mather, Wis., 1907. .- 73
Exposed minimum thermometers oyer peat and sanded bogs at the surface, and at elevations of 5 inches

andi s6uinches4 Bertini Wastes ceras- ers Soe ee a he ce oe ae ee nce e cena eee eee e se ceeains aes eee Se 76
Maximum and minimum temperatures at different elevations, Station 9, Mather, Wis : 7
Average minimum temperatures for the season of 1907 for all ioone together with soil temperatures,

IER OGTES \ Vi) Ss eee ers oe Deine et ee 2 eS See ee oa ee ee 78
Relationjbetweenidew-point and: minimuny temperatures = s-- 2. << - 8 ae os oe i i ee 84
(DAVE NoMaH naa abaya Me Jeera Viol Re eee ee eae oe aes ee) pee cee Be Se Ae See ae ee 88
Hogyover marshes andulow temperatures = 25223 22 te ae = a es ee ees Se ee eames e 88
Special aoeerecione on critical nights at the Berlin marsh, September, 1906_...-.....-..--------------- 89
Becta k trostjOn! thier Gk We Ln yess sees nse esr a ee re ee ee lsh a ee mi ec ec 9]
Disadiwantace from) retlowinet 2 <ereesem ees se ac cles Sie re ae ea a cee = 92
Special data in connection with forecasting frost in the cranberry marshes---- 92
Discussion of daily weather maps and local conditions in connection with frosts i

in 1906 92
Discussion of daily weather maps and local conditions in connection with frosts

in 1907 95
Comparison between temperatures in the bog at Mather, Wis., and at United States Weather-Bureau

lievee., ALG Omagh WISE © oe a ee ee See 9 See I ca ee eee Ee ees eae ee eae 110
Temperature conditions in the bogs during the seasons of 1908 and 1909._...._......-..-..-----.--.---- 114
Meaipenanineran the: water Ube TeservOlb. os- - sake owen eames 2 aa ae ee eno anes cie nace Se Soacee 114

CO NGGUSLO Ngee IEEE ot once GL Soh cree ea are a eee ae ae Sat coe oust Suse epee Sho 116
Advantages gained from sanding, draining, and cultivating..........-.-------------------------------- 116
A study of the general and local conditions necessary for frost in the marshes-_-.-...--.---------------- 117

(3) :

Fia.

. State of Wisconsin. Map showing principal counties in which cranberries are grown
. Appleton marsh, Mather, Wis., showing north section of bog, also brush where lower reservoir is

. Daily weather map, 8 a. m., August 7, 1904
. Daily weather map, 8 a. m., August 8, 1904
. Fitch cranberry marsh, Berlin, Wis., looking north along county line ditch where Stations 2, 3, and 4

. Fitch marsh, Berlin, Wis., showing car track on bog, dwellings, warehouses, and shanties
. Station 5, Fitch marsh, Berlin, Wis. In ferns and canebrakes
. Temperature curyes for Stations 3 and 4, Mather, Wis., September 23 to 30, 1906
. First figure, traces showing average hourly soil temperature for the season of 1907 at a depth of 3

. Graph of maximum daily soil temperatures in bog, Mather, Wis., 1907
3. Thermograph and anemometer records on July 27, 1906, Mather, Wis....--.----------------------
. Thermograph record on the marsh, Berlin, Wis., noon, August 30, to noon, September 1, 1906, show-

. Temperature curves of air, soil, and water, Mather, Wis., September 23 to 30, 1906
. Temperature curves of soil at Stations 3 and 5; also of air and water, Mather, Wis., September 16 to

LAGS RAVE TONS:

located. View from upland

. Diagram of the Appleton cranberry marsh, showing location of cultivated sections, the uplands, instru-

ment stations, reservoirs, etc., Mather, Wis

are located

. Station 1, Mather, Wis. Instrument shelter on upland near dwelling. Photograph made in 1906_--
. Station 2, Mather, Wis. In bog over sphagnum moss and long grass outside cranberry marsh
. Station 8, Mather, Wis. Newly sanded, thinly vined
. Station 4, Mather, Wis. Newly sanded, heavily vined
. Station 5, Mather, Wis. In uncultivated bog
2. Station 6, Mather, Wis. Old sanded, heavily vined ....----.-.----.------------.--------- See ees
. Stations 7 and 7a, Mather, Wis. In scalped section and on moss adjoining
. Station 8, reservoir, showing wide ditch and floating bog, Appleton marsh, Mather, Wis
. Station 9, Mather, Wis. In garden on upland
. Station 10, warehouse, Appleton marsh, Mather, Wis. Anemometer on cupola. Sunshine recorder

on comb of building. -

inchesand 6) inches: Station, Mather, Wise see ae ela ee allel eee al lire
Second figure, traces showing average hourly soil temperature for the season of 1907 at depths of 3
inches and 6 inches, Station 5, Mather, Wis

. Graph of maximum and exposed minimum air temperatures and soil temperatures in bog, Mather,

Wis., 1907

ing effect of passing clouds on temperature

. Traces of thermograph in shelter on upland and in vines on marsh. Uncorrected readings. Berlin,

Wis., noon, September 4, to noon, September'5, 1906. ---- <= -- <2 - = a en gee
’ ? i ’ p 7

23, 1906

. Temperature curves in shelter and in open in ‘‘the ferns.’’ Uncorrected readings. Berlin, Wis., noon
I P' : ) ,

September 29, to noon, October 1, 1906

. Traces of thermographs in shelter, both at Mather and Berlin, Wis., from noon, September 23, to

noon, September 24, 1906

. Thermograph traces in open over bog, from noon, June 5, to noon, June 6, 1907, showing effect

of flowing of marsh on temperature of air at stations 3 and 5, Mather, Wis.-.--.--.-..-..--------

. Temperature curves in the vines on the marsh, Berlin, Wis., from noon, September 13, to noon,

September 14, 1906, and from noon, September 27, to noon, September 28, 1906

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19

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22
23

24
25

ACKNOWLEDGMENTS.

The assistance of those who have taken part in this investigation is hereby acknowledged:
Mr. R. N. Covert, United States Weather Bureau, performed work in the field at Mather in
1906 and prepared several of the drawings used in the publication; both Mr. G. M. Richards
and Mr. E. H. Haines, United States Weather Bureau, carried on the field work at Mather
during the season of 1907, and the latter also made the computations appearing in the tables.
A vast amount of tabulated data has been prepared, although few of the tables have been
published, as a whole, for want of space.

Acknowledgment is also made of courtesies extended by Mr. H. R. Laing, manager of the
Stanley Marshes at Berlin, Wis.; Judge John Gaynor, Grand Rapids, Wis.; Prof. A. R. Whitson,
of the University of Wisconsin; Mr. J. N. King, Mather, Wis.; the Federal Cranberry Com-
pany, South Carver, Mass.; and Mr. J. J. White, of New Lisbon, N. J.

Prof. W. J. Humphreys, United States Weather Bureau, has kindly read the manuscript
and has offered valuable suggestions for which the writer is greatly indebted.

(5)

AN INVESTIGATION OF TEMPERATURE AND FROST CONDITIONS IN THE
CRANBERRY MARSHES OF WISCONSIN.

INTRODUCTION.

Cultivation of cranberries confined to three States—The cultivation of cranberries in the
United States is confined mainly to three States—Massachusetts, New Jersey, and Wisconsin.
In Massachusetts the cranberry-growing region in turn is limited almost entirely to the counties
of Plymouth, Barnstable, and Bristol; in New Jersey, to Cape May, Atlantic, Gloucester, Bur-
lington, Ocean, and Monmouth counties; and in Wisconsin, to Wood, Jackson, Juneau, and
Monroe counties in the Wisconsin River Valley, and to Waushara and Winnebago counties in
the Fox River Valley. (Fig. 1 for map of Wisconsin.) For several years there has bean a
marsh in the village of Cameron, Wis., and recently one was started in the Lake Superior
region near the town of Ashland, Wis. The cultivation is slowly extending to Michigan and
Minnesota. and even Oregon, but the cultivated marshes in the three states last named are
at present comparatively of no importance. There are, of course, wild cranberry marshes in
several of the Northern States, but the berries picked therefrom are seldom sufficient to supply
even local needs. They are of little consequence as compared with the fruit produced in the
cultivated marshes of Massachusetts, New Jersey, and Wisconsin.

_ The cultivation of cranberries as an industry is by far older and more successful on Cape
Cod than elsewhere. Nearly every bog, whether large or small, on the Cape, has been con-
verted into a cranberry marsh, and there we find the highest state of cultivation, the bogs being
almost invariably sanded, well drained, and free from weeds. The Massachusetts bogs are
individually small as compared with those found on the extensive moorlands of New Jersey
and Wisconsin; and often one cranberry marsh in Massachusetts is made up of several small
sections. That of the Federal Cranberry Company, near South Carver, Mass., which annually
produces about 10,000 to 14,000 barrels of berries from a total area of 180 acres, is composed
of 18 little bogs, separated naturally by hard land, but connected, nevertheless, artificially by
ditches for the purpose of flooding; while, on the other hand, the Wisconsin moorlands are
extensive and often stretch for many miles. The Wisconsin River Valley, the chief cranberry-
growing section of the State, comprises an area of about S00 square miles, 550 of which are
marsh land, the remaining portion being “islands” or hard land. In topography, the moor-
land sections of New Jersey more nearly resemble those of Wisconsin than they do those of
Massachusetts. The average Massachusetts crop is about 300,000 barrels, while New Jersey
and Wisconsin contribute 150,000 and 75,000 barrels, respectively.

Occurrence of low temperatures and frost in moorlands.—During clear cool nights the air
usually is much colder over bottom lands, where the cranberry grows, than on neighboring
slopes and uplands. This is especially true when but little wind or a calm prevails. During
such nights the ground loses its heat rapidly by radiation, and the air lying immediately above
is cooled. When cold heavy air lies over uplands and slopes it gradually settles through gravity
to lower levels, being replaced by warmer air brought from above, which is in turn cooled. In
fact, a gradual descending flow is established from the uplands to the valley, so that the cold
air of the hilltops is drained away. Quite frequently crops in bottom lands suffer severely
from frost, while on neighboring uplands the temperatures are not injurious. It is well known
that the tobacco fields on the slopes of the Connecticut River often escape injury when damag-
ing frosts occur lower down. The cranberry, moreover, has its habitat only in the bottom

(7)

8

lands where frost is most likely, but protection may be afforded by covering the bog with
water stored in adjacent reservoirs.

Cultivating, draining, and sanding.—Protection to a considerable extent may also be
obtained by cultivating, draining, and sanding the cranberry marsh. In bottom lands the
vegetation is generally dense and the soil damp. Leaves and grasses are excellent radiators,

STATE OF WISCONSIN.

Scale of Miles.

oO 10 20 90 40 $0 60 70

Ashland

°
Cameron

—*
=
Ww
2
=)
—

La Crosse

r
'
1

Milwaukee

SHOWING PRINCIPAL COUNTIES IN WHICH
CRANBERRIES ARE GROWN.

Fic. 1.—Map showing principal counties in which cranberries are grown.

and consequently lose their heat rapidly. The heat lost by radiation passes through the air,
and does not warm it if the air is dry; but when the air is moist some of the heat is absorbed.
Moreover, where the vegetation is dense, the soil beneath is screened from insolation, so that it
is heated but little by the sun during the day, and has but a small supply of heat stored up.
As a consequence the temperature of air lying over a field with a dense growth of vegetation is

9

relatively low during any cold clear night. Cultivation, by reducing the amount of vegetation,
permits greater heating of the soil during the daytime, and consequently there is a larger store
of heat to give out at night.

The peat soil found in bottom lands, on account of its capillarity, brings water to the
surface, and the cold produced by the evaporation of this moisture is considerable. This is
especially the case where the drainage is poor.- Ditches, run at frequent intervals in the marsh,
serve to drain the water from the surface and to reduce the amount of evaporation; and, at the
same time, to conduct water of comparatively high temperature from adjacent reservoirs to
the bog when frost threatens.

The moisture at the immediate surface may also be reduced by sanding—placing a layer
of sand on the surface of the peat—because sand, almost wholly lacking in capillarity when
coarse, does not bring the water to the surface. Moreover, sand on account of its low specific
heat is warmed more easily, and acts as a conserver of heat. A sanded surface absorbs solar
radiation tolerably well, and gives out heat by radiation only slowly. It cools largely by con-
duction to the atmosphere, thus serving to modify night temperatures by heating the air lying
above.

Very few of the Wisconsin bogs have been sanded, and many have a rank growth of vege-
tation, grasses and ferns often attaining a height of 2 feet or more. Frequently canebrakes
and sagebrush are found. The uprights from the cranberry vines are usually: more than 6
inches in height, and occasionally 12 inches or more. The growth of the vines is very rank,
and the marshes are seldom kept clean, so that even when the vines are laden with berries, one’s
attention is attracted to the vegetation rather than to the fruit. On the other hand, the Cape
Cod marshes are invariably sanded and the vines are thin, the uprights seldom reaching a height
of more than 5 inches, as the coarse sand employed dwarfs the vines. The berries, moreover, are
usually so plentiful that one hardly notices the vines. The contrast between the Massachusetts
marshes and those of Wisconsin is so pronounced that the growers in Wisconsin have been said
to raise vines, and those on Cape Cod berries. This statement has some foundation in that the
yield per acre on the Cape is about double that in Wisconsin. The marshes in New Jersey
perhaps take middle ground between those in Massachusetts and Wisconsin. They are usually
well cultivated, but only infrequently sanded. In fact, not 15 per cent of the New Jersey bogs
are sanded. The growers there prefer to confine the cranberry culture to the natural peat soil,
believing that it produces a crop of better quality than does a sanded bog, and that the expense
of sanding is not justified by the increased returns. The right kind of sand is near at hand for
the Cape Cod growers, but it is not easily available for many of the growers in New Jersey and
Wisconsin. A coarse sand, resembling gravel, is ordinarily used, fine sand packing too hard
and being therefore valueless.

The drainage in the bogs of Cape Cod, moreover, is excellent, the marshes during the
growing season usually being as dry as an ordinary prairie—in strong contrast to the dampness
of the Wisconsin bogs. The little need for reflowing on the Cape permits the growers there to
keep the ditches dry during the summer season, but the Wisconsin growers are obliged at all
times to keep a certain amount of water in the ditches in order to facilitate reflowing when
frost is expected. The Wisconsin marshes are consequently more or less damp during the
entire season. Cultivation, moreover, is practiced on Cape Cod, preventing the rank growth of
vegetation and weeds that screen the soil from the sun’s rays. Cultivating, draining, and
sanding thus serve to cause higher soil temperatures in the daytime, and, as a result, relatively
higher air temperatures at night.

These facts—the advantages gained from cultivating, draining, and sanding—were quite
apparent to the writer after a preliminary investigation; and an effort will be made in this
report to show in detail, by figures, the relation between the air temperature and the character
of the soil and vegetation lying beneath.

Enemies to the cranberry crop.—The great enemies to the cranberry are frosts, floods,
droughts, worms, and fire; and while the damage from frost is seldom very great in Massa-
chusetts and New Jersey, frost is the berry’s greatest enemy in Wisconsin. The meteorologist is

10

chiefly interested in the frost problem, as far as cranberry growing is concerned. However,
floods and freshets during the growing season frequently work havoc with the cranberry crop,
and it was because of the floods in the spring of 1908S that the crop in the vicinity of Berlin,
Wis., was nearly a complete failure. In that year it was not possible to completely draw off the
winter flow until the last of June, instead of in May as usual, and consequently the crop of ber-
ries in some bogs was confined to the tops of the vines while in others the crop was a total failure.
Such surplus of water not only destroys the crop of the current year, but also weakens the
vines so that they show the injurious effects for several years afterwards. The freshets of the
spring and summer of the year 1906 were responsible for great damage to the New Jersey crop.
Tf a flood covers the marsh during extremely warm weather there is damage to the vines and
berries from scalding, the reflection of the heat from the surface of the water cooking the berries
until they resemble baked apples. This liability to damage is always considered by the growers
in reflowing their marshes in order to drown the vine and fruit worms, and it is necessary to
select a period of cool and cloudy weather, if possible, so as to get the best results with the least
injury. Damage is also liable from lack of water, not only in the insufficient supply available
for reflowing the marsh for frost protection or otherwise, as in Wisconsin in 1909, but because
in seasons of great drought the vines become parched and extensive fires are likely to occur. As
a result of the drought of 1894, 95 per cent of the vines in the Wisconsin River valley were de-
stroyed by fire, but the marshes have since been replanted. In 1909, 60 to 75 per cent of the
Wisconsin crop was lost in the severe frosts of September because of lack of water for reflowing.

Comparison of temperatures in Massachusetts, New Jersey, and Wisconsin.—From a study
of the temperature conditions in the three states during the growing season it is evident that
the temperature is usually much lower in Wisconsin than in the eastern cranberry-growing
sections. From a comparison made between temperature readings observed in shelters on
hard land at Plymouth, Mass., Whitebog, N. J., and Mather, Wis., in the midst of the respective
cranberry districts, for the months of May and September, 1906—critical months in the cranberry
industry and fairly typical ones—it was found that the minimum temperature at Plymouth
averaged higher by 5.1° in May and 4.5° in September than at Mather; while at Whitebog, for
the same months, the minimum temperature averaged 8.1° and 7.6°, respectively, higher than
at Mather. The average readings at the respective stations were as follows:

| May. | September

| a ee
Mather, Wis. 2:=..ssetes- e -sease-ce 41.9 50.5. |
Plymouth, Sa hener Ae oot eet 47.0 55.0 |
NWIHILE DOP MING U Biot saan eee eee | 50.0 58.1 |

The differences between these averages represent approximately the relation between the
minimum temperature readings in the bogs in the various States, although for purposes of
comparison it was found necessary to use readings made on hard land. The first frost in the
New Jersey bogs in autumn usually occurs from two to three weeks later than in Wisconsin.
In 1906, for instance, the first light frost at Whitebog occurred on October 8, and a heavy frost
was not reported until October 11, while in Wisconsin the first frost was noted September 14°
and the first killing frost on September 27.

Frost is so damaging in the Wisconsin bogs that means of protection from it must be the
first provision made by the cranberry grower. Damaging frosts invariably occur there in the
month of May, often in June, rarely in July, occasionally in August, and invariably again in the
month of September; while midsummer frosts are unknown in the East and seldom occur in the
month of June. In the East severe frosts do not occur so late in the spring or so early in the
autumn; and consequently the seasons in Cape Cod and New Jersey are much longer than in
Wisconsin. The season in the latter state is quite short, and it is only during a year in which

aA)out two weeks later than the average.

11

the crop season has a temperature far above the normal that the cranberry grower in Wisconsin,
without means of protection from frost, can hope to gather even a fair crop.

Flooding to ward off frost.—It is apparent from the foregoing that, although the Wisconsin
crop is usually smaller than that of either Massachusetts or New Jersey, it has special need of
proper protection from frost, and hence the need of accurate frost warnings. The large majority
of the Wisconsin and New Jersey marshes and a limited number of those in Cape Cod are connected
with vast reservoirs, which are used for flowing the bogs in winter in order to prevent winter
killing, and for reflowing during the growing and picking season for the purpose of warding off
frost. In fact, as stated above, the first thought of the Wisconsin grower is to provide ample
water supply. Some of the bogs in Massachusetts have no water supply, even for winter flowing,
but all the bogs in Wisconsin and nearly all those in New Jersey have ample supply for this pur-
pose. Growers usually turn on the winter flow in November and keep it on throughout the entire
winter. Some Wisconsin growers take the winter flow off again about April 15, but the majority
retain it until after the first of May, and a few until the last of May. Those who keep the flow
on until late in May do so believing that the water prevents the hatching for that season of the
fruit worms with which the marshes have been afflicted. Some growers who take the winter
flow off the marsh early reflow during June and keep the water on for a few days, if a period of
cool weather prevails, in order to guard against the fruit worm. It is supposed that the eggs
are laid in May along the dams, and that if, through drowning, they are prevented from hatching
during the month of June, the worms will not appear that season. As a period of three months is
sufficient to mature the crop, should the water be retained until June 1, the cranberries would
ordinarily be ripe for picking about September 1. Frequent reflowing, however, if the fruit
is set, Injures the vines and the berries as well. Moreover, in flowing and reflowing, damage
is sometimes done to the crop by lime or other impurities in the water.

Most of the Wisconsin marshes can be reflowed in about four hours, but there are a few in
that state that can not be satisfactorily flooded in anticipation of frost. In the marshes of
the East, of course, as stated above, frosts are not as serious as in Wisconsin because of their
more favorable geographical location. On Cape Cod, moreover, where intensive farming is
practiced in the shape of sanding, draining, and weeding, there is not the same need for reflowing
to ward off frost. Only about 30 per cent of the Cape Cod bogs can be reflowed as a means of
warding off frost, and this can not be done twice in one week in more than 10 per cent of these
bogs during a season of normal rainfall. In New Jersey somewhat better conditions as regards
water supply prevail. Many of the bogs, as the excellent one at Whitebog, for instance, usually
have ample water supply. With such limited water protection in Wisconsin as is usually
available in Massachusetts bogs, success in the industry would be quite impossible. In reflowing
a marsh the amount of water used depends upon the severity of the frost expected; sometimes
it is sufficient merely to raise the water in the ditches; at other times to bring it up to the surface
of the marsh; and, in extreme cases, to completely cover the vines and berries.

The Appleton marsh at Mather is a typical Wisconsin bog, and is usually provided with
ample water supply. (Figs. 2,3.) The reservoirs, both upper and lower, are largely floating
bogs. Wide ditches connect the reservoirs with the cultivated sections and smaller ditches
run through the sections from 80 to 100 feet apart. Water is usually present in the ditches to
a depth of 1 to 2 feet, the surface of the water averaging perhaps about 12 inches below the
surface of the marsh itself. These ditches are provided with gates to regulate the flow from
the reservoirs. There is also a gate at the foot of the marsh (marked ‘‘B” on Fig. 3), which
is shut during flooding and opened later in order to drain the water off. While 3 acres of reservoir
are generally sufficient for flooding 1 acre of vines, yet the acreage of the marshes of Wisconsin
usually has about one-tenth planted in vines, and the rest is given over to reservoirs and protec-
tion of water rights. ;

12

Previous knowledge of low temperatures in the Wisconsin bogs.—It has been knownefor many
years that the minimum temperature in the Wisconsin bogs on clear cool nights falls far below
the readings of the instruments at the nearest Weather Bureau station, and that frost often
occurs in these bogs when there is no evidence of it on hard land. Prof. Willis L. Moore, now
Chief of the United States Weather Bureau, was the first forecaster to give this subject special
attention. It was in 1893, while in charge of the Milwaukee office, that he visited several of
the bogs in the Wisconsin River valley. Later, other officials from time to time have visited
these marshes. Professor Whitson, of the Wisconsin Experiment Station, undertook an investi-
gation in 1904 in connection with the Branch Experiment Station located at Cranmoor. As
a preliminary to the investigation started by the United States Weather Bureau, efforts were
made to secure reliable data from various Wisconsin growers relative to the occurrence of frost
and freezing temperatures during previous years, but it was found that very few of them had
kept a record of any value. Some data, however, have been furnished by Mr. C. H. Johnson,
manager of the Wyatt and Purdy marsh at Valley Junction. His statement shows that during

Fic. 2.—Appleton marsh, Mather, Wis., showing north section of bog, also brush where
lower reservoir is located. View from upland. Direetly beyond the brush is located the
main section. Shelters at Stations 3 and 4 appear on the extreme left.

the period of twenty years from 1885 to 1904, inclusive, frost usually occurred in the summer at
Valley Junction before the end of August. In 1885 heavy frost was recorded on August 22, in
1890 light frost occurred as early as August 10, and heavy frost in the same year on August 23.
In several years of this period frost oceurred more than once during the month of August, but
Mr. Johnson has no record of its occurring in July; however, in a few instances, frost has been
observed in that month by other growers.

The frost which occurred on June 11, 1903, in Wisconsin, did much damage, and, as a
result, less than half a crop was harvested in that year. Some of the growers lost nearly all,
although others, because of their location and better facilities for protection, secured nearly a
full crop. The frost of August 8, 1904, reduced the crop of berries to about 60 per cent of that
usually secured. No damage resulted in marshes which had been flooded. before the frost.
Unfortunately, some of the growers did not have their ditches clean, and the water in them was
low, so that there was great delay in reflowing; and, as a consequence, considerable damage was
done by the frost.

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14

This freeze of August 8 is remembered as more severe than any previous one in midsummer
within the recollection of the Wisconsin cranberry growers. The day before, August 7, was
cloudy, owing to a slight disturbance which was centered over Lake Michigan. The sun’s
rays were obstructed by dense clouds which kept the temperature of the air in the shade down
to a maximum of 65° to 70°. The clouds, however, cleared away just at sunset and the wind,
which was fresh during the day, became light in the evening, and the barometer rose steadily.
Thermometers exposed in the vines in peat bogs at Mather and Cranmoor, Wis., recorded
minimum readings of 29° and 26°, respectively, on the morning of August 8, and frosts were
severe generally throughout the moorlands. No frost was reported that morning from any
of the regular Weather Bureau stations, except Escanaba and Houghton. The minimum
temperature at La Crosse, Wis., was 48°; Green Bay, Wis., 45°; Duluth, Minn., 50°; and
St. Paul, Minn., 48°—all being readings from instruments located in shelters on the roofs of

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Fic 4.—Daily weather map. 8 a. m., August 7, 1904.

buildings. It would seem as if only an extraordinary condition could produce such low tempera-
tures in midsummer.

A special study should be made of the weather maps of August 7-8 (Figs. 4, 5), showing
the general weather conditions prevailing throughout the entire country. On August 7 the
slight disturbance, marked “‘low,’’ was central over Lake Michigan, while an area of high
barometer, inclosed by the isobar of 30.2 inches, covered the Dakotas. The temperatures in
North Dakota were in the forties, and the lowest reading was 40° at Minnedosa, Manitoba.
The “low” remained nearly stationary during the greater portion of the day, causing the cloudi-
ness and the relatively low day temperatures in Wisconsin, above referred to. It advanced east-
ward, however, by evening. On the morning of August 8 the high was directly over Wisconsin,
with the center still mclosed by the 30.2-inch isobar.

As a general principle, it may be stated that the most favorable conditions as regards the
production of low temperatures locally in the damp lowlands are an overcast sky during the

15

daytime, so that the soil is not heated by insolation; clearing at sunset, so that there may be
active radiation at night; a rismg and a comparatively high barometer which permits a settling
of the cold air toward the ground; a fresh wind in the daytime, which reduces the temperature
of the surface of the soil by the cold of evaporation, and which dies down at sunset and conse-
quently does not interfere with the gradual settling of the cold air to the ground; and compara-
tively low humidity, as radiation from the ground through dry air is freer, or, in other words,
the lower the humidity the less the absorption of heat by the air. On August 7-8, 1904, all
the conditions were apparently present for the production of abnormally low minimum tempera-
ture, viz: Cloudiness and fresh breeze during the day, followed by clearing in evening, rising
barometer, falling of the wind, and comparatively low humidity.

Beginning of the investigation.—As stated above, it was found that but few of the Wisconsin
erowers had kept any record of temperature and frost conditions in the bogs. Visits were

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made to several of the marshes and communication was had with many of the growers for the
purpose of securing any available data in anticipation of the proposed investigation. These
men are usually intelligent and keen, and intensely interested in their work, and consequently
it is strange that so little attention had been given to the preservation of temperature records,
as definite knowledge of the subject of temperature in the bogs should be of permanent value.
Moreover, there had been a wide divergence of opinion among the growers regarding the problem
which was being undertaken, but all seemed to be interested and willing to cooperate. The
growers stated that occasionally frost attacked one section of a marsh and left the remainder
untouched, without apparent cause; also, that damage was sometimes done to one marsh
while another adjoming escaped injury. They were naturally puzzled over these unusual
features. In the investigation which Prof. A. R. Whitson ¢ had started at the Cranmoor Experi-
ment Station in 1904, the observations were restricted almost entirely to artificial conditions

@ Wisconsin Bulletin 119, A Report on Cranberry Investigation.
51936°—Bull. T—19——_2

16

created for the purpose. The section at the Branch Experiment Station planted with cran-
berries is not representative of the Wisconsin cranberry marshes in actual operation, But rather
of the conditions prevailing on Cape Cod. The plat of ground at Cranmoor is so small that the
various thermometers used in Whitson’s investigation were comparatively close together, and
all were affected more or less by the same conditions. Whitson apparently lost sight of the
fact that a thermometer exposed at any point is largely affected by its environment, as well
as by the conditions at the immediate point of exposure. While Whitson has endeavored to
lead the way, and to induce Wisconsin growers to adopt eastern methods of sanding, cultivating,
and draining, the latter have been very slow to follow. For certain reasons that will develop
later the majority of the Wisconsin growers have not considered it advisable to follow the
Massachusetts method in sanding and cultivating.

It was deemed best to conduct the investigation by the Weather Bureau as far as practicable
in typical bogs, fully representing the various conditions existing. In beginning this work in June,
1906, special cranberry marsh stations were established at Cranmoor, Mather, Berlin, and Cameron
and continued throughout the season. The Cranmoor station was at the Wisconsin Branch

Fic. 6.—Fitch cranberry marsh, Berlin, Wis., looking north along county line ditch where
Stations 2, 3,and 4 are located, Fog in the distance on north side of the marsh just after
daybreak.

Experiment Station in charge of Professor Whitson, referred to above. It is situated in the
center of the Cranmoor region, and adjoins the well-known Gaynor-Blackstone marsh. The
Appleton marsh at Mather was selected because it is typical of the Mather district. (Figs. 2,
3.) Both Cranmoor and Mather are located in the extensive moorlands of the Wisconsin
River valley. The Berlin station, established at the Fitch marsh, is 8 miles northeast of the
city of Berlin in the Fox River valley, and in a much less extensive moorland. (Fig. 6.) The
Fitch marsh is old and fairly productive, but poorly drained and lacking in satisfactory means
for reflowing. The Cameron station was situated in the northwestern part of the State, and
the marsh at that point was selected on account of its geographical location and because it was
in a narrow gully between stretches of hard land. At these four stations special local observers
were secured. While at Cranmoor, the observer was Mr. O. G. Malde, an assistant to Pro-
fessor Whitson of the Experiment Station, at the remaining stations the persons employed
were managers of the respective marshes. All of the local observers except the one at Cameron
-had long experience in making observations. In July, 1906, moreover, an experienced observer
was sent from the Chicago office to Mather to conduct observations in detail, and the writer

17

himself spent the greater portion of the season in personal work at Mather and Berlin in order
to secure the data first-hand.

An extensive equipment was secured for the Mather and the Berlin stations for the purpose
of going into the subject exhaustively, and thus finding the true reasons for the comparatively
low temperatures in the bogs and their great variation. It was expected that the work in 1906
would be merely preliminary and that no definite results could be secured in so brief a period;
that only sufficient data could be obtained in the first season to prepare more definitely for the
work of 1907. This proved to be true, as considerable experimenting was required to determine
how and where the various instruments should be exposed. Moreover, the soil thermographs,
ordered from abroad the previous winter for this special work, did not arrive in this country
until almost the end of the season, and the results obtained from some of them for the month of
September, while they were in operation, are of little value. It was extremely difficult to
adjust them so as to secure accurate records. Furthermore, the observations made at Cameron
were found to be unreliable, and they have not been used in this discussion. The result of the
experience with the Cameron observer suggests that observations for scientific purposes should
never be intrusted to an untrained observer, even though he receive compensation. The data
must be accurate; otherwise the deductions and conclusions have little value. The observa-
tions appearing in this bulletin, with the single exception of Table 12, were made by regular
employees of the Chicago Weather Bureau office.

The stations at Berlin and Cameron were closed at the end of the season of 1906. In 1907
the cooperation of the Cranmoor Experiment Station was continued and the work at Mather
was much enlarged, trained observers from the Chicago office conducting the observations there
from early in May until the end of October. Also during the seasons of 1908 and 1909 a limited
number of observations were secured from Cranmoor and Mather. Moreover, observations
made at these two stations, beginning with 1905, have been telegraphed daily to the forecast
center at Chicago for the use of the forecaster in issuing frost warnings for the Wisconsin cran-
berry marshes. The Berlin marsh had no facilities for telegraphing and its report was not
transmitted daily.

Characteristics of stations at Cranmoor, Berlin, and Mather.—The three marshes selected for
the investigation are widely separated and fairly representative of the conditions prevailing in
Wisconsin marshes. Owing to the high state of cultivation at the Cranmoor Experiment Station
there is usually no need for reflowing during the entire cranberry season in order to ward off
frosts. This is in strong contrast to the conditions prevailing in the Gaynor-Blackstone marsh,
immediately adjoining, which represents the average conditions found in the Wisconsin bogs.
The Appleton marsh at Mather differs from the Gaynor marsh in that the greater portion of it
has been sanded. It was sanded in 1898 to a depth of about 2 inches, and sanding was again
done in the winter of 1905-6, but in the meantime a layer of peat an inch or two in thickness had
accumulated over the formersanding. Having ample water supply, it can usually be reflowed
in about four hours. This marsh was fairly dry during the season of 1906, but in 1907 it was,
unfortunately, at frequent periods very wet. This latter condition was due primarily to heavy
rains and to the breaking of the dams in the reservoir of a marsh immediately adjoining. The
water ‘‘backed up” on the Appleton marsh at times, and it was drained off with difficulty;
and consequently, the conditions as regards moisture were not as typical of that marsh in 1907
as in 1906 and the exposure of the instruments, as a result, not as satisfactory. Some of the
instruments exposed at. the surface of the bogs were, at times, covered with water. The reflow-
ing in anticipation of frost also affected the exposure of the instruments, but that was a com-
plication that could not be avoided, and in these cases, the readings have either been estimated
or thrown out entirely.

The Fitch marsh at Berlin (Fig. 6), as stated already, could be reflowed only with great
difficulty, and it was seldom attempted, the course usually taken in anticipation of frost being
to raise the water high in the ditches. The marsh was naturally wetter than the Appleton
marsh, the drainage not being as good. In the season of 1906, When observations were made

18

at Berlin, there was little change in the amount of moisture in the bog, except immediately
following the heavy rain of July 29, when 4.99 inches fell in a few hours during a thunderstorm.
As a result of this fall over the bog and the drainage from the surrounding country, the water
was over a foot in depth on the marsh, and several days were required to drain it off.

The stations that were established at the Appleton marsh at Mather in 1906 were con-
tinued during the season of 1907 without change as regards location, although the character of
the equipment was improved considerably. (Fig. 3 shows plan of marsh, giving locations
of cultivated sections, reservoirs, uplands, brush, woods, etc. The figures mark the stations
and the letters mark the gates that control the water supply.) In comparing Figures 2 and 3
it should be noted that in the photograph (Fig. 2) the marsh in the foreground, which is inter-
sected by numerous ditches for the purpose of flowing and reflowing, is identical with the culti-
vated sections in which Stations 3 and 4 are located, appearing in Figure 3. The adjoining
uplands or islands [any stretch of hard land in the bog region is called an island], have an ele-
vation of 10 to 15 feet above the surface of the marsh. The peat and muck in this marsh is

Fic. 7.—Station 1, Mather, Wis.

Instrument shelter on upland near dwelling. Photograph made in 1906. Shelter lowered
from an elevation of 8 feet to 5 feet in 1907. Rain gages about 20 feet to the right. They do
not appear in the picture. -Garden in the background where Station No. 9 was located.

from 10 to 25 feet in depth, and the soil of the surrounding islands is a sandy loam, mostly
covered with grass, with brush and trees at intervals.

Equipment of the Mather Station.—The instruments at Mather were located at stations
widely separated and in the midst of large sections as far as possible typical of the conditions
prevailing at the points where the instruments were exposed. An exception was made in this
respect at Station 7. The followine was the equinment in operation in 1907:

Station 1, north of the dwelling house on Long Island. The shelter (shown in the photo-
graph, Fig. 7, taken in 1906) was lowered in 1907, so that the floor was about 5 feet above
the ground, instead of 8 feet as in 1906. Equipment: Maximum, minimum, and exposed
thermometers, also air thermograph, all in the shelter, Station 1 was also provided with an
Assman aspiration psychrometer, attached to the northeast corner of the dwelling, and two
rain gages. A barograph was kept in the dwelling.

Station 2 (Fig. 8), in the bog over a dense growth of sphagnum moss, outside of the
cranberry marsh proper. The moss probably reached to a depth of 6 feet, and, like a sponge,
was saturated with water. The station had, however, the advantage of being outside the

19

Fic. 8.—Station 2, Mather, Wis.

Photograph made in

In bog over sphagnum moss and long grass outside cranberry marsh.
907.

1906. Thermometers at various elevations up to 36 inches attached to posts in 1

Fic. 9.—Station 3, Mather, Wis.

Newly sanded, thinly vined. Photograph made in 1907. Grasses seen in the photograph
were not present in 1906, and the vines were not so dense.

20

cultivated sections that were flooded in anticipation of frost, and consequently the conditions
as regards moisture varied less here than elsewhere in the bog. Equipment: Air thermograph
and maximum and minimum thermometers in the shelter about 5 inches above the surface of
the marsh. Outside and immediately to the north of the shelter were two posts on which
were fastened 6 maximum and 6 minimum thermometers facing south at the following eleva-
tions: Surface, 24 inches, 5 inches, 74 inches, 12 inches, and 36 inches; also minimum ther-
mometers at additional elevations of 10 inches and 15 inches; 2 soil thermometers in the moss
at depths of 3 inches and 6 inches, respectively; soil thermograph, the bulb of which was
exposed at a depth of 3 inches in the moss.

Station 3 (Fig. 9), in the cultivated section was heavily sanded during the winter of
1905-6. It was thinly vined during 1906, and relatively so as compared with the other stations
in the cranberry marsh in 1907, but the vegetation was then more dense than in the previous
year. It may be considered as representing the best conditions on the bog as regards sanding,
cultivating, and draining. Equipment: Minimum thermometer in the shelter at an elevation
of about 5 inches above the surface of the bog; minimum thermometer in the open at the sur-

Fic, 10.—Station 4, Mather, Wis.

Newly sanded, heavily vined. Photograph made in 1907.

face of the marsh, also at elevations of 5 inches and 36 inches above the marsh; maximum
thermometers similarly exposed at the surface and at 36 inches above the marsh, the thermome-
ters at 5 inches and at 36 inches being fastened to a post; air thermograph which rested on the
surface of the soil; soil thermometers at depths of 3 inches and 6 inches, respectively; soil
thermographs, the bulbs of which were similarly exposed.

Station 4 (Fig. 10), also a heavily sanded section, but the vines and vegetation relatively
dense. This exposure may be considered as representing the best conditions prevailing on the
bog as regards sanding and draining. Equipment: Minimum thermometer in shelter at an
elevation of about 5 inches above the surface of the bog; minimum thermometers in open, at
the surface of the bog, and at an elevation of 5 inches; maximum thermometer at the surface
of the marsh; an Assman aspiration psychrometer fastened to the shelter; soil thermometers
at depths of 3 and 6 inches; soil thermograph, the bulb of which was placed in the soil at a
depth of 3 inches; anemometer fastened to the top of shelter and attached to a single register
inside, the cups of the anemometer being 4 feet 7 inches above the ground.

Station 5 (Fig. 11),inan uncultivated portion of the bog, but close to the cultivated sec-
tions. It had never been sanded, the soil being plain peat, and it had a dense growth of vines

21

Fic, 11.—Station 5, Mather, Wis.

In uncultivated bog. Photograph made in 1906,

FiG. 12.—Station 6, Mather, Wis.

Old sanded, heavily vined. Photograph made in 1906.

22

and other vegetation, including numerous patches of sphagnum and wood moss. This location
represents the poorest conditions on the cranberry marsh as regards cultivation and drainage,
and it was consequently wetter than Stations 3 and 4. Equipment: Minimum thermometer
in shelter at an elevation of about 5 inches above the surface of the marsh; minimum thermom-
eters in the open at the surface of the bog, and at an elevation of 5 inches; maximum thermom-
eter at the surface of the bog; air thermograph placed in the open on the surface of the marsh;
soil thermometers exposed at depths of 3 inches and 6 inches; soil thermographs, the bulbs of
which were similarly exposed. During the season of 1907, the vines surrounding the soil
instruments died out, and gradually changed from the conditions prevailing in 1906. This
was due to unavoidable trampling of the vines by the assistant who made the observations.
With the purpose of maintaining the original conditions as far as possible, the exposures of
these instruments were changed twice during August.

Station 6 (Fig. 12), ina cultivated section which had been sanded about 1898, but which
had never been sanded a second time; so that a laver of peat an inch or two in thickness,
formed from the decayed vegetation, covered the old sand. There was a dense growth of

Fic. 13.—Stations 7 and 7a, Mather, Wis.

In scalped section and on moss adjoining. Photograph made in 1906.

vines around the station and the drainage was similar to that of Station 5. Equipment:
Minimum thermometer in the shelter about 5 inches above the surface of the marsh; minimum
thermometers in the open at the surface of the marsh, and at an elevation of 5 inches; maximum
thermometer at the surface of the bog; soil thermometers at depths of 3 and 6 inches; soil
thermograph, the bulb of which was exposed at a depth of 3 inches. The soil thermograph
was fairly satisfactory for all months except October, when it became defective.

Station 7 (Fig. 13), located outside the cultivated bog in a section of bare peat, scalped
especially for the purpose in 1906, in the midst of a dense growth of sphagnum moss. This
station was at the lower end of the marsh, and consequently more damp than the cultivated
sections. Equipment: Minimum thermometer in the shelter about 5 inches above the surface
of the bog; minimum thermometers in the open at the surface of the peat, and at an elevation
of 5 inches; maximum thermometer at the surface of the peat; soil thermometers at depths of
3 inches and 6 inches; soil thermograph, the bulb of which was exposed at a depth of 3 inches.

Station 8 (Fig. 14), the reservoir. This station was in a ditch about 4 feet in depth, and
from 20 to 25 feet wide, lying between the floating marsh on the west and a dam on the east.
Equipment: Water thermometer; soil thermograph, with the bulb exposed in the water at a

Fic. 14.—Station 8, Mather, Wis.

Reservoir showing wide ditch and floating bog. Observer taking an observation of water
temperature.

Fic. 15.—Station 9, Mather, Wis.

In garden on upland. Photograph made in‘1906. This station was supplied in 1907 with
additional thermometers in instrument shelter and attached to the posts up to an elevation
of 36 inches.

24

depth of about 12 inches. This instrument although officially known as a soil thermograph
might in this case properly be called a water thermograph.

Station 9 (Fig. 15), over sandy loam in the garden in the rear of the dwelling on Long Island.
It was established for the purpose of making some comparison between the conditions on hard
eround and in the adjoining bog. The garden was planted, but well cultivated and drained.
Squipment: Minimum thermometer in the shelter about 5 inches above the surface of the
soil; 6 minimum and 6 maximum thermometers facing south at the following elevations: Sur-
face, 24 inches, 5 inches, 74 inches, 12 inches, and 36 inches, also minimum thermometers at
additional elevations of 10 inches and 15 inches; soil thermometers at depths of 3 and 6 inches.

Station 10 (Fig. 16), the warehouse. Equipment: Anemometer and sunshine recorder
exposed on the cupola of the warehouse, about 50 feet above the marsh, and about 35 feet
above the ground on the upland. These instruments were attached to a double register in a
room in the warehouse. The wind vane was exposed on a building near the warehouse.

Equipment of the Berlin Station.—It is hardly necessary to go into details regarding the
equipment at Berlin (Fig. 6). The investigation there was confined to a portion of the year

|

Fic. 16.—Station 10, Warehouse, Mather, Wis.

Anemometer on cupola. Sunshine recorder on ridge of roof.

1906, with a rather incomplete set of instruments. The peat and muck in this marsh reaches
to a depth of 20 to 26 feet, and there is a stretch of hard land on the immediate border about
3 feet above the surface of the marsh. The soil of this hard land consists of yellow clay. A
short distance beyond there is a gradual slope to ordinary dark soil.

A portion of the equipment used in this discussion follows. Station 1, which was almost
on the edge of the bog, was provided with an instrument shelter in which were exposed maximum
and minimum thermometers and an air thermograph. There was also a rain gage close at
hand. (Fig. 17.)

Station 2, over a peat bog which had been carefully weeded before the observations were
begun. Equipment: Minimum thermometers exposed in the open at the surface and at an
elevation of 5 and 36 inches, respectively, above the surface of the marsh.

The sections around Stations 3 and 4, to an extent of about 40 feet square, had been espe-
cially sanded for use in the investigation. The marsh, as a whole, had a rank growth of vege-
tation, and had never been sanded. At Station 3 were minimum thermometers exposed in the
open at the surface and at 5 and 36 inches above the surface; also a soil thermometer at a

‘

Fic. 17.—Fitch marsh, Berlin, Wis., showing car track on bog, dwellings, warehouses, and
shanties. Cross in photograph shows location of Station 1 in 1906.

Fic. 18.—Station 5, Fitch marsh, Berlin, Wis. In ferns and canebrakes.

26

depth of 3 inches. This station well represents the best conditions obtainable from eultivating
and sanding, and fair conditions as regards draining. Station 4 had the same character,
except that it was slightly lower than Station 3, and consequently wetter through poorer
drainage. The equipment consisted of minimum thermometers exposed in the open at the
surface and 5 inches above. Stations 2, 3, and 4 were situated in a line about 100 feet apart.
The thermometer shelters at Stations 2 and 3 may be seen in Figure 6, which gives a view of
a considerable portion of the Berlin marsh at dawn. No shelter was used at Station 4. The
shelters at the other stations on the bog were used for housing the recording portions of the soil
thermographs during the short time that they were in operation. These instruments proved
defective in 1906, and consequently the records have not been used.

Station 5 (Fig. 18), in a section termed the “ferns,” about 1,000 feet north of Stations
2,3, and 4. The equipment consisted of maximum and minimum thermometers placed at the
surface of the bog and at an elevation of 5 inches, respectively. The upper thermometers here
were not fastened to a post, but merely placed on top of a bed of vines and ferns, which were
pushed down in a compact mass to provide a resting place for the instruments at the desired
height. In all other instances at Mather and Berlin the instruments exposed at an elevation
above the surface were attached to wooden supports. Station 5 was also provided with a soil
thermometer at a depth of 3 inches. Some additional instruments were included in the equip-
ment at the various stations, but it seems unnecessary to refer to them. The object has been
to present in this report merely such observations made at Berlin as may supplement the more
complete data at Mather.

The thermometers used in this investigation were all carefully tested in the Instrument
Division at Washington before being shipped to the cranberry marshes; they were daily exam-
ined in order to detect possible defects, and exchanges in the instruments were made occa-
sionally between the various stations at both Mather and Berlin, so as to obviate the effect
of any possible instrumental error.

DISCUSSION OF THE PROBLEM.

Minimum temperatures in shelters, and in the open, both at 5 inches above the surface.—In
order to determine the relation existing between the readings of thermometers in shelters and
those exposed in ‘“‘the open,” as are the instruments generally used by the cranberry grower,
minimum thermometers were placed at various stations at Mather, in “the open” at 5 inches
above the surface, corresponding in elevation to the thermometers placed in the respective
shelters. During the day the surface of any solid upon which the sun shines becomes hotter
than the air above it, because the solid is a much better absorber of heat than the air; while at
night, especially when the sky is clear, the air loses its heat more slowly than a solid, such as
vegetation or soil, because the air is a very poor radiator of heat. The readings of the instru-
ments in the shelters indicate the true temperature of the air at the various stations, while the
readings of the thermometers outside the shelters, strictly speaking, represent the temperatures
of the instruments themselves, but they may be considered to indicate approximately the tem-
perature of the vines and plants at the height of 5 inches. It is probable that the temperature
of the vegetation was even lower than that recorded by these exposed minimum thermometers.
The differences, however, can not be large, because the exposed minimums often registered
readings as low as 28° without apparent damage to the vegetation. It is quite impracticable
to secure daily readings of the temperature of plants or leaves that may be comparable. The
reading of the thermometers exposed in the open might properly be termed “‘sensible tempera-
tures,” but in this bulletin all such readings, whether maximum or minimum, will be referred
to as exposed readings, or readings in the open.

Table 1 shows in detail the daily readings and differences at each station, and Table 1a
shows the averages for the various months and for the season of 1907. The average difference
for the entire season was least at Station 9 on the upland, 1.4°, where there was a clean soil and
very little vegetation. The average difference on the bog was least at Station 3, 2.5°, also where

bo
“I

the vegetation was thin; and at Station 7, 2.7°, over peat, in the scalped piece, but closely
surrounded by sphagnum moss. The difference was greatest at Station 5, 3.6°, and at Station
6, 3.7°, where the vegetation was dense. The average difference at Station 4 was 2.6°—but
slightly greater than that at Station 3. This difference was not larger because the location of
the thermometers exposed at the 5-inch height at Station 4 was thinly vined as compared
with the other portions of that section. In fact, a close relation was found to exist between
these differences and the density of vegetation. On account of the great radiation of heat from
vegetation, the exposed minimums were relatively much lower where the vegetation was dense
than where the soil was clean. At all stations the least difference usually occurred during the
month of May, with an increase irregularly toward midsummer with increasing vegetation, and
then a falling off, which was later followed by another maximum in October. The gains and
losses were not uniform at the various stations, simply because there was a lack in uniformity
in the changing of the vegetation. The conditions changed because there was trampling of
the vines and grasses, more at some stations than at others, and for various other reasons. It
is probable that if all the conditions as regards vegetation, soil, and moisture were identical for
the whole bog, or even for the section in which the instruments were located, approximately
the same differences would occur at each station on each night; but the amounts of these differ-
ences would probably change as the nights became longer or shorter, and as the character of
the weather varied from day to day. Moreover, if a uniform relation existed during the entire
season as regards vegetation, between the places of exposure of the outside thermometers and
the location of the shelter itself, the relation between the various differences of the readings
inside and outside would not change materially.

The reason for the great differences in October is not because of increasing vegetation, but
rather in spite of a decrease. It is due to the fact that the nights were much longer and com-
paratively cold, thus permitting great loss of heat from the plants by radiation and conduction.
The greatest difference at Station 2 was 6.5° on October 11; at Station 3, 4.7° on October 31; at
Station 4, 6.3° on October 22; at Station 5, 9.9° on July 10; at Station 6,7.9° on July 16; at
Station 7, 6.4° on May 18; and at Station 9, 7.2° on August 10. There were, on the other hand,
many days when there was only a slight difference in the readings, and there were a few instances
in which the outside thermometers read slightly higher than those exposed in the shelters.
When the difference was great at one station, it was usually relatively great at the other stations;
likewise, when there was but a slight difference at one point, a like condition prevailed at the
other stations. On nights of slight differences the sky was invariably overcast, while clear to
partly cloudy conditions with comparatively high barometer prevailed when great differences
occurred, which fact indicates that radiation is the controlling factor. Formation of dew on
the bulbs of the outside thermometers, followed by a freshening of the wind and consequent
evaporation of the moisture, was occasionally the cause of low readings of certain of these
instruments. Dew doubtless often formed and disappeared during the night without being
observed.

The mean depression of the outside thermometers below those in the shelters at the six
stations on the bog for the entire season of 1907 was 3°, and, including the record at Station 9 on
the upland, the depression for the same period was 2.8°. Prof. Willis I. Milham,* in experiments
conducted at Williamstown, Mass., on thirty-six cold and generally cloudless nights in the
winter of 1904-5, while the ground was covered with snow, found that the average difference
between the readings of a minimum thermometer exposed in a shelter and one in the open was
3.9°, and that the greatest difference on any one night was 7.8°. In making comparisons
between these figures and the results at Mather over vegetation, it should be borne in mind
that the latter are for the entire growing season without regard to the cloudiness and the tem-
perature prevailing. The average difference on clear nights at Mather no doubt equals that
determined by Professor Milham.

aMonthly Weather Review, July, 1905.

28

The temperature in the shelter on the upland at Station 1-may be considered the'$tandard
with which other temperatures observed at Mather during this investigation should be compared.
However, the readings at Station 1 have not been included in Tables 1 and 1a, because it was
first desired to determine the relation existing between shelter and exposed temperatures at the
same elevation. By referring to Table 18, which will be discussed in detail in turn, it should be
noted that there is a great difference between the shelter readings on the bog and on the upland,
the difference varying with the character of the soil and vegetation, as in the case of the observa-
tions in shelter and in open at the various stations, referred to above in connection with the
discussion of Tables 1 and 7a. Where the differences were great between the readings in shelter
and open, relatively large differences were noted between the readings in those shelters and the
shelter at Station 1; while, on the other hand, at stations where smaller differences were observed,
the shelter readings approached more nearly the shelter readings at Station 1.

TaBLe 1.—MrnrmuM TEMPERATURES IN SHELTER AND IN OPEN AT 5-INCH HEIGHT, FoR Eacu Station, TOGETHER
WITH THE DIFFERENCE BETWEEN READINGS, MATHER, WIs., 1907.

Station 2. Station 3. Station 4. Station 5. Station 6. Station 7. “Station 9.

Day of ; g 3 5 ron i cual = Pad | ; = ba ¢

moat (SL Le 1B] ele | ee ee |e Sle leet col eal Suleuh edie bs

— Orel a ~ ° 5 < ° ane ° 3 =] fo] Se) fo) = = 3° im

gM Ua ela Vf Qf Tel =A Om he I oie (Peale Re Spe NS Ca Sty Peep fe Sat er ees

a | A = a >) q Bh i) A DB 5 6 n 2 a a | A ras) aa i) a
: 5.2 |—1.5 | 37.3 | 35. : : 5. 2.0 | 37. : hs : : 8 | 36. ; , 4 | 36. OF,
le emsesins 61.0 | 60.0 |—1.0 | 61.6 | 59.6 |=2.0 61.4 | 59.0 |—2.4 | 61.2 | 68.9 |—2.3 | 60.9 | 57.2 |—3.7 | 61.0 | 58.0 |—3.0 | 61.5 | 59.8 | —1.7
1S ee 45.0 | 45.0| 0.0) 45.7 | 45.0 ipad 45.8 | 45.1 |—0.7 | 45.1 | 45.1 | 0.0 | 45.0 | 44.9 j—0-1 45.0 | 44.9 |—0.1 | 45.0 | 45.0 0.0
Wy -aoSca5 36.0 | 36.3 |+0.3 | 37.0 | 36.7 |—0.3 | 37.0 | 37.0] 0.0 36.7 | 36.9 |+0.2 | 36.8 | 37.0 |+0.2 | 36.8 | 36.7 |—0.1 | 36.0 | 36.0| 0.0
ies So 34.8 | 34.1 |—0.7 | 35.4 | 34.6 |—0.8 | 35.5 | 34.6 |—0.9 35.3 | 34.8 |—0.5 | 35.0 | 34.2 |—0.8 | 35.1 | 34.3 |—0.8 | 35.0 | 34.8 | —0.2
WSs since 35.0 | 32.4 |—2.6 | 40.3 | 38.4 |—1.9 | 40.3 | 37.3 |—3.0 | 36.0 | 33.0 |—3.0 | 32.5 | 33.0 |+0.4 | 35.4 32.3 |—3.1 | 39.9 | 39.1 | —0.8
LGE osc ons 35 3 | 32.0 |—3.3 | 45.4 | 40.9 |—4.5 | 45.1 | 39.0 |—6.1 | 40.1 | 39.1 |—1.0) 41.2 | 39.3 |—1.9 | 39.8 | 33.4 |—6.4 | 46.0 | 44.9 | —1.1
19 eee 33.0 | 28.2 |—4.8 | 36.8 | 32.6 |—4.2 | 36.3 | 32.0 |-4.3 | 36.6 | 31.0 |—5.6 | 38.6 | 32.3 |—6.3 | 37.8 | 32.1 |—5.7 | 37.3 | 35.0 | —2.3
Oe aercsas 21.4 | 18.0 |—3.4 25.3 | 21.3 \—4.0 25.1 | 20.0 |—5.1 | 21.6 | 19.3 |—2.3 | 24.8 | 17.8 |—7. 21.8 | 18.9 |—2.4 | 26.8 | 23.8 | —3.0
PA ae mr 23.2 | 21.0 |—2.2 | 25.7 | 22.8 |—2.9 | 25.4 | 22.3 1—3.1 | 22.2} 17.0 |—5.2 | 24.5 | 19.8 |—4.7 | 23.7 | 22.0 |—1.7 | 25.3 | 23.0 tees
y+ EES 43.8 | 44.0 |+0.2 | 44.3 44.0 |\—0.3 | 44.5 | 44.2 |—0.3 | 44.5 | 42.0 |—2.5 | 44.1 | 43.0 |—1.1 | 44.0 | 43.9 |—0.1 | 44.1 | 44.2 | +0.1
7s Ee 43.8 | 43.9 |+0.1 | 44.3 | 43.9 |—0.4 | 44.2 | 44.0 |—0.2 | 44.0 | 43.7 |—0.3 | 44.1 | 44.0 |—0.1 |a44. 2 |a43.9 |—0.3 | 44.0 | 44.0 0.0
was 42.5 | 40.2 |—2.3 | 43.8 | 41.3 |—2.5 | 43.5 | 42.0 |—1.5 | 40.3 | 34.0 |—6.3 | 43.3 | 39.3 |—4.0 |@42.9 [240.0 |—2.9 | 43.4 | 41.8 | —1.6
25. - 44.8 | 44.0 |—0.8 | 45.3 | 44.0 |—1.3 | 45.2 | 44.1 |—-1.1 45.0 | 43.8 —1.2 | 45.0 | 43.9 |—1.1 |a44.9 |a44.0 |—0.9 | 44.6 | 44.0 | —0.6
sa oe 45.0 | 45.2 |+0.2 | 45.5 | 45.2 |—0.3 | 45.7 | 45.2 |—0.5 45.2 | 45.0 |—0.2 | 45.2 | 45.0 |—0.2 |a45.2 |a45.0 |—0.2 | 45.1 | 45.1 0.0
io eaee (COIN OY" aoe ace | CP) @)aacceee (ODN @) ip eeeaee ty (e yd eee @a)) @elt-a:— Cie @) eae (8) | {@)) }:=~22
28. a. sen (@)}) |e --= 4 (8) }) Cie (2) 3) (0) |e Da) FCC) Be ee (i ACCA Sei cose yO Cy aeeaee (0) | (0) |....--
Oe ee 34.0 | 29.8 |—4.2 | 38.0] 34.9 |—3.1 | 37.2 | 32.5 |—4.7 | 36.0 | 29.3 |—6.7 | 38.5 | 34.7 |—3.8 | 36.0 | 30.8 |—5.2 | 38.8 | 36.3 | —2.5
SO 55-28 38.9 | 36.0 —2.9 44.7 | 41.1 —3.6 | 43.8 | 39.5 |—4.3 40.4 | 36.0 —4.4 | 43.0 | 39.0 |—4.0 | 40.9 37.0 |—3.9 | 44.0 | 42.3 | —1.7
BR be erie 46.5 | 45.0 |—1.5 | 48.0 | 45.8 |—2.2 | 47.8 | 45.9 |—1.9 | 47.6 | 45.9 |—1.7 | 47.9 | 45.4 |—2.5 |a47.2 45.4 —1.8 | 47.6 | 46.8 —0.8
Means - 38.9 | 37.2 —1.7 41.4 | 39.3 |—2.1 | 41.2 38.8 ee 39.7 | 37.2 2.5 40.4 38.0 |—2.4 | 39.9 | 37.6 |—2.3 | 41.2 20 — 1d

Station 2
Station 3.
Station 4.
Station 5.

a Affected by water.
Sphagnum moss.
Newly sanded, thinly vined.
Newly sanded, heavily vined.
Peat with moss, heavily vined.

Highest and lowest readings are in italics.

> Under water.

Station 6. Old sanded, heavily vined.
Station 7. Sealped piece, bare peat.
Station 9. Sandy loam on upland.

Means are for 18 days.

29

TaBLe 1.—Mryimum TEMPERATURES IN SHELTER AND IN OPEN AT 5-INCH Hereut, ror Eacu Station, ToGETHER
WITH THE DIFFERENCE BETWEEN READINGS, MATHER, Wis., 1907—Continued.

Station 2. Station 3. Station 4. Station 5. Station 6. Station 7. Station 9.

Day of Big (eet 5 s 6 2 b © 5 g . g A s
= o) By = ° o s (=) 5 = 2) 5 = 3 by » | o 5 = 3 o
SPs (es Se) RPS se Pe eee | ee |e he ae he] |
PeReeees ees ee pea ea Pa a faa ja pe la lal ala

JUNE ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° | 2 ° ° 9 ° °

UGS onsen - 31.7 | 27.9 |—3.8 | 34.9 | 31.0 |—3.9 | 34.9 | 30.5 |—4.4 | 31.4 | 96.2 |—5.2 | 36.0 | 35.3 |-0.7 34.5 | 28.7 |—5.8 34.5 | 32.2 | —2.3

Dee ees Soe 32.3 | 29.4 |—2.9 | 37.0 | 34.0 |—3.0 | 36.1 | 33.0 |—3.1 | 31.4 | 27.9 |—3.5 | 35.0 | 29.8 |—-5.2 34.8 | 30.7 |—4.1 | 36.2 | 32.8] —3.4

Dace 54.0 | 53.0 |—1.0 | 54.9 | 52.3 |—2.6 | 54.8 | 51.0 |—3.8 | 53.6 | 46.9 |—6.7 | 53.5 | 47.0 |-6.5 53.5 | 50.0 |—3.5 | 55.1 | 53.8 | —1.3

C's 2 5s > 38.4 | 35.2 |—3.2 | 42.7 | 39.6 |-3.1 | 41.8 39.0 |—2.8 | 40.2 | 35.0 |—5.2 | 40.3 | 36.5 |—3.8 | 40.3 | 36.6 |—3.7 | 41.6 40.4 | —1.2

Mirae teieate 41.8 | 38.0 |—3.8 | 43.9 | 39.7 |—4.2 | 43.5 | 41.4 |—2.1 | 43.3 | 41.5 |-1.8 | 44.0 | 41.5 |-2.5 | 43.3 41.5 |—1.8 | 43.8 | 42.9] —0.9

: =3.5 34.0 231.3 —2.7 \a33. 4 \430.7 |—2.7 |a30.7 |a26.8 |—3.9 |232.0 \a28.2 |—3.8 } 31.1 | 27.1 '—4.0 33.0 | 31.5 | —1.5

=2.2 | 47.9} 47.5 |—0.4 | 47.7 | 46.0 |—1.7 | 47.0 | 43.8 |—3.2 | 47.7 | 44.0 |—3.7 | 47.5 | 45.1 —2.4 | 47.3 | 46.6 | —0.7
—3.5 | 35.0 32.2 |—2.8 | 35.1 | 32.0 |—3.1 | 30.8 | 26.5 |—4.3 | 34.3 | 29.4 |—4.9 | 31.4 27.9 |—3.5 | 33.5 | 31.8 | —1.7
i -5 |—3.4 40.0 : 37.4 —2.6 | 39.9 | 35.2 |—4.7 | 35.1 | 30.5 |—4.6 38.3 | 33.9 |—4.4 | 36.0 | 32.0 |—4.0 | 39.2 | 37.9 | —1.3

10. 25- <3 53.9 | 53.3 |—0.6 54.6 53.2 |\—1.4 | 54.6 | 53.2 |—1.4 | 54.0 | 53.0 |—1.0 | 54.3 | 52.9 |—1.4 | 53.9 | 53.0 |—0.9 | 54.5 | 53.4} —1.1

VOC eee 44.1 | 39.1 |—5.0 | 46.2 42.2 \—4.0 | 45.5 | 41.7 |—3.8 | 44.2 | 38.4 |—5.8 | 45.2 | 40.7 |—4.5 | 44.8 | 40.1 \ipee 46.0 | 43.7 | —2.3

Oommen 51.2 | 50.5 |—0.7 53.0 | 51.0 —2.0 52.9 | 52.1 |—0.8 52.5 | 51.0 |—1.5 | 52.3 | 50.2 |—2.1 | 53.0 | 51.4 \-1.6 53.0 52.5 | —0.5

TS eee 37.3 | 34.4 |—2.9 | 42.6 | 39.6 |—3.0 42.3 ) 39.1 |—3.2 | 36.2 | 32.4 |—3.8 | 39.4 | 34.8 —4.6 | 37.3 | 33.6 |—3.7 | 42.9 | 41.1] -1.8

1 Cpa 35.0 | 31.0 |—4.0 | 39.9 | 37.9 |—2.0 | 39.4 | 36.3 |—3.1 | 33.8 | 29.6 |—4.2 | 33.0 | 33.0] 0.0| 34.6 | 31.1 |—3.5 | 37.5 | 36.1 | —1.6

ew eeres 38.7 | 35.0 |—3.7 | 42.0 | 39.3 |—2.7 | 41.4 | 39.0 |—2.4 | 37.6 | 34.0 |—3.6 | 39.5 | 36.1 —3.4 | 38.0 34.8 |—3.2 | 42.0 41.0] —1.0

1GY fan's 5 48.6 | 46.0 |—2.6 | 54.0 | 51.2 |—-2.8 | 52.9 | 50.2 |—2.7 | 48.9 | 45.5 |—3.4 | 50.4 | 46.8 |—3.6 | 49.5 | 46.6 |—2.9 53.8 | 52.0 | —1.8

(om oa 66.0 | 62.9 |\—3.1 | 69.0 65.8 |—3.2 | 69.1 | 65.4 |—3.7 | 68.5 | 62.5 |—6.0 | 68.0 | 64.0 |—4.0 | 69.0 | 65.9 |—3.1 68.0 | 66.5 | —1.5

1 oli Ee 52.5 | 49.6 |—2.9 | 58.0 55.2 |—2.8 56.9 | 54.9 |—2.0 | 52.7 | 48.9 |-3.8 | 55.0 | 50.6 |—4.4 55.0 | 51.0 |—4.0 | 57.3] 55.7 | —1.6

IGE ate ctos 50.2 | 46.8 |—3.4 | 56.2 53.3 |—2.9 | 55.8 | 52.5 |—3.3 | 53.4 | 48.7 |—4.7 | 53.4 | 47.5 |—5.9 | 54.0 | 49.3 —4.7 | 56.1 | 54.9 | —1.2

20 re series 45.2 | 42.3 |—2.9 | 51.0 48.0 \-3 0} 49.8 | 47.5 |—2.3 | 51.0 | 42.4 |—8.6 | 47.8 | 43.4 |—4.4 | 46.0 | 42.2 —3.8 | 50.1 | 47.9 | —2.2

Die ae 45.0 | 41.4 |—3.6 | 49.3 | 46.5 |—2.8 | 48.8 | 46.1 )—2.7 | 44.0 | 40.3 |—3.7 | 46.8 | 42.4 |~4.4 | 45.0 41.8 |—3.2 | 48.6 | 46.6 | —2.0

=2.2 61.8 | 60.4 [1 4 | 61.5 | 60.1 |—1.4 | 61.1 | 59.6 |—1.5 | 61.1 | 59.1 |—2.0 | 61.1 | 59.8 }—1.3 | 61.7 | 60.6 | —1.1
\—4.1 60.0 | 57.7 \-2. 3 | 59.9 | 57.1 |—2.8 | 59.0 | 55.2 |—3.8 | 60.0 | 56.3 |—3.7 | 59.2 | 56 0 |—3.2 | 59.8 | 57.5 | —2.3
4.3 | 56.0 | 53.8 |—2.2 | 55.2 | 53.0 |—2.2 | 52.5 49.5 |—3.0 | 53.9 | 50.8 |—3.1 | 53.4 | 49.6 |—3.8 | 54.1 | 53.2] —0.9
|=2.6 | 57.9 | 56.3 |-1.6 57.4 | 55.9 |—1.5 | 55.9 | 53.1 |—2.8 | 56.2 | 53.2 |—3.0 | 56.2 | 53.5 |—2.7 | 57 5 | 56.5 | —1.0
|—6.1 | 48.1 | 46.1 |-2.0 | 47.9 | 46.0 |-1.9 | 47.8 | 45.7 |—2.1 | 48.3 | 43.8 |-4.5 | 48.0| 46.0 |-2.0| 48.1 | 47.2 —0.9
l=4.1 | 44.5 | 42.0 —2.5 | 43.4 40.9 |—2.5 | 39.2 | 34.0 |—5.2 | 40.8 | 35.1 |—5.7 | 38.2 | 35.0 |—3.2 | 44.5 | 42.8 17,
|—4.5 | 44.3 | 41.1 |—3.2 | 43.8 | 41.0 |—2.8 | 38.6 | 35.2 |—3.4 40.5 | 37.5 |—3.0 | 39.8 | 36.8 |—3.0 | 43.9 | 42.1 | —1.8
|=2..2 51.4 | 48.9 2.5 50.0 | 48.0 |—2.0 | 44.6 | 41.1 |—3.5 | 47.8 | 42.8 |—5.0 | 46.1 | 43.0 |—3.1 | 51.1 49.8 | —1.3
j—2.4 | 56.9 | 54.1 |—2.8 | 55.5 | 53.0 |—2.5 | 51.0 | 47.4 |—3.6 | 54.2 | 48.7 |—5.5 | 53.1 | 49.4 |—3.7 | 56.8 | 54.1 | —2.7
[=3:1 | -48.9 46.3 [=2.6 48.4 | 45.7 \—2.7 | 45.7 41.8 |—3.9 | 47.0 | 43.2 |—3.8 | 46.3 | 43.0 |—3.3 | 48.4 46.8 | —1.6
a Affected by water.

Station 2. Sphagnum moss. Station 6. Old sanded, heavily vined.

Station 3. Newly sanded, thinly vined. Station 7. Scalped piece, bare peat.

Station 4. Newly sanded, heavily vined. Station 9. Sandy loam on upland.

Station 5. Peat with moss, heavily vined.

Highest and lowest readings are in italics,

30

TasLe 1.—Miniium TEMPERATURES IN SHELTER AND IN OPEN aT 5-INcH HEIGHT, For Eacu prAmiOn giipesscen
WITH THE DIFFERENCE BETWEEN READINGS, MaTHeER, Wis., 1907—Continued.

| Station 2. Station 3. Station 4. Station 5. Station 6. Station 7. Station 9.
| |
= ra ‘Thea Pe le hy calmed ae aos
man} ete fe)el/ehelelelelelelelte|eheim te le eee
be eB IES | So Be 1S ES. Peal ee eS: oS ee ees ia es Hee ie ee
le |elel3|& SSE 2 ete 2 ee bee ease
}@a@)A;/Aa la] es aiAl}T Al @I|A])A]La | &B}/Al]a}] ae] alsa] alsé
| | joey | |
1c 0 Reagan Mas Fh 2 |W sal Recital ester lees el han) gen Pee emcee OS lng? ile vibes
re eee Be | 55.0 | 52.0 |—3.0 | 58.8 | 57-1 |-1.7 | 58.5 | 57.0 |—1.5 | 58.8 | 55.9 |—2.9 | 58.7 | 54.3 |—4.4 | 59.0 | 58.1 |—0.9 | 59.0] 57.8 | —1.2
eae red 32.4 | 29.4 |—3.0 | $8.4 | 34.8 |—3.6 | 37.4 | 34.3 |—3.4 | $1.2 | 27.9 |—3.3 | 35.2 29.0 |—6.2 | 33.0 | 29.7 |—3.3 | 36.9 | $3.9 | —3.0
Wine ee 41.4 | 38.5 |-2.9 | 48.0 | 45.0 |—3.0 | 47.1 | 44.7 —2.4| 40.2 | 36.2 —4.0| 44.1 | 38.3 |—5.8 | 43.0 | 39.2 |—3.8 | 47.7 | 45.0) —2.7
hoon one 47.3 | 44.7 |-2.6 | 51.6 | 48.9 —2.7| 50.8 | 48.8 —2.0| 50.8 | 43.9 |—6.9 | 49.9 | 46.0 |—3.9) 47.4 | 45.0 |-2.4) 51.0 | 49.5) —1.5
Reser 60.6 | 59.4 |—1.2 | 61.3 | 60.3 —1.0 61.2 | 60.5 —0.7 | 60.8 59.7 —1.1 | 61.0 61.5 |+0.4 [057.5 054.7 |—2.8 | 61.0 | 60.0) —1.0
6:2 53.0 52.8 |—2.2 | 59.0 57.0 —2.0| 58.0 | 56.2 —1.8 548 52.0 —2.8 | 56.8 | 52.1 |—4.7 |a55.5 52.1 —2.8 | 58.2 | 57.3) —0.9
2 | 0 / 43.7 |—5.3 | 48.9 46.3 |—2.6 | 50.4 | 49.0 —1.4
a 50.0 |—5.8 | 57.0 53.4 |—3.6 | 58.1 | 56.2| —1.9
E. ofl) age i : : ; E : .5 | 51.4|-6.1| 56.9 52.5 |-4.4| 60.4! 59.9) —05
10 50.8 | 47.8 —3.0 | 49.8 | 47.7 —2.1 | 50.9 41.0 —9.9| 47.0 42.2|-4.8) 45.9 42.2 |-3.7 | 50.0] 47.6) —2.4
60.6 | 60.3 |—0.3 | 60.8 | 60.0 —0.8 61.1 | 60.1 |—1.0 | 61.5 + 59.9 |—1.6 | 61.0 | 60.1 |=0.9 | 61.0 | 60.1 / —0.9
12 2.2 49.5 | 46.5 |—3.0| 48.4 | 46.1 —2.3 | 46.2 | 39.9 |—-6.3 | 46.3) 41.8 |—4.5 | 45.0 | 41.5 |-3.5 | 49.2 | 47.0 | —2.2
13 -7 53.0 | 50.0 |—3.0 | 51.6 | 49.2 |—2.4 | 48.4 | 44.0 |—4.4] 51.3 | 45.9 l-5.4 49.9 | 45.9 |-4.0 | 52.0 | 49.4) —2.6
14 -5 62.2 | 59.0 /—3.2 | 62.0 | 59.1 —1.9 | 61.2 | 56.8 |—4.4] 61.5 56.8 |—4.7 | 61.3 | 58.2 |—3.1 | 62.0 | 60.0) —2.0
15. . .2| 68.3 | 67.8 |—0.5 | 68.1 | 67.8 |—0.5 | 68.2 | 67.1 |—1.1| 68.0 | 66.7 |—1.3 | 68.0 | 68.2 |+0.2 | 68.1 BON os
-0 53.1 | 50.0 |—3.1 | 52.2 | 50.0 |—2.2 | 51.1 | 45.3 |—5.8| 54.4 46.5 |—7.9 | 48.9 | 46.1 |—2.8 | 51.7 | 50.4) —1.3
-3. 35.1 | 51.3 —3.8 | 52.1 | 49.0 —3.1 50.0 | 45.0 |-5.0 | 53.2 47.3 —5.9 | 54.0 | 47.9 |—6.1 | 56.0 | 53.9 |—21
-4 51.0 | 47.6 |—3.4 | 50.1 | 47.8 |-2.3 45.8 42.6 |—3.2 | 47.9 43.8 —4.1 46.0 43.1 |—2.9 50.2) 49.0 —1.2
-O0 57-1 | 54.8 |—2.3 | 56.8 548 —2.0 53.9) 51.0 |-2.9 | 56.0 51.5 —4.5 | 54.1 | 51.6|-2.5 | 56.8 55.1) —1.7
8 59.8 | 56.7 -3.1 | 59.0 55.1 —3.9 56.2 | 51.3 |—4.9 | 58.0 | 52.5 5.5 | 58.6 | 56.2/-2.4/ 60.3 58.9) —1.4
: -8 65.0 | 63.2 —1.8 | 64.8 | 63.0 —1.8 62.2] 59.9 |—2.3 | 63.0 | 60.0 —3.0| 62.8 | 61.1 |—1.7 | 64.8 | 64.0 —0.8
-3|-2.7 63.5 62.0 |-1.5 | 63.2 | 61.4 —1.8) 64.0] 61.9 |—2.1/| 64.5 62.3 —2.2 261.3 058.5 |—2.8 | 63.9 63.0) —0.9
-9 |—5.1 53.2 | 50.1 |—3.1 | 52.2 | 48.8 |—3.4 |a50.3 |o45.9 |—4.4 251.0 246.7 |—4.3 ja50.1 047.3 |—2.8 | 52.1 | 49.9 | —2.2
-7 |—2.3 64.0 | 60.0 —4.0 | 64.0 | 59.8 —4.2 Ja61.5 [957.1 | 4.4 962.2 057.9 —4.3 a61.3 258.5 |—2.8 | 65.0 63.1) —1.9
.5 3.3 53.7 | 50.9 —2.8 | 53.0 | 50.8 —2.2 250.1 ja45.7 |—4.4 250.8 246.5 —4.3 [049.9 047.1 |—2.8 53.0 51.6 | —1.4
ba) j-40 49.4 | 47.0 —2.4 | 48.5 46.3 —2.2 [046.5 042.1 |—4.4 047.2 042.9 —4.3 246.3 243.5 |—2.8 | 49.0 47.8) —1.2
-0 3.9 46.9 43.4 —3.5 | 45.9 43.0 —2.9 | 45.0 | 40.0 |—5.0 243.2 238.9 —43 242.3 939.5 |-2.8 | 44.9 43.4 —1.5
.3 |—1.3 | 58.9 | 57.0 |—1.9 | 59.2 | 56.5 —2.7 | 57.5 | 53.2 |—4.3 | 58.4 | 54.0 |—4.4 [056.2 [053.4 |—2.8 | 59.0 | 56.9 | —2.1
1 |—3.2 | 56.1 | 54.0 |—2.1 | 55.9 | 53.2 —2.7 | 55.0 | 51.5 |—3.5 | 56.1 | 53.0 |—3.1 | 56.5 | 55.0 |—1.5 | 56.1 | 55.0) —1.1
-0 |—1.5 | 51.0 | 48.1 |—2.9 | 49.9 | 46.4 —3.5 | 50.0 | 41.6 |—8.4 | 48.9 | 43.2 |—5.7 | 49.5 | 45.9 |-3.6 | 52.0 | 49.9) —2.1
5 |—4.4 | 56.1 | 53.1 —3.0 | 55.2 52.0 —3.2 | 54.4) 50.0 j—4.4 | 55-0 | 49.8 —5.2 | 55.3 | 53.0 |—2.3 | 57.0 | 55.7 | —1.3
Means..| 51.8 | 49.2 |2.6 | 55.6 53.0 —2.6 | 54.9 52.4 |-2.5 53.1 | 48.8 |-4.3 53.8 | 49.6 —4.2)| 53.0 50.2 |—2.8 | 55.4 | 53.8 | 1.6

-

i

a Estimated; actual readings valueless on account of reflowing or heavy rains.

Station 2. Spagnum moss.
Newly sanded, thinly vined.
Newly sanded, heavily vined.

Station 3.
Station 4.
Station 5.

Peat with moss, heavily vined.

Station 6. Old Sanded, heavily vined-.

Station 7. Scalped piece, bare peat.
Station 9. Sandy loam on upland.

Highest and lowest readings are in italics.

31

TaBLe 1.—Mintiwum TEMPERATURES IN SHELTER AND IN OPEN av 5-INcH HerGut, FoR Eacu Sration, TOGETHER
WITH THE DIFFERENCE BETWEEN READINGS, Matuer, Wis., 1907—Continued.

Station 2. Station 3. Station 4. Station 5. | Station 6. | Station 7. Station 9.
|
S E fie P z
Bae eo) eb a) ple ee] eke age fia g g | 3 Z ell sad g sis g sul Z
Se eee sees eee | She ees ie es is te | & he | B
eee leIF isla leis lai |2 PlElelel|eleleis
ae faube se | A fe Pe Ae | a) a pe |e eo} e@ |e pale la | 4
” | e hb eo |
aucust.| ° e ie Hy ce ° Cm Wee alee ° ° Oe |) 0 ° ° ° ° eo | © °
ioe ease | 51.7 47.0 —4.7 54.9 | 51.2 |—3.7 | 53.4 | 49.1 |—4.3 | 51.0 | 44.0 =u 0 51.6 | 45.5 |—6.1 | 51.4 } 47.1 |—4.3 54.9 | 52.8 —2.1
2 42.8 | 39.1 |—3.7 | 45.3 | 43.3 |—2.0 | 45.0 | 42.5 |—2.5 | 44.3 | 40.9 |—3.4 | 44.0 | 41.5 |95 44.8 | 43.0 |—1.8 | 45.0 | 43.9 —1.1
Bocccc=de 43.1 | 40.0 |—3.1 | 47.9 | 44.5 |—3.4 | 47.0 | 43.8 |—3.2 45.8 | 41.9 |—3.9 46.0 | 41.8 422 46.9 | 45.0 —1.9 | 46.8 | 46.5 —0.3
fee = 36.2 | 34.1 |—2.1 | 44.9 | 42.1 |—2.8 | 43.2 | 39.7 |—3.5 | 36.9 | 33.0 |—3.9 | 41.5 | 36.0 |—5.5 | 38.0 | 32.8 —2.2 | 38.9 | 87.7 —1.2
5.....---| 58.9 | 57.9 |—1.0 | 59.1 | 58.3 |—0.8 | 59.1 | 58.2 |—0.9 | 59.0 | 58.0 |—1.0 | 59.0 | 57.5 |—1.5 | 59.2 | 58.0 |—1.2 | 59.0 | 58.2) —0.8
Gaea-—e ete 48.1 | 46.0 |—2.1 | 53.4 | 51.0 |—2.4 | 52.1 | 49.0 |—3.1 | 47.9 | 44.8 |—3.1 | 49.9 | 45.9 —4.0 | 48.1 | 45.4 —2.7 } 53.5 | 51.3 | —2.2
Usradoees | 51.3'| 48.2 |—3.1 | 57.0 | 54.8 |—2.2 | 56.4 | 54.0 |—2.4 | 56.1 | 54.0 |—2.1 | 56.3 | 53.4 —2.9 | 56.1 | 54.4 —1.7 | 56.7 | 55.1) —1.6
8 | 53.0 51.0 2.0 56.0 54.0 |—2.0 | 55.6 | 55.3 |-0:3 52.0 | 50.1 |—1.9 | 55.0 | 51.1 —3.9 | 55.0] 51.5 —3.5 | 55.0 | 53.6 | —1.4
| 54.1 | 51.9 |—2.2 | 51.5 | 48.0 |—3.5 | 53.4 | 49.0 —4.4 | 51.3 | 48.8 —2.5 | 53.4 | 51.9) —1.5
59.5 | 57.8 |—1.7 | 55.8 | 53.0 |—2.8 | 59.1 | 55.5 |—3.6 | 57.0 54.3 —2.7 | 59.2 | 52.0 | —7.2
| 70.0 | 68.3 |—1.7 | 71.3 | 69.0 |—2.3 | 70.0| 68.5 |—1.5 | 71.8 | 69.8 |—2:0)| 78.6 | 70.9 | —2.7
48.6 | 44.0 |\—4.6 | 45.2 | 41.0 —4.2 | 50.0} 43.2 —6.8 48.0 42.7 —5.3 | 51.0 | 49.0 | —2.0
48.9 | 45.9 |—3.0 | 44.0 | 40.6 —3.4 47.0 | 42.0 —5.0 | 44.8 | 41.4 |—3.4 49.5 | 47.5 —2.0
52.7 | 50.0 |—2.7 | 48.3 | 45.0 |—3.3 | 50.5 | 46.1 |—4.4 | 49.1 | 46.1 |—3.0 52.7 | 50.4 | —2.3
49.6 |—4.0 56.4 | 53.4 |—3.0 | 56.0 | 53.0 |=3-0 54.5 | 50.2 14.3 | 55.5 | 51.1 |—4.4 | 54.8 | 50.6 \—4.2 56.1 | 54.0 } —2.1
57.7 |—1.7 | 61-7 | 60.3 |—1.4 | 61.5 | 60.2 ee) 61.0 } 58.6 |—2.4 | 61.0 | 58.2 leas 61.3 | 59.3 |—2.0 | 61.3 | 61.3 0.0
43.4 |—3.6 | 51.1 | 48.6 |—2.5 | 49.8 | 47.6 |—2.2 42.8 | 43.6 |+0.8 | 49.2 | 44.1 |—5.1 | 48.7 | 44.3 \—4.4 51.2 | 49.0 —2.2
47.7 |—3.3 | 55.5 | 52.3 |—3.2 | 54.2 | 51.5 |—2.7 | 50.2 | 46.7 |—3.5 | 54.1 | 48.7 |—5.4 | 52.0 | 48.9 |—3.1 | 56.0 54.2 —1.8
64.7 |—0.3 | 65.0 | 65.0) 0.0 65.0 | 64.8 —0.2 | 64.9 | 64.8 —0.1 | 64.9 | 64.3 —0.6 65.0 65.0| 0.0) 65.0 | 65.0 0.0
34.1 |—4.8 | 43.3 | 39.8 |—3.5 | 42.0) 38.5 |—3.5 | 40.6 | 34.8 |\—5.8 | 41.0 | 36.3 —4.7 | 44.8 43.5 |-1.3 | 42.5 | 40.8 —1.7
35.7 |—4.1 | 49.0 | 44.6 |—4.4 | 47.7 | 43.6 |—4.1 | 40.7 | 35.6 \—5. 1 | 46.8 | 40.4 |—6.4 | 41.8 | 38.8 |—3.0 | 46.5 | 44.7 | —1.8
33.9 |—3.8 | 42.5 | 39.5 |—3.0| 41.4 | 38.4 |—3.0 | 37.5 | 33.6 |—3.9 | 40.0 | 35.3 |—4.7 | 39.0 | 35.6 |—3.4 42.6 | 40.8 1s
47.2 |—4.0 | 51.7 | 48.3 |—3.4 | 54.5 51.1 |\—3.4 | 50.1 | 46.1 |—4.0 | 51.9 | 47.3 \—4.6 51.2 | 48.0 |—3.2 | 53.5 | 52.4 | —1.1
41.0 |—3.7 50.9 | 47.6 |—3.3 50.8 | 46.8 |\—4.0 49.6 | 44.3 —5.3 | 50.8 | 46.5 i= 3 \a51.7 49.2 |—2.5 | 52.5 | 50.0 | —2.5
32.7 |—5.4 | 44.3 | 40.8 |—3.5 | 43.4 | 38.7 |—4.7 | 38.2 | 33.3 |—-4.9 41.2 | 35.6 |—5.6 | 42.6 | 38.3 |—4-3 46.0 | 44.2 —1.8
42.5 |—3.9 | 50.4 | 47.8 |—2.6 | 49.8 | 47.0 |—2.8 45.0 | 41.0 |—4.0 | 47.9 | 43.8 |—4.1 | 48.4 | 44.8 |—3.6 | 50.0 | 49.0) —1.0
56.5 |+1.4 | 55.8 | 55.0 |—0.8 | 55.6 | 55.2 |—0.4 | 55.7 | 55.6 |—0.1 | 57.5 | 55.6 |—1.9 | 56.0 | 55.8 |—0. 2 | 55.2 | 57.0) +1.8
49.9 |—4.1 | 57.0 | 53.4 |—3.6 | 56.0| 53.5 |—2.5 | 54.4 | 50.5 |—3.9 | 55.4 | 51.3 |—4.1 | 56.0 | 52.6 |—3.4 | 57.0 | 54.9 | —2.1
| 43.7 |—3.9 | 51.6 | 49.5 |—2.1 | 51.1 | 48.6 |—2.5 | 46.8 | 44.0 |—2.8 49.6 | 45.3 ee 50.1 | 48.6 |-1.5 | 51.4 | 50.6 —0.9
62.3 |—1.2 | 63.8 | 63.3 |—0.5 | 64.4 | 63.7 |—0.7 | 63.7 | 62.6 |—1.1 | 61.8 } 62.7 |+0.9 | 64.0} 62.1 =1.9 62.3 63.8 +1.5
52.4 |—2.5 | 57.6 | 55.8 |—1.8 | 57.6 55.4 |—2.2 54.9 52.7 |—2.2 | 56.5 | 53.5 |—3.0 |@55.7 | 53.8 |-1.9 58.0 | 56.9) —1.1
47.1 =3.0 | 53.8 51.2 —2.6 | 53.1°| 50.6 —2.5 50.3 | 47.1 —3.2 52.1 | 48.3 |—3.8 | 51.6 49.0 |—2.6 53.4 | 51.9 —1.5
“ — 7 Y it
a Estimated; actual readings vatueless on account of reflowing or heavy rains.
Station 2. Sphagnum moss. Station 6. Old sanded, heavily vined,
Station 3. Newly sanded, thinly vined. Station 7. Scalped piece, bare peat.
Station 4. Newly sanded, heavily vined. Station 9. Sandy loam on upland.

Station 5. Peat with moss, heavily vined.
Highest and lowest readings are in italics.

51936°--Bull. T—10——3

32

Taste 1.—MIniMuM TEMPERATURES IN SHELTER AND IN OPEN AT 5-INCH HEIGHT, FOR EacH STATION TOGETHER
WITH THE DIFFERENCE BETWEEN READINGS, MATHER, Wis., 1907—Continued.

Station 2. | Station 3. | Station 4. Station 5. Station 6. Station 7. Station 9.
| = : ; ; : E fas
Day of is g “0 3 a 8 f 8 a $ a 8 ; S
St) aa Vics Piel Sed Ne MeN ey asl vees) te)
no | =) a Bina a ics) a a io) (2) a i) a n a ia) n g A
| i alata } By ia ; | ; i
SEPTEM- | | |
BER. onl sae. ° ° ° OF hie? ° ° ° ° Bt oS ° ° ° ° ° °
Ue hese 65.0 | 60.9 |—4.1 | 67.1 | 63.8 |—3.3 | 67.5 | 63.4 |—3.1 | 66.5 | 61.7 |—4.8 | 66.6 | 62.4 |—4.2 | 66.2 | 62.8 |—3.4 | 69.6 | 66.7 | —2.9
DEP eae 47.0 | 41.9 |—5.1 | 52.9 | 50.4 |—2.5 | 52.3 | 49.6 |—2.7 | 50.0 | 45.5 |—4.5 | 50.6 | 45.7 |—4.9 | 51.5 | 49.1 |—2.4 | 52.6 | 51.4 | —1.2
Biescees 45.1 40.5 |—4.6 | 50.2 | 47.9 |—2.3 | 49.5 | 46.0 |—3.5 | 47.0 | 41.3 |—5.7 | 47.7 | 42.5 |—5.2 | 49.5 | 46.4 |—3 1 | 50.1 | 48.9 | —1.2
Beta te 45.1 | 44.7 |—0.4 | 53.4 | 51.0 |—2.4 | 52.7 | 50.0 |—2.7 | 52.1 | 48.8 |—3.3 | 52.9 | 50.6 |—2.3 | 52.5 | 51.5 |—1.0] 52.7 | 52.0] —0.7
Behe ae 40.9 | 35.5 |—5.4 | 44.5 | 43.0 |—1.5 | 43.9 | 42.8 |—1.1 | 43.4 | 41.3 |—2.1 | 44.0 | 42.3 |-1.7 43.0 | 39.4 |—3.6 | 43.8 | 43.6 | —0.2
6......_.] 38.0 | 33.4 |—4.6 | 41.0 | 37.9 |—3.1 | 40.7 | 38.2 |—2.5 | 35.7 | 32.6 |—3.1 | 38.6 | 34.9 |—3.7 | 37-1 | 34.5 |—2.6 | 40.9 39.4 | —1.5
iS E A 55.8 | 54.9 |—0.9 | 55.5 | 55.7 |+0.2 | 55.8 | 55.9 |+0.1 | 55.9 | 55.5 |—0.4 | 55.9 | 55.5 |—0.4 | 55.9 | 55.6 |—0.3 | 55.0 | 55.6 | +0.6 ©
Shee sca: 55.9 | 55.6 |—0.3 | 56.7 | 56.6 |—0.1 | 56.0 | 56.6 |+0.6 |253.6 |@50.8 |—2.8 | 56.7 | 56.4 |—0.3 | 56.7 | 56.8 |+0.1 | 56.7 | 56.7 0.0
a Roeaeoer 36.5 | 30.3 |—6.2 | 39.8 | 37.1 |—2.7 | 39.7 | 35.6 |—4.1 | 36.0 | 33.7 |—2. 3 | 39.5 | 34.4 |—5,.1 | 39.5 | 37.4 |—2.1 | 39.5 | 38.4 | —1.1
LO: 22 oae 35.5 | 30.3 |—5.2 |a37.8 [35.3 |—2.5 |a37.2 |a35.2 |—2.0 |a35.1 |a32.3 |—2.8 |a36.4 |a33.2 |—3.2 | 33.9 | 31.6 |—2.3 | 38.2 | 36.8] —1.4
eee 42.2 | 37.4 |—4.8 | 45.6 | 43.3 |—2.3 | 44.6 | 42.3 |—2.3 | 41.0 | 36.5 14.5 42.6 | 38.7 |—3.9 | 43.2 | 38.9 |—4.3 | 46.5 | 45.4 | —1.1
12) 552228 40.5 | 36.6 |—3.9 | 44.6 | 42.2 |—2.4 | 43.3 | 40.2 |—3.1 | 40.5 | 37.0 |—3.5 | 43.4 | 38.4 |—5.0 | 39.5 | 37.0 |—2.5 | 46.3 | 44.8 | —1.5
139.3248 44.0 | 40.3 |—3.7 | 47.0 | 46.1 |—0.9 | 46.6 | 43.8 |—2.8 | 43.3 | 39.7 |—3.6 | 45.6 | 41.7 |—3.9 | 44.6 | 41.1 |—3.5] 48.0 | 46.3 | —1.7
1 ae aseee 59.4 | 57.3 |—2.1 | 59.7 | 57.4 |—2.3 | 60.1 | 57.3 |—2.8 | 59.5 | 54.9 |—4.6 | 59.7 | 54.8 |—4.9 | 59.3 | 54.0 |—5.3 | 57.0 | 57.4 | +0.4
ee sas * 58.0 | 53.6 |—4.4 | 60.1 | 57.3 |—2.8 | 59.7 | 56.6 |—3.1 | 56.9 | 53.0 |—3.9 | 58.7 | 54.8 |—3.9 | 58.3 | 55.1 |—3.2 60.0] 57.5 | —2.5
8 eee 65.5 | 64.2 |—1.3 | 65.8 | 64.8 |—1.0 | 66.0 | 64.8 |—1.2 | 65.6 | 64.5 |—1.1 | 65.5 | 64.4 |—1.1 | 65.6 | 64.8 |—0.8 | 65.4 | 64.8 | —0.6
a eer 47.6 | 43.6 |—4.0 | 52.5 | 49.5 |—3.0 | 51.7 | 48.9 |—2.8 | 46.8 | 43.5 |—3.3 49.0 | 44.0 |—5.0 | 48.0 | 44.8 |—3.2 52.3 | 50.4 | —1.9
TR ee 57.9 | 56.0 |—1.9 | 58.3 | 57.8 |—0.5 | 58.4 | 57.6 |—0.8 | 58.0 | 56.1 |—1.9 | 58.0 | 57.8 |—0.2 | 58.1 | 58.3 |+0.2 58.0] 57.7 | —0.3
192 ee 60.6 | 58.0 |—2.6 | 61.1 | 59.6 |—1.5 | 61.0 | 59.6 |—1.4 | 60.8 | 58.8 |\—2.0 | 60.7 | 58.8 |—1.9 | 60.6 | 59.5 |—1.1 60.6 | 59.9 | —0.7
20 M58 58.8 | 57.2 |—1.6 | 59.5 | 56.7 |—2.8 | 59.2 | 57.3 |—1.9 | 59.2 | 56.2 |—3.0 | 59.2 | 56.2 |—3.0 | 59.4 | 57.9 |—1.5 | 59.5 | 58.6 | —0.9
4 ene 35.0 | 29.5 |—5.5 | 38.5 | 36.4 |—2.1 | 37.5 | 34.0 |—3.5 | 35.6 | 31.1 |—4.5 | 36.8 | 31.5 |—5: 3 | 35.3 | 31.1 |—4.2 37.6 | 35.3 | —2.3
DOA oe ote 29.0 | 22.7 |—6.3 }a31.1 |428.6 |—2.5 |a30.5 |@28.5 |—2.0 | 25.2 | 19.7 |—5.5 | 27.6 | 20.0 |—7.6 | 27.0 | 22.7 |—4.3 | 30.2 | 27.8 | —2.4
Bee soe 42.8 | 37.0 |—5.8 | 44.2 | 41.4 |—2.8 | 43.9 | 40.4 |—3.5 | 43.7 | 30.0 |—4.7 | 43.9 | 39.3 |—4.6 | 44.0 | 41.7 |—2.3 | 43.5 | 42.4 | —1.1
ee 43.3 | 40.3 |—3.0 | 43.3 | 42.0 |—1.3 | 43.0 | 42.7 |—0.3 | 42.7 | 41.7 \—1.0 | 43.1 | 41.6 |—1.5 | 43.0 | 42.9 |—0.1 | 43.2 | 42.4 | —0.8
VEN me aha 25.4 | 19.5 |—5.9 |a28.0 |a25.5 |—2.5 |a27. 4 25.4 |—2.0 | 25.0 | 20.6 |—4.4 | 25.2 | 20.6 |—4.6 | 26.5 | 25.0 |—1.5 | 27.6 | 26.3) —1.3
3) eS A 29.3 | 24.7 |—4.6 |@33.8 |@31.3 |—2.5 |033. 2 a3. 2 —2.0 | 26.4 | 22.6 |—3.8 | 29.5 | 23.7 |—5.8 | 28.8 | 26.0 |—2.8 | 31.5 | 29.3 | —2.2
p(B ees 32.1 | 27.0 |—5.1 | 33.7 | 31.2 |—2.5 | 33.6 | 31.3 |—2.3 | 30.0 | 26.1 |—3.9 | 31.43 | 27.4 |—3.9 | 31.2 | 28.1 |—3.1 | 33.3 | 31.6 | —1.7
2 ne See 38.7 | 34.6 |—4.1 | 39.0 } 37.2 |—1.8 | 38.7 | 37.9 |—0.8 | 38.5 | 36.9 |—1.6 | 38.6 | 37.5 |—1.1 | 38.5 | 37.0 |—1.5 | 38.8 | 38.0 | —0.8
p.2 et res 28.9 | 24.6 |—4.3 | 30.0 | 27.7 |—2.3 | 29.7 | 27.4 |—2.3 | 26.3 | 23.3 |—3.0 | 28.0 | 24.6 |—3.4 | 28.0 | 26.0 |—2.0 | 29.8 | 28.6 | —1.2
S0E sca 26.1 | 18.8 |—6.3 | 26.6 23.4 |—3.2 | 26.0.) 22.4 |—3.6 | 21.7 | 16.6 |—5.1 | 24.6) 18. 1 |—6.5 24.0 | 20.5 |—3.5 | 26.7 | 24.7 | —2.0
Means .| 44.3 | 40.4 |—3.9 | 46.7 | 44.6 |—2.1 | 46.3 | 44.1 |—2.2 | 44.1 } 40.7 |—3.4 | 45.3 | 41.7 \—3. 6 | 45.0 | 42.6 |—2.4 | 46.5 | 45.3 | —1.2
| ea | a | ne | ad | OP

a Estimated; actual readings valueless on account of reflowing or heavy rains.

Station 6. Old sanded, heavily vined.
Station 7. Scalped piece, bare peat.
Station 9. Sandy loam, on upland.

Station 2. Sphagnum moss.

Station 3. Newly sanded, thinly vined.
Station 4. Newly sanded, heavily vined.
Station 5. Peat with moss, heavily vined.

Highest and lowest readings are in italics.

33

TaBLE 1.—MrnIMuM TEMPERATURES IN SHELTER AND IN OPEN AT 5-INcH Heraur, ror Eacu Sration, TOGETHER
WITH THE DIFFERENCE BETWEEN ReEavpincGs, MATHER, Wis., 1907—Continued.

Station 2. Station 3. Station 4. Station 5. Station 6. Station 7. Station 9.

Day of é od ; 3 . ag J ' as 3 Wek
3 fo) 5 s ° i s =} 5 3 3 a} 2 ° 8 s ° a 2 cs) i
Be eS Ie ey) Se SS REE 1) ER Mean Spe Rta Revel SCSp MI eicoaen)[ erie Eat
7) i} a n <3) =) n <3) =) nm ics) fa) 7a) ica) = n <3) =) a <3] i=)

|
OCTOBER. ° ° ° ° ° ° ° ° ° ° | ° ° ° ° ° | ° ° °
30.0 |—3.0 | 33.2 | 29.8 |—3.4 | 29.5 | 25.6 |—3.9 | 32.0 | 26.9 |—5.1 | 31.5 | 28.5 |-3. 0 | 34.0 | 32.3 | —1.7
46.6 |—4.6 | 52.2 | 48.8 |—3.4 | 58.0 | 46.7 |—5.3 | 52.5 | 47.5 |—5.0 | 51.9 | 48.0 |—3.9 | 52.0) 50.0 | —2.0
41.2 |—2.2 | 42.7 | 40.4 |—2.3 | 39.0 | 35.5 |—3.5 | 41.4 | 36.8 |—4.6 | 43.2 | 38.0 |—5.2 | 44.8 | 43.6 | —1.2
34.0 |—4.5 | 36.5 | 32.5 |—4.0 | 33.3 | 29.5 |—3.8 | 35.3 | 29.3 |—6.0 | 35.5 | 30.5 |—5.0 | 40.0] 38.4 | —1.6
35.1 |—3.2 | 37.5 | 33.7 |—3.8 | 34.8 | 30.3 |—4.5 | 35.1 | 28.7 |—6.4 | 35.3 | 31.7 |—3.6 | 40.3 | 39.0 | —1.3
38.6 |—3.8 | 41.5 | 38.1 |—3.4 | 41.4 | 35.6 |—5.8 | 43.9 | 39.0 |—4.9 | 40.6 | 37.0 |—3.6 | 43.8 | 41.8 | —2.0
42.7 ;—2.8 | 44.5 | 41.4 |—3.1 | 41.6 ) 38.0 |—3.6 | 44.3 | 39.5 |4.8 | 42.7 | 40.3 |—2.4 | 47.3! 45.3 | —2.0
19.5 |—3.2 | 21.8 | 17.7 |—4.1 | 18.8 | 12.8 |—6.0 | 20.1 | 14.6 |—5.5 | 21.5] 17.5 |—4.0 | 22.5 | 19.8] —2.7
35.4 |—3.0 | 40.0 | 34.8 |—5.2 | 40.5 | 34.0 |—6.5 | 40.7 | 34.9 |—5.8 | 40.0 | 37.7 |—2.3 | 39.6 | 37.5 | —2.1
28.4 |—3.3 | 31.4 | 27.0 |—4.4 | 31.4 | 24.8 |—6.6 | 32.5 | 26.5 |—6.0 | 31.4 | 28.1 |—3.3 | 33.0 | 31.5] —1.5
31.0 |—4.0 | 34.6 | 29.7 |—4.9 | 30.6 | 28.3 |—2.3 | 33.4 | 28.5 |—4.9 | 34.4 | 29.5 |—4.9 | 34.7 | 33.7 | —1.0
27.6 |—1.8 | 28.8 | 26.7 |—2.1 | 28.2 | 25.9 |—2.3 | 28.6 | 26.2 |—2.4 | 28.6 | 26.4 |—2.2 | 29.0 | 28.0 | —1.0
19.5 |—2.2 | 21.6 | 16.9 |—4.7 | 17.5 | 12.0 |—5.5 | 19.0 | 13.0 |—6.0 | 20.0 | 16.0 |—4.0 | 23.0 | 21.6 | —1.4
17.8 |—2.6 | 19.8 | 16.8 |—3.0 | 16.0 | 12.4 |—3.6 | 19.5 | 14.0 |—5.5 | 20.4 | 17.0 |—3.4 | 21.0 | 18.9 | —2.1
41.4 |—2.1 | 43.6 | 42.3 |—1.3 | 43.0] 41.5 |—1.5 | 43.7 | 42.0 |—1.7 | 43.0 | 41.7 |—1.3 | 43.4 | 42.6 | —0.8
34.3 |—2.0 | 35.7 | 33.2 |—2.5 | 33.5 | 29.4 |—4.1 | 35.0 | 32.3 |—2.7 | 34.5 | 32.6 |—1.9 | 35.8 | 35.5 | —0.3
30.7 |—2.7 | 32.6 | 29.4 |—3.2 | 31.5 | 28.4 |—3.1 | 33.7 | 29.6 |—4.1 | 32.8 | 30.8 |—2.0] 35.6 | 34.2 | —1.4
21.5 |—3.0 | 23.6 | 20.0 |—2.6 | 23.3 | 20.7 |—2.6 | 22.7 | 22.5 |—0.2 | 23.8 | 22.6 |—1.2 | 23.6 | 23.0] —0.6
19.6 |—3.7 | 22.4 | 16.5 |—5.9 | 18.4 | 13.8 |—4.6 | 21.1 | 15.4 |—5.7 | 21.7 | 19.0 |—2.7 | 25.5 | 23.0 | —2.5
24.6 |—2.7 | 26.6 | 24.7 |—1.9 | 26.3 | 23.5 |—2.8 | 26.6 | 24.8 |—1.8 | 26.5 | 24.5 |—2.0 | 27.1 | 25.8 | —1.3
15.4 |—3.2 | 18.4 | 13.8 |—4.6 | 14.0] 9.8 ;—4.2 | 17.0 | 12.5 |—4.5 | 17.3 | 14.6 ;—2.7 |-17.5 | 15.6 | —1.9
32.3 |—3.7 | 35.7 | 29.4 |—6.3 | 34.3 | 26.5 |—7.8 | 35.7 | 28.0 |—7.7 | 34.6 | 29.3 |—5.3 | 38.3 | 35.7 | —2.6
23.6 |—3.0 | 26.0 | 21.0 |—5.0 | 23.6 | 18.8 |—4.8 | 25.7 | 20.3 |—5.4 | 25.8 | 22.7 |—3.1 | 28.5 | 26.6 | —1.9
21.4 |—3.3 | 24.7 | 19.3 |—5.4 | 18.8 | 14.7 |—4.1 | 21.6 | 16.0 |—5.6 | 22.4 | 19.0 |—3.4 | 25.7 | 23.2} —2.5
22.4 |—3.4 | 25.3 | 21.7 |—3.6 | 25.0 | 21.5 |—3.5 | 26.0 | 22.0 |—4.0 | 26.7 | 25.6 |—1.1 | 26.5 | 25.3 | —1.2
14.4 |—3.2 | 18.0 | 13.1 |—4.9 | 13.7 | 9.3 |—4.4 | 17.5 | 11.7 |—5.8 | 18.0 | 18.7 |—4.3 | 16.5 | 14.8 | —1.7
31.7 |—2.3 | 33.7 | 31.4 |—2.3 | 32.6 | 31.6 |—1.0 | 33.7 | 31.6 |—2.1 | 33.4 | 31.9 |—1.5 | 33.7 | 33.2 |] —0.5
13.5 |—3.2 | 16.0 | 10.7 |—5.3 | 11.0 | 6.4 |—4.6 | 14.3] 8 6|—7.7 | 14.0 | 11.8 |—2.2 | 16.4 | 13.6] —1.8
23.5 |—4.2 | 28.4 | 22.3 |—6.1 | 29.1 | 21.7 |—7.4 | 29.6 | 22.8 |—6.8 | 30.3 | 25.8 |—4.5 | 31.0 | 29.0 | —2.0
36.0 |—0.7 | 36.8 | 36.2 |—0.6 | 36.6 | 35.7 |—0.9 | 36.5 | 36.3 |—0. 2 | 36.5 | 36.1 |—0. 4 | 36.6 | 36.7 | +0.1
29.3 |—4.7 | 35.0 | 31.1 |—3.9 | 34.5 | 29.5 |—5.0 | 35.3 | 28.8 |—4.5 | 35.0 | 30.5 |—4.5 | 35.5 | 34.3 | —1.2
28.5 |—3.1 | 31.2 | 27.4 |—3.8 | 29.2 | 25.0 |—4.2 | 30.8 | 26.1 47 30.8 | 27.7 |—3.1 | 32.3 | 30.8 | —1.5

Station 2.
Station 3.
Station 4.
. Station 5.

Sphagnum moss.

Newly sanded, thinly vined.

Newly sanded, heavily vined.
Peat with moss, heavily vined.
Highest and lowest readings are in italics.

Station 6. Old sanded, heavily vined.
Station 7. Sealped piece, bare peat.
Station 9. Sandy loam on upland.

3+

Tapie la.—MonrHty AND Seasonat Means or MinimuM TEMPERATURES IN SHELTER AND IN OPEMPAT 5-INCH
Heraur, wirn DirrERENCE BETWEEN THE Reapincs, Maruer, Wis., 1907.

i
May.@ June. July. Aug. | Sept. Oct. Means.
| }
fe ae As EL | | Ls = =
Station 2: | a e a Shi a ° °
Shelters-(.0020 6. eee <tr AS A is le Se or eee eee 38.9 45.4 51.8 50.1 44.3 30.0 43.4
TON 9 2]81:(.0 lace oe at See aE ae eM seve oar = Tee Scenes 37.2 42.3 49.2 | 47.1 40.4 25.2 40.2
TD TELONCA ieee cel i I eee eee Shy Hil —2.6 | —3.0 —3.9 —4.8 =u)
1 | =
Station 3: |
Bhelteretege oe oth: eae ee ae ere ae ae 41.4 48.9 55.6 53.8 | 46.7 31.6 46.3
fiposed 2 2. f-c Cnn se ane ee gnome tomers eee ae Sree eats 39.3 46.3 53.0 | 51.2) 44.6 28.5 43.8
Difference —2.1 —2.6 —2.6 | —2.6 —2.1 | —3-1 | =2.5
| =
Station 4:
STI eencordpie tonne <GhSep ac decscanansaeeioole se ersebe she eetomsheS 41.2 48.4 54.9 53. 46.3 31.2 45.8
Wxposed oa): ene e sae = eee a seh e eee mains ermine er oan en 38.8 45.7 OES A GOMG 44.1 27.4 | 43.2
Difference ee pete cee ao ea ta ae a a ed eet | 7" 2.7 er) —2:5 —2.2 | —3.8 —2.6
|
Station 5: | . |
Shelterssc-5 ee eee eee eee ens Soca ae ae ee Leta oe aces | 39.7 | 45.7 53.1 50.3 44.1 29. 2 | 43.7
Exposed l iaz2 41.8 48.8 yes 40.7| 25.0 | 40.1
Difference esses eee eos ae ee ee ee ee ise eee | 2.5 3.9 4.3 3a 3.4 —4,2)| —3.6
Station 6: |
40.4 47.0 53.8 52.1 45.3 30.8 44.9
38.0 43.2 49.6 48.3 Al. 7, | 26.1 41.2
Differences eases WR ae Se Gis Shae Sesoecesoba eens —2.4 —3.8| —4.2 —3.8) —3.6 == 47 307
Station 7: | |
Shelters) see eeee= Ae St EER eR PRE oti arn ee Pinata SEE 39.9 46.3 53.0 51.6 45.0 30.8 44.4
FRexPOSEC Sewer eee ee ace ete ae orate cee eee ener 37.6, 43.0 50.2 49.0 | 42.6 27.7 41.7
WMifferance see she doe Se 2 jade ctieloceiola, seas elstee eae ae iain iol —2.3 | —3.3 —2.8 —2.6 =2.4 | —3.1 —2.7
Station 9:
Shelterecrre store ss eet ei cna nets ai de MeO eee eta receer ee 41.2 | 48.4 55.4 53.4 46.5 | © 32.3 46.2
40.1 | 46.8 53.8 51.9 45.3 30.8 44.8
Diferenidert: otc Lee A i eee, SRR Ae ee Se Sug | Se | ag || Sa | =i Ds

a Means for eighteen days.

Station 2. Sphagnum moss.

Station 3. Newly sanded, thinly vined.
Station 4. Newly sanded, heavily vined.
Station 5. Peat with moss, heavily vined

> Mean difference all stations, —2.8°.

Station 6. Old sanded, heavily vined.
Station 7. Scalped piece, bare peat.
Station 9. Sandy loam on upland.

30

Readings of exposed minimum thermometers at the surface and at the 5-inch height.—It was
found impracticable to place thermometers in the shelters at a lower elevation than 5 inches
above the surface of the ground, and consequently readings of instruments exposed at this
elevation in the open were used in connection with the discussion of Tables 1 and la. Having
found the difference prevailing between minimum thermometers exposed inside and outside of
shelters, it seemed advisable to determine the difference between the readings of the mmimum
thermometers so exposed in the open and of additional instruments placed at the immediate
surface. The cranberry vines extend along the surface, their uprights reaching above several
inches, and readings of instruments placed at different elevations at any particular station
indicate approximately the temperature which the vines and leaves experience. Again, the
temperature at the immediate surface is naturally largely governed by the conditions of the soil
beneath, and the readings of the surface thermometers were therefore needed in connection
with the discussion of soiltemperatures.

It seemed advisable, as far as practicable, to have the thermometers at the 5-inch height
placed directly above the surface instruments, in order that the conditions of the soil and vege-
tation beneath might be the same for both exposures. This method was followed at all stations
except Station 4, where, on account of the special conditions prevailing, it was found necessary
to place the surface minimum on the ground a few feet distant from the instrument exposed at the
5-inch height. The vegetation over which the surface thermometer was placed at this station
was more dense than at the point where the upper thermometer was exposed, referred to in the
discussion of Tables 1 and 1a. In all cases the lower minimum thermometers rested upon the
ground, although at Stations 2 and 9 they were at the same time fastened to the base of the
post which supported other instruments. Were the conditions exactly the same regarding soil
and vegetation over a large area at each station, a better comparison would be secured by
placing the upper instrument at a point sufficiently removed from the surface thermometer so
that it would not shield in the slightest degree the lower instrument, but it is most difficult to
secure in a bog surface and soil conditions that are exactly similar for a considerable area.
There is certain to be a variation in the character and quantity of the vegetation, and some-
times in the character of the soil, even in a small area. These varying conditions may be also
considered as factors in the comparison previously made between thermometers exposed in the
open and in shelters.

Space does not permit the publication of the daily readings of the two exposed minimums
at the several stations, but Table 2 shows the monthly and the seasonal averages for the year
1907. The readings were generally higher at the surface than at the 5-inch height, and espe-
cially so during clear, cool nights. During cloudy and windy weather there was but little differ-
ence, and sometimes the surface instrument even registered lower. In fact, at the surface at
Station 4, the average for the entire season was slightly lower at the height of 5 inches, but a
satisfactory comparison was not possible at that point, for reasons given above.

There was also a complication at Station 7, in that these thermometers were placed in the
middle of a scalped piece, 10 feet square, surrounded by a section of dense sphagnum moss.
As stated in a previous paragraph, the instruments were exposed usually over a surface that was
representative of a large section of the bog surrounding it, because the temperature naturally
is affected by the surface conditions, not only at the point of exposure, but for a considerable
area in the vicinity. However, at Station 7 the scalped area was only a relatively small section
within an extensive field of sphagnum moss. Moreover, the soil at this station during 1907
was very damp, and the consequent evaporation affected the surface thermometer more than
the one at 5 inches.

The depression of the thermometers at the 5-inch height was greatest during cold, clear
nights, with comparatively high barometer and light wind, when radiation was freest, appar-
ently for the same reason that the exposed minimums registered lower than those in shelters.
(Table 1.) The moisture resulting from dew, rain, or reflowing sometimes affected the readings
of the instruments, especially when water covered the bulbs of the thermometers. For instance,
dew occasionally formed on the bulb of the upper thermometer when the lower was perfectly

36

dry, and at other times the lower thermometer remained wet from rain, the cold of eyporation
sometimes lowering the readings of the instrument, especially when rain was followed in the
nighttime by wind. At such times the upper thermometers were usually higher than the
lower ones—an inversion of the usual conditions. Often this difference amounted to several
degrees. On the other hand, water from a warm rain remaining on the bulb of a thermometer
often served to raise its reading when the air remained humid and calm.

There seemed to be no uniformity in the variation from month to month, although usually
the differences were greatest in October. The average depression of temperature at the 5-inch
height below that at the surface for the season of 1907 was 1°. The average depression on clear,
cool nights probably reached 4°. There were several instances of differences exceeding 6°. The
greatest average monthly depression of the upper thermometers for any one month was 3°, at
Station 5, in October. At Station 4 the lower thermometer averaged 0.4°, 0.5°, and 0.1° lower
in May, June, and July, respectively, than the upper thermometer. However, in. September and
October, at Station 4, the lower minimum averaged higher than the upper one by 0.1° and 0.2°,
respectively, and in August there was no difference. The lack in uniformity of the vegetation at
Station 4 has been referred to above.

In the year 1906 similar data were available for Stations 3, 5, 6, 7, and 9 for the months
of August and September. The average depressions of the thermometers at the 5-inch height
below those at the surface for the month of August in the years, 1906 and 1907, respectively,
were as follows: Station 3, 3° and 2.5°; Station 5, 1.6° and 1.7°; Station 6, 1.2° and 1°; Station
7, 3° and 0.2°; Station 9, 0.6° and 0.7°; for the month of September, 1906 and 1907: Station 38,.
4.7° and 1.3°; Station 5, 2.4° and 2.3°; Station 6, 1.6° and 1.4°; Station 7, 4.8° and +0.3°9;
Station 9, 1° and 0.3°.

It is not easy to state the exact reasons for these great differences in temperature. Of
course, the upper thermometers were so placed that there was freer radiation from them than
from those at the surface; yet it is not thought that the difference in radiation should be sufficient
reason for such great differences in temperature, reaching a maximum difference of 6° and even
7° on several nights. The fact that the thermometer exposed at the surface at Station 4 aver-
aged lower during more than half the season than the one at the 5-inch height, and that at that
station the thermometers were placed several feet apart, and not one directly above the other,
as at other stations, might suggest that at the remaining stations the surface thermometers
generally registered higher because they were shielded by the thermometers immediately above.
It is, however, difficult to believe that the very slight interposition of the upper thermometer
could be responsible for differences of several degrees, as often occurred. The fact that the
surface thermometer at Station 4 was located on a surface more densely covered with vegetation
than the place where the upper thermometer at the same station was located should partially
account for the apparent inconsistency in the readings at that station. There was so much
water at Station 7 in 1907 as compared with 1906 as to seriously affect the comparison of the
thermometer readings, and it is because of the great amount of evaporation in 1907 at the
surface that the lower minimum averaged relatively lower than in 1906.

In a marsh grasses and uprights from the vines interfere slightly with radiation from the
thermométers placed on the surface, and it is probable that a thermometer or leaf exposed at an
elevation above the surface loses its heat more rapidly by radiation than if it rested upon the
surface, because the upper one is not shielded in any way, and while the radiation is going on
from the lower one, at the same time heat is bemg conducted to it from the ground beneath.
A thermometer resting upon the surface of the bog becomes a part of the soil or vegetation upon
which it rests, as it were, and is benefited by the free conduction of heat to it from the ground,
while the conduction to and through the air is very slight in comparison; because of these differ-
ences in radiation and conduction, the surface thermometer usually registers a higher tempera-
ture than the instrument a few inches above. For the same reason, the temperature of the
vegetation at the surface and 5 inches above would vary as these temperatures have varied,

4 Surface instrument registered lower.

37

especially when the surface vegetation is shielded by vegetation above. It is a matter of
common knowledge that in the bogs the cranberries growing at the tops of the uprights a few
inches above the ground are often damaged by frost, while those lying on or near the ground
escape injury.

The readings of exposed minimum thermometers at a number of different elevations will
be discussed in detail later in connection with Tables 13 and 14, in order to show approximately
the height above the ground at which the lowest minimum occurs.

TABLE 2.—MoNnTHLY AND SEASONAL MEANS OF Minimum TEMPERATURES IN OPEN AT SURFACE AND AT 5-INCH
Heicutr, wirh DirrFERENCE BETWEEN THE Reapincs, MaruHer, Wis., 1907.
| May.@ | June. | July. Aug. Sept. Oct. | Means.?
pa |eeeeeees Ee 2 =
= = | |
Station 2: Gg | ° | Q ° ° ° °
Stitt eee, Inne eGo eee tnbee: Heenan Soa eCC eR oon Osea eB arom r 37.6 43.3 52.0 49.4 41.9 41.9
Fiftaveii, eek Serene CAL SB ene nn CaP arinen or Sacre Rar anenren ores! | 37.2 42.3 49.2 47.1 40.4 40.2
iS ATTA ea Se ole bah Rc say OER Je Eee ee ea | 0.4! 1.0 | 2.8 | 2.3 1.5 Pal | Stee
|
Station 3:
Surface | 40.4 48.8 55.5 53.7 45.9 28.8 45.5
GRC Ne sup, 4a aes ROR DROS Naa sabe aeesr seaceceeaen see | 39.3 46.3 | 53.0 51:2 44.6 28. 5 | 43.8
TEAR neal lee Re ta tee Oa nO econ en a a | ih 2.5 | 2.5 1.3 0.3 =i
i =i = —
Station 4: | |
EA a erga LL ats Sa ASME LCR Mere Gere Skee ne Ee ieee eae 38.4 45.2 | 50.6 44.2 27.6 | 43.1
jie. 0b ea sceas neat @e epee es epee ec ane ea eoeeer eas Soe ac aad 38.8 45.7 | 50.6} 44.1 27.4 | 43.2
BYR oS eo ce ON Re ede a ce ne ne | +04) 40.5 | Cu) =e SON seit
—| é
Station 5: | | |
|
Sart ce ee ee hae et cece Pareto ent ne aae henna eave 43.5 | 48.8 43.0 28.0 | 41.7
“apps ty eels CoD hee ok Sep ye a Aree ea 37.2 41.8 7.1 40.7 25.0 | 40.1
| | Be | q |
Witerenicesee Mees serene eee ee eseene res on see as ames rac } +0.1 —1.7) —1.0)} a7} 2.3 3.0 | 1.6
| | =
Station 6: | | |
Hina CTs ace Silo. tdi sh Sees U cs JORG RACERS Ros Aer ea Sa ener ene CSDOSEEe ere | 38.7 44.05 50.3 49.3 43.1 28.3 42.3
38.0 43.2 49.6 | 48.3 41.7 26.3 | 41,2
TDS EU ee oO pe a eR 0.7 =oig)| eon) eo) Paka —2.0 itil
Station 7: |
|
Shobd One Ee ct Ewin Ae cn pao a RP RS BSA 6c Oe See G SO eee 37.6 44.0 51.2 49.2 42.3 27.9 42.0
5 inch... 37.6 43.0 | 50.2 49.0 42.6 27.7 | 41.7
i rs | Cae |
TICE OCR tee eee ean tate nin hes SA SSE So O10) ecto aol 20%) ora) 012) 0.8
Station 9: |
PRRs Ween bn cag eect Se a a ne ee 40.9 48.7| 55.0 526 45. 311 45.6
Carat b eee ea oe he in badecd sone oak DAUR EA Oe ce! OER OSE Per errr 40.1 46.8 | 53.8 51.9 45.3 30.8 | 44.8
ID patel ese eye a een cos oc Se Enno Seer Se re Oe eT —0.8 1.9 1.2 0.7 0.3 0.3 —0.8

a Means for eighteen days.
Station 2. Sphagnum moss.
Station 3. Newly sanded, thinly vined.
Station 4. Newly sanded, heavily vined.

b Mean difference all stations, 1.0°.
Station 6. Old sanded, heavily vined.
Station 7. Scalped piece, bare peat.
Station 9. Sandy loam on upland.

Station 5. Peat with moss, heavily vined.

Observations of temperatures in soil and at the surface in different locations, Mather, Wis.,
1906 and 1907.—This discussion has already shown that there is a wide difference in temperature
at various points at the surface and a few inches above, in the same bog, and that the vegetation
in bottom lands is subjected to temperatures of varying degree. It seemed desirable to deter-
mine what relation, if any, exists between the temperature at and near the surface and the
character of the soil and its covering. Observations made at Mather, Wis., during 1906 and
1907 of soil temperatures in connection with exposed thermometers above the surface furnish
interesting data bearing on this subject. The average readings are herewith given for September,

38

1906, for four selected stations, this being preliminary to the more extensive observations of
the following year. ° i
AVERAGE TEMPERATURES FOR SEPTEMBER, 1906, MarHeER, WIS.

j
Station 3. | Station 4. | Station 6. | Station 5.
= —— — = —— ————
° ° ° °
ibe okaeobacls(eliveradk oleh leben eh bls CCE Sk eres A sos oao se ccnacossdn seanodsosrensoecosesnons 64.2 63.2 | 61.1 59. 8
Minimum soil temperature, 3 inches. Ae Bb sr he senso see Sseemnsce 2 BEaee 56.1 59. 1 59.1 59. 2
Nightly loss of soil heat, 3 inches - Sse =: Sino oaaee Bee ae Se 8.1 4.1 2.0 6
Exposed minimum at surface... ol. 2 47.9 44.2 44.1

Station 3, newly sanded and thinly vined, representing best conditions of sanding, draining, and cultivating.
Station 4, newly sanded and heavily vined, representing best conditions of sanding and draining.

Station 6, old (9 years), sanded and heavily vined, stratum of peat, 1 inch in thickness, over old sand.
Station 5, uncultivated marsh, peat, and sphagnum moss, poorly drained.

The soil thermometers were placed at a depth of 3 inches, and it was found by a series of
eye observations and by comparison with the soil thermograph traces that the maximum soil
temperatures usually occurred at about 6 p.m. and the minimum soil temperatures at about
7 a.m. (See Fig. 20, showing average hourly soil thermograph readings at Stations 3 and
5, Mather, Wis., 1907.) The above table shows that the highest maximum soil temperatures
and the lowest minimum soil temperatures at the depth of 3 inches and the highest exposed
minimums occurred in the sanded sections, bare or thinly vined and well drained, while the lowest
maximum soil temperatures, the highest minimum soil temperatures, and the lowest exposed
minimums were found in the uncultivated marsh, which was poorly drained and had a thick
growth of vegetation and sphagnum moss.

Prof. W. J. Humphreys” says: ‘‘The better the absorber, other things being equal, the
warmer it gets during insolation and the more it heats the air, while the better the radiator it
is, the colder, as a rule, it and the air adjacent become during the night. When the atmosphere
is clear and dry, and therefore diathermanous, the cooling of objects and their liability to frost
depends largely upon their capacity to radiate at ordinary temperatures. A good radiator
under these conditions loses heat partly by radiation through the atmosphere to space. It
cools rapidly, but the heat it gives off does not all go to warming the air, for, as explained, a
part of it is directly lost to space. On the other hand, an object that radiates poorly gives
off heat slowly, and what it does give off is in a large measure by conduction to the atmosphere.
It tends to conserve both its own temperature and that of the surrounding air, and thereby
diminishes the probability of frost.”

As stated before, during the day the surface of any solid upon which the sun shines becomes
hotter than the air above it. A thermometer resting upon the ground becomes a part of the
soil or vegetation, as it were, and the readings of the instrument indicate relatively high or
low maximum temperatures in the daytime and relatively high or low minimum temperatures
at night, depending upon the radiation, absorption, and conduction of heat under the various
existing conditions. The vegetation as found in the bogs is an excellent radiator and absorbs
well, but of course conducts and transmits heat to the soil very slowly. The heat lost from
vegetation is largely by radiation through the air without heating it sensibly. Peat soil is
also a good absorber and radiator, but it is a poor conductor; but the heat received at the
surface is partly conducted into the peat. The sanded surface is not as good an absorber, but
it is a much better conductor of heat. The heat, moreover, of the sand in the presence of air
is lost largely by conduction to it, and consequently serves to heat the air lying immediately
above—in strong contrast to the conditions over a heavily vined surface or plain peat, where
the loss is mainly by radiation.

A knowledge of these facts is important in connection with the more extensive observations
made at Mather during the season of 1907, readings of exposed maximums and of exposed

« Bulletin of the Mount Weather Observatory, Vol. IT, pt. 3.

39

minimums being made as well as of soil temperature. The Stations 3, 4, 5, and 6 selected are
fairly representative of the conditions prevailing in a cranberry bog. Only the summary of
the conditions for 1907, including maximum and minimum averages, appears in Table 3. There
is not sufficient space for the daily readings. Four stations, as in the previous year, are suffi-
cient for this comparison, and an additional number would merely repeat the results here
furnished. The readings of the maximum and the minimum thermometers are from instru-
ments exposed in the open at the surface. The soil thermometers at the various stations were
placed at a depth of 3 inches in the vicinity of the surface thermometers. For purposes of this
discussion it would have been better if the bulbs could have been placed just beneath the sur-
face. But in a bog it is rather difficult to determine where the actual surface begins, as it is
generally covered with vines, grasses, leaves, and decaying vegetation, gradually turning to
peat. Where the vegetation is dense, the effective surface is actually above the surface of the
soil. The sanded surfaces differ radically from the surfaces that are not sanded. On account
of these circumstances and because of the difficulty of maintaining the soil thermometers in an
upright position, except at a moderate depth, so as to firmly secure them, no attempt was made
to obtain readings of the soil temperature at a depth less than 3 inches. In the original tables,
of which Table 3 is the summary, the readings of the soil thermometers which were made at
6 p. m. are entered under the succeeding date, and the differences between these readings and
the following 7 a. m. readings show the nightly loss or range in soil temperature.

The difficulty in an investigation of this kind is to maintain uniform conditions at the
various stations, so that data may be fairly comparable at all times during the season, but this
is quite impossible, as the vegetation is likely to remain uniform at one station, while at other
stations it may either increase or decrease in density. During the season of 1907 the conditions
at Stations 3 and 4 changed but little, the surface at Station 3 being relatively clean, while at
Station 4 the vegetation remained dense. The vines at Station 5 were dying out after mid-
summer to such a degree as to seriously affect the readings of the instruments. In fact, twice
during the month of August a change in the location of the soil instruments was made in order
to counteract the changing conditions. The density of the vegetation at Station 6 steadily
decreased as the end of the season approached, but there was no change in the location of the
instruments as at Station 5. If the cranberry vine were a bush, as some people believe, there
would not be much difficulty in maintaining uniform conditions of foliage, but it is a vine
spreading in all directions from the crown, so that constant trampling at one place often affects
the condition of the vegetation several feet distant.

There is, for the reasons given above, a greater uniformity in the readings at Stations 3
and 4 than at the other stations. At Station 3 for the entire season the exposed maximums
averaged the lowest and the exposed minimums and the 6 p. m. soil temperatures the highest,
although the 7 a. m. soil temperatures averaged the lowest. At Station 5 the exposed maxi-
mums averaged the highest from May to August, inclusive, but in September the maximum
at Station 4 was slightly higher and in October much higher than at Station 5. The lack in
uniformity was undoubtedly caused by the steady change in vegetation at Station 5, as referred
to above. This change at Station 5 is also apparent in the comparison of the minimums at
Stations 4 and 5, the average minimum in October at Station 4 actually being lower by 0.4°
than at Station 5, while in the other months it was considerably higher. The persistency of
the dense vegetation at Station 4 until the end of the season is quite apparent from the read-
ings of the instruments, especially in October. It was at Station 4 that the surface minimum
averaged lower than at the 5-inch height, as referred to in the discussion of Table 2. On account
of the enforced change of the soil instruments at Station 5 in August, these readings are not
strictly comparable in September and October with the soil data at the other stations.

At Stations 4, 5, and 6 the soil was so shielded from the sun’s rays as to prevent its warm-
ing to any great degree, much of the absorbed energy being used to produce plant growth and
evaporation, and consequently the loss or range of heat was small as compared with that at
Station 3. The difference in range of soil temperature at the 3-inch depth at certain stations,

40

caused by variation in soil and covering, at Mather, Wis., is graphically shown in gFigure 19;
also in Figure 20, which shows the average hourly soil temperature at depths of 3 and 6 inches
at, Stations 3 and 5. .

While the 7 a. m. or minimum soil temperature readings at the depth of 3 inches at Station
3 averaged lower than at the other stations, it is probable that the minimum temperature of
the soil at the immediate surface at Station 3 averaged higher than at the other locations,
because the exposed mimimum temperature was higher. As the exposed maximum tempera-
ture at the various stations was affected by the vegetation, so also was the exposed minimum,
FESUEELES ELE LE

(28 29 30.
== ==

Mt
}

Fig. 19.—Soil temperature curves at three inch depth for Stations 3, 4, and 5, Mather, Wis., September 23 to 30, 1906. Station No. 3, soil
temperature in bog newly sanded, thinly vined, 3 inches deep ; Station No, 5, soil temperature in peat bog with moss 3 inches deep
; Station No. 4, soil temperature in bog newly sanded, heavily vined, 3 inches deep —x—x—x—x—x—.

the lowest minimums prevailing generally at the stations where the maximums were the
highest. Obviously the increasing vegetation, serving to raise the exposed maximum in the
daytime, was also responsible for the great radiation at night, especially during clear weather,
and as a consequence the minimums were lowest where the vegetation was densest and highest
where it was thinnest. While the loss of heat at night from the vegetation is largely by radia-
tion and through the air without warming it, at places where the surface was sanded the loss
of heat was bea by conduction to the air above. Although the vegetation was dense at
Station 4, the surface had been recently sanded, and the surface at Station 6 had been sanded

in 1898. The influence of this sand-
el mn SEES ESTE:

tion 6 is apparent in the readings
of the maximum soil tempera-
ture, the range in soil temperature,
and the exposed minimum tem-
perature, as compared with similar
readings at Station 5, although a
layer of peat an inch in thickness
had formed over the sand at Sta-
tion 6. The vegetation at all three

ing at Station 4 and even at Sta-
8 32252 >.

—— _———— = tes SS
SS 25525 i=
SSSS=- === ==

Hl
Hi

== F=- stations was dense and prevented
252 |

=== great heating of the soil, but nev-
== == t+ ertheless the sand, being a better

conductor of heat than the peat,
Fig. 20.—(1) Traces showing average hourly soil temperature for the season of 1907 brought a oreater supply of heat
c n= . rs i t=) my
ata depth of 3 inches and 6 inches, Station 3, Mather, Wis. (3 inches : tl il i A fe
6 inches -) (2) Traces showing average hourly soil tempera- mto 1€ SOU, thus conserving 1t to
tures for the season of 1907 at depths of 3 inches and 6 inches, Station 5, Mather, be given off later at night by con-
Wis. (3 inches . 6 inches :) : Ob An :
duction and radiation. The sand,
then, was probably as much responsible as the better drainage for the higher exposed mini-
mum temperatures at Stations 4 and 6, as compared with Station 5, the drainage at both
Stations 5 and 6 being relatively poor, soar Pae in a considerable loss of heat through evap-
oration of the moisture at the surface. The conditions at Station 6 resembled those at Stations
4 and 5 equally, because although the vegetation at Station 6 was dense until after midsum-
mer, it gradually died away, and for this reason the exposed maximums averaged during

October even lower than those at Station 3.

41

These observations in 1907 confirm those of 1906 in that the highest maximum soil tem-
peratures and the lowest minimum soil temperatures at the depth of 3 inches, the greatest
range in soil temperature, and the highest exposed minimums occurred in the thinly vined,
well drained, and sanded sections, while the lowest maximum soil temperatures and highest
minimum soil temperatures, the least range in soil temperature, and the lowest exposed mini-
mums were found in the uncultivated marsh, which was poorly drained and heavily vined.
Moreover, the highest average exposed maximums occurred where the vegetation was dense,
while the lowest average maximums occurred in the sanded and thinly vined section. Other
things being equal, the higher the maximum temperature on any one day the higher was the
maximum soil temperature at the depth of 3 inches and the ensuing exposed minimum tem-
perature. Again, other things being equal, the higher the maximum soil temperature on any
one day the higher was the ensuing exposed minimum temperature. In other words, there
was a close relation between the daily maximum air temperature and the soil temperature and
a close relation between the soil temperature and the ensuing exposed minimum temperature.
It is for this reason that in the spring and fall, when the ground is cold, frost occurs in the bogs
much more easily than in the summer, when the soil is warm.

The high exposed minimums at Station 3, as compared with those at the other stations,
are quite remarkable, and the advantages from cultivation, drainmg, and sanding are well
illustrated. The difference between the minimum temperatures at Station 3 and at the other
stations is least in October, and this is probably because frost had entered the surface of the
soil. Whereas sand during the crop season is most valuable in warding off low night tem-
peratures, it is probable that after frost has once entered the soil its character is not of much
consequence. While the exposed maximums on cloudy days varied little at the different sta-
tions and did not reach a high degree, the minimum temperatures on cloudy nights differed
little and were relatively high. There was, moreover, but little difference between the mini-
mums on windy nights. At no station during the season did the temperature of the soil at
the depth of 3 inches fall to the freezing point, the lowest reading being 33.8° on the morning
of October 28 at Station 3. On the same day the readings at the other stations were as follows:
Station 4, 37.1°; Station 5, 40.3°; and at Station 6, 37°; but at all stations on the bog the
ground at the immediate surface was frozen.

The range in the exposed minimum temperature at the surface of a bog, as shown by
Tables 2 and 3, does not, of course, actually represent the extremes, the exposed minimums at
the 5-inch height as a rule registering lower than those at the surface. In later tables embody-
ing the daily readings of the exposed minimums, both at the surface and 5 inches and their
respective differences, will be shown in detail the extreme differences at the coldest and the
warmest places on the bogs.

The highest exposed maximums were reached about July 20, the greatest being 128.1°
on that date at Station 5. On the same date the exposed maximum at Station 3 was 110°;
at Station 4, 121.7°; and at Station 6, 120°. The soil temperature readings at 6 p.m. at Stations
4, 5, and 6, reached their maximum from four to five days later, there being an irregular increase
from the beginning of the season in May to the summer maximum, and, in turn, a decrease
from the maximum to the minimum near the end of October. The highest soil temperatures
at the various stations in July were as follows: Station 3, 76.3° on the 20th; Station 4, 69.7°
on the 24th; Station 5, 71° on the 25th; and Station 6, 71.5° on the 24th. The maximum
of the season, however, at Station 3, in the thinly vined and sanded section, was not reached
until August 31, when a temperature of 78° was registered. The exposed maximums at Station
3 seldom registered higher than 110°, but at Stations 4, 5, and 6, where the vegetation was
dense, the readings frequently exceeded 120°. The greatest daily range between the exposed
maximum and the exposed minimum at any one station was at Station 5, 89.9°, on July 2,
from a maximum of 119.9° to a minimum of 30°. The daily range in exposed temperature
was seldom less than 20°, except at Station 3. At that station there were a few instances of
ranges less than 10° in October, and one or two others during the balance of the season.

42

There is, of course, a direct relation between the air temperature and the soil tenaperature,
an increase of heat during the day serving to raise the temperature of the soil; and this, in
turn, prevents low minimum temperatures at night. Where the air temperature was low in
the daytime, and, as a result, the soil remained cold, low minimum air temperatures were sure
to follow, provided the weather at night was clear, so as to permit free radiation of heat.
While usually there was a loss of heat from the soil at night, occasionally the temperature of
the soil rose. On October 2, during a cloudy, warm night, following a cold day, the tempera-
ture of the soil rose at the various stations, the increase reaching a maximum of 1.7° at Station
6. On certain cloudy, warm nights there was a slight rise in the soil temperature at Stations 4,
5, and 6, while a fall occurred at Station 3. The greatest nightly loss in soil temperature was
at Station 3, 17.8° on October 18, from a maximum of 57° to a minimum of 39.2°, while at the
other stations the nightly loss in soil temperature seldom exceeded 5°. The range in soil
temperature is a measure of the heat absorbed during the day and lost at night by the soil, and
responds from day to day to changes in insolation.

The amount of heat received in the daytime by the soil at the different locations is shown
in a measure by the 6 p. m. soil-temperature readings. At the 3-inch depth the average for the
season of 1907 at Station 3 was 62.6°, as compared with 58° at Station 4, 56.6° at Station 5,
and 57.2° at Station 6. (Tables 3 and 19.) Moreover, at the 6-inch depth, the average soil-
temperature readings were as follows: Station 3, 59.8°; Station 4, 56.2°; Station 5, 55.2°;
Station 6, 55.6°. These figures not only show that the temperature of the soil near the sur-
face in the thinly vined and sanded section is usually much higher than in the other sections,
but also that the heat reaches to a greater depth. In this connection, see Figure 20, showing
the soil-temperature curves at both 3 and 6 inches at Stations 3 and 5 for the season of 1907.
The range in temperature of the soil immediately beneath the surface is undoubtedly greater
than at the depth of 3 inches. It should be evident that where the soil temperatures are high,
more heat may be lost by conduction and radiation from the soil before the point of critical
air temperature at or immediately above the surface is reached, even if the loss by radiation
through the air be at the same rate at all locations. However, the radiation from a peat bog
with a heavily vined surface is much freer than where the surface has been sanded and is thinly
vined, the loss of heat from the latter probably being largely by conduction to the air, and there-
fore slower. The sanded and thinly vined surface conserves the heat, not only in the soil,
but also in the air immediately above, while a dense growth of vegetation prevents the soil
beneath from being heated considerably in the daytime. The degree to which the temperature
falls during the night depends largely upon the warmth of the soil, and when the heating
during the day has been shght, and the ensuing night is clear, thus permitting rapid radiation,
low minimum air temperatures must result, as stated above.

It is apparent from this discussion that the air temperature is controlled largely by the
character of the soil and its covering. Such a remarkable variation as is here shown explains
why frost may visit one portion of a bog, while another portion may escape injury. On any
clear, cool night the cold air, as it settles gradually through gravity, overspreads the bog, and
here and there are found warm places and cold places and others having an intermediate
value, depending upon the character of the soil and its covering. It is as if heaters of varying
power were scattered over the bog, giving off heat to the air immediately above, some in greater
quantities and others in less. The difference in temperature of a surface covering is some-
times apparent when the first light snow falls in the autumn or early winter, before the ground
becomes cold, the snow melting where the ground is bare of growth, but remaining where the
vegetation is dense. Likewise, under similar conditions, snow melts when it falls upon a
concrete walk, though remaining on a board walk; and the first frost of the season is always
seen on the latter. The heat stored in the bare soil and in the concrete walk is conducted
to the surface, and affects the temperature at the surface as does a sanded and thinly vined
soil in the bogs. Figures 21 and 22 will supplement Table 3.

43

TABLE 3.—MoNTHLY AND SEASONAL MEANS or MAXIMUM AND MINIMUM TEMPERATURES AT SURFACE IN OPEN, WITH
Rance; atso MEANS or Sow TEMPERATURES, 3-INCH DEPTH, AND OF Loss DURING THE NicHt, Marner, WIs.,
1907.

[The 6 p. m. soil temperatures occurred the previous day.]

May.@ June. July. Aug. | Sept. | Oct. Means.
|
Station 3: |
Surface— o | ° ° ° o «| ° °
Mi eax irvine eee eee an te ee De iran do gaia esac ee =e 79.5 | 95.7 99.6 89.9 80.9 62.1 84.6
MN Sor oe Se seo Seo Se Nec omat Soaencs one beeen DOac re sScreaee Bae 40. 2 48.8 | 55. 5 53.7 45.9 28.8 45.5
39.3 46.9 | 44.1] 36.2 35.0 33.3 | 39.1
| ie | |
| |
56.3 65.9 71.8 | 68.6 63.2 49.6 62.6
48.0 56.9 63.1 61.4 55.3 41.9 54.4
_— | — |__ — SE ———
Bahai =9.0 | =8:7 | 7.2| 7.9 | Mf 8.2
Station 4: | | |
Surface— | ' |
Maxim en eet te tate = ree ae ese eee Sen | 84.5] 103.4] 110.1 | 99. 4 | 85.4 72.7 92.6
UR nbn he a, coasdbamoct Samo ncidnc se Rate Sher Acosccee Sencaeae ec 38. 2 45.2 | 52.3 50. 6 44.2 27.5 43.0
Tamm Pe ene sep reer ead cero A racic eCity ee cteretciciman 2a ce 46.3 58.2 | 57.8 | 48.8 41.2 45.2 | 49.6
Soil, 3 inch— | |
GED Ee eee oe eae Meares eo A oad Bin Bos achat 50.5 60.2 | 66.9 | 64.6 59.3 46.6 58.0
Tease te uote lee ososbeeei ad aeger tea cee RE eee aaeeeeeee | 47.6 56.5 | 63.2 | 61.5 56. 5. 44.0 | 54.9
TOSS rae e aera yesh ser igs ee oe oe ese oee eins Soex te oanees eek Seaed 2.9 3.7 3.7 | 3.1 2.8 2.6 3.1
Station 5: | |
Surface— | |
OM sok a Ue eet ar ee eee a et ec cna mee taclsd 84.7 104.4 112.2 101.3 85.0 64.7 | 92.0
|
INIT TiaRS) spo oc se ses ages aaa ae on AU ae eee Oa sel aes ae 36.8 43.5 49.8 48.8 | 43.0 27.9 41.7
TSS SS Co aioe Sie i ae oe ee 47.9 60.9 62.4 52.5 42.0 36.8 | 50.3
Soil, 3 inch— | | |
ijeawiticads ie a. OSE Sas agdas Se nose Cesar ae eee An eee ee eee 48.6 57.9 | 66.2 | 64.0 57.2 45.9 | 56.6
Tae Weed temas selene 226s aS N-S sh eee eicie ds: ecRtere sate eeeh bean 47.6 55.6 | 63.6) 62.1 56.5 45.5 | 55.1
BSE Sees A Se Se AON ert ee ee ee 1.0 2.3 | 2.6 1.9 0.7 0.4 | 1.5
| j= = — ioe —
Station 6: | |
Surface—
MEST oeenists fete ome Sete cise ee Peet eeckines caeeste sae ais 80. 1 99.8 105.9 97.1 81.4 60 1 87.4
Minimum 38.6 44.0 50. 3 49.3 43.1 28.3 42.3
TRB PG Ue een ence nate «as eee ects clan a2 ae Heke ees Melos 41.5 | 55.8 | 55.6 47.8 | 38.3 31.8 45.1
Soil, 3 inch— | |
| 49.5 50.1 65.9 63.6) 585 46.6 57.2
47.3 | 56.3 63.4 61.4 56.3 44.6 54.9
| -2.2 | =28 2.5 2.2 | 2.2 2.0 2.3
! |

@ Means for sixteen days.

Station 3. Newly sanded, thinly vined. Station 5. Peat with moss, heavily vined.
Station 4. Newly sanded, heavily vined. Station 6. Old sanded, heavily vined.

Air temperatures and soil temperatures at Station 7 and Station 7a, Mather, Wis., September,
1906.—The facts brought out by the comparative data appearing in Table 3 are accentuated
by observations made in 1906 at Station 7, and at a supplementary station, 7a, which show
how much the minimum temperature at an elevation above the surface depends upon the
environment. When the investigation was commenced in 1906 at Mather it seemed desirable
to have one station located in a section of plain peat, absolutely free from vegetation. No
such section was available, nor was it practicable to scalp a portion of the cranberry marsh
proper for the purpose. An area, however, 10 feet square, in the midst of an extensive field
of sphagnum moss, immediately outside, was cleaned up. Thermometers were placed in the

4+

center of the scalped piece, Station 7, and 5 or 6 feet distant over the moss, Station#a, near
the edge. Station 7a was not continued in 1907, and as Station 7 itself was under water for a
considerable portion of the same year, data for 1907 at that Station are not as serviceable
as they otherwise might be. Data for September, 1906 (Table 4), furnish some interesting
results. The average exposed minimum at the surface of Station 7 was much higher than at
the surface at Station 7a, there being a difference of 5.6°. On every day the minimum was
higher at the surface of Station 7 than at the surface at Station 7a, with but a single exception,
and a maximum difference of 11° occurred on September 25—a remarkable variation in tem-
perature within a distance of 5 or 6 feet. This is because, in a soil covered with a thick layer
of moss, the opportunity for conduction down is not good, and much of the absorbed solar
energy is used in producing plant growth. Thus the moss-covered soil does not store up as much
sensible heat as does the bare soil, although the moss and the bare peat are equally good radiators.

The difference between the average minimums for the month at an elevation of 5 inches,

however, was only 0.5°, Station 7 still reading higher on the average, although there were
several instances where it was lower. The minimum at the 5-inch height at Station 7 averaged
4.8° lower than at the surface, while at Station 7a the temperature at 5 inches averaged 0.3° higher
than at the surface. This inversion of the usual conditions at Station 7a was doubtless caused by
the warmth from the area of bare soil adjoining. In other words, the temperature at the
5-inch height over the bare peat at Station 7 was affected by the surrounding area of sphagnum
moss, and consequently lowered, while the temperature over the adjoining moss at Station 7a
was affected in the other direction, but in a lesser degree, by the small area of bare peat imme-
diately adjoming. There was probably a slow circulation of air at night between the moss
and the bare soil. These results indicate quite plainly that while the temperature at the
surface depends upon the character of the soil and vegetation at the point of exposure, the
temperature a few inches above is affected not only by the character of this vegetation and
the soil immediately beneath, but by the environment as well. If the scalped piece were
greater in extent, 40 or 50 feet square or more, the thermometers exposed in the center of the
area 5 inches above the ground would probably not be considerably affected by the surrounding
moss. The thermometer on the moss, however, near the edge of this larger scalped piece,
would, on the other hand, be affected even more than in the case of the small 10-foot area
used in this investigation.

Table 4, under the soil-temperature column, at the 3-inch depth, illustrates the great
range in temperature of the clean soil as compared with that covered with a dense growth.
The avepage 6 p. m. reading at Station 7 was 65.8°, as compared with 61.3° at Station 7a.
The maximum soil temperature was 73° at Station 7 on September 12, while it was only 63.8°
at Station 7a on the same day. The average loss of heat during the night at Station 7 was
6.1°, as compared with 0.2° at Station 7a, while the minimum, or 7 a. m. soil readings, averaged
lower at Station 7 than at Station 7a, at the 3-inch depth. The greatest loss in soil tempera-
ture at both stations was on September 14, 11.2° at Station 7, and only 1.2° at Station 7a.
On September 16, during a warm, rainy night, following a cool day, the soil temperature at
Station 7 actually rose 0.5°, while at Station 7a the rise was 0.6°. On the night of September
2 the soil temperature at Station 7 rose 0.2°, while at Station 7a the rise was 0.4°. These
were the only instances where the temperature rose in the nighttime at Station 7, but there
were a number of instances where the temperature rose at Station 7a, its soil being so protected
from the sun’s rays that the change in temperature was not only small, but lagged behind that
at Station 7. The moss loses its heat rapidly and receives heat from below but slowly, partly
because the supply there is not great and partly because the connection, being mainly through
the stems, is not such as to give good conduction. On the other hand, the bare peat soil has
a good supply of heat to draw upon and has direct connection with the atmosphere above.

While the minimum temperature at the depth of 3 inches was lower in the bare section
than in the moss, it is quite certain that at the immediate surface the temperature in the bare
soil was higher. It is apparent that the bare soil conserves the heat, while a soil covered with
a dense growth, such as moss, is heated but little by the sun’s rays, an exposed minimum there-

45

fore at the immediate surface of the clean section registering much higher than over the moss.
The varying temperature of the ground is further evidenced by the habits of cattle in pasture.
On warm summer nights they le down where the ground is covered with grass, so as to be
cool, while on cool, clear nights they seek the warmer bare soil.

TABLE 4.—MinrimumM TEMPERATURES IN OPEN AT SURFACE AND 5-INCH HEIGHT, TOGETHER WITH DIFFERENCES: ALSO
Som TemPeratuRE READINGS SHOWING Loss DuRING NicutT, MATHER, Wis., SEPTEMBER, 1906.

[The 6 p. m. soil readings are those which occurred the previous day.]

|
Station 7 (over bare peat). | Station 7a (over sphagnum moss).
|

Pay of month. | Soil pease 3inches | | Soil renee bee 3 inches
; Surface. | 5 inches. Peet | = _____} Surface. | 5 inches. Dien: a
| 6p.m. | 7 a.m. Loss. 6 p.m. 7a.m. Loss.

= = | — ——- | =
43.5 38.8 —4.7 65.3 57.8 = 7.5 37.8 36.0 —1.8 61.0 60.7 —0.3
61.5 60.7 —0.8 62.1 62.3 + 0.2 61.0 61.2 +0.2 60.8 61.2 +0.4

42.5 35.0 —7.5 65,2 58.5 — 6.7 32.2 31.0 —1.2 61.8 | 61.5 —0.3

41.4 35.0 —6.4 67.0 57.3 — 9.7 34.4 34.0 —0.4 61.3 60.8 —0.5

40.0 32.4 | —7.6 67.0 57.3 — 9.7 31.1 30.6 —0.5 60.8 60.4 —0.4

42.4 35.7 =—6.7 | 66.5 57.2 = 913: 36.0 35.5 —0.5 60.3 | 60.0 —0.3

49.0 43.4 —5.6 | 67.8 | 60.3 IF ag 7.5 43.2 43.7 +0.5 60.3 60. 4 +0.1

52.2 46.8 | —5.4 | 69.8 61.8) —8 | 46.4 47.0 +0.6 60.8 61.0 +0.2

53.1 | 47.2 | —5.9 71.3 62.9 — 8.4 47.3 47.0 —0.3 61.4 | 61.6 +0.2
60.8 56.0 —4,8 72.8 66.3 — 6.5 59.2 57.8 +2.6 62.1 62.5 +0.4

61.5 61.8 | +0.3 71.0 67.2 — 3.8 62.0 57.9 —4.1 | 62.8 63.3 +0.5

62.2 59.5 —2.7 73.0 67.2 — 5.8 60.1 60.4 +0.3 63.8 63.9 +0.1

50.3 7.2 —3.1 69. 2 62.5 — 6.7 47.3 48.3 +1.0 | 63.8 63.4 —0.4

36.2 29.3 —6.9 67.0 55.8 —11.2 29.0 28.1 —0.9 62.8 61.6 —1.2

47.0 45.0 —2.0 62. 2 51.8 —10.4 44.3 46.0 +1.7 61.0 60.3 —0.7

62.5 61.0 —1.5 61.6 62.1 + 0.5 62.0 62.3 +0.3 60.3 60.9 +0.6

60.7 57.4 —3.3 68.3 64.3 — 4.0 57.1 58.0 +0.9 61.9 62.4 +0.5

62.4 58.3 —4,1 70.3 65.8 — 4.5 7.8 58. 2 +0. 4 63.0 63.3 +0.3

55.4 51.1 —4.3 71.2 64.7 — 6.5 49.2 51.2 | +2.0 | 63.7 63.7 0.0

56.0 53.3 —2.7 69.4 63.5 — 5.9 54.0 54.1 | +0.1 63.5 | 63.2 —0.3

54.1 49.5 —4.6 65.4 62.4 — 3.0) 48.8 50.2 +1.4 63.0 | 62.8 —0.2

50.7 44.3 —6.4) 67.0 60.8 — 6.2 42.8 43.20 +0.4 | 62.8 | 62. 2 —0.6

46.7 40. 2 —6.5 | 60.5 57.8 | — 2.7 40.0 41.1 +1.1 61.8 | 61.1 —0.7

44.0 37.5 —6.5 59.7 56.2) — 3.5 35.8 36.0 +0.2 | 60.7 |. 60.0 ONE

45.0 36.8 —8.2 | 62.5 | 56.4 — 6.1 34.0 35.2 +1.2 | 60.1 60.0 —0.1

45.8 41.5 —4.3 63.3 | 59.5 Va 3.8 38.0 40.3 +2.3 59.8 | 60.2 +0.4

33.2 27.0 —6.2- 61.3 52.0 — 9.3 26.9 25.3 —1.6 59.7 58.7 —1.0

36.7 30.4 —6.3 61.0 207 nes 28.4 | 29.0 +0.6 58.2 57.7 —0.5

43.0 42.0 | —1.0 57.8 56.5 — 1.3 35.0 42,2 +7.2 57.6 57.8 +0.3

29.3 22.5 —6.8 59.0 49.8| — 9.2 24.8 | 20.3 —4.0 57.8 57.0 —0.8

49.0 44.2) 418 65.8) 597] —6.1 AGS Fea ROE GER Gen Sah

Highest and lowest readings are in italics.

46

=

TABLE 4.—COMPARISON OF MINIMUM TEMPERATURES AT STATIONS 7 AND 7a, MATHER, WIS., SEPTEMBER, 1906.

Surface. | 5-inch height.

Day of month. = = ie | 7 =
Station 7. | Station 7a. | Difference. | Station 7. | Station 7a. | Difference.

| 5 | 3 3 : 5 :
De ee cee oct Mee ek! AA AE = a i | 43.5 | 37.8 = iy 38.8 36.0 = OaS
NPN ENO re fi non aE) eee ea 61.5 61.0 | — 0.5 60.7 61.2 | +0.5
Be NO oh. g Salk aece cis od ee ee eee a ee ree 42.5 | 32.2 | —10.3 35.0 31.0 Se
BR EE tao Seiad ll tient Meee Oh crt SR ee ee a ae 41.4 | 34.4 | — 7.0] 35.0 34.0 —1.0
ee ae oe ema RS eo LE Coat ae 40.0 | Bich — 8.9 | 32.4 30.6 Sih
see eee Pree n Gere 8 Soa te Ataf | 42.4 36.0 a 35.7 35.5 —0.2
TM Te ES eS Loot Rn Oe TE = Dae | 49.0 | 43.2 — 5.8 | 43.4 43.7 | +0.3
Aes RO ec sR te Sa ae Ry ea ee | 52.2 | 46.4 — 5.8 | 46.8 47.0 | +0.2
bs ARP Re ees Neh PNT eo a A il ile Pease A pred ALE | 53.1 | 47.3 —5.8| 47.2 47.0 | =0:2
LO ee oe ete Ree es ae RE eon On ee Oe ee 60.8 | 55.2 — 5.6 56.0 57.8 +1.8
DLE eek ce eee ar cee oe ee ee ey, See Ue em 61.5 | 62.0 | + 0.6 61.8 57.9 —3.9
TRE IRR on iss SEARCH Ra Bete SSD aa Sea apie Mee ee eS ha 62.2 60.1 | = phil 59.5 60.4 +0.9
13 Wappen kee ae erent at pe as eRe Ca 50.3 47.3 | = BLO 47.2 48.3 .| Jers
Ta eR Care LD Meg Sear naeT ou ee ae en ee eta | 36.2 29.0 = Ti 29.3 28.1 =p
TS Pee ee as Soe eee. eR eee Sn Sen Ee oe 47.0 44.3 | = EG 45.0 | 46.0 | +1.0
MG Sere ate Ae eee co sae RE ae PLS en el: Se mas See oe) 62.5 62.0 | — 0.5 61.0 62.3 | 1.3
UGE SeSS aes SecaSs Serres aad eneabde Eck oatececenortice canEesbceesoseeadsar 60.7 57.1 | — 3.6 57.4 58.0 +0.6
TS UAC AM dee crocs nee we TEED, (ol Saree ane Snes Oe 62.4 57.8] — 46 58.3 | 58.2 | —0.1
U earek ie Se cee ire meee re, a REE te eg te ee ot eae ey nn 55.4 DD G52 51.1 51.2 | +0.1
ee tere ed ee 56.0 540) 5 = 2.0 53.3 54.1 | +0.8
oe CARMI 0 ESA FEO EL ISM INS v.12 oe AM eR SR 54.1 48.8 = 5,5) 49.5 50.2 | +0.7
de rn cae BAe ane Hae ee TS PISS Nas aoe ee 50.7 42.8 — 7.9 44.3 43.2 | —1.1
Fae ae Baten gs St ae hl Se SB BP ey 46.7 40.0 = (iy 40.2 41.1 | +0.9
44.0 35.8 | — 8.2 37.5 36.0 —1.5
45.0 34.0 | —11.0 36.8 35.2 —1.6
45.8 38.0 | = 7583 41.5 40.3 1.2
33.2 26.9 1633 27.0 25.3 = ili
36.7 28. 4 | = 8} 30.4 29.0 | aly
43.0 35.0 | — 8.0 42.0 42.2 | +0.2
29.3 24.3 | — 5.0 22.5 20.8 | —2.2
49.0 ae — 5.6 44.2 43.7 —0.5

Highest and lowest readings are in italies.

Minimum temperatures at the coldest and the warmest points on the bog, Mather, Wis.—
From the foregoing it is obvious that great extremes of temperature occur in any bog, and
that there is a wide range in minimum temperature in various portions of the same bog. It
has, moreover, been found from the discussion of previous tables that at four selected stations
the exposed minimum surface readings were highest at Station 3 and lowest at Station 5, and
that at both Stations 3 and 5 the exposed minimum at the 5-inch height registered lower
than the one at the surface. Stations 2 and 5 were equally cold, Station 5 being in the cran-
berry bog, in an uncultivated section, while Station 2 was immediately outside, in a field of
sphagnum moss. The observations at Station 5, although sometimes interrupted by reflowing,
are preferable in this comparison with Station 3, because of the location of the station among
the vines. Stations 3 and 5, then, may be considered as being the warmest and the coldest
places on the bog, and the exposed minimums at these two stations will be discussed in detail;
first, between the readings of the surface thermometers at both stations during the season
of 1907; second, between the surface minimum at Station 3 and the minimum at the 5-inch
height at Station 5; and, third, between the last-named readings and the readings of the mini-
mum in the shelter at Station 1, which, of course, should be the standard for comparison with
other stations. (See Tables 5, 5a, 6, 6a, 7, 7a.)

The exposed minimums at the surface at Station 3, the thinly vined, sanded, and well
drained section, were usually higher than those at Station 5, over peat and moss, heavily vined
and with poor drainage. (Table 5.) The difference between the readings gradually but
irregularly increased from spring to midsummer, after which it decreased until the end of the
season. The average difference by months was as follows: May, 3.3°; June, 5.3°; July, 5.7°;

47

August, 4.9°; September, 2.9°; October, 0.8°; while the greatest daily difference in each month
was 8.9°, May; 8.8°, June; 9.6°, July; 10.2°, August; 7.1°, September; and 4.3°, October.
The daily readings at Station 3 were almost invariably much higher than at Station 5, with the
exception of the month of October; and but three times during May, June, and July did the
instruments at Station 5 register higher than at Station 3. These differences were 0.3° on May
15, 1° on June 26, and 1.6° on July 22. In August and September there were no instances in
which the thermometers at Station 5 registered higher than at Station 3, while in October there
were ten days. The changed relation between the readings in October is undoubtedly due to
the fact that frost had entered the sanded soil at Station 3, as well as the peat soil at Station 5;
and it is probable, as has been said before, that when once frost enters the soil, its character,
whether it be peat or sand, is of little consequence in affecting night temperatures. Moreover,
the vegetation at Station 5 was gradually dying out toward the end of the season, while at
Station 3 the conditions changed but little. It is interesting to note that on the coldest day of
the entire season, October 28, the temperature at Station 3 was 13.9°, 0.3° lower than at Station 5,
14.2°. In the other months, however, the minimums at the sanded section were several degrees
higher than in the uncultivated bog. At Station 5 there were several instances of freezing
temperature during the first decade of June, and one on July 2; on that date the exposed
minimum at the surface of Station 5 registering 30°, while at the surface at Station 3 the reading
was 38.8°. Whenever the readings of the instruments were seriously affected by reflowing to
ward off frost, a proper explanation has been made in the tables, and the values of the readings
estimated. It is unfortunate that on September 22, 25, and 26 actual readings of the instru-
ments at Station 3 were not available, as the portion of the bog in which that station was located
was covered with water. In Table 5a will be found the monthly and the seasonal averages
for the exposed minimums at the surface of Stations 3 and 5.

A still further comparison is made in Tables 6 and 6a, showing the difference in readings
between the surface thermometer at Station 3 and the thermometer at 5 inches at Station 5.
These may be accepted as being approximately the extremes of minimum temperature to which
the vegetation in the bog is subjected. The surface minimum at Station 3 averaged higher
than any other minimum exposed in the open, while the thermometer at 5 inches at Station 5
averaged the lowest. The average and extreme differences between these instruments were,
of course, even greater than those noted in the discussion of Table 5. The average seasonal
difference was 4.4°, and the greatest average monthly difference was 7° in June, while the least
monthly differences were 3.2° and 3.8° in May and October, respectively. The greatest daily
difference in May was 7°; in June, 11.9°; July, 11°; August, 12.8°; September, 10.6°; and in
October, 9°. There were but five instances throughout the entire season when the daily
minimum at the surface of Station 3 was lower than the upper thermometer at Station 5. The
lowest reading in May at the surface at Station 3 was 21.1°, while at 5 inches at Station 5 on
the same day the reading was 17°; in the other months the lowest readings were respectively
as follows: June, 33.8° (estimated), and 26.2°; July, 38.8° and 27.9°; August, 42.5° and 33°;
September, 24.5° and 16.6°; and in October, 13.9° and 6.4°.

51936°—Bull. T—10——4

48

TABLE 5.—COMPARISON OF MINIMUM TEMPERATURES IN OPEN AT THE SURFACES OF STATIONS 3 AND 5, wee DIFFrER-

ENCES. MATHER, Wis., 1907.

May.@ | June. July.
Day of month. — ass -—— | Sap eos
Station 3. | Station 5. | Difference.| Station 3. | Station 5. | Difference. Station 3. | Station 5. | Difference.
| | | =
és 5 5 c : :
34.0 30.9 =hil 59.5 | 56.0 =33:5
38.3 29.6 Sea 38.8 | 30.0 aia
52.9 48.0 —4.9 47.2 | 40.9 —6.3
43.0 35.5 = 51.5 46.3 S59)
44.1 42.0 =i 58.2 58.0 | —0.2
33.8 28.6 | Sel 57.9 53.0 —4.9
49.5 45.2 | —4.3 50.5 | 45.0 — 55
36.1 28.1 | —8.0 54.4 48.2 —6.2
42.4 34.8 =H 58.8 51.5 8)
piney |e tater | ba BS bee 53.7 | 52.7 | -1.0 50.0 43.0 720
ies Leet | Picea wile te TIS Bee 44.0 | 42.7 | =i,9 62.0 61.3 Sui
53.1 | 51.0 | =i 49.6 43,2 | =6.4
42.6 33.8 | =or8) 52.9 46.8 | —6.2
39.3 31.0 = 61.0 57.0 | =4.0
39. 42.9 | 41.0 =159 68.9 | 66.2 Ti
36.9 36. E 53.5 | 45.9 76 54.0 47.1 —6.9
39.0 32.4 =6:6 66.6 | 60.2 6.4 | 53.3 46.7 i513
41.9 34.0 =7.9 57.7 50.4 =S 51.2 43.7 725
35.0 33.1 —1.9 56.3 | 47.8 =8.5 56.9 | 51.3 —5.6
23.7 | 16.8 | —6.9 | 51.0 | 44.0 =7.0 58.1 71.0 Fil
21.1 | 18.3 =2)8 49.3 | 43.8 —5.5 | - 65.9 | 60.2 Esl)
44.9 40.8 | =41 62.3 | 59.4 —2.9 © 63.8 | 465.4 +1.6
45.0 43.8 | = 102, 60.3 | 56.5 =—aa8 55.0 47.0 —8.0
42.1 33.2 —8.9 54.9 | 50.4 | —4.5 62.2 58.2 —4.0
45.0 45.0 0.0 58.9 56.1 238) 54.9 46.8 Sil
46.0 45.4 —0.6) 49.0 50.0 +1.0 52.8 43.2 —9.6
(b) (Ns A eee, | 44.0 36.8 | UP 47.5 39.2 =}
(b) [ayer y Nae en 45.0 37.1 =i) 58.1 54.0 =i
35.9 33.0 =2:9)| 50.0 42.3 Tai 58.0 51.0 720
43.0 38:4 | —4.6 | 55.4 | 49.0 —6.4 50.3 43.0 = 708
48.3 46.7 | == 1416 |eoeee eee ie ces eee Hehe nnor ee 57.4 50.4 a0
Mearis@- aoa. kee 40.4 37.1 —3.3 | 48.8 | 43.5 53) iis 49.8 | —5.7
| | |

- aMeans for eighteen days.
> Readings not obtained; marsh flooded. d Affected by water.

Station 3. Newly sanded, thinly vined. 7 Station 5.
Highest and lowest readings are in italics.

Peat with moss, heavily vined.

c Estimated; actual readings valueless on account of reflowing.

49

TABLE 5.—COMPARISON OF MINIMUM TEMPERATURES IN OPEN AT SURFACES OF STATIONS 3 AND 5, wiTH DIFFER-
ENCES, MarHer, Wis., 1907—Continued.

‘ August. | September. | October.
Day of month. Se es aes an 7

Station 3. Station 5. | Difference. | Station 3. | Station 5. | Difference.) Station 3. | Station 5. | Difference.

° ° ° ° ° ° | ° ° °
55.1 50.9 | iD 64.1 61.4 ihe 30.8 28.5 os
49.0 | 42.2 | — 6.8 53.9 46.8 | iii 46.1 AA .0
47.1 | 43.0 | = SI 48.8 43.3 | =5.5 | 41.6 38.3 3.3
43.1 35.0 = kil 52.7 48.8 | —3.9 33.6 32.0 3.5
61.3 ” 58.6 = Phy 46.7 42.0 | =4.7 | 36.3 32.0 3
53.0 46.2 698 41.2 36.0 —5.2 38.7 37.0 ti
59.0, 55.0 = 7410) 56.5 55.6 | —0.9 42.1 39.7 2.4
56.6 | 52.0 — 4.6 57.2 56.2 | =1.0] 21.8 | 5 a3
54.0. 49.6 = if 39.0 36.6 —2.4 34.6 | A
59.8 54.0 | = it 37.0 a 34.1 —2.9 28.5 0.0
68.7 66.0 | = 7 43.7 39.2 4.5 30.1 +0.2
49.7 | 43.0 | — 6.7 43.3 40.0 =a18) 28.4 : +0.3
48.9 | 43.0 — 5.9 45.7 42.8 =2.9 | 19.0 | 8 —0.2
52.3 | 46.3 — 6.0 56.5 55.0 S145 (eu 4 +0.7
56.6 | 50.6 — 6.0 57.7 54.3 —3.4 40.7 41.8 41.1
62.1 | 59.0 = Beil 65.1 64.5 —0.6 33.1 | 31.8 ile)
51.2 44.5 37) 51.0 46.5 | =4.5 30.8 | 30.5 —0.3
54.8) 50.0 = nad 59.0 58.6 | ore 23.6 25.4 +1.8
65.5 | 65.0 — 0.5 60.4 59.5 | —0.9 | 19.7 | 18.8 —0.9
46.6 37.9 eer 59.4 | 58.0 —1,4 | 26.3 97.0 +1.3
48.4 | 38.2 —10.2 37.4 35.2 = || 17.5 | 14.6 =3il
48.5 | 38.0 = 45 a 30.3 24.7 | —5.6 28.5 | 27.3 SD)
54.0 48.1 — 5.9 41.7 41.3 —0.4 24.5 | 21.8 =e
50.7 46.1 | = G5 44.0 | 43.3 =0:7 | 21.3 20.5 —0.8
42.7 | 36.8 — 5.9 a27.2 24.8 —2.4 | 23.6 23.5 ={i)11
49.8 43.8 — 6.0 233.0 | 26.7 =6.3 | 16.8 14.7 ==9)55I
57.2 57.0 =— 012 32.7 28.8 —3.9\| 32.3 32.0 —0.3
54.0, 52.1 | =e 38.4 38.0 =i} 13.9 14.2 +0.3
50.7 46.0 | = Ay 30.0 26.5 aye 24.6 94.4 —0.2
62.9 62.1 | 008 24.5 21.3 = 302. 36.2 35.9 —0.3
56.3 | 54.2 OT | Bae ee Ln |---see-c-== | 30.0 30.6 +0.6
Sua} 48.8 — 4.9) 45.9 43.0 —2.9 | 28.8 28.0 —0.8

TABLE 5a.—MONTHLY AND SEASONAL MEANS, STATIONS 3 AND 5, MaTHer, Wis., 1907.
May. June. July. August. September. October. Seasonal

Surface: ° 2 = : _ by *
Statlomid ee Saran Sete. 5.5 Se eaten eee eee 40.4 48.8 55.5 53.7 45.9 28.8 45.5
Stabionihosre ase here oe beeen ne ee ea 37.1 43.5 49.8 48.8 43.0 28.0 Al.7
Mifference 25-7 8S eee ese. oan oneee ee aoe — 3.3 — 5.3 — 5.7 — 4.9 — 2.9 — 0.8 — 3.8

a Estimated; actual readings valueless on account of reflowing.

Station 3. Newly sanded, thinly vined.

> Means for eighteen days.

Station 5. Peat with moss, heavily vined.

Highest and lowest readings are in italics.

50

TABLE 6.—COMPARISON OF MrnrtmumM TEMPERATURES IN OPEN AT SURFACE OF STATION 3, AND AT 5 INCHES AT Sta-
TION 5, THE WARMEST AND COLDEST PLACES ON THE MARSH, RESPECTIVELY; ALSO Dairy DIFFERENCES,

MartuHer, Wis., 1907.

May.@ June. July.
Day of month. Pe Te Th |
Station 3— Station5—| Differ- | Station3—|Station5—)| Differ- | Station3—|Station5—| Differ-
surface. | 5 inches. | ence. surface. 5 inches. ence. surface. 5 inches. ence.
= = Ee | |

° ° | ° ° | ° ° ° ° °
34.0 | 26.2 eas 59.5 55.9 ENG
38.3 | 27.9 —10.4 38.8 27.9 —10.9
52.9 | 46.9 | — 6.0 47.2 36.2 =—1f.0
43.0 35.0 — 8.0 51.5 43.9 — 7.6
44.1 41.5 — 2.6 58.2 59.7 + 1.5
BCR eee ee as oe Meee Soca Baa tin ee Same ann ee 633.8 + 26.8 = 7.0) 57.9 52.0 — 5.9
49.5 43.8 — 5.7 50.5 42.5 — 8.0
36.1 26.5 — 9.6 54.4 49.4 — 5.0
42.4 30.5 —11.9 58.8 51.9 — 6.9
53.7 53.0 — 0.7 50.0 41.0 — 9.0
44.0 38.4 — 5.6 62.0 60.1 —1.9
37.3 35.0 —2.3 53.1 51.0 — 2.1 49.6 39.9 — 9.7
56.5 58.9 +2.4 42.6 32.4 —10.2 52.9 44.0 — 8.9
46.8 45.1 —1.7 39.3 | 29.6. — 9.7 61.0 56.8 — 4.2
39.0 36.9 | —2.1 42.9 34.0 — 8.9 68.9 Yip | —1.8
36.9 34.8 —2.1 53.5 45.5 — 8.0 54.0 45.3 — 8&7
39.0 33.0 | —6.0 66.6 62.5 | — 4.1 53.3 45.0 — 8.3
41.9 39.1 | —2.8 57.7 48.9 — 8.8 51.2 42.6 — 8.6
35.0 31.0 | —4.0 56.3 48.7 — 7.6 56.9 51.0 — 5.9
23.7 19.3 —4.4 51.0 42.4 — 8.6 58.1 51.3 — 6.8
ble | 17.0 —4.1 49.3 40.3 | — 9.0 65.9 59.9 — 6.0
44.9 42.0 —2.9 62.3 59.6 = 257, + 63.8 61.9 — 1.9
45.0 43.7 —1.3 60.3 55.2 — 5.1 55.0 645.9 — 9.1
42.1 | 34.0 | —8.1 54.9 49.5 — 5.4 62.2 b57.1 — 5.1
45.0 | 43.8 —1.2 58.9 53.1 — 5.8 54.9 045.7 — 9.2
46.0 | 45.0 —1.0 49.0 45.7 — 3.3 52.8 b42.1 —10.7
(c) | (¢) 1A eeee eee 44.0 34.0, —10.0 47.5 40.0 — 7.5
(©) (¢) Sassen ees 45.0 35.2 — 9.8 58.1 53. 2 — 49
35.9 | 29.3 —6.6 50.0 41.1 = 58.0 51.5 = 6.5
43.0) 36.0 —7.0 55.4 47.4 — 8.0 50.3 41.6 — 8.7
48.3 | 45.9 SEN eee sar SG bans soar esac nobonocabeea 57.4 50.0 — 7.4
Meansret o<2-otteu es 40.4 | 37.2 =59 48.8 41.8 =70 55.5 48.8 = 67

@ Means for eighteen days.

+ Estimated; actual readings valueless, on account of reflowing or heavy rains.
¢ Readings not obtained; marsh flooded.

Station 3. Newly sanded, thinly vined.

Station 5. Peat with moss, heavily vined.
Highest and lowest readings are in italics.

ol

TABLE 6.—COMPARISON Or MINIMUM TEMPERATURES IN OPEN AT SURFACE OF STATION 3, AND AT 5 INCHES AT
STaTION 5, THE WARMEST AND Coupest Puaces oN THE MarsH, Respectivety; atso Day DirrerENces,

Martuer, Wis., 1907—Continued.

]
August. September. October.
Day of month. =< a
| Station 3—| Station 5— Differ- | Station 3— | Station 5— Differ- Station 3— | Stations—| Differ-
surface. 5 inches. ence. surface. 5 inches. ence. surface. 5 inches. ence.
° ° ° | ° 1 ° ° ° ° °
55.1 44.0 —11.1 64.1 | 61.7 — 2.4 30.8 25.6 —5,2
49.0 40.9 — 8.1 53.9 45.5 — 8.4 46.1 46.7 +0.6
47.1 41.9 — 5.2 48.8 41.3 — 7.5 41.6 35.5 —6.1
43.1 33.0 —10.1 52.7 48.8 — 3.9 33.5 29.5 —4.0
61.3 58.0) — 3.3 | 46.7 41.3 — 5.4 36.3 30.3 —6.0
53.0 44.8 — 8.2} 41.2 32.6 — 8.6 38.7 35.6 —3.1
59.0 - 54.0) = 5,0)| 56.5 55.5 — 150 42.0 38.0 —4.0
56.6 50.1 — 6.5 57. 2 @50.8 — 6.4 21.8 12.8 —9.0
54.0 48.0 — 6.0 39.0 33.7 — 5.3 34.6 34.0 —0.6
59.8 | 53.0 — 6.8 a 37.0 432.3 — 4.7 28.5 24.8 —3.7
68.7 69.0 + 0.3 43.7 36.5 = 7.2 30.1 28.3 —1.8
49.7 41.0 — 87 | 43.3 37.0 — 6.3 28.4 25.9 —2.5
48.9 40.6 } — 8.3 | 45.7 39.7 — 6.0 19.0 12.0 —7.0
52.3 45.0 — 7.3 56.5 54.9 — 1.6 17.7 12.4 —5.3
56.6 | 50. 2 — 6.4 57.7 53.0 — 47, 40.7 41.5 +0.8
62.1 58.6 — 3.5 | 65.1 64.5 — 0.6 33.1 29.4 —3.7
51.2 43.6. TeG: | 51.0 43.5 — 7.5 30.8 28.4 —2.4
54.8 46.7 | — 81) 59.0 56.1 — 2.9 | 23.6 20.7 —2.9
65.5 64.8 | — 0:7 60. 4 58.8 | — il 19.7 | 13.8 —5-9
46.6 34.8 —11.8 59.4 56.2 = 34 | 26.3: | 23.5 —2-8
48.4 39.6 —12.8 37.4 3l.1 — 6.3 17.5 9.8 —7-7
42.5 33.6 — 8.9 | 230.3 19.7 —10.6 28.5 26.5 —2-0
54.0 46.1 — 7.9 | 41.7 39.0 — 2.7 24.5 18.8 —5.7
50.7 44.3 — 6.4 | 44.0 41.7 — 2.3 21.3 14.7 | —6-6
42.7 33.3 = 9.4) 27.2 20.6 — 6.6 23.6 | 21.5 | —2.1
49.8 41.0 | — 9.8 | 233.0 22.6 —10.4 16.8 9.3 —7-4
57.2 595.6 — 1.6 32.7 26.1 — 6.6 32.3 31.6 —0-7
54.0 50.5 — 3.5 38.4 36.9 — 1.5 13.9, 6.4 —7-5
50.7 44.0) — 16:7) 30.0 23.3 — 6.7 24.6 21.7 —2.9
62.9 62.6 — 0.3 | 24.6 16.6 — 7.9 36.2 35.7 —0-5
56.3 52.7 7 OAH Be eee apogee Seceamsaccec bec: ack 30.0 29.5 —0-5
53.7 | 471 — 6.6 | 45.9 40.7 — 5.2 28.8 25.0 | ate
TABLE 6a—Monrtuty AND SEASONAL MEANS, Sratron 3, SurFAcE, AND Sratron 5, 5 Incues, Marner, Wis.
1907.
May.® June. | July. August. September.) October. oe
Station: 3—suriace: <=. 2. -<- peste eee oes eee 40.4 48.8 55.5 53.7 45.9 28.8 45.5
Station S—5 inches) <a cae. 2 soso eee ee ee eetelias ccc 37.2 41.8 48.8 47.1 40.7 25.0 40.1
Diterencte: a5. as sere ccr nee as eee cece —3.2 —7.0 —6.7 —6.6 — 5.2 — 3.8 — 5.4
| |

a Estimated; actual readings valueless, on account of reflowing or heavy rains.

Station 3. Newly sanded, thinly vined.

Station 5.

Highest and lowest readings are in italics.

» Means for eighteen days.

Peat with moss, heavily vined.

52

Comparison of minimum temperatures at Station 1, in shelter, and on bog at Stations® and 5,
Mather, Wis.—While the comparisons made in Tables 5 and 6 have been between the warmest
and the coldest stations on the bog, the temperature in the shelter at Station 1 on the upland
may properly be considered the standard, and a comparison between the thermometer therein
and one in the open at the height of 5 inches at Station 5 and the one at the surface at Station 3
should be of special interest. Of course, the exposed minimum at Station 5 was much lower
than the one’in the shelter at Station 1, the average difference being 6.7°. (See Tables 7 and
7a.) The least monthly average difference was 4.5° in May, and the greatest 8.3°, in October.
The greatest daily difference in May was 12° on the 29th; in June, 11° on the 27th; in July,
12° on the 3d; in August, 14.2° on the 25th; in September, 11.6° on the 22d; in October, 14.6°
on the 24th. With but few exception the temperature at Station 5 was lower than at Station 1
and markedly so on clear, cool nights. When the sky was overcast and the night windy the
difference was much less.

The comparison between the shelter at Station 1 and the surface at Station 3, however,
affords far different results. The temperature at Station 3 was, as a rule, only slightly below that
in the shelter at Station 1, the seasonal average difference being 1.3°. In the summer the differ-
ence was very little, being only 0.1° and 0.2°, but it was greater in the spring and in the fall, espe-
cially in October when the average difference was 4.5°. At Station 5, as has been stated before,
the difference was 8.3° for October. It is probable that these great differences in October were
due to the number of comparatively cool nights which were gradually increasing in length and
which afforded a longer period for radiation and consequent loss of heat from vegetation. The
daily differences between the readings in the shelter at Station 1 and those in the open at Station
3, the sanded section, were often unimportant, and on many days there was a reversal, the tem-
perature actually reading higher over the sanded section in the bog, especially in the summer months.
This inversion occurred on fourteen days in June, fourteen days in July, fifteen days in August,
ten days in September, but in no instance in October. These results—the comparatively high
minimum temperatures at the surface of the sanded bog—really seem remarkable, and could
hardly be believed unless great care had been taken in the observations. In this connection
it is interesting to note that the minimum temperature in the shelter at Station 3 averaged
for the season only 0.5° below that in the shelter at Station 1, while the minimum in the shelter
at Station 5 averaged 3.1° below that in the shelter at Station 1. (See Table 18.) The advan-
tages gained by sanding are still further emphasized by observations made at Berlin, Wis.,
where the exposed minimum at the surface of a sanded section during the month of September,
1906, actually averaged higher by 0.5° than the minimum in the shelter at Station 1, on adjoining
hard land, while the exposed minimum at the 5-inch height at Station 5, the coldest point on
the Berlin bog, averaged 9.5° lower than that in the shelter at Station 1. (Table 9.)

From the comparison of these observations made at Stations 3 and 5, at Mather, it should
be apparent that a thinly vined, sanded, and well drained soil is a most important factor in
conserving heat—in strong contrast with a heavily vined moss-covered surface which absorbs
but little heat, and at the same time radiates rapidly.

53
TABLE 7.—COMPARISON OF MiInIMUM TEMPERATURES IN SHELTER AT STATION 1, AND IN OPEN aT 5-1NcH HEIGHT AT
SratTion 5, THE COLDEST PLACE ON THE MARSH, AND IN OPEN AT SURFACE AT STATION 3, THE WARMEST PLACE ON
rue Marsu, ILLUSTRATING THE ADVANTAGES OBTAINED FROM SANDING, DRAINING, AND CULTIVATING, MATHER,
Wis., 1907.

May. June.
Day of month. Binion eines Station 3— pies Station 1— Sr aaehes | Station 3— Die:
above sur-| Difference.| surface rs above sur-| Difference., surface | Miia
shelter. face ex= exposed. Stations 1 shelter. incre || | exposed. Stations 1
posed. and 3. posed. | and 3.
36.0 26.2 — 9.8 4.0 — 2.0
38.7 27.9 —10.8 38.3 — 0.4
50.1 46.9 — 8.2 52.9 — 2.2
41.2 35.0 — 6.2 43.0 +18
44.4 41.5 — 2.9 44.1 — 0.3
34.0 32.5 — 1.5 33.8 — 0.2
47.6 43.8 — 3.8 49.5 +1.9
36.0 26.5 =— 9.5 36.1 + 0.1
41.0 30.5 —10.5 42.4 + 1.4
54.5 53.0 —1.5 53.7 — 0.8
47.0 38. 4 — 8.6 44.0 — 3.0
52.8 51.0 — 1.8 53.1 + 0.3
43.7 32.4 —11.3 42.6 —1.1
38.9 29.6 — 9.3 39.3 + 0.4
43.0 34.0 — 9.0 42.9 — 01
53.8 45.5 — 83 53.5 — 0.3
70.0 62.5 — 7.5 66.6 — 3.4
58.6 48.9 — 9.7 57.7 — 0.9
57.0 48.7 — 83 56.3 — 0.7
50.6 42.4 — 8.2 51.0 + 0.4
48.7 40.3 — 8.4 49.3 + 0.6
61.4 59.6 —1.8 62.3 + 0.9
60.2 55.2 — 5.0 60.3 + 0.1
54.0 49.5 — 4.5 54.9 + 0.9
57.8 53.1 —47 58.9 +11
48.2 45.7 — 2.5 49.0 + 1.2
45.0 34.0 —11.0 44.0 — 1.0
43.0) 35.2 —7.8 45.0 + 2.0
51.0 41.4 — 9.6 50.0 — 1.0
58.0 47.4 —10.6 55.4 — 2.6
Se See ee a te ee tere nerouee =
49.0 fied ee eate2 48.8 | — 0.2
@ Not included in average. > Under water.

Station 1. On upland.

Station 3. Thinly vined, newly sanded, and well drained section of marsh.

Station 5. Heavily vined, peat with moss, and poorly drained section of marsh.
Highest and lowest readings are in italics.

o4

TABLE 7.—COMPARISON OF MINIMUM TEMPERATURES IN SHELTER AT STATION 1, AND IN OPEN AT S-INCH HEIGHT AT
Sratron 5, THE CoLtpEst PLace ON THE MARSH, AND IN OPEN AT SURFACE AT STATION 3, THE WARMEST PLACE
ON THE MarsH, ILLUSTRATING THE ADVANTAGES OBTAINED FROM SANDING, DRAINING, AND CULTIVATING, MATHER,
Wis., 1907—Continued.

July. August.
= — = ain —
Day of month. Station 1 Seen Station 3— Ditter: Station 1 oe naties Station 3— Der
| ~~ | above sur- Difference.) surface A above sur- | Difference., surface Fi
shelter. | “face ex- | exposed. Sistions 1) shelter. | “face ex- exposed. pied
posed. | ; posed. 3
° ° ° ° ° ° ° ° ° ©
59.1 55.9 — 3.2 59.5 + 0.4 55. 0 44.0 —11.0 55.1 + 0.1
38.3 27.9 —10.4 38.8 + 0.5 45.8 40.9 eet) 49.0 + 3.2
48. 2 36. 2 —12.0 47.2 — 1.0 48.1 41.9 12 47.1 — 1.0
51.0 43.9 | = fol 51.5 + 0.5 38.9 33.0 —15.9 43.1 + 4.2
60.2 59.7 | — 0.5 58. 2 — 2.0 59. 2 58. 0 — 1.2 61.3 se 2a
58. 2 52.0 — 6.2 57.9 — 0.3 54.0 44.8 — 9.2 53.0 = 1.0
50.7 42.5 = 8.2 50.5 — 0.2 57.0 54.0 — 3.0 59.0 + 2.0
59.4 49.4 —10.0 54.4 = hl) 55. 0 50.1 =) 56. 6 ae tals}
61.0 51.9 = Ohi! 58.8 = 2.2 52.8 48.0 = 4.8 54.0 + 1.2
50.0 41.0 — 9.0 50.0 0 59.0 @° — 16,0 59.8 + 0.8
60.0 60.1 + 0.1 62.0 + 2.0 14. 2 69.0 — 5.2 68.7 — 6.6
51.3 39.9 —11.4 49.6 =—1.7 52.7 41.0 =I. 7 49.7 — 3.0
53. 8 44.0 = B)st) 52.9 — 0.9 50.0 40.6 = Hhe 48.9 =1
62.4 56.8 = lo 61.0 — 1.4 52.8 45.0 — 1.8 52.3 — 0.5
68.3 67.1 — 1.2 68.9 | + 0.6 56.1 50. 2 = FE) 56.6 + 0.5
51.0 45.3 = Oeil 54.0 + 3.0 61.2 58. 6 — 2.6 62.1 + 0.9
56.8 45.0 —11.8 53.3 — 3.5 52.2 43.6 — 8.6 51.2 = 1-0
50. 4 42.6 — 7.8 51.2 + 0.8 57.0 46.7 —10.3 54.8 — 2.2
56.0 51.0 — 5.0 56.9 + 0.9 65.0 64.8 — 0.2 65.5 + 0.5
61.0 51.3 = 9.7 58.1 — 2.9 43.0 34.8 — $2 46.6 + 3.6
64.2 59.9 — 4.3 65.9 +17 47.0 35.6 —11.4 48.4 gr ie
64.0 61.9 aaatk 263.8 — 0.2 43.0 33.6 = hs 42.5 — 0.5
62.8 | @45.9 = (ett) 55.0 | + 2.2 53.7 46.1 — 7.6 54.0 + 0.3
64.0 a57.1 16.9 62. 2 — 18 54.1 44.3 — 9.8 50.7 — 3.4
52.6 a45.7 — 6.9 54.9 + 2.3 47.5 33.3 —14. 2 42.7 — 48
49.0 a42.1 — 6:9 52.8 + 3.8 50.7 41.0 = 9:7} 49.8 — 0.9
45.0 40.0 — 5.0 47.5 + 2.5 55.5 55. 6 + 0.1 57.2 a ai /
58.9 53. 2 — hr 58.1 — 0.8 58. 0 50.5 — 7.5 54.0 — 4.0
56.7 51.5 — 5.2 58. 0 + 1.3 51.2 44.0 = fe 50.7 — 0.5
53.0 41.6 | —11.4 50.3 = Phil 64.0 62.6 — 1.4 62.9 —aikenh
57.6 50. 0 — 7.6 57.4 10:2) 58.3 52.7 = 5:6 | 56.3, = 2.0
55.6 48.8 | == (HE) 55. 0 = (ihil 53.9 47.1 = HE 53.7 — 0.2
|

a Not included in average; affected by water.
Station 1. On upland.
Station 3. Thinly vined, newly sanded, and well drained section of marsh.
Station 5. Heavily vined, peat with moss, and poorly drained section of marsh.
Highest and lowest readings are in italics.

50

TABLE 7.—COMPARISON OF MINIMUM TEMPERATURES IN SHELTER AT STavTioNn 1, AND IN OPEN Av 5-tNcH HEIGHT AT
Sratron 5, THE ConpEsT PLACE ON THE MarsH, AND IN OPEN Av SURFACE AT STATION 3, THE WARMEST PLACE
oN THE Marsn, ILLUSTRATING THE ADVANTAGES OBTAINED FROM SANDING, DRAINING, AND CULTIVATING,
Maruer, Wis., 1907—Continued.

September. October.
Day of month. So EP omcess Station 3— Diler Station 1— ectes | Station 3—| Differ-
SHelter above sur-| Difference.| surface Stations 1 Bheltent above sur- Difference.| surface Statinie 1
face ex- exposed. FanGleh face ex- exposed. and 3.
posed. posed.
° ° ° ° ° ° ° ° ° °
70.0 61.7 — 8.3 64.1 —6.9 33.0 25.6 — 7.4 30.8 — 2.2
53.1 45.5 — 7.6 53.9 +0.8 51.5 46.7 — 4.8 46.1 — 5.4
50.5 41.3 — 9.2 48.8 —1.7 45.6 35.5 =10.1 41.6 — 40
52.0 48.8 — 3.2 52.7 +0.7 41.0 29.5 —11.5 33.5 — 7.5
44.2 41.3 — 2.9 46.7 +1.5 41.2 30.3 —10.9 36.3 — 4.9
41.0 32.6 — 84 41.2 +0.2 44.0 35.6 — 8.4 38.7 — 5.3
54.0 : 55.5 “165 56.5 +2.5 49.5 38.0 —11.5 42.0 — 7.5
56.5 250.8 — 5.7 57.2 +0.7 22.8 12.8 —10.0 21.8 — 1.0
40.0 33.7 — 6.3 39.0 —1.0 40.0 34.0 — 6.0 34.6 = Ge!
38.0 432.3 — 5.7 237.0 —1.0 34.6 24.8 — 9.8 28.5 — 61
45.0 36.5 — 8.5 43.7 —1.3 34.6 28.3 — 6.3 30.1 — 4.5
48.0 37.0 —11.0 43.3 —4.7 29.3 | 25.9 — 3.4 28.4 — 0.9
49.9 | 39.7 —10.2 45.7 —4.2 24.6 12.0 —12.6 19.0 — 5.6
62.0 54.9 — 7.1 56.5 —5.5 22.5 | 12.4 —10.1 17.7 — 4.8
63.0) 53.0 —10.0 57.7 —5.3 44.0 41.5 = PAG) 40.7 | — 3.3
66.6 64.5 — 2.1 65.1 —1.5 35. 5 29.4 — 6.1 33.1 — 2.4
53.0 43.5 | — 9.5 51.0 —2.0 38.6 28.4 —10.2 30.8 — 7.8
57.9 56.1 | —1.8 59.0 +1.1 24.2 20.7 — 3.5 23.6 — 0.6
61.3 58.8 — 2.5 60.4 —0.9 27.3 13.8 —13.5 19.7 — 7.6
59.9 56. 2 — oHif 59.4 —0.5 27.5 23.5 — 4.0 26.3 — 1.2
37.9 31.1 — 6.8 7.4 —0.5 19.0 9.8 — 9.2 17.5 —1.5
31.3 19.7 —11.6 230.3 —1.0 40.0 26.5 —13.5 28.5 —11.5
44.6 39.0 — 5.6 41.7 —2.9 29.6 18.8 —10.8 24.5 — 5.1
43.2 41.7 = te 44.0 +0.8 29.3 14.7 —14.6 21.3 — 8.0
28.2 20.6 — 7.6 a27.2 —1.0 27.6 21.5 — 6.1 23.6 — 4.0
0 22.6 —11.4 233.0 —1.0 18.9 9.3 — 9.6 16.8 — 2.1
LiL 34.0 31.6 = 24 32.3 —1.7
0 17.0 | 6.4 —10.6 13.9 — 3.1
Br 3.25 21.7 —10.8 24.6 — 7.9
5 37.2 | 35.7 = 1.5 36.2 — 1:50
36.8 29.5 — es 30.0 — 6.8
2 = | |
33.3 25.0 — 83 28.8 —4.5
os — = u .
a Estimated; actual readings valueless on account of reflowing or heavy rains.
Station 1. On upland.
Station 3. Thinly vined, newly sanded, and well drained section of marsh.
Station 5. Heavily vined, peat with moss, and poorly drained section of marsh. ;
TABLE 7a.—MoNTHLY AND SEASONAL MEANS OF TABLE 7.
| Seasonal
May.@ June. July. | August. |September.| October. areas!

: ° ° e | ° ° ° °
Srationie chalter= ee cee ate cert own Ee L ER ar Soe 41.7 49.0 55.6 | 53.9 47.1 33.3 46.8
Station 5—5 inches above surface exposed 37. 2 41.8 48.8 47.1 40.7 25.0 40.1

fe) Fifisronice Hee eee WSs acs. 222). san shee eee =4.5 =e —6.8 —6.8 —6.4 -8.3 | 6.7
Station(3—surface exposed. --.-.-+-.:-.-2.--2+--.-+---=2-: 40.4 48.8 55.5 53.7 45.9 28.8 45.5
Difference—Stations1 and3-...........-.------------------ —1.3 | —0.2 —0.1 —0.2 —1.2 —4.6 —1.3

a Means for eighteen days.
Highest and lowest readings are in italies.

56

Curves of air and soil temperatures at Stations 1,3, and 5, Mather, Wis., 1907 .—Ineorder to
indicate more graphically the relation existing between the air temperature and the temperature
of the soil at the depth of 3 inches, and also between the soil temperatures at depths of 3 and 6
inches, Figures 21 and 22 have been prepared, showing curves for the season of 1907. The
maximum temperature given is that recorded in the shelter at Station 1, equally applicable
to Stations 3 and 5, and may be considered to represent in a measure the amount of insolation
received from day to day. These graphs should supplement Tables 3, 5, 6, and 7.

From the beginning of the season and until midsummer the temperature of the soil at both
Stations 3 and 5 rose gradually, apparently in direct proportion to the amount of heat which the
different soils absorbed and conducted under the varying conditions of covering as regards
vegetation, etc. The temperature of the soil at the 3-inch depth at Station 3, the sanded and
thinly vined section, responded quickly to the various changes in insolation, and the range in
soil temperature at this depth was relatively great from day to day, because of the slight depth
at which the bulb of the soil thermometer was exposed, and also because of the good conductivity
of the sanded soil. At the 6-inch depth at the same station the changes in temperature followed
closely those at the 3-inch depth, but on account of the additional 3 inches in depth the changes
from day to day were not so marked. At Station 5, peat soil with moss and dense vegetation,
the.temperature at 3 inches responded but slowly to changes in temperature of the air, because
of the poor conductivity of the soil, and the fact that the dense growth of vegetation prevented
the soil from absorbing much heat from the sun’s rays. At the 6-inch depth the changes
from day to day were even less. It is interesting here to note that, because of the dense vege-
tation and greater depth and the fact that the little heat received at the surface of the peat was
conducted slowly to the soil beneath, the maximum heat of one day was not felt at the 6-inch
depth at Station 5 until the day following. This lagging of the maximum heat is also noted
at the 3-inch depth at the same station, but in a lesser degree, while almost invariably the maxi-
mum heat of one day was conducted on the same day to both depths at Station 3, the sanded
section. These variations in soil temperature are shown graphically on May 19 and 30, June
7 and 19, July 6, August 11, and September 1. In this connection it may be noted that sudden
falls in temperature of the air, as shown by the minimum temperature curves (Fig. 21), were
felt but little at either depth at Station 5, and on July 21, while the temperature of the soil at
both depths at Station 3 fell in response to a sudden decline in temperature of the air, the tem-
perature of the soil at the depth of 6 inches at Station 5 was not influenced in the least, but even
continued to rise gradually, the maximum heat recorded at the two first-named locations on
July 20 not being felt at the 6-inch depth until the 22d, two days later.

Until the latter part of July the difference between the soil temperatures at the various
depths was remarkably uniform. (Fig. 22.) From this time on until the end of the season
the lines representing the seasonal march of soil temperature lose the relative positions which
they occupy during the first part of the season. This is on account of the gradual approach of
longer nights and shorter days with their attendant colder weather, so that more heat was lost
from the sanded surface and less heat taken in, in proportion, than was lost and taken in
by the peat soil. Hence, while a large amount of heat was lost each night from the peat
soil, an even larger amount was lost from the sanded surface itself. On account of the greater
susceptibility of the sand to changes in insolation as compared with that of the heavily vined
peat soil, and because the heat in the peat which accumulates during the warm months is
not lost as quickly as that im the sanded soil, we find the temperature of the soil on cold
nights at both depths at Station 3 falling below the temperature of the soil at both depths at
Station 5. These changes were apparent as early as August 1, when under the influence of a
cool day, the soil temperature in the sanded section fell so much more than did the temperature
in the peat soil, that the readings at all exposures were about the same, the temperature at
6 inches at Station 3 being 1° lower than at the corresponding depth at Station 5. Other such
changes are well shown on August 20 and 26, September 3 and 21. On September 25, under the
influence of continued cool weather, the temperature at both depths at Station 3 fell below

that at both depths at Station 5 for the first time during the autumn. This is also noted on
October 9, 12, 19, and 27.

*L06T2°SIM ‘IaqIBIV ‘Soq url Soinzesodura] [[os pus so1nje1edur9} I1B WINUIIUIM posodxd puv unuTxeUt JO YdvIN—Tz ‘1

TINA ae
ee

Ta

OZ Ol
YIGWILAIS Lsnony

MAY

SESS eS
a
|S
y|% | lie
Q
9
fe
iS}
Sly =
— ———— in
sh 2
e
Wy %
K x
Q Sime
ry SH
Ys s
~
Y Ld
SS
a —ae : ies
aS Se ‘. =
es = i
de iS
oO
a 1 O33 N
Ny 25 SS =
SiS my SS 8
S SS rk) i
© Va ial} &
> Sonn S
Nis FS et B
~ = S
CI S
KY .
=)
Ss)
< on §
<CRHbi
S %
Ks <
Sir SSSI Sis
S SS
= S
Ss
ue < y
= LAs
| a i
Wy
S
BS

Fig. 22.—Graph of maximum daily soil temperatures in bog, Mather, Wis.

08

From a study of the graph, as showngin Figure
21, it is extremely interesting to note the tend-
ency of the soil temperature during the months
of August and September at the 3-inch depth at
Station 5 to fall below that at the 6-inch depth
at the same station, and it was noted to be
actually lower for the first time on September 5.
From the 20th on the readings at the former
depth were almost continuously below those at
the latter depth. In fact, by referring to Table
19, it will be found that the soil temperature
at 6 inches at Station 5 began to gain on the
temperature at 3 inches at the same station as
early as July, and by the following amounts:
July, 0.6°; August, 0.8°; September, 1.2°; Octo-
ber, 1.3°. This is because after a certain date,
apparently late in July, the temperature of the
soil at 3 inches began to decrease while that at
6 inches began to decrease also, but more slow-
ly; so that during the month of October the
temperature at the 6-inch depth was usually
higher than at the 3-nch depth. This shows
that while the peat soil at 6 inches under a thick
erowth of vegetation takes a longer time to
become heated than at the three other locations,
it retains its heat longer. The reason that gen-
erally during October the soil temperature at 3
inches at Station 5 was the lowest of the four
exposures, with the readings at 6 inches be-
tween it and the 3-inch depth at Station 3, was
probably because that, although it was not as
easily influenced by the insolation as that at
Station 3, still the temperature at 3 inches at
Station 5 was not nearly as high even in mid-
summer, so that when cool weather approached
it remained relatively low. On the other hand,
the temperature at 3 inches at Station 3 was
lower during cool, cloudy weather, and warmer
during warm, sunshiny days; at the same time
the temperatures at 6 inches took intermediate
values because of their greater depth and conse-
quent slower changes.

Minimum temperatures at the coldest and the
warmest points on the bog at Berlin, Wis.—It is
possible to make a comparison between the read-
ings of the minimum thermometers exposed in
the bog at places at Berlin, that are considered
the warmest and the coldest referred to in pre-
vious paragraphs, and also to compare these
readings with the readings of a thermometer
in a shelter on hard land on the edge of the
bog. The readings are found in Tables 8 and 9,
and, although given only for the month of Sep-
tember, 1906, will serve to supplement the Mather

59

observations. Station 3 at Berlin was located in a newly sanded, thinly vined, and well drained
section, similar to Station 3 at Mather, while Station 5 at Berlin was in the midst of a dense
growth of vegetation, including vines, grasses, canebrakes, and ferns. In fact, this station was
commonly called the “ferns.” The uprights from the vines reached to a height of from 12 to
18 inches. It was a wild place, not resembling the conditions one would expect to find in a
cultivated cranberry marsh; but cultivation was not practiced in reality at Berlin. Although
it was the coldest point in the Berlin bog, the vegetation there was not similar to that prevailing
at Station 5 at Mather. While moss, which is largely responsible for low night temperatures,
was found at Mather, there was no indication of it whatever at Berlin, but the rank growth
of vines and grasses because of generally poor cultivation was a fitting substitute.

It is not intended to make any detailed comparison between the readings of the thermom-
eters at Stations 3 and 5 at Berlin at corresponding positions, but to compare the readings
at the surface at Station 3 with those at the 5-inch height at Station 5, the warmest and the
coldest exposures on the bog. However, in Table 8 are first given the readings of the minimum
thermometers at both the surface and 5 inches, and the differences between the readings at each
station; and in the lower column, are given the differences between the readings at the surface
at Station 3 and the 5-inch height at Station 5. It is proper to state that the upper thermom-
eter at Station 5 was not attached to any support, but was placed upon the vegetation which
had been pressed down to a compact mass so that the thermometer rested 5 inches above the
surface of the soil near the surface instruments. The lower thermometer was not shielded in
the slightest degree by the upper one, but the radiation was freer at the higher elevation than
from the lower thermometer which was obstructed laterally and obliquely by the dense vege-
tation. At Station 3 the higher thermometer was fastened to a post immediately above the
thermometer which lay upon the ground.

The average difference for the month between the surface thermometer at Station 3 and
the upper thermometer at Station 5 was 10°, and the maximum daily difference was 17.1° on
the 4th. On only one day during the month was there an inversion of the usual conditions,
September 2, and this was because there was water on the thermometers after a heavy rain,
In fact, the readings of the instruments on that day should properly be excluded. These differ-
ences in temperature at Berlin were even greater than those observed at Mather.

The minimum thermometer in the shelter at Station 1 at Berlin, which was located on the
edge of the bog, may be considered the standard as was that at Station 1 at Mather, and a
comparison between the warmest and the coldest points on the bog at Berlin with this standard
is important. For the month of September, 1906, the upper exposed thermometer at Station 5
averaged 9.5° below that in the shelter at Station 1, while a maximum difference of 16.4°
occurred on September 3, and on sixteen days there were differences exceeding 10°. (Table
9.) In comparing the surface readings at Station 3 with the standard, it will be found that
the exposed minimum over the sanded section actually averaged for the month higher by 0.5°.
It, moreover, was higher on eighteen days, while on three days the readings were the same.

These results indicate the great advantage gained in draining, cultivating, and sanding a bog.
In spite of the fact that the thermometer at Station 3 was exposed at the surface of the soil in the open
where the radiation was perfectly free, it averaged higher than the one in the shelter on hard land.
The conditions at Station 3 resemble approximately the improved conditions found in the
Cape Cod marshes, while those at Station 5, on the other hand, are representative of the poorest
conditions found in Wisconsin. It would seem as a result of these observations that the Wis-
consin growers should feel obliged to adopt the Massachusetts methods.

60

Taste 8—Minmtum TEMPERATURES IN THE OPEN AT SURFACE AND AT 5-INcH Heticur with DIFFERENCES, FOR
Sratron 3, Heaviny SANDED, THINLY VINED, AND Sratrion 5, Peat, Heaviry Vinep, DENSE Gro or VEGE-
TATION AND FERNS, THE WARMEST AND CoLpEST Parts oF THE MArsu, RESPECTIVELY; ALSO DIFFERENCE
Between Surrace, Station 3, AND 5-IncH Hereur, Sration 5, Berwin, Wis., SepremBer, 1906.

Station 3. Station 5. | Difference—
Station 3,
Day of month. surface, and
Surface. | 5 inches. | Difference.| Surface. | 5 inches. | Difference. pad ,

° ° ° ° ° ° °

51.5 45.5 —6.0 40.2 38.7 —1.5 —12.8
58.2 59.0 +0.8 263.0 263.1 +0.1 + 4.9
52.0 43.5 —8.5 37.0 35. 0 —2.0 —17.0
51.0 41.5 —9.5 37.5 33.9 —3.6 —17.1
45.0 35.9 —9.1 32.0 28.3 "Ai —16.7
52.0 42.9 —9.1 39.8 36.0 —3.8 —16.0
55.0 50.0 —5.0 47.4 44.0 —3.4 —11.0
56.8 at 7 —4.1 49.0 46. 2 —2.8 —10.6 ;
59.0 54.9 —4.1 52.0 49.7 —2.3 — 9.3
64.5 60.0 —4.5 56.0 54.0 —2.0 —10.5
66.0 64.6 —14 60.0 60.7 +0.7 — 5.3
63.9 59.5 —4.4 56.6 54.8 —1.8 — 9.1
53.9 52.8 —ld 52.3 50.8 105) — 3.1
43.9 35.0 —8.9 32.6 28.8 —$.8 —15.1
48.1 44.7 —3.4 42.8 41.0 —1.8 — 7.1
56.0 55.4 —0.6 53.9 52.8 —1.1 — 3.2
62.3 59.0 =3.3 56.0 54.4 —1.6 — 7.9
64.0 60.0 —4.0 55. 8 55.8 0.0 — 82
60.0 58.1 1iit) 52.9 52.0 —0.9 — 8.0
60.0 58.0 —2.0 58.0 57.5 —0.5 = 2.5
60.0 54.3 6.7 50.9 49.0 —1.9 —11.0
55.1 48.5 —6.6 45.8 42.1 —3.7 —13.0
50. 4 45.0 —5.4|° 42.4 38.9 =—3.5 —11.5
41.0 34.0 —7.0 31.8 28.9 —2.9 —12.1
45.0 40.0 —5.0 38.0 34.3 —3.7 —10.7
54.8 53.8 ¢—1.0 50.0 48.9 —l1 — 5.9
40.3 30.8 —9.5 28.0 24. 4 —3.6 —15.9
43.0 35.7 —8.3 31.5 28.0 —3.5 —15.0
54.3 53.5 —0.8 53.6 53.0 —0.6 = 13
$9.6 31.0 —8.6 27.6 23.0 —3.7 —16.6
53.6 | 48.7 —4.9 45.8 43.6 —2.2 —10.0

a Water on thermometers, and grass and vines very wet, due to rain.
Highest and lowest readings are in italics. :

61

s ef = -
TABLE 9.—CoMPARISON or Minimum TEMPERATURES IN SHELTER, STATION 1, AND IN THE OPEN AT 5-INCH HEIGHT
AT Station 5, PEAT AND HeAvity VINED, AND AT SURFACE AT STATION 3, THINLY VINED AND NrEwty SANDED,
BERLIN, Wis., SEPTEMBER, 1906.

| |
Stati Station A Station Differ- | | Station y | Station Differ-
Perotmente |i sk) cae | mee | See || ea oe [EEE ee aed eta fe
ter. | exposed. | posed. | land3. | ter. | exposed. | posed. | land 3.

a & 5 2 ot 3 A 3 eal .
Wh Et eae il | 50.0 aul Sake 51.5 41.5 | TR See aS 62.0 5454) =i 78G 62.3/ +0.3

De ee et 65.7 263.1 — 2.6 58.2 Sab. Vis tia Ree een 64.0 5558) — 1852 64.0 0

Bes Be 51.4 35.0 —16.4 52.0 SUNG) Peete sre craeee ee 60.0 | 52.0) — 8.0 60.0 | 0
Boe tees al sis 46.8 33.9 —12.9 51.0 apo l| Pack ceonaccoemce 58.6 57.5 afer 60.0 | +1.4
Li isda Poa econ 42.0 28.3 | —13.7 45.0 AUCH) | Wileos snes on cease 59.0 | 49.0} —10.0 60.0 +1.0
(if Net a 47.6 36.0) —11.6 52.0 +65.6 | PP is Ree a 53:9) |) a2) ede 55.1 41.2
gaa et ee aS 56.0 44.0; 12:0 5530) ime tele Ot 232 eee se. once 50.3! 38.9) =11.4 50.4) +0.1
Semen oe td 57.4 46.2] —11.2 56.8 = 0.6 |) Bene eee sees 38.4] 98.9) = 9.5 41.0) +-3:4
Cis. See a | 56.1 49.7| = 6.4 59.0 Segal 23 ee eee 47.0| 34.3) —12.7 45.0| —2.0
1 laps AGE eae eters ome 64.5 54.0] —10.5 64.5 On| (26 eee eee oe 56.4 48.9| —7.5 54.8) 1.6
Re see cee st, 69.0 | 60.7| — 8.3 66.0 —6H))| Re-7/seece aseceeesasee 36.0 | 24.4| —11.6 40.3 | 44.3
1 baa eecdeccs 62.9} 548] — 8.1 63.9 +1.0 | PD Bee se-cbheue sos] ATs!) 238i) tgs 43. | +1.9
1S eee 54.0 5058) —a3e7 53.9 =()3! | D0 eee eee ee 53.9 53.0| — 0.9 54.3 | +0.4
je ine aed eat (ee eeaaes 28.8] 12.5 CEO))) | Sule ull) Saat cee ore 38.0 23.0) —15.0 39.6 +1.6

[any eae eee 51.9] 41.0] —10.9 Bab) BS —__—— - -
ign Ae ears | 57.9 | 52.8 ent | 56.0 1.9 Means....-. 53.1 43.6 — 9.5 | 53.6 +0.5
t | i

a Water on thermometer, and grass and vines very wet, due to rain.
Highest and lowest readings are in italics.

Minimum temperatures over dry and moist sand, Stations 3 and 4, Berlin, Wis.—In order to
further supplement the extensive observations made at Mather, a comparison was made between
the surface minimum thermometers at Berlin, at Stations 3 and 4, dry and wet sand, for Septem-
ber, 1906. This comparison was made because data of the kind desired were not available at
Mather, the sanded sections there being all comparatively dry. Both these stations were located
in the thinly vined section, and there was apparently no difference in the character of the two
stations, except that one was much wetter than the other. (See Table 10.) The temperature
at the surface at Station 4 averaged 2.4° lower than that at the surface at Station 3, and there
was an extreme difference: of 7.3° on September 30, when the thermometer at Station 3 regis-
tered 39.6°, and the one at Station 4, 32.3°. On the following day, October 1 (not included in
this table), the minimum at Station 3 registered 35.8°, and at Station 4, 27.3°, the difference being
8§.5°. It was on this date that the berries were frozen generally in the bog except in the dry sanded
section. On only one day did the thermometer at Station 3 register lower than the one at
Station 4. The increased amount of moisture at Station 4 is solely responsible for the rela-
tively low temperature readings, on account of the heat lost in the evaporation at the surface.
While the reading of 64° on September 2 is included in the table and in the averages, it is not
consistent with the other readings, and was due to water on the bulb of the instrument after a
heavy rain.

Tasie 10—Mintmum TEMPERATURES IN THE OPEN AT SURFACES OF STATIONS 3 AND 4, WITH DirrFERENCES, BERLIN
Wis., SEPTEMBER, 1906.

Day of month. Bite Station Dike | Day of month. Sr Stabe piers Day of month. Braun Stevie Peo
aaa é 3 5 5 a | vil 5
ile eae lates 47.8 =33 47) || eI Dea eee 63.9 @2.1) ~—1.8|] 23......-..2.-. | 50.4 7.1) -3.3
DW Meet Pe: 58.2| @64.0 ares AF Water ee 53.9 53.0 2209) ete eee 41.0 37.4 3.6
Rie eae ae 52.0 48.0 =450)| a4. eee 43.9 37.7 STO eee ee 45.0 42.7 —2.3
{eee 51.0 48.0 =30)| 15k eee ee 48.1 47.0 ETH (Mog es ok ee 54.8| 52.8 —2.0
pease 45.0 43.2 =158)|(hteseee eee 56.0 BESS) |e ON vena een 40.3 a5 | eae
Geet Fy 52.0 48.1 SFM} aig feemy gee | 62.3 GOSS: 185) |e ee ee 43.0 38.0 —5.0
poe ae 55.0 52.1 22950 Il gone ened 64.0 63.0 = aIM0)|| hoses Beane 54.3 53.4 0.9
yer He 56.8 56.0 =O) Sill soneeeel eae 60.0 Gee)! 2 SOG eres ere eee 39.6 $2.5) —7.8
ine epg heeds 59.2 59.4 2/012) || 200 sees ee 60.0 59.0 =i!
10... osu: eee 64.5 64.3 B02 OU 9 nee 60.0 56.1 —3.9 Means i=) 2003-6), 9) 5t-2)) | oe=2-4
Lit Fue eee 66.0 65.0 ES TKOi| Sopra ees 55.1 51.3 =3.8

a Water on thermometer, and grass and vines very wet, due to rain.

Both stations thinly vined and heavily sanded, but Station 3, dry sand, and Station 4, wet sand.
Highest and lowest readings are in italics.

62

Minimum temperatures over peat bogs, heavily vined and thinly vined, Berlin, Wis., September,
1906.—In Tables 8 and 9 appear the readings of exposed minimum thermometers located at
Station 5, in the ferns at Berlin, the coldest point in the Berlin bog. As stated above, the vegeta-
tion was very rank there. Station 2 at Berlin resembled Station 5 in its peat soil and want
of good drainage, but it had in the spring of 1906 been thoroughly weeded, so that the vege-
tation was thin. Stations 2 and 5, then, may therefore well represent respectively thinly
vined and densely vined locations. The record of the exposed minimums for September, 1906,
at an elevation of 5 inches above the surface, Table 11, shows that Station 5 averaged 3.4°
lower than Station 2. A maximum difference of 6.6° occurred on September 27, and if we
exclude the readings of September 2, when water was on the bulb of the thermometer at Station
5, after a heavy rain, there is not a single instance in which the minimum at Station 2 was lower
than the one at Station 5. The great differences in temperature are due entirely to weeding,
the soil in the thinly vined section during the growing season being much warmer than a soil
covered with dense vegetation. Radiation, however, should be just as free from a thinly vined
peat soil as from one heavily vined.

It is as important to cultivate as it is to practice drainage. Of course it is impossible
to determine absolutely the advantage in exact degrees gained by cultivation, draining, or
sanding. While there is an average difference of 3.4°, as shown by Table 11, between the
minimum thermometers in the thinly vined and the heavily vined sections, a difference of
2.4°, as shown by Table 10, between the minimum thermometers on wet and on dry sand, a
difference of 1.7° between thermometers on peat and sanded bogs, both thinly vined, and a
difference of 2.2° ‘between the surface and 5 inches, it is obvious why an average difference of
10°, as shown by Table 8, can exist between a minimum thermometer exposed at the most
favorable location as far as drainage, sanding, and cultivating are concerned, and another in a
most unfavorable location, an unsanded peat section with a very dense growth of vegetation,
and poor drainage. It is not strange, therefore, that in a bog where there is a variation in the
conditions of sanding, draining, and cultivation, the range in minimum temperature is con-
siderable, and that a portion of a bog is seriously injured by frost, while another portion com-
pletely escapes. It should be apparent why the experiment station at Cranmoor, Wis., where
intensive cranberry growing is practiced, does not require reflowing of its bog on many cold
nights in order to escape injury, when the crop of an unimproved bog might be completely
wiped out unless protected by reflowing. For the same reason, the Cape Cod growers, on account
of the excellent condition of their marshes, are seldom forced to use water for protection except
in the late autumn.

TasLe 11.—Minimum TEMPERATURES IN THE OPEN AT 5-INCH HEIGHT, AT STATIONS 2 AND 5, with DIFFERENCES
Bertin, Wis., SEPTEMBER, 1906.

set Antone
Station | Station | 7; | Station | Station ; Station | Station F
Day of month. | 2—5- 5—5- | Der: Day of month.| 2—5- | 5—5- Difter- || Day of month.| 2—5- 5—5- iis
inch. inch. | : inch. inch. ra) inch. inch. ence:
er. = ~ % a [- 1S a
° | ° ° ° ° | ° ° ° °
Me atenedochpecd 41.6 | 38.7 2a) 2eeeeee ose 57.4 54.8 SHAG ||| 8s sas 43.8 38.9 —4.9
Qs ee eecee LE) CCc blll | SGN). hae oes 53.0 50.8 HOY 9) WOM a cooon sede 32.5 28.9 8.6
Be ASreeeoeocisd 39.5 35.0 | a | We eae bo 33.0 | 28.8 42 |) 20... eo eee 38.7 | 34.3 | —4.4
t Be Seis sascetac, 38.9 33.9 DAO Sl ocw n= eee 44.5 41.0 Se O hee esters a ele ts 52.8 48.9 —3.9
Set aneee snes 33.1 28.3 Sa het || URE SS sacs 54.9 52.8 dll We Tieecceeoeccnce 31.0 | 24.4 | —6.6
Oe ea sassse coche 40.8 36.0 ra SNe oa ootioc 57.3 54.4 ees Spo corcd ocd 31.9 | 28.0 —3.9
Pesce s~tnceete 47.6 44.0 — Salt Some aac ane sate 57.6 55.8 a it eee melee fatal ite 53.6 53.0 —0.6
ren Ss2Sncias 50.0 46.2 | Abi) ||| Uae Sase. 58.0 52.0 —6.0 |) 30............. 28.8 23.0 —5.8
Oe Aas ore 52.4 49.7 CAH |e eee Sosscae 58.0 57.5 —0.5 = ii =
10: zee ee | 57.4] 54.0 SFU oye lees 51.4 49.0 =2.4 || BAERS [GEE )| CRD ia
Ue ee ater 64.0 60.7 =e || Pade nese aes =| 47.0 42.1 —4.9

a Water on thermometer, and grass and vines very wet, due to rain.
Station 2. Peat bog, thinly vined.
Station 5. Peat bog, heavily vined, with dense growth of vegetation and ferns.
Highest and lowest readings are in italics.

———————— eee

63

Minimum temperatures over peat bog and sanded bog, thermometers exposed at 5 inches above
the surface, at Cranmoor, Mather, and Berlin.—Having made a comparison between the exposed
minimums in various portions of the same bog at both Mather and Berlin, it is interesting
to note how the readings vary in different bogs, for the season or a portion of the season,
when the minimum thermometers are exposed in the vines over different soils at the height
of 5 inches above the surface. In Table 12 we have a comparison between Cranmoor,? Mather, .
and Berlin for the months of August and September, 1906, at certain selected stations over
peat and sanded bogs. The locations in each marsh were respectively the coldest and the
warmest points, although it should be understood that the exposures of the thermometers
given were at an elevation of 5 inches above the ground, the minimums, of course, registering
higher at the surface where the radiation was less free. The sanded surfaces at the three
stations closely resembled each other, while the exposures in the peat bog were over moss at
Cranmoor and Mather and in the ferns at Berlin, there being no moss at the latter station.
The vegetation was dense, however, in all three peat bogs, it being densest at Berlin. The
average daily and the average monthly readings at any particular station are in themselves
of little consequence in the discussion of Table 12, as there may be a variation in temperature
because of the difference in geographical location. The average readings at corresponding
locations at Cranmoor, Mather, and Berlin for the two months did not vary materially, but it
is with the differences between the exposed minimums over the peat and the sanded bogs in
which we are especially interested. For the two months the temperature over the sanded bog
averaged higher than over the peat, as follows: Cranmoor, 5.3°, Mather, 4.4°, and Berlin 5.4°;
the greatest daily difference was 11° at Cranmoor on August 30 and at Mather on September 15,
and 19° at Berlin on August 11. At no time did the minimum over the peat register higher
than that over the sand at any one of the three stations, with the single exception of September
2 at Berlin, when the instrument in the peat bog was affected by water, after a heavy rain.
There were several dates, however, invariably on cloudy nights, when there was no difference
between the readings of the instruments over the peat and the sand; but, of course, on these
nights the temperature was high and there was no danger from frost.

In 1907 and 1908 data are available for the season at Cranmoor and Mather only, the
Berlin station having been discontinued. It did not seem necessary to publish the tables
for these two years. The most important features, however, were as follows: At Cranmoor
in 1907 the differences averaged greatest during the summer months of July and August, 6.7°
and 6.6°, respectively, while at Mather the greatest average monthly difference was 4.2° in
September, this being 0.1° higher than the average for August. The greatest difference at
Cranmoor on any one day was 12° on June 27, while the greatest difference at Mather was 8°
on September 2 and 3 and October 5. In 1908 the average difference was 4.5° at Cranmoor and
4° at Mather, and the greatest difference on any one day occurred on August 5, 11° at Cranmoor,
and at Mather the greatest difference, 8°, occurred on seven different days.

« Observations over sanded bog made at Cranmoor Experiment Station and those over peat at* the Gaynor-
Blackstone marsh immediately adjoining.

51936"—Bull. T—10—5

64

TABLE 12.—MinruuM TEMPERATURES IN OPEN OVER PEAT BoG with DENSE VEGETATION, AND IN ES OVER .
Sanpep Boe, porn ar THE Hericut or 5 INcHEs, THE LaTreR REPRESENTING Best RESULTS FROM SANDING,
DRAINING, AND CULTIVATING AT CRANMOOR, MATHER, AND Berurn, Wis., AUGUST AND SEPTEMBER, 1906.

[P. indicates peat bog; S. indicates sanded surface; Diff. indicates excess of temperature of sanded surface over that of the peat bog.]

August, 1906. September, 1906.
Day of month. Cranmoor. Mather. Berlin. Cranmoor. Mather. Berlin.
ip S. | Diff.| P. S. | Diff. te Ss | Diff. 'P. S. Ditt iP Ss. | Diff.| P. Ss. Diff.
|
| ° ° ° ha) ° c ° ° ° ° ° ° ° ° | ° | ° ° °
7 55| 57] +2 45 56} +11 38 46 + 8 38 44/+ 6 39 46) +7
+ 2 55] 57) + 2 52 56) + 4 61 61 0 55 64/49 63 59); —4
| +6 55| 59/ +4] 57) 63) +6) 32) 43) +11) 35) 43/48) 35) 43) +8
+8 48 54| + 6 50 52] + 2 35 42\+7 36 40} 4+ 4 34 41 ae
0 64 64 0 66 66 0 32 41; +9 33 40| +7 28 36} +8
7 48 53 | + 5 41 54 | +13 37 45) +8 36 42)+6 36 43) +7
+1| 58] 6o/+2] 56] 62/+6] 42] 50/+8] 44) 49/45) 44) 50) +6
+7 59 62/ + 3 60 64) + 4 47 52) + 5 47 53] + 6 46 53 ap
+ 2 64 66 | + 2 61 64 | + 3 AT 54] + 7 48 53 | + 5 50 55] +5
+7 60 64) + 4 55 63) + 8 53 60| +7 56 60] + 4 54 60} + 6
+8 51 57 | + 6 48) 67] +19 58 62) +4 63 65) +2 61 66) +4
+3 44 49) +5 45 61 | +16 60 eo) + 2 60 61} +1 55 60) +5
+9 47 52) + 5 39 45] + 6 49 51) + 2 48 49) +1 51 53] + 2
+8 48 53) + 5 44 50] + 6 28 36) + 8 31 34/4 3 29 35/ +6
+8 45 50} + 5 44 50 | + 6 47 49| +2 40 51} +11 41 45) +4
+7 51 56) + 5 49 57| +8 59 59 0 58 65) +7 53} 55] + 2
+5 54 59) +5 62 65] + 3 58 61} 4+ 3 57 60 | + 3 54 59 +5
+ 2 55 60) + 5 54 58} + 4 58 62) +4 58 62} +4 56 60} +4
+4 58 62) +4 58 58 0 56 Syl || sr il 50 56) + 6 52; 58|/ +6
+6| o3/ 67|/+4| 64] eol+5| 54) 55/41] 54) 55/47] 58] 58 0
+4 64 68| +4] 65 70) +5 52 56); +4] 49 55 | + 6 49 54) +5
+3] 64| 67|+3!] 60] 64/+4)] 41| 49/+8] 44] 49/+5] 42) 48) +6
+4| 65) 69/+4| 61] 61 0} 37| 45/48] 41] 46/+5] 39] 45) +6
+ 1 60 60 0 60 (lisp a 34 )+8 38 42/44 29 34); 45
0 65 69; 4+ 4 66 67 | +1 35 42) 4+ 7 38 43) 4+ 5 34 40; +6
+2 62 63) + 1 68 68 0 40 ES) ars 40 42/42 49 54] +5
+5 81| @40) + 9 30 38) +8 26 33) +7) 28 34) + 6 24 $1 +7
ae re 34] @42/) +8 36 44)4+ 8 26 331 +7 31 36 | +5 28 36) + 8
+8 52 56) + 4 48 52) + 4 51 54) +3 36 39) + 3 53 54] +1
+11 36 42,4 6 36 46 | +10 17 29) +12 25 28| +3 23 31 +8
| =POil!-936)|0 422i Gale sehe ei) iG) eeree | eaaer| pen ene fcsescjeeeees Beas [ee Jeeeeee|eeeeee
(Means peas eee eo 52.2 | 57.4 |4+5.2 | 53.3 | 57.3 |+4.0 | 52.2 | 57.9 |+5.7 | 43.7 | 49.1 |+5.4 | 43.9 | 48.7 +4.8 | 43.6 | 48.7 | +5.1
| : u \
a Water on thermometer, from rain.
Highest and lowest readings are in italics.
TaBLE 12a.—MEANS oF TABLE 12.
August. | Septeuts Means
Cranmoor: 2 °
Pea bi) bogs pag. Senate: etoe een SIE Ce sa Se a eS eet a 52.2 43.7 47.9
Sanded surface 57.4 49.1 53.2
IDA Fe (217110 ee eae ee RS Oe ee een eae noe ese n arr nore a Sear e oes sao DO IN Cina ase SI + 5.2 + 5.4 + 5.3
Mather:
Veter tao op SEE E Rat oe oc Seer Os = HOE CACO Sar nm eo okaw ater onus her aree rears soe g ctwoscdocdaetese se eee 53.3 43.9 48.6
Sanded surface 57.3 48.7 53.0
Wifference:=2.225 6 sac se soe ewe ss Fee eee oe = SSE Soe So ee Bee ae oe ee + 4.0 + 4.8 + 4.4
Berlin: ’
Beat bogs... 2 2 52.2 43.6 47.9 a
Sanded surface 57.9 48.7 53.3
Difference + 5.7 + 5.1 + 5.4

65

Readings of exposed minimums at various elevations over bog and upland, Stations 2 and 9,
Mather, Wis.—In the preceding pages there have been discussed the variations in temperature
at various locations at the surface and at the height of 5 inches, and the connection existing
between these temperatures and the temperature of the soil at the point of exposure. Excepting
the minimum thermometers that were exposed in the shelters at Stations 1 at both Mather
and Berlin, no reference has previously been made in this paper to the reading of an instrument
higher than 5 inches above the surface.

In order to supplement the comparison of exposed minimum thermometers at the surface
and 5 inches above, readings were made at Mather of instruments at Stations 2 and 9 placed as
follows: Surface, 24 inches, 5 inches, 73 inches, 10 inches, 12 inches, 15 inches, and 36 inches
above the surface. The character of these stations of course differs radically, Station 2 being
located in the bog over sphagnum moss, while Station 9 was in the garden on the upland where
the surface was comparatively clean and the soil a sandy loam. The difference in elevation
between the two stations is about 15 feet. The results would have answered the purpose
better had both the stations selected for this comparison been located on the bog. Daily,
monthly, and seasonal averages appear in Tables 13, 13a, 14, 14a.

At Station 2 the minimum temperature averaged lowest for the entire season at the 5-inch
height, the average being 40.1°. The temperature gradually increased thence upward and down-
ward, being 41.8° at the surface and 43.2° at the 36-inch height, the surface reading therefore
averaging 1.7° higher than at 5 inches and 1.4° lower than at 36 inches. In every month the
average temperature was highest at 36 inches, with a secondary maximum at the surface. In
May and June the temperature averaged slightly lower at 2} inches than at 5 inches. For
the entire season the temperature at 5 inches averaged only 0.2° below that at 23 inches.

At Station 9 on the upland the average difference between the thermometers was not so
great. The temperature at 24 inches averaged lowest, 44.5°, instead of at 5 mches, as on the
bog, but the difference was very slight between these two elevations—0.1°. The surface ther-
mometer averaged highest, 45.5°, but there was only 1° difference on an average between the
two extremes, while the average surface reading was 0.6° higher than at 36 inches. The
average for the entire season fairly represents the conditions prevailing each month, the highest
in each case occurring at the surface and the lowest at 2} inches.

While at Station 2 the minimum thermometer was usually the lowest at either 24 inches
or 5 inches above the surface, and the temperature averaged higher for each month and the
season at 36 inches than at the surface, yet on clear, cool nights, when radiation was the freest,
the exposed minimum at 36 inches usually registered lower than at the surface. Moreover, on
the coolest nights the difference between the exposed minimum at the surface and the 5-inch
height was the greatest, occasionally exceeding 6°, as in October. (See Table 2.) On warm
nights, however, almost without exception, the temperature at 36 inches registered consider-
ably higher than at the surface, the maximum difference occurring on June 17, 6.7°, a partly
cloudy night. On that date the surface thermometer was 62.1°, the one at 36 inches 68.8°,
and at 5 inches 62.9°, this reading being higher than at the surface, and the lowest reading
occurring at 24 inches, 62°. At Station 9, of course, the variation was not so great, but it is
interesting to note that while the average temperature at this station at the surface was higher
than at 36 inches, and this fact was most pronounced on cold, clear nights, nevertheless, on
warm nights the reverse was the case, the temperature at 36 inches almost invariably being
higher than at the surface; or, in other words, at both stations, on clear, cool nights the ther-
mometers at the 36-inch height usually registered lower than at the surface, and on warm
nights the thermometers at 36 inches usually registered higher than at the surface, it being
understood, however, that on both cool and warm nights the lowest temperature at both Stations
2 and 9 occurred neither at the surface nor at 36 inches, but at some point between the two,
usually at 24 or 5 inches.

On June 17, referred to above, when at Station 2 the surface thermometer registered
62.1°, and at 36 inches 68.8°, the readings at similar exposures at Station 9 were 67.1° and

66

67.3°, respectively, the upper thermometer at Station 2 on the bog actually reading higher
by 1.5° than the one at Station 9 on the upland. On August 10, when the surface instruments
at Stations 2 and 9 registered, respectively, 52.6° and 53.1°, the readings at 36 inches were,
respectively, 57.8° and 51.8°, the one on the bog therefore registering 6° higher than the one
on the upland.

It is important to note that at both Stations 2 and 9 there is an abrupt change im tempera-
ture between the surface and 24 inches, the readings of the surface instruments bemg kept up
by the conduction of heat from the ground, although unequally. Above 23 inches the change
at Station 9 is gradual. The average difference between the readings at.15 inches and 36
inches was only 0.1°, while at Station 2 on the bog the difference was 2.1°. Moreover, at Station
2 the average range for the season was 3.1°, from the minimum of 40.1° at 5 inches to the maxi-
mum of 43.2° at 36 inches. At Station 9 the average range for similar exposures was only
0.3°, from a minimum of 44.6° at 5 inches to a maximum of 44.9° at 36 inches. However, the
extremes at Station 9, as has been stated before, were at the surface and 24 inches, 45.5° and 44.5°,
respectively, the range being but 1°. Where the minimum thermometers were placed directly
one above another, as at Stations 2 and 9, it is obvious that the thermometer at 24 inches is
shielded as much by the six thermometers above as the one at the surface by the seven ther-
mometers; but, nevertheless, the radiation amidst vegetation should be freer as the elevation
increases. The lower down the thermometers are the more the radiation from them is interfered
with, laterally and obliquely, by the surrounding vegetation. A thermometer or leaf elevated
above the ground loses its heat more rapidly than if it rests upon the surface, because in the
former case there is likely to be freer radiation in all directions; moreover, the heat conducted from
the soil beneath affects the thermometer or leaf resting upon the surface and prevents its tem-
perature from falling as low as it would if located a few inches above. Of course colder air,
being heavier, gradually sinks to lower levels, but this process is very slow, while the processes of
radiation and conduction may continue active. The problem is a complicated one, as many
factors are involved, such as humidity, wind velocity, condition of the sky, barometric pressure,
length of night, general temperature conditions, the temperature and composition of the soil, and
its moisture and the character of its covering. It is quite difficult, however, to explain why
the exposed minimum was almost uniformly lower at a few inches above the surface, except on
the theory that the surface thermometer receives heat from the soil beneath. In any case,
these results are important, as they show approximately the variation in minimum temperature
to which vegetation in the bogs is subjected.

67

TaBLE 13.—Minrimum TEMPERATURES IN OPEN AT ALL ELEVATIONS AT STATION 2, OvER SPHAGNUM Moss ON THE
Marsn, MatuHer, Wis., 1907.

May. | June
Day of month. cl we ees |
Sur- | 23 5 7k 19 P20 eats) 36 | Sur- | 23 5 73 10 12 15 36
face. \inches. inches.|inches.|inches. inches. inches.|inches.| face. |inches.|inches. inches.|inches.{inches.|inches. inches.
° come. 2 ° ° ° ° ° ° ° ° ° ° ° ° °
Sar Gortescatiae [eee eeleeeeeesl S023) (etre eral) £8.00)! (28°8))) 283i" 2828 32.3
f -Benp A Pecnued easosae beoceos 30.4] 29.6] 29.4] 29.8] 29.8] 29.0] 30.1 32.8
Dee Bsad beatae eencaes ao eaaee 50.0 | 52.2] 53.0] 53.0} 53.0] 52.8] 53.8 54.0
36.0] 35.4] 35.2] 35.3] 35.9] 35.5] 36.4] .38.0
36.7 7.6 | 38.0} 38.8] 39.1 38.9 | 40.0 40.9
30.1 28.0} 27.9) 28.0) 28.0) 27.9) 28.9 29.3
43.0] 44.0! 44.8] 45.0! 45.3 | 45.0! 46.0 46.5
30.2 | 28.0) 27.9] 28.1 28.5} 28.0} 29.0 30.8
34.3 | 32.8] 32.9] 32.8] 33.0] 32.8] 33.9 36.0
52.0] 53.0] 53.3] 53.1 53.0] 52.8] 53.8 53.8
Beene ||Eaoecoel yaeaade 40.2} 38.9] 39.1 39.5 | 39.8} 40.0] 41.1 43.8
34.7 | 35.0 | 36.1 50.9] 50.4) 50.5] 50.5} 50.5) 50.4) 50.2 51.9
59.5 | 59.6| 61.0| 35.0] 34.4 | 34.4) 34.7] 35.0] 35.9] 36.0 39.3
43.9 | 44.0] 44.8 | 82.3] 31.4] 31.0) 31.1 31.1 31.0} 32.0 35.0
35.0 | 35.1] 35.7] 37.0] 35.0} 35.0] 35.0] 35.3] 35.3] 36.1 37.8
33.0 | 34.9] 34.1 47.8 | 46.0} 46.0 | 46.1 46.1 | 46.0| 47.0 49.2
33.4 | 34.3 | 37.4 2.1| 62.0) 69.9) 68.9} 65.0| 65.3) 66.8 68.8
33.9 | 35.1 39.5 | 51.0] 49.5| 49.6) 49.8] 49.8] 49.8 | 50.6 | 53.8
28.6 | 29.3] 33.3 | 48.0] 46.5) 46.8 | 47.0| 47.4] 47.5| 48.9 51.0
18.0| 18.2) 20.2) 43.8] 42.3 | 42.3 | 42.2) 42:5 | 42:5] 43.1 45.5
20.6 | 20.5) 22.1 43.0] 41.5] 41.4] 41.4] 41.6] 41.5] 42.0 44.0
43.0] 43.0] 44.0] 59.8] 58.5] 59.0) 59.2] 59.5] 59.5 | 60.0 60.7
| 42.9 | 43.0} 44.0] 55.0) 53.7] 58.9; 54.0] 54.1) 541] 55.1 57.8
| 40.8] 41.9] 42.3] 50.8] 49.4] 49.6] 49.9] 50.0) 50.1 51.0 53.2
| 43.0 | 43.0] 48.7] 54.6] 52.9) 53.0] 53.0] 53.1 | 53.4 | 54.0 55.3
44.2| 44.0] 45.0] 42.4] 41.0] 40.9] 41.1 41.8) 421 43.1 44.5
| 27.0] 27.3] 29.0] 38.0] 35.8] 35.2] 35.4] 35.9 | 36.0) 36.5 38.6
27.4] 27.8| 32.4] 39.6] 36.8] 36.7] 36.8] 87.0 | 37.0 | 37.3 39.0
30. 1 30.5] 35.2] 44.8] 42.5] 42.6] 42.8) 43.0] 43.0] 43.7 46.7
36.3 | 36.4] 40.9] 51.0] 48.9] 48.9] 49.0] 49.0] 49.0] 50.6 53.1
LET SER ee Hla anes pros aoc] seco ose| (seceoed| tora eeidcecellbecessaallsnopore
|
Meanismeee sae es 36.8 | 36.0| 36.2] 36.4] 36.7] 36.0] 36.3] 388] 43.3 | 42.2) 42.3] 42.5) 42.7) 42.7 | 43.5 | 45.4

a Means for twenty days. !
Highest and lowest readings are in italics.

68

Tasie 13.—MrinimumM TEMPERATURES IN OPEN AT ALL ELEVATIONS AT STATION 2, OvER SPHAGNUM Moss ON THE
Marsu, Matruer, Wis., 1907—Continued.

July. August.
Day of month. z i |
Sur- 2k a) 7h 10 12 15 36 Sur- 2} 5 7s 10° |. 12 15 35
face. |inches. inches. inches.|inches. inches.|inches.|inches.| face. inches.|inches.|inches. inches: inches: inches.|inches.
° ° © ° ° ° ° ° ° ° ° ° 3; # Tone ° °

51.6] 52.0} 52.8 54.3 | 54.9] 55.9] 56.4 51.3 | 47.7 | 47.0] 47.0} 46.9 | 46.9 | 47.0 49.7

29.9) 29.4) 89.5) 29.6 29.7 | 30.0| 31.2) 44.4 | 40.0] 39.1 39.4 | 39.5) 39.7] 39.9 42.0

38.6 | 38.5] 38.7] 38.9) 39.0] 39.8] 42.1 43.0 | 40.5 | 40.0] 40.1 40.3 40.4 | 40.6 42.9

2| 44.4] 44.7) 44.7 44.8 | 44.9 45.0] 46.9 | 35.9 | 34.6] 34.1] 83.2] 83.1 | $3.3) 33.4 c 35.4

0; 59.0] 59.4] 59.5] 60.0] 60.0| 60.5] 60.5] 58.0] 58.0] 57.9] 58.0) 58.0 | 58.0 | 58.0 58.4

1 52.6 | 52.8] 52.9 53.0 | 53.0} 54.8] 56.0) 49.4 | 46.8] 46.0] 46.0] 46.0 46.1 46.2 49.0

8! 43.7] 43.3! 43.8| 44.0!) 44.0) 44.3! 46.2] 51.0) 48.7] 48.21 48.1 48.2! 48.5] 49.3 53.0

9] 47.6] 47.0] 47.7 47.8 | 48.0} 49.0} 53.0] 54.2) 51.6] 51.0} 51.0] 50.5] 50.8] 50.9 53.4

0} 51.4] 51.0} 51.0] 51.3 51.7 | 52.2) 55.7] 52.0] 49.0] 48.9) 49.2] 49.0] 49.4] 49.6 52.0

7| 42.8] 42.3) 42.5] 42.8 43.0) 43.2] 46.0] 52.6] 54.5] 54.6) 54.5] 54.5] 549] 54.4 57.8

9} 60.7] 60.2) 59.9] 60.0) 60.0; 60.0] 60.1 70.0} 70.0} 70.5 | 70.8} 71.0| 71.0} 70.9 72.0

2) 42.2] 42.3) 42.1 42.0| 42.1 42.4 | 45.1 44.9 40.3 |} 40.1 40.1 40.0} 40.3) 40.3 45.2

8| 44.6) 446) 448] 44.7 44.8 | 45.2) 48.8] 45.0) 42.2) 42.0) 42.5| 42.3) 42.5] 42.5 45.3
56.6 | 56.4) 56.7] 57.0 57.5 | 58.4} 60.5] 48.8] 46.2] 46.0| 46.5| 46.4) 46.5] 46.2 48.9

67.4) 67.8) 67.9) 68.0| 68.0) 68.1 68.2) 51.9} 49.7] 49.6 | 50.0} 49.7] 50.0] 51.6 54.0

46.6 | 46.3] 46.4] 46.5) 46.7] 47.0] 48.2] 59.6] 57.7 | 57.7 | 58.2] 57.8] 57.9] 57.9 60.0

45.1 45.0] 45.1 48.2 | 45.7 | 46.4 50.0] 46.4] 43.6 | 438.4 43.8 | 43.6] 43.6] 46.1 47.4

45.0] 44.5] 43.9) 44.0} 44.2] 44.6) 46.0] 50.2) 47.7] 47.7) 47.9] 47.6] 47.7] 48.0 52. 2

52.0} 51.8} 51-9] 52.0 | 52.0} 52.5] 54.5] 64.7] 64.7] 64.7 64.9) 64.6] 64.7] 64.8 65. 2

50.2] 50.0] 50.3] 50.5 | 51.0] 52.0) 55.0] 380] 34.6) 341 34.7) 34.6] 34.3] 35.0 38 5

60.5 | 60.2] 60.1} 60.0} 60.2] 61.0] 62.9; 39.5] 36.2] 35.7) 36.5 36.3) 36.4] 36.6 40.3

57.0] 57.3] 57.4] 57.9| 58.5] 59.4] 61.7) 35.6) 34.6] 33.9! 34.6) 34.2] 34.3] 34.5 37.3

50.2; 48.9] 49.0) 48.7 | 48.8) 49.1 50.0 | 50.0} 47.6, 47.2 | 48.0; 47.6 | 47.7) 48.0 52.3

59.0 | 587] 58.8] 588 | 589] 59.7] 61.7] 44.0] 41.6] 41.0) 41.7] 41.5] 41.8] 42.5 46.5

51.1} 49.5} 49.3] 49.2) 49.4 | 50.0) 50.9] 35.9] 33.2] 327) 34.0) 34.0] 34.6) 35.0 39.0

42.8 | 42.3] 42.4] 42.5 | 42.8 | 43.0] 45.0] 45.0] 42.8] 42.5| 43.4] 43.4] 43.6] 43.9 46.5

41.3 | 41.0] 40.6 | 40.6 | 40.8 | 41.0) 42.2] 57.0] 57.0] 56.5) 57.0] 56.5] 56.4) 56.7 56.6

55.0] 55.3] 55.4] 55.7) 56.0] 56.5) 58.5] 51.4] 50.0] 49.9) 50.7] 50.6] 50.9] 51.0 53.6

48.2 | 48.1 48.1 48.0 | 48.1 49.0 | 52.0] 46.0] 44.5] 43.7| 44.6] 44.6] 44.8) 44.9 47.6

45.1] 45.0] 44.9) 44.5) 44.4) 44.5] 47.9] 62.6] 62.5] 62.3] 62.7] 62.6] 62.7| 62.5 63.8

42.9} 48.5] 48.5] 48.4] 48.6] 48.9] 51.0] 53.5) 52.5] 52.4] 52.7] 52.7) 53.0) 53.5 55.8

49.2 | 49.2} 49.2} 494) 49.6] 50.1 52.1 49.4] 47.4] 47.1 | 47.5] 47.3] 47.5 47.8 50.4

Estimated; actual readings valueless on account of heavy rains.

Highest and lowest readings are in italics.

———

a

69

Tasie 13.—MinrmumM TEMPERATURES IN OPEN AT ALL ELEVATIONS AT STATION 2, OVER SPHAGNUM MOSS ON THE
Marsu, Marner, Wis., 1907—Continued.

September. October.
Day of month.
Sur- 5 7k 10 12 15 36 Sur- 24 5 7k 10 12 15 36
face. |inches.|inches.|inches.|inches.|inches.|inches.|inches.| face |inches. inches. inches.|inches.|inches.|inches.|inches.
° ° ° °

-6) 27.8] 27.8] 28.3] 28.0 29.9

-1) 46.2] 46.2) 46.4] 46.0 61.0

-7 | 36.8 7.0} 37.0} 37.0 39.0

73] 28.5] 28.7] 29.1] 29.6 33.1

-O| 28.4] 28.7) 29.5] 29.3 33.0

7 | 84.7] 35.1) 35.5 | 35.5 41.5

-4| 38.5] 38.6] 38.7] 38.6 42.6

.9 17.2| 17.5 17.6 | 17.8 19.2

-8| 34.5] 35.0) 35.5] 35.0 39.0

0] 26.4] 26.5] 26.7] 26.5 29.3

0} 27.0) 27.3 | 27.5 27.2 30.6

-7 | 24.0) 24.4) 24.5] 24.3 26.5

.8| 17.0 EES RAGS EY Gre 19.0

-6}) 16.8) 17.3) 17.4] 17.5 18.9

-4| 40.6] 40.9] 41.3] 41.0 42.0

4] 30.6] 31.0] 31.4] 31.4 33.1

-4| 28.4] 28.7 28.7 | 28.5 30.0

-6] 19.2] 19.6] 19.3 19.6 20.5

-9} 19.0} 19.4] 19.6] 19.8 21.0

-9| 23.3] 23.6] 23.8] 23.7 25.3

-2| 14.2] 14.6 14.7 14.7 15.0

-7 | 32.5] 33.0] 33.4) 33.5 35.4

-9| 23:5] 23.6) 23:7) 23.6 24.0

17.7] 19.4] 19.8! 20.3] 20.6 22.5

17.2] 18.9] 19.5 19.7 19.4 21.9

12.5] 13.8] 14.0} 14.5] 14.5 14.9

29.4] 30.4] 30.2} 30.0] 29.5 29.8

10.0) 11.6] 12.3 12.5 12.5 13.2

25.7 | 26.3| 26.7] 26.9] 26.5 26.4

34.8] 35.9] 35.9] 36.0] 35.5 35.6

29.4) 30.4] 31.0] 31.5] 31.5 32.6

25.2 | 26.5} 26.8] 27.1} 27.0 28.9

TaBLE 13a.—MonTHLY AND SEASONAL MEANS OF MINIMUM TEMPERATURES IN OPEN AT ALL ELEVATIONS, STATION 2,

Marser, Wis., 1907.

|
May.a June. July. August. | 3 nee | October. | Means.
| =|
ies : ; ; : :
BITE wahoo Se eonsrer acs sco bott joes: son Tocatese nen RH SSR CRO SER Ee ne 36.8 43.3 62.0 49.4 41.9 27.5 41.8
DISA, 58 3 it iese nes eho a2 Ss pp ease eee sr oo AS n ener Dee eee Oe 36.0 42.2 49.2 47.4 40.8 26.0 40.3
ly SRE ate ere Soest eS ase geSenciot 2 2 aead hase Se SSRs Sera 36.2 42.3 49.2 47.1 40.4 26.2 40.1
74 inches... 36.4 42.5 49.2 47.5 41.3 26.5 40.6
10 inches... 36.7 42.7 49.4 47.3 41.4 26.8 40.7
36.0 42.7 49.6 47.5 41.7 27.1 40.8
36.3 43.5 50.1 47.8 41.8 27.0 41.1
38.8 62.1 60.1 43.8 28.9 43.2

Highest and lowest readings are in italics.

a Means for twenty days.

70

Tasie 14.—MinmuM TEMPERATURES IN OPEN AT ALL ELEVATIONS AT STATION 9, OVER SANDY LOAMPON THE
TPLAND, Matuer, Wis., 1907.

May.a June.
Day of month. a Re 2
Sur- 2h 5 Th 10 12 15 | 36 Sur- 23k 5 74 10 12 15 36
face. |inches.|inches.)inches.|inches.|inches. Hoes: Pets. face. inches.|inches.|inches. inches. inches. inches. inches.
| =
° °* ° ° ° ° °

3222) 32.:2)) 323°] 32.4)!' 3252) 3o03 33.1

34.3) 34.8) 349) 34.9) 34.9) 34.8 35.5

53.6 | 53.8) 54.0] 53.8] 54.0] 54.0 54.3

40.3 | 40.4) 40.5 | 40.5; 40.5] 40.4 40.1

42.5 | 42.9 | 43.0] 43.0 43.0] 43.0 43.7

Slee leon Shasta Slat) Slat 6Slee, 81.4

46.5 | 46.5 | 46.8] 46.7 46.7] 46.6 46.7

31.8} 31.8] 31.8] 31.8 31.8] 31.2 31.8

37.9 | 37.9] 37.9 | 37.8 37.8] 37.5 37.6

53.3 | 53.4] 53.5] 53.4 53.5] 53.7 52.9

43.5 | 43.7 | 43.8) 43.9 44.0] 43.9 44.2

36.7 | 36.7] 37.0 7.0] 37.0} 37.0} 37.0} 53.0] 52.3] 52.5] 52.6) 52:3) 52.0] 52.0] $52.0
69.8 | 69.8 | 60.5) 58.7 | 58.5) 60.5) 60.9} 42.0] 40.0] 41.1 41.2] 41.2) 41.3] 41.3 41.9
45.2) 45.0] 45.2) 45.0) 45.1 45.0 | 44.9] 38.9] 36.0] 36.1 36.2} 36.0) 36.1 36.0 36.0
36.3 | 36.0] 36.1 36.1 36.0] 36.0] 35.5] 42.5] 41.0] 41.0] 41.0] 40.8] 40.9] 40.5 40.6
35.0] 34.8] 34.8] 35.0! 35.0] 33.3] 34.9] 54.5] 52.0] 52.0] 52.1] 52.0] 52.0] 52.0 52.0
39.4} 39.1 | 39.3] 39.3] 39.1] 39.3] 39.4] 67.1] 66.4] 66.5| 66.4) 66.8) 67.9| 66.9 67.3
44.7) 449] 45.3 | 45.6) 46.0] 46.0] 47.0] 59.0] 55.8] 55.7] 55.7] 55.7 55.8 | 55.5 55. 8
34.9 | 35.0] 35.7] 36.0) 36.0] 36.0] 36.9] 55.1 54.8] 54.9] 55.0) 54.9] 54.8] 54.9 55.0
23.7 | 23.8] 24.0] 24.8) 24.9] 25.0] 25.9} 51.6] 47.8] 47.9] 47.9} 47.9| 47.7] 47.8 47.9
22.9) 23.0) 23.1 23.1 28. 1 23.0 | 23.8] 49.8 | 46.3] 46.6] 46.9) 46.9] 46.9] 46.9 46.4
44.2 | 44.2] 44.6] 44.1 44.2| 44.3] 44.0] 60.9] 60.7} 60.6] 60.5] 60.6] 60.7] 60.8 60.9
44.0) 44.0] 44.0] 44.0] 44.0] 44.0] 44.0] 59.1 57.4 57.7} 57.9 | 57.9] 58.0] 58.1 58.5
41.8) 41.8) 41.8] 41.9] 42.0) 41.6] 42.0] 55.0} 53.2] 53.2] 53.1 53.0] 53.0) 53.0 52.9
43.9 | 44.0] 43.9] 44.0] 44.0] 43.9] 46.7] 56.9] 56.7] 56.5] 56.7| 56.5] 56.6] 56.8 56.8
45.1 45.1 45.2 | 45.0} 45.1 45.0 | 45.0] 47.0} 47.0] 47.2] 47.3] 47.3] 47.1 47.3 47.4
31.4] 31.6] 32.0] 32.0) 31.9] 32.0] 32.1 44.8 | 42.7] 42.8] 42.9] 42.9] 42.9] 43.2 43.3
30.8] 31.1 31.6] 31.5) 31.6) 31.8) 32.0] 46.0! 42.0] 42.1 42.0 | 41.9] 41.7] 41.8 41.7
36.1 36.3 | 36.7 36.8 | 37.0) 36.9) 37.6] 52.1 47.8 | 48.0] 48.1 48.0 | 48.0] 49.2 49.3
42.0) 42.3) 42.2] 42.1 42.0] 42.0) 42.8] 56.2] 53.9) 54.1 54.4] 54.2] 54.3] 54.4 55.0
46787) 485801" 46 09h 46-81 (46.180 0 4624419 4674 lees ae |e ere | eee | Sea | eee | eesotme| Gado sen) acts =
39.2] 39.3) 39.5] 39.4] 39.5 | 39.4] 39.9 48.7] 46.7] 46.8] 46.9| 46.9) 46.9] 46.9 47.1

@ Means for twenty days.
Highest and lowest readings are in italics.

71

TaBLeE 14.—MinimuM TEMPERATURES IN OPEN AT ALL ELEVATIONS AT STATION 9, OVER SANDY LOAM ON THE
Upianp, Maruer, Wis., 1907—Continued.

July. August.
Day of month. te Sl peaeee|
Sur- 24 5 7k 10 12 15 36 Sur- 2h 5 7k 10 12 15 36
face. |inches.|inches.|inches.|inches.|inches./inches.|inches.| face. inches. inches. |inches.|inches.|inches.|inches.|inches.
° ° ° ° ° ° ° ° ° ° ° ° ° ° °

57.8 | 57.8) 57.9] 57.7] 57.9 57.9 | 58.0] 54.0] 52.8) 52.8] 52.9| 52.6) 52.7] 52.7 52.8

88.7 | 83.9) 342) 34.5) 34.7) 84.8] 85.0] 43.9] 43.8| 43.9] 44.0] 44.0] 44.0] 44.1 44.1

44.8) 45.0] 45.2) 45.2] 45.3] 45.5] 45.9] 46.7] 46.5] 46.5] 46.7] 46.6] 46.6] 46.7 46.8

49.8) 49.5) 49.8] 49.5] 49.6] 49.7] 49.3) 387] 387.2) 87.7 7.6 Gali Yara) GG 87.2

59.1} 60.0] 60.5] 60.3] 60.7] 60.8] 59.4] 59.0] 58.2) 58.2] 58.1 58.0} 58.2] 58.6 58.3

57.4 | 57.3) 57.5 | 57.3] 57.4] 57.5) 57.4] 52:9] 51.0] 51.3] 51.5 51.5} 51.8] 52.0 51.6

49.2| 49.0] 49.0) 48.9] 48.9] 49.0] 48.9] 55.0] 55.0) 55.1 55. 2 55.1 55.4 | 55.6 56.0

56.0) 56.2] 56.5) 56.4] 56.5] 56.7] 57.1 55.2 | 53.6} 53.8] 54.0] 53.7 |) 54.0] 53.8 53.6

59.7 | 59.9] 60.0} 59.8} 60.0} 60.0] 60.0] 52.1 6250))- 51-9))| 51.9') 51.8) )| 51.7 | 51.7 51.6

48.0] 47.6) 47.5 | 47.3] 47.2] 47.4] 47.1 53. 1 51.9'] 52.0) 51.9] 5.7) 51.7) 51.8 51.8

60.1 | 60.1 60.1 | 60.1 60.1 | 60.2} 60.0] 71.1 TLCO WN ROs9s | 7LAOM las || adeaon | ncdtno: 72.0

46.8 | 47.0} 47.3) 47.4] 47.5 | 47.8] 48.9] 50.0] 49.0] 49.0] 49.1] 49.1 49.3 | 49.2 49.6

49.1 | 49.4] 49.5 49.7} 49.8) 49.9] 50.1 48.4 47.4 | 47.5] 47.6 | 47.5) 47.5] 47.5 47.5

59.9 60.0 60.1 60.2} 60.3; 60.5) 60.9] 51.0) 50.2] 50.4; 50.8 | 50.6] 50.9 |+ 50.9 50.8

68.0 | 68.0| 68.0| 67.9| 68.0| 68.0) 68.8| 54.2| 53.8] 54.0] 54.4 | 54.1 54.5 | 54.4 | 54.6

50. 5 50.4, 50.2 50.1 50.0 50.1 50.0 62.0 61.0 61.3 61.2 61.2 61.3 61.4 | 61.2

53.8 | 53.9 | 54.2) 540) 541] 54.2] 54.6 49.9} 48.9 | 49.0] 49.4] 49.2] 49.5] 49.5 | 49.7

49.0 | 49.0) 49.0] 48.8] 48.9] 48.8] 48.7] 54.8) 540] 54.2] 544] 544] 54.5] 54.9 54.0

55.0 | 55.1 55.1 55.0] 55.2] 54.0) 54.0] 65.1 64.8 | 65.0] 64.9] 647] 64.8] 65.0 64.1

58.8 | 58.9] 59.1 59.0} 59.0] 59.2) 59.5] 42.0} 40.6] 40.8] 41.8] 41.0] 41.0] 40.9 41.2

64.0 64.0 63.7 63.5 62.8 63.6 63.0 45.2 44.5 44.7 44.8 44.6 44.7 44.6 44.5

62.9 | 63.0 | 63.0) 63.0] 63.0] 63.3 63.4 | 41.6 | 40.7 | 40.8} 41.0] 40.9] 40.9 | 40.7 40.8

49.7 49.9} 50.0] 50.1 50. 3 50.5) 50.6 | 52.0] 51.9] 52.4] 52.8] 52.4] 52.6) 52.6 52.7

62.8} 63.1 63.4 | 63.4] 63.7] 63.8 | 64.1 49.5 | 49.9) 50.0] 50.0] 50.7] 50.2 | 50.8 51.9

51.6 51.6 51.5 51.4 51.5 51.5 51.3 44.0 43.8 44.2 44.3 44.3 44.5 44.5 44.7

47.5| 47.8 | 47.8 7.7 | 47.8) 47.9] 48.0] 51.7 | 48.7 | 49.0] 49.1 49.0} 49.1 49.1 49.1

43.3 | 43.4) 43.2 | 43.1 43.1 43.1 43.0] 58.0} 57.0| 57.0} 57.2] 56.7] 57.0] 57.0 56.5

56.8 | 56.9 7.1 57.1 57.0} 57.4 57.9 | 55.6 | 54.7) 54.9] 55.1 55.0] 55.2] 55.2 55. 4

54.9.) 55.0} 55.2] 55.0] 55.2] 55.3) 55.9] 51.7] 50.5] 50.5| 50.4] 50.4] 50.5] 50.2 50.1

49.8} 49.9] 50.0} 49.9] 50.0] 50.1 50.4 | 64.0) 63.7] 63.8] 63.8] 63.7] 63.9] 63.8 63.7

55.4 | 55.7] 56.0] 55.8] 56.0] 56.0] 56.3] 57.4| 56.4 | 56.7] 57.0] 57.0] 57.2] 57.1 57.2
(MeanSwes-nc--cecl es 55.0) 53.7 | 53.8) 53.9] 53.8) 53.9 | 54.0] 541 52.6 | 51.8] 51.9 52.0] 51:9 | 52.1 51.8 52.1

’ ' i

Highest and lowest readings are in italics.

72

Taste 14.—Mriyimum TEMPERATURES IN OPEN AT ALL ELEVATIONS AT SratTion 9, OVER Sanpy LOAM ON THE
Urnanp, Marner, Wis., 1907—Continued.

ee

September. October.
Day of month. ee ee ee ee aa
; Sur- 2h 5 7k 10 12 15 36 Sur- 2h 5 7 10 12 15 36

face. jtaches. inches: inches. inches. inches. inches.inches.) face. inches. inches. inches.|inches.|inches. anes
66.7 | 66.7 | 66.7) 67.0 7.0) 67.2| 33.8) 32.2] 32.3| 32.4| 32.4] 32.2] 32.4 32.1
51.4 | 51.6] 51.6| 51.6] 51.7) 51.7) 49.6 | 49.6 | 60.0, 60.3 | 60.3 | 50.5} 650.7 61.4 .
48.9 | 49.0] 48.9) 49.1 49.0 | 49.0) 44.4 | 43.5 | 43.6 43.6) 43.6] 43.5 | 43.7 43.4
52.0 | 52.2 | 51.8) 52.1] 52.0] 51.9] 37.7] 38.3] 38.4) 38.6] 38.6] 38.6] 38.6 38.9
43.6| 43.6| 43.5 | 43.5 | 43.5] 43.5 | 38.0) 38.7] 39.0] 39.3| 39.4] 39.4] 39.3 39.6
39.4 | 39.4) 39.4) 39.4] 39.2] 39.1 | 42.1 | 41.6] 41.8/ 42.3] 42.4] 42.5] 42.8 43.6
55.6| 55.7| 55.5| 55:7| 55.6] 53.5| 46.1 | 45.0] 45.3) 45.5] 45.5] 45.6] 45.6 45.7
56.7| 56.7] 56.7) 566] 56.6| 56.5 | 22.5 | 20.0} 19.8] 19.8] 19.7] 19.7] 19.6 19.5
38.4} 38.5 | 38.4) 38.3) 38.3 | 38. 4 | 36.4 37.2 | 37:5 | 37.7] 37.7] 37.9} 38.0 38.5
36.8 | 36.9 | 36.7) 36.7] 36.7] 36.5) 31.6| 31.2] 31.5| 31.7] 31.8] 31.8] 31.9 32.0
45.4| 45.5 | 45.5! 45.5] 45.5) 45.5) 33.0] 33.6] 33.7] 33.8] 33.8] 33.8] 33.9] 34.0
44.8 | 44.9 | 45.0 | 45.0 | 45.0 45.4 | 27.4 | 28.0] 28.0] 28.4] 28.3 | 28.2] 28.2 28.4
46.3 | 46.4 | 46.3} 46.5] 46.4) 46.4) 21.5] 21.6] 21.6] 21.6] 21.6] 21.8] 21.7 21.7
57.4 | 57.2 | 57.5 57.9 | 58.1 57.3 | 21.7 18.8 | 18.9 19.3} 19.3 19.3} 19.3| 19.3

57.5 | 57.2| 57.6| 57.9 42.8] 42.8
64.8 | 64.8] 64.7] 65.0| 65.0] 65.0] 36.4] 35.5 | 35.5] 35.5| 35.5] 35.4] 35.5] 35.0
50.4] 50.5| 50.4/ 50.5] 50.4 | 50.1) 344] 33.8 | 34.4) 34.6
57.7 | 87.8| 57.6| 57.6| 57.7| 57.3] 23.2] 23.0| 23.0] 23.2) 23.1| 23.0] 23.0) 23.0

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KS
a
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59.9 | 60.0 | 59.7) 60.3) 60.2) 60.1 | 23.8 | 22.7 | 23.0) 23.6 | 23.6 | 23.6 | 23.6 23.7
58.6 | 58.8] 58.7 | 58.3) 58.6) 58.8) 25.4] 25.7 | 25.8) 26.1| 26.0} 26.1) 26.0 26.1
35.3) 35.5) 34.6 35.5 | 35.5 | 35.6] 18.4] 15.6] 15.6) 16.2) 16.2) 16.2) 16.2 15.8
27.8 | 28.1 | 28.3) 28.0] 28.2] 28.6| 34.4] 31.9] 35.7] 363] 36.4] 36.4) 36.7 37.3
42.4 | 42.5 | 42.5 | 42.5) 42.6) 42.6] 26.6] 26.5] 26.6| 26.8] 26.8] 26.8) 26.9 27.0

42.4| 42.4| 42.38] 42.4] 42.6] 41.5! 23.4] 23.0] 23.2] 23.3] 23.3] 23.4] 23.5 24.0
26.3 | 26.4] 26.4| 26.4) 26.5) 26.5] 24.6] 25.3) 25.3] 25.5] 25.5] 25.5) 25.6 25.7
29.3 | 29.4) 29.3 | 14.7, 14.6

|
| |
31.6 | 31.6) 31.4 | 31.6 | 31.5) 31.4] 32.6] 32.8} 33.2] 33.4] 33.3] 33.3] 33.4) 33.1
|
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38.2 | 38.2) 38.0] 15.2) 13.5) 13.6) 13.8) 13.8) 13.8) 14.0 14.1
28.6) 28.5) 28.3] 29.9] 28.8] 29.0} 29.0] 29.1] 29.1] 29.0 28.9
25.1 | 25.2) 25.4] 36.7] 36.6] 36.7) 36.7 | 36.6] 36.4/| 36.6 36.1

pectonallsenoses Jrcecces|eeetec [eer ees|eeee ee 33.9 | 34.0] 34.3] 34.3] 34.4] 34.4 34.5 |

45.3} 45.4 | 45.3 | 45.4 | 45.4 | 45.3 | 31.1] 30.5] 30.8] 31.0 | 31.0} 31.0} 31.0 31.1

| | 1

34.7

TaBLE 14a.—MonTHLY AND SEASONAL MEANS OF MinimuM TEMPERATURES IN OPEN AT ALL ELEVATIONS, STATION 9,
Maruer, Wis., 1907.

May.a June. July. August. Se em October. | Means.
BGULACCe Reece eo ee tere eee eran ee Bo etne et eso a Ber 39.9 48.7 55.0 62.6 45.6 81.1 45.5
Dain CH eget ses ese eee sae ts Se re ot eae rae es 39.2 46.7 53.7 61.8 45.2 30.5 445
Sinches =... = ces sence ss sae e =e) 39.3 46.8 53.8 51.9 45.3 30.8 44.6
7} inches 39.5 46.9 53.9 52.0 45.4 31.0 44.8
10 inches 39.4 46.9 53.8 51.9 45.3 31.0 44.7
12 inches 39.5 46.9 53.9 52.1 45.4 31.0 44.8
15 inches 39.4 46.9 54.0 51.8 45.4 31.0 44.8
O6\inches =o. soos kee de Seat sae een eee seat cee ae ee eee ce | 39.9 | 47.1 54.1 52.1 45.3 31.1 44.9

@ Means for twenty days.
Highest and lowest readings are in italics.

73

Comparison of wind movement over upland and marsh, and effect on temperature, Mather,
Wis., 1907.—Not as much variation in temperature occurred at Station 9 as at Station 2,
because the former was on the upland where there was more breeze, which mixed the air at different
elevations. On clear, cool, quiet nights the cold air settles gradually through gravity toward
the surface of the earth, but if the night is windy, the air at different elevations is mixed together
so that the temperature of the air over a considerable area is nearly uniform. The greatest
difference locally is on a clear night when a calm prevails, so that there is no interference with
the gradual settling of the cold, heavy air to the surface.

Of course the velocity of the wind is least near the surface of the earth, due to friction,
and the velocity increases with the elevation. Anemometers placed on the upland and
on the bog at Mather show that the variation, even for a slight elevation, is quite
decided. (See Tables 15 and 15a.) The anemometer on the upland was located on the
cupola of the warehouse, 32 feet 7 inches above the ground and 45 feet 10 inches above
the level of the instrument on the marsh. (Fig. 16.) The mean hourly velocity of the wind
on the upland for the five months, June to October, inclusive, was 9 miles, while on the marsh
it was just half that amount, 4.5 miles. This proportion, moreover, was maintained for the
various months. The highest average hourly movement for both exposures was from 12 to 1
p- m., it being 13.7 miles on the upland and 7.9 miles on the bog. The lowest average for any
one hour was 6.3 miles on the upland between 2 a. m. and 3 a. m., while on the lowland the
lowest was 2.3 miles, this occurring between 9 p. m. and 10 p. m., and also from midnight to
4a.m. For some reason the average on the lowland was slightly higher between 10 p. m. and
midnight, while on the upland there was a gradual decrease every hour from the maximum at
1 p. m. to the minimum at 3 a.m. The lowest hourly average movement in the individual
months occurred in only one hour in each case. As a rule there was a falling off of the wind
after the hour of greatest heat, the movement declining more rapidly in proportion over the
bog than on the upland. Frequently at night an absolute calm prevailed on the bog.

On several mornings when there was a moderate to fresh wind velocity there was usually
a difference of less than 2° between the extremes of the various thermometers at Station 2 on
the bog. On August 19, when a fair breeze prevailed, this difference was only 0.6°. There
were, on the other hand, many instances of nights of either light wind or of no wind, when a
great variation occurred in the readings of the thermometers at different elevations, as on May
30, June 30, July 7 and 13, and October 14, the range at Station 2 being from 4° to 5°. When
the wind over the bog was light or calm during the night, the variation in temperature was
invariably greater than the average, and when there was a breeze at night the variation was less.

Because of the greater movement of the air with increased elevation, the temperature
of the air over the upland did not vary as much as on the bog. While there was an average
extreme difference of 3.1° between all the readings at Station 2 on the bog for the season, this
difference at Station 9 on the upland amounted to only 1°. (Tables 13a and 14a.)

74

Taste 15.—Averace Hourty Winp VeLociry on UpLanp AND MarsH, MarHeEr, WIs., sue

June. July. August. September. Gone Means.
Hour of day. == = ] =
ey “ars. ee Marsh. ee Marsh. else Marsh. es, Marsh. ‘Ups Marsh.
|
—_— | | = ee
eb 6 tote SaaS Eee Stee eeencooSar | 64 1.9 6.2 1.8 5.9 2.0 7.3 2.9 7.0 2.8 6.4 2.3
BOW emteas sees be Sod akasitds teeceenel 6.5 | 1.9 5.5 1.8 6.7 2.0 7.7 3.1 eal 2.8 6.5 2.3
Biawmeeesees sy. . ees Se Cee eee eee s| PORTE me T AS 5.2) 1.9 6.1 2.0 71 2.7 (pal 3.0 6.3 2.3
4da.m...-. Sea anew cringe aag7 00S 6.2 | 1.9 5.5 | 1.7 5.7 1.9 7.6 Spi 7.5 2.8 6.5 2.8
Sa he Been Bee Sepa me merrce soe asso ae 6.6 | 2.1 5.6 | 1.9 6.7 23 8.1 3.6 7.5 3.2 6.7 2.6
(ica 6 ee eee Sa RE Page aap eerce 6.7 | 2.9 5.4 2.5 5.9 2.6 8.1 3.7 7.4 3.1 6.7 3.0
NK SEIN ees a ese oe ee ieee 7.8 | 4.0 6.0 3.4 1.2 3.5 8.1 3.9 7.4 BEG] 7.3 3.6
Siagvam’. 2452-2 5. 0a cee eee ence eee ees 10.1 5.3 7.1 4.0 8.1 4.6 9.1 5.0 8.8 4.3 8.6 4.6
Qfavm so... 6-8 od one Soe enon 10.8 6.1 7.3 4.7 10.0 5.8 10.8 6.0 11.3 6.1 10.0 5.5
DU it eer See ee ele th Se em | 11.9 6.4 9.2 5.5 11.4 6.6 12.9 7.1 13.0 7.4 11.3 6.6
VO. Wore) 2 ee ee os ee 2 12.5 6.9 10.1 6.0 12.0 6.9 14. 2 8.3 13.1 7.6 12.4 Tod
12 noon. 5 hen See ee ae CER eee 13.1 {al 10.4 6.4 12.5 7.5 14.6 8.6 13.4 8.0 12.8 Tea
TE at 0 eSecria StS eC bc SUSE eer San emee.c. Whe 12.9 7.2 bea 6.7 14.0 8.2 15.8 8.7 14.7 8.7 13.7 7.9
SAND AEN eee te ered he alee ein teeta 13.4 7.3 11.4 6.8 13.3 7.9 14.8 8.5 13.6 8.1 13.5 ed,
SD Me a woes a satin Dea eee Speen 13.0 7.0 11.8 7.0 12.9 7.5 14.3 8.1 13.9 8.1 13e2) 7.5
CTD Pate MoS ahr Seri stouegeam eda. sade 12.8 7.0 11.5 6.9 13.1 7.6 13.2 725 13.5 7.5 12.8 T3
SPH ese eaait osteoma 12.3 6.5 11.2 6.3 11.6 6.7 11.2 6.4 11.1 6.1 11.5 6.4
10.3 | 6.5: 9.4 | 5.3 9.5 5.3 8.5 4.5 8.3 3.7 9.2 5.9
8.2 3.9 6.9 3.4 8.0 3.5 7.3 3.0 7.9 ely 7.7 3.4
6.8 23 5.3 1.9 6.9 2.9 7.5 3.1 Matt: 3. 1 6.8 2.7
6.6 | 2.1 5.5 1.6 6.6 2.3 7.8 3.2 Tort 3.1 6.8 2.5
6.7 | 2.0 5.9 1.9 6.3 2.0 7.5 2.8 7.7 3.0 6.8 2.3
UU Ps) 238 ev faqs eee shee Base ecceaee 6.9 2.3 5.9 2.2 6.3 PER} 7.6 3.2 6.9 2.8 6.7 2.6
AZ midnight 5-8-2) coos ee ae oer 6.7 Ze 5.8 2.2 6.3 223 | 7.7 3.0 Wo 2.6 6.7 2.4
PSN hoe oot SEOs oboe ie OR | 92| 43] m7/ sal o8s] al) “o.0)|) soi] Wauell eiesh| aco) ieee
| | | |

Anemometer on warehouse (upland), 32 feet 7 inches above ground.
Anemometer on marsh, 4 feet 7 inches above ground (Station 4).

Anemometer on warehouse, 50 feet 5 inches above surface of marsh at Station 4.
Difference between elevations of anemometers, 45 feet 10 inches.

TasBLe 15a.—AveraGe VELOCITY OF THE WIND, BY MonTHS, ON MARSH AND UPLAND, TOGETHER WITH AVERAGE
: ror Frve Montus, Martuer, Wis., 1907.

| | ]
| June. | July. August. Se pen October. | Means.
| |
shett LE _ {a ey |
‘= : }
Uplandse et tater ie aie Sa See Ae Oe ecard SS el A RCT 9.2 7.7 8.8 9.9 9.6 | 9.0
Marsh 2so-c0> =e Pochasitehe esas 28s smortysiscexetossstcs Faroe Beas 4.3 3.9 | 4.4 5.0 4.8 | 4.5

Highest and lowest readings are in italics.

As has been said before, the air over the bog was often light and even calm on clear, cool
nights. When the breeze freshened, the temperature invariably rose near the surface of the
bog, although it might at the same time fall on the upland. At Station 5, under such conditions,
on July 27, 1906, at Mather, Wis., following a fall in temperature, a rise of 9° occurred between
2.45 a. m. and 3.45 a. m., while during a portion of that period the temperature at Station 1
fell 4°, followed by a rise of the same amount. When the breeze subsided after 4 a. m., the
temperature fell again both on the upland and the moorland. With the freshening of the
wind, the air over the moorland at different elevations evidently became mixed together and
a rise in temperature was the result. Over the upland, 15 feet higher, although a fall in tem-
perature occurred with the first freshening of the wind, the temperature began to rise later, after
the breeze had continued for an hour, and the air at different strata for a considerable eleva-
tion had become mixed together. (Figure 23 shows the thermograph traces and the wind
velocity on both upland and lowland.) :

a

STATION |

STATION S

Fic. 23.—Mather, Wis.

Thermograph and anemometer records on July 27, 1906,
illustrating marked effect of wind on temperature on bog
as compared with that on upland.

While at night the effect of the wind on the temperature is often apparent, it is even more
pronounced when some clouds at the same time pass over the moorland. Passing clouds
arrest the fall in temperature, and sometimes even cause the temperature to rise. A
breeze, of course, usually attends the movement of clouds over a bog. Thermograph traces
showing these irregularities are quite interesting. Such a condition is illustrated by Figure 24,
noon to noon, August 30-September 1, 1906, Berlin, Wis., showing the trace of a thermograph

located on the bog.

AUGUST — SEPTEMBER
30th. 31 St. St.
noon mdt. noon mdt. noon

Reng e
Fy

| Lr
tt : “Ant

222 ‘= === ———— SSuc=4ee= ==e==
2222 Zeuce === ==S5====S========
Fic. 24.—Berlin, Wis.

Thermograph record in the marsh. From noon, September 30, to noon, October 1, 1906.
The trace shows the effect of passing clouds upon the temperature, both day and night.

76

Ordinarily a breeze does not cause such a change in temperature on the upland asyon the
moorland. As the cold air settles over the moorland close to the surface on clear, cool nights,
a slight freshening of the wind brings warmer air from above, raising the temperature near the
surface. This effect, however, can not always be noticed on the upland. The fall in tempera-
ture in the shelter on the upland may be steady through the night until the coldest pot has
been reached, while at the same time the thermograph trace of the instrument placed on the
bog may show considerable irregularity. Such a condition was noted during the night of
September 4—5, 1906, Berlin, Wis., when the wind during the evening up till 11 o’clock was
“puffy.” (Fig. 25.)

Exposed minimum thermometers over peat and sanded bogs at the surface, and at elevations
of 5 inches and 36 inches, Berlin, Wis.—Because the locations of Stations 2 and 9 at Mather
were unlike, not only as regards the character of the soil and its covermg, but also as regards
elevation, the exposed temperatures between similar heights above the ground are not com-

R parable. If both stations had been located on the
oe PreEMes 5th bog, a true comparison might be made between
Ps on mdt noon the temperatures of the two stations at several elev: -

n : tions. In the case of Stations 2 and 9 the differ-

70) gs 0 ence in elevation is probably as important a factor
(JE F as the difference in the character of the soil.

SS 22> : In order to supplement Tables 13 and 14, Table

E f 7 16 has been prepared from daily mmimum readings .

7G = = made at Berlin, Wis., during September, 1906, from

: 7 Instruments exposed at the surface, 5 inches and

== ~ 36 inches above the surface, at Stations 2 and 3,

sae i : peat and sanded bogs, respectively, about 100 feet
apart and on the same level. Both locations were
comparatively clean, the portion of the bog in which
they were located having been weeded in the spring
of that year. On account of the clean surfaces
the temperatures were naturally much higher than
: where the vegetation was dense. Another station,
- : 5, that was maintained at Berlin, and to which refer-
—o ence has been made, was much colder than Station
+ - 2, but a thermometer at an elevation of 36 inches
= was not included in the equipment of that station.
: ~ The temperature at both Stations 2 and 3 aver-
IN VINES Tse. aged lowest at the 5-inch height, 47° and 48.6°,
IN SH Se ary = ie respectively. The temperature was highest at the
Traces of thermograph in shelter on upland and in SUTface, 50.6° and 53.6°, while at the height of 36
vines on marsh, noon, September 4 to noon,September 5, inches there were intermediate values, 48.7° and
1906. Uncorrected readings. The trace of instrument ‘
exposed in the vines is irregular, caused by variation in 49° respectively. The temperature each day was
wind anovenlent: almost invariably lowest at both locations at the
5-inch height, as has been previously shown, and likewise almost invariably highest at the surface.
While in the sanded bog the surface thermometer registered on an average 5° higher
than the one at 5 inches, in the peat bog the difference was 3.6°. Moreover, the surface
thermometer in the sanded bog registered 4.6° higher than the one at 36 inches, while in the
peat bog the difference between the thermometers similarly placed was but 1.9°. At both
locations it was warmer at the surface than at the elevation of even 36 inches. This would
naturally be expected over the sanded surface. As stated above, the peat soil at Station 2
was comparatively warm, that portion of the bog having been thoroughly weeded at the
beginning of the season. The peat was, of course, colder than the sanded section, and it was
for this reason that at Station 2 the difference between the readings at 36 inches and the surface
was less than at Station 3 in the sanded section.

li
+44
HH

i

Ut

For similar positions at Stations 2 and 3 the average difference was greatest between the
surface thermometers, 3°; at the 5-inch height the average difference was 1.6°, while at the
height of 36 inches the average difference was only 0.3°. Large differences usually prevailed
at the surface, while at 36 inches there was but a single instance of a difference of 1.5° or more,
that being 1.6° on September 30, when the temperature was comparatively low. Sometimes
the temperature over the peat at the greater elevation was slightly higher than over the sanded
surface, and occasionally on days when the difference between the readings of the surface
thermometers were marked, as on September 1, 3, 4, and 14, there was but very little difference
at the height of 36 inches. These differences in minimum temperature should be considered
as entirely due to differences in the character of the soil, as the vegetation and moisture at the
stations were practically the same.

The surface of the peat at Station 3 was sanded, especially for the work of this investigation;
and while the sand served to raise the night minimums at the surface and a few inches above,
it is apparent that its influence was practically lost at an elevation of 3 feet. Ordinarily it
should be expected that the differences between the thermometers at two stations at the same
heights would decrease with increase of elevation, but this fact can not be demonstrated unless
the stations are comparatively close together and all conditions favorable. At Mather,
where the stations were far apart, the problem was more complicated.

TasBLE 16.—MinimuM TEMPERATURES IN OPEN AT SURFACE, 5 INCHES ABOVE AND 3 FEET ABOVE THE SURFACE,
AT Srations 2 aND 3, OveR PEAT AND SAND, RESPECTIVELY, TOGETHER WITH DirrFERENCES BETWEEN THE
Reapines, BERLIN, Wis., SEPTEMBER, 1906.

Station 2. Station 3. | Differences. DAR SrenCES oa
Day of month. A Tiane ma | ; ees hie Tae
Surface. |. 5 3 feet. |Surface. 7 3 feet Seiad Vesueae aud Srieeand Seren Surface 5 3 feet
‘| inches. : "| inches. | * “| 5inches. | 3 feet. 5 inches. 3 feet. ‘| inches. |“ °°"
| |
41.6 45.5 51.5 45.5 45.8 —2.6 | +1.3 | —6.0 —5.7 —7.3 —3.9 —0.3
59.3 59. 0 58. 2 59.0 59. 2 +0.9 +0.6 +0.8 +1.0| +0.2|) +0.3 —0.2
39.5 43.2 52.0 43.5 43.5 5.4 | 1.7 8.5 | —8.5 —7.1 —4.0 —0.3
38.9 41.0 51.0 41.5 41.9 4.1 2.0 9.5 | —9.1 —8.0 —2.6 —0.9
33.1 34.8 45.0 35.9 35.9 —5.3 | —3.6 =9)1 | —9.1 —6.6 | —2.8 —1.1
40.8 42.0 52.0 42.9 42.5 —5.4 —4.2 —9.1 —9.5 —5.8 —2.1 —0.5
47.6 51.2 55. 0 50.0 51.0 —3.2 +0.4 —5.0 | —4.0 —4.2 —2.4 | +0.2
50.0 52.4 56.8 52.7 52.3 3.6 | 1:2 4.1 —4.5 —3.2 —2.7 +0.1
52.4] 54.5] 50.2| 549| 54.6 =4.8 | i =4.3 =5|| <2) a5 |) ais
57.4 59. 4 64.5 60.0 60.0 4.6 2.6 4.5 —4.5 —2.5 —2.6 —0.6
64.0| 65.2] 66.0) 64.6| 65.6 =e 40.1 = =|) =a) |) =e! Sa
57.4 59. 0 63.9 59.5 59. 6 —4.7 —3.1 —4.4 —4.3 —1.8 —2.1 —0.6
53.0. 53.2 53.9 52.8 52.9 1.6 1.4 1.1 —1.0 +0.7 +0.2 +0.3
33.0 34.7 43.9 35.0 35.1 2.6 0.9 8.9 —8.8 —8.3 —2.0 —0.4
44.5 46.6 48.1 44.7 46.9 —1.0 +1.1 —3. —1.2 —2.6 —0.2 —0.3
54.9| 56.1] 56.0| 55.4] 56.0 1.5 | 0.3 0. 0.0; +04) —05| +01
57.3| 58.5] 623! 59.0] 58.4 2.3 | jit 3.3 =|) =2y|| =|) <an,ii
57.6 60.0 64.0 60. 0 60.5 —4.0 | 1.6 4.0 Sho) 2.4 2.4 0.5
58.0 58.6 60. 0 58. 1 58. 4 1.6 | 1.0 | 1.9 —1.6 —0.4 —0.1 +0. 2
58.0 57.8 60.0 58.0 58.7 0.9 iloak| 2.0 —1.3 —1.1 0.0 —0.9
51.4 55.0 60. 0 54.3 55.3 —§.2 2.6 5.7 4.7 —2.4 —2.9 —0.3
47.0 48.5 55.1 48.5 48.3 7.0 5.5 6.6 —6.8 —1.1 —1.5 +0.2
43.8 45.5 50. 4 45.0 45.6 4.7 | 3.0 | 5.4 4.8 1.9 —1.2 —0.1
32.5 33. 4 41.0 34.0 33.5 3.2 | 2.3 | 7.0 7.5 —5.3 =155 al
38.7 40.6 45.0 40.0 40.8 8.9 7.0 | 5.0 —4.2 +2.6 —1.3 —0.2
52.8 55.1 54.8 53. 4 55.1 —0.5 +1.8 —L4 +0.3 —1.5 —0.6 0.0
31.0] 30.4} 40.3| 308] sos 2.9 3.5 | 9.5 —10.0| —6.4| 40.2] +0.1
31.9 35.7 43.0 35.7 36.1 —7.9 4.1 | 7.3 | 6.9 3.2 —3.8 —0.4
53. 6 53.5 54.3 53.5 53.0 1.2 | 1.3 |} 0.8 | 1.3 +0.5 +0.1 +0.5
28.8) 31.4| 39.6] 31.0] 33.0| 5.2 | 2.6 | 8.6 =965) 286) Ra =i
47.0 48.7 53.6 48.6 49.0 —3.6 | 159 —5.0 | —4.6 | —3.0 | —1.6 —0.3
i ! | | |

Highest and lowest readings are in italies.

78

Maximum and minimum temperatures at different elevations, Station 9, Mather, Wis. —It
having been shown in the discussion of Table 3 that the readings of the exposed Maximums
and minimums located at the surface varied with increasing and decreasing vegetation, it
seemed advisable to show the changes in maximum as well as minimum temperature at a single
station at different elevations above the surface. Table 17 contains a summary of the maximum
temperature readings at Station 9 on the upland from May to September, inclusive, 1907, at
the surface, 5 inches and 36 inches above the surface. The exposed minimums at these eleva-
tions are also given and are the same readings that appear in Table 14. The minimum read-
ings, however, in this particular case are not of much importance.

There was a steady fall in. maximum temperature, with increasing elevation for all the
months, it being much higher at the surface than at the elevation of 36 inches. The average
maximum for the season at the surface was 84.1°; at 5 inches, 79.8°; and at 36 inches, 76.2°.
The greatest differences occurred in June and July. On several days the difference exceeded
15°, the greatest difference between the surface and 36 inches being 18.6° on July 20, when
the surface reading was 109.3°, and that at 36 inches 90.7°. While these readings do not
represent the air temperature any more than the exposed minimums do, they indicate approxi-
mately the degree of heat which affects the vegetation at different elevations. The changes,
as a rule, are more abrupt between the surface and 5 inches than between 5 inches and 36 inches.
The exposed maximums at the surface registered higher on an average because the surface of
any solid upon which the sun shines becomes hotter than the air above, the air being heated
slightly by radiation and conduction, and largely by convection. All the time while the sun
is shining the air resting upon the surface is warmer than the air above, the exposed maximums
naturally registering lower with increasing elevation. On cloudy days there was but little
difference between the readings of the various thermometers. (For state of weather see
Table 22.) The range between the exposed maximum and minimum temperatures was almost
always greater at the surface than at the other positions, this difference also decreasing with
increase of elevation.

TABLE 17.—MonTHLY AND SEASONAL MEANS or MaximMuM AND MinimuM TEMPERATURES IN THE OPEN aT
DirrERENT ELEVATIONS, STATION 9, MATHER, Wis., 1907.

May.a June. July. Aug. Sept. Means.
Surface: “4 5 | ° ¥ ° 2

Maxinittm 5° 92 cost aon tae esac k asc s ann ante nae Deen or eee en ere 69. 2 89.4 | 93.7 87.4 80.8 84.1
I Ota Fe Fela sot enn Seco Nan Ree ato Se He aero ae SHOR DESCD DOMSeE Rea Ca aae 40.0 48.7 | 55.0 52.6 45.6 48.4
Ranges eee le ELS, . ee Ae eet eel 29.2 40.7 38.7 34.8 35.2 35.7

5 inches: |
Maximum’. Sete ee a Soo eo Sas oe cece eae See ee chee aE ee eee 65.8 84.4 | 5 $4.3 75.9 79.8
Minimum = 45. son Ae a Soe Sencha a oe Shee Dea oe Pee 39.4 46.7 | 53.8 51.9 45.3 47.4

— i)

|
RENE G reSe s)— — Sp ee ee ee re or ee P| 26.4 37.7 | 34.7 32.4 30.6 32.4

36 inches:
Maximum. <-- 2-1-4 ER ee Fe ey ie ney Aenea Ey mead ao ee 63.3 80.7 84.1 80.3 72.6 76. 2
Minimum? eee oes SEE aie oe Se Ane AAP coeiie ea: SSA SSCA 40.1 47.1 | 541 52.1 45.3 | 47.7
RAMBO ioe. Shoe sceee see sees isda gees “ SR Baieice eae ee ee 23. 2 33.6 30.0 28.2 27.3 | 28.5

|

a Means for nineteen days.

Average minimum temperatures for the season of 1907 for all locations, together with soil
temperatures, Mather, Wis.—Table 18, giving the average minimum temperature for all expo-
sures on the marsh at Mather for the season of 1907, together with the average departure
from the minimum temperature in the shelter at Station 1, will supplement data already given.
There may, at times, seem to be a discrepancy between the averages in some of the tables.
On this account the footnotes should in every case be carefully read. Records of some instru-
ments are available for the entire season at Mather from May 1, but in most instances the

‘

f(s:

record began on May 12. There were, however, interruptions at some stations on May 27 and
28, on account of reflowing the bog in anticipation of frost. Reflowing also affected the readings
at other times during the season.

The principal feature of interest in Table 18 will be found in the monthly and seasonal
departures of the various readings from those in the shelter at Station 1. We can see here at
a glance the points of lowest and highest temperature, assuming, of course, that the temperature
in the shelter of Station 1 is the standard. Of the minimums in shelters, those at Stations 2
and 5 were the lowest, averaging lower than Station 1 by 3.4° and 3.1°, respectively. The
next lowest, as should be expected, was at Station 7, the average difference being 2.4°. This
station was in the scalped piece, in the midst of an extensive field of sphagnum moss. The
average differences for the remaining stations were as follows: Station 6, old sanded and
heavily vined, 1.9°; Station 4, newly sanded and heavily vined, 1°; Station 9, sandy loam on
the upland, 0.6°; and Station 3, newly sanded and thinly vined, 0.5°. The influence of
sanding, draining, and cultivating is well illustrated by these figures. There is usually an
interesting relation between these average shelter readings, on one hand, and the maximum
soil temperature and the range in soil temperature at the 3-inch depth on the other. Station
7 is the only important exception, and this is because, although the soil temperature was
relatively high in this small bare section, the air temperature was affected by the surrounding
field of sphagnum moss.

The average shelter reading at Station 9 on the upland was 0.1° lower than that at Station
3, the warmest place on the bog, and the thermometers exposed in the open at the surface at
both these stations averaged also within 0.1° of each other, the one at Station 9 being 0.1°
higher than the one at Station 3. As has been stated before, the coldest point on the bog was
at an elevation of 5 inches at Station 5, where the average was 6.7° below that in the shelter
at Station 1, while the thermometer at 5 inches at Station 2 averaged 6.6° below. The greatest
average monthly departure was also at the 5-inch height at Station 5, where the radiation was
freer than at the surface, the October minimum averaging 8.3° lower than the one in the shelter
at Station 1, and an extreme difference of 14.6° was recorded on October 24. The greatest
differences between the exposed minimums and the minimum in the shelter at Station 1 as a
rule occured in October, when radiation was greatest, because of the long, cool nights.

The seasonal averages of 40.2° and 40.1° at Stations 2 and 5, respectively, are so close
that either might be selected as the coldest point. Sometimes in this bulletin the one at Station
2 has been used, and at other times the one at Station 5, according as the one or the other better
answered the purpose. Station 2, over sphagnum moss, was located outside the cranberry
marsh proper, and was ordinarily not affected by reflowing of the marsh; while Station 5 was in
the cranberry bog, but in an uncultivated section, representing the average conditions prevailing
in an old bog, without improvement in the way of draining, sanding, and cultivating, just as
Station 3 shows approximately the best results prevalent in the Wisconsin bogs. Here, then,
are wide differences between the readings of 34 different thermometers in various portions of
the bog and a neighboring ‘‘island.’’ There are, of course, reasons for these variations, the
readings being affected by the character of the soil and vegetation surrounding each instrument,
and often by the height of the imstrument above the soil.

As previously stated, while sanding, up to a certain point, is of highest importance in
preventing low night temperatures, the character of the soil is of little consequence after frost
has entered it. This is evident because the differences between the minimum temperatures
are not nearly so great in the month of October as in the warmer months. The temperatures
over the sanded surfaces, as compared with the shelter readings at Station 1, are by far the
lowest in October. At Station 3, for instance, the average departure at the surface for October
was 4.5°, while the average for the entire season was but 1.3°, and in the month of July the
average was but 0.1°. At Station 4 the minimum thermometer similarly located averaged
5.7° lower than the shelter at Station 1 for October, while the average departure for the season
was but 3.7°. These facts are in strong contrast with the conditions prevailing at Station 5,

51936°—Bull. T—10-—6

80

over peat and moss, where the minimum thermometer at the surface in October averaged 5.3°
lower than in the shelter at Station 1, which was only 0.2° greater than the average d@parture
for the entire season, 5.1°. The greatest monthly departure at Station 5 was 5.8° in July, at
the time it was least at Station 3. Although the temperature at the surface at Station 3 in
October was relatively low, it was, nevertheless, not as low as at the other stations in the bog.
This may or may not show that the sanded surface, after frost has entered it, has greater power
for warding off lower temperature than the peat and moss soil. It may be that after frost
enters the soil the capacity for heat does not vary with the character of the soil, and that
rather the difference in minimum temperature over two such surfaces depends then upon the
character of the vegetation, and that in this instance in October the surface thermometer at
Station 3 averaged higher than the surface at Station 5 only because Station 3 was thinly
vined as compared with the relatively dense vegetation at Station 5.

As explained in previous paragraphs of this bulletin, the temperature at and near the
surface of the bog is governed largely by the character of the soil and its covering. That this
is true may be shown by a comparison of the minimum temperature readings with the soil
temperature readings, especially at the depth of 3 inches. Table 19 gives the average monthly
and the seasonal readings of soil thermometers placed at depths of 3 and 6 inches at the various
stations. This table is the summary of extensive data which, for lack of space, it was found
impracticable to print. By comparing Tables 18 and 19 it will be found that the exposed
minimum temperatures at the surface at the various stations, as a rule, averaged highest where
the 6 p. m. or maximum soil temperatures at the 3-inch depth were the greatest, and also where
the range in soil temperature at the 3-inch depth was the greatest. Station 7-in the scalped
piece is an exception to this rule, for reasons already given. In other words, the highest mini-
mums occurred at places where the soil was heated considerably in the daytime, while at places
where the soil temperature varied little on account of dense vegetation and lack of sanding
and draining, the exposed minimum thermometers registered the lowest. The range in soil
temperature at the 3-inch depth was naturally much greater than at the depth of 6 inches, and
where the covering was exceptionally dense there was practically no range in soil temperature
at the latter depth, as at Stations 2 and 5. It is evident, by referring to Figures 20 and 22,
and to the soil temperature figures at the 3-inch and 6-inch depths in Table 19, that the clean
soil during the daytime is not only heated considerably near the surface in the thinly vined
and bare sections, but also that the heat descends to a greater depth, and it is because of this
heat stored in the ground that the air above does not become as cold at night. The greater
conduction of heat by the sanded soil at Station 3 and the sandy loam at Station 9 than by
the plain peat at Station 7 is partially shown by the soil temperature readings at these stations,
although a considerable portion of the heat received at Station 7 was expended in the evapo-

ration of the superfluous moisture. The average daily ranges at Station 7 at the depths of 3
9 5

and 6 inches were, respectively, 5.1° and 1.4°, while at Stations 3 and 9 the ranges were, respec-
tively, 8.2° and 4°, and 10.1° and 7.7°.

ase

TasLe 18.—MonrHty AND SEASONAL MEANS OF ALL Minimum THER

81

or Sration 1, Marner, Wis., 1907.

MOMETERS, WITH DEPARTURES FROM MEAN

May.a June. July. August. September. October.
| ne a | =z Sea- Bea
Month-| Month-| Month-| Month- Month-| Month-| Month-) Month-| Month-| Month-| Month-| Month-| S°D2l cee
ly ly de- ly ly de- ly |lyde| ly ly de- ly ly de- ly | ly de eS eres
mean ear ae mean. parture.| mean. BEEEES mean. [PEGERS mean. |parture.| mean. /parture
Ea is : : ; Sails ve : : ¢ : : ? | f g :
Shelterisesss- s2o-c- sane pA (| Ee eae 4020) Soeean =~ PEG Peaeeee Boe 0) [eee eee UTM lon seeeoe Ech eee QGI8)|- cece
Station 2 (moss over peat): | | | | | |
‘Shelter: -=----.---4- 38.9 | —2.8 45.4| —3.6 51.8) —3.8 50.1} —3.8 44.3 | —2.8 30.0 | —3.3 43.4 —3.4
SHOACE* oe enn 37.6 —4.1 43.3 —5.7 52.0 —3.6 49.4) —4.5 41.9 —5.2 27.5| —5.8 41.9 —4.9
2p inch eso eee = $7.0 | —4.7 42.2 —6.8 49.2 —6.4 ne) Os. 40.8 —6.3 26.0} —7.3 40.4 —6.4
Chega an eee 37.2) —4.5 42.3 —6.7 |; 49.2 —6.4 7.1 —6.8 40.4 —6.7 25.2 —8.1 40.2 —6.6
fp SAE NES eee BOS er 37.4 —4.3 42.5 —6.5 49.2 —6.4 47.5 —6.4 41.3 —5.8 26.5 —6.8 40.7 —6.1
LGamches=-s-2-- == Ss 37.7 —4.0 42.7 —6.3 49.4 —6.2 47.3 —6.6 41.4 —5.7 26.8 —6.5 40.9 —5.9
12s CHESS eae eee 87.0 —4.7 42.7 —6.3 49.6 —6.0 7.5 —6.4 41.7 —5.4 27.1 —6.2 40.9 —5.9
Poin CHES tee ists =/<toln 37.3 —4.4 43.5 —5.5 50.1 —5.5 47.8 —6.1 41.8 —5.3 27.0 —6.3 41.2 —5.6
SbaNnGheSs==-esenee esse 39.2 —2.5 45.4] —3.6 52.1 —3.5 50.4 —3.5 43.8 —3.3 28.9 —4.4 43.3 —3.5
Station 3 (newly sanded, |
thinly vined): |
Sheltemmece esac 41.4) —0.3 48.9) —0.1 55.6 0.0 53.8; —0.1 | 46.7 —0.4 31.6 —1.7 46.3 —0.6
Surfaces. 225225. -sc5-- 40. 4 -1.3 48.8 —0.2 55.5 —0.1 53.7 —0.2 45.9 —1.2 28.8 —4.5 45.5 -1.3
INCHES cae sea ee 39.3 —2.4 46.3 —2.7 53.0 —2.6 51.2 —2.7 44.6 —2.5 28.5 —4.8 43.8 —3.0
BONTCR ES Ue Sean as 39.2 —2.5 45.9 —3.1 51.7 —3.9 48.3 | —5.6 42.7 —4.4 29.2) —4.1 42.8 —4.0
Station 4 (newly sanded, |
heavily vined): |
Shelter: --2-4--.+---—- 41.2) —0.5 48.4] —0.6 54.9) —0.7 53.1 | —0.8 46.3 | —0.8 31.2] —2.1 45.8 —1.0
Snriacebere se esce enn 38.4) —3.3 45.2] —4.0 52.3) —3.3 50.6 | —3.3 44.2) —2.9 27.6 —5.7 43.1 —3.7
DaANCHeS ee so aw 38.8] —2.9 45.7 | —3.3 52.4) —3.2 50.6 | —3.3 44.1) —3.0 27.4 —5.9 43.2 —3.6
Station 5 (peat and moss,
heavily vined): |
Shelton sceeeste= ss 39.7] —2.0 45.7 | —3.3 53.1) —2.5 50.3 | —3.6 44.1 | —3.0 29.2, —4.1 43.7 —3.1
Baca sss eevee ey 37.1) —4.6 43.5] —5.5 49.8) —5.8 48.8 | —5.1 43.0} —4.1 28.0) —5.3 41.7 —5.1
buinche@ee = oe). 37.2} —4.5 41.8] —7.2 48.8 | —6.8 47.1) —6.8 40.7) —6.4 25.0 | —8.3 40.1 —6.7
Station 6 (old sanded,
heavily vined): |
Shelters. 2-- 25. <2. 40.4 | —1.3 47.0} —2.0 53.8 | —1.8 52.1} —1.8 45.3 | —1.8 30.8) 2.5 44.9 —1.9
SIMACe Nee Jonas se amis = 38.7 | —3.0 44.0| —5.0 50.3 | —5.3 49.3 | —4.6 43.1 | —4.0 28.3. —5.0 42.3 —4.5
DMN CheS ser case osee 38.0) —3.7 43.2) —5.8 49.6 | —6.0 48.3 | —5.6 41.7 | —5.4 26.1) —7.2 41.2 —5.6
Station 7 (scalped peat): | |
Shelternwe cas. aca 39.9] —1.8 46.3 | —2.7 53.0 2.6 51.6 —2.3 45.0 —2.1 30.8 —2.5 44.4 —2.4
Surlace® seers esos sc 37.6 | —4.1 44.0) —5.0 51.2} —4.4 49.2) —4.7 42.3| —4.8 27.9) —5.4 42.0 —4.8
I AYICH Se see ae een 37.6} —4.1 43.0} —6.0| 50.2) —5.4 r 49.0 —4.9 42.6) —4.5 27.7| —5.6| 41.7 —5.1
Station 9 (sandy loam): ] |
Shelters. ee -s- =~ 41.2| —0.5 48.4 —0.6 55.4) —0.2 | 53.4 —0.5 46.5 | —0.8 32.3 —1.0 46.2 —0.6
{Site OCC ig ee eee ee 40.9} —0.8 48.7 | —0.3 55.0] —0.6) 52.6) —1.3 45.6 —15 31.1 —2.2 45.6 —1.2
2h inches:22- <2... --=-- 40.1} —1.6 46.7 —2.3 53.7| —1.9 BS) oa 45.2|- —1.9| 30.5) —2.8 44.7 —2.1
SING RCS san see eee 40.1 —1.6 46.8| —2.2 53.8 —1.8; 51.9 —2.0 45.3, —1.8| 30.8 —2.5 44.8 —2.0
*eiluches>. 45 S225 5255 - 40.4) —1.3 46.9 —2.1 53.9 —1.7 52.0 —-19} 45.4 —1.7 31.0 —2.3 44.9 —1.9
LOWnCh ese n e 40.3. —1.4 46.9 —2.1 53.8 —1.8 51.9 —2.0 45.3 —1.8 31.0 —2.3 | 44.9 -1.9
Winches... ..----===2: 40.3 —1.4 46.9 —2.1 53.9 —1.7 52.1 —-1.8 45.4 —1.7 31.0 —2.3, 44.9 —1.9
Lotinches*=-455< 202 26 | 40.3 | —1.4 46.9 —2.1 54.0 —1.6 51.8 —2.1 45.4 -1.7 31.0} —2.3| 449 —1.9
26 inches... ..-- = 40.8 —0.9 47.1 54.1 —1.5 52.1 —-1.8 45.3 —-1.8 31.1 —2.2 45.1 —1.7

Stations 1 and 9 on upland; others on bog.

—1.9

@ Mean for eighteen days.

Highest and lowest readings are in italics.

One thermometer in shelter at each station; others exposed in open.

82

TasLe 19.—MonTHLY AND SEASONAL Means or Som THERMOMETER READINGS AT 3 INCH AND 6 INcH DeEpTH,
Maruer, Wis., 1907. »

[The 6 p. m. readings occurred the previous day, and “ Difference” shows the change during the night.]

fe et ae is |
May.e June. July. August. pen len October. | Means.
Station 2: |
3-inch depth— i. in || x ei a 5 2
Bae ese cic FEI: Tee calle Leese cee aay eee eee 39.6 56.0. 65.0 62.3 57.3 46.0 54.4 :
Treen ke oe eee I ae Ey ee, eee Te 37.5 53.0 62.6 61.2 56.5 | 45.4 52.7
Differences!) ~ =f enc. usaceke aoe meee aan eae eae ae eee je eon 3.0 2.4 11 0.8 0.6 iss
6-inch depth— ‘ | hea | | |
ipo 1 Bee Rela ieee’ Aen res CRIA RAE tics PARE eS Leet 2d 2% 34.8 52.8 | 63.2 62.2 58.3 | 48.2 53.3
Ties, lesa eet ead Mere Resi Pe Lee eel t ORY eee a Be 34.7 53.2 63.4 62.3 58.2 | 48.1 53.3
WM ifference- .c- fes en Sere citer een sw eR ee ee oe eee — 0.1 + 0.4 + 0.2 + 0.1 — 0.1 — 0.1) 0.0
Station 3: >
3-inch depth—
55.8 65.8 71.8 68.6 } 49.6 62.6
48.0 56.9 63.1 61.4 55.3 41.9 544
I iflaran ce ee. ae, een ee eee ens een eee eee SE Si —s 889i) —a8ar ||) arr) een | ear =P
6-inch depth— ian |
(if ofa Vg ES Reto oe se nee Uc eae a Re aaron avs Gn olor eSee 53.6 62 68.3 65.7 61.0. 47.9 59.8
CP She Tid Sen ce ee i a os Se ees, en once Senne 50.0 57.5 63.7 62.1 or 44.4 55.8
WOE es Per Pe ae ae ee se eo RR ee ee ee eee 3.6 4.6 4.6 3.6 — 3.9 — 3.5 — 4.0
Station 4: ci
3-inch depth— |
(inh hs 2d Sader Sec epin ae staat eee cee AEE sri see Ban 50.3 60.3 66.9 64.6 59.3 | 46.6 58.0
Fees TO sere seat eke ae dye as ee Se) ee 47.5 56.5 63.2 61.5 56.5 | 44.0 54.9
DWifkerencesso3c Siero paces eke ena a ee aoe ee eee ya eee — 2.8 — 3.8 — 3.7 — 3.1 — 2.8 — 2.6 — 3.1
6-inch depth— ig j ar.
ig e)es cee pe aR Ae a ee Geno een eee Sopra Spt 47.7 57.1 64.2 62.9 58.5 46.5 56.2
7a.m.. 47.6 56.5 63.5 62.3 57.8 | 46.0 55.6
DSK Cee cee ee Mee aan Sec hal Oa ece a BAe RE 4 Sea) S08) “sa7)] =o6) =o07! =f — 0.6
| —
Station 5: b i
38-inch depth—
Gio Nn Set see a sta ne, Oe acto nee ciae ears eee ee seme ee 48.5 5 66.2 64.0 57.2 45.9 56.6
OF RU tas ae ce tee as SI cee aes Oe ae RRR ENE 47.5 55. 6 63.6 62.1 56.5 | 45.5 55.1
aD {erence est Be. vot ee eee sens erent ee Eee eee a SONY 3G SG) Sie || SO res
6-inch depth— ri = |
yp Ans eees face so sc ce ag SNe eR pr _- p e 47.1 | 54.8 63.7 62.3 56.7 46.7 55.2
UL ht ise WRN ie Aenea Rae SOE ce eet nam ee nee der ee amen | 47. 55.0 63.5 62.2 56.9 46.6 55.2
= I | — =
IDV GEMS io ocean ogo ge seen soem Shen ses sae beeeeo cade see Sta + 0.2 | = (|| =O = (0D) = Thi 0.0 .
Station 6: | {
3-inch depth— | |
ia Seay area RS Oe SO ge er te ee 49.4 59.1 65.9 63.6 58.5 46.6 | 57.2
TACO tin Pee 2 Sanat RGN ee ee ee ae NS 47.3| %6.3| 63.4 61.4 56.3 44.6 54.9
Difference: Asses esse toc cafe. meses ee ero te Se eee ene — 2.1 — 2.8 — 2.5 — 2.2 — 2.2 — 2.0 — 2.3
6-inch depth— am ‘| |
Game .c ioc ssn RO MeL en, eh ae ORD 46.8| 56.4) 63.2 6230} baum 47.1 55.6
DGB Se Ne aR a Ar rite SOrineinA” ABATE EERE of shit ane c oaeS 46.9 66.0] 62.9 61.9} 57.7 46.8 55.4
| t __| # == |
LOT ONS ee onan ice Sabeseb aoc enon a tnactnceeaneke ch oaeH +01) — 0.3) 0.3 0.4 | 0.4 0.3 — 0.2

@ Means for seventeen days.

» On August 10 and 12 a light covering of moss was placed around and between soil thermometers at Station 5. On August 25,at Station 3
position of box on which soil thermograph rested was changed so as to allow more sunshine around soil thermometers during morning hours. On
August 24, at Station 5 positions of soil thermographs were changed and placed under proper conditions of live moss and vines.

Station 2. Sphagnum moss. Station 5. Peat with moss, heavily vined.
Station 3. Newly sanded, thinly vined. Station 6. Old sanded, heavily vined.
Station 4. Newly sanded, heavily vined.

Highest and lowest readings are in italics.

83

Taste 19.—Montuty AND SEASONAL Means oF Sor, THERMOMETER READINGS AT 3 IncH AND 6 INCH DEPTH,
MarHer, Wis., 1907—Continued.

| |
May. June. July. | August. | P°PTeM | Ootoher.| Means.
Station 7:
3-inch depth— | ° ° ° ° 7 +
(Hobe se ane: BS stan Se OSB eS PRR ER AB DS a5 Sk RRS SeB eS Moet | 49.5 61.9 68.8 66.9 61.4 48. 6 59.5
TA tin ade Se goers Sea: SEI heap atk a A RN 45.9 56.2 63. 4 62.0-| 5516 | 43:6 54.4
Mi ferericceest eee Renee Se ar ee ee ee 3.6 5.7 5.4 4.9 | 5.8 | 5.0 Fal
6-ineh depth— |
(jon Wl ate Se cE ads apoae screestaneropbsasanaaee sean sesce teen | 45.1 58. 7 66.1 65.1 59. 3. 7st 56.9
Tinto Cae ech a oe Pa a RR ag? 23 ae ee See 44.9 56.9 64.4 63.5 | 57.7 45.8 | 55.5
D) I GLEN GE Seas Pry oe rae es ee icin teu NTIOR see camer son 0.2 1.8 17 | 1.6 —16} —13 lea
Station 9: | | |
3-inch depth—
eV Oh Wedh-w mise SR Sn DSS ane watitn Space Semen Os: Bosesie sa soSuer ae 56.8 69.1 fay 70.9 63.5 | 53.0 64.8
|
(Cg nies ange: nS BSE BECOE BDO REE REC Aa Rot oe aie 7.2 | 58. 0 64 61.4 54.8 | 42.7 54.7
Dene Wicecee tee eerie Aen reel ea pee een ae ee 9.6 | 11.1 11.2 9.5 | 8.7 | 10.3 10.1
|
6-inch depth—
GPSS MMS ee we alge mts mm = wlan oni ww im = minimal lela wicini mnie = 55. 67.9 74.4 70.8 63.0 52.0 63.9
The OLN te eee eas eee eee es Sa Se na ares Sense eeese tastes = 48.6 58.9 65.3 62.8 | 56. 6 | 44.7 56.2
Ip oranicasseee ees essere ey tr ta Seed Pane ae pos As 6.7 9.0 9.1 8.0 6.4 | 7.3 | 7.7
i}
Station 7. Scalped piece, bare peat, in a field of sphagnum moss. Station 9. Sandy loam on upland.

Highest and lowest readings are in italies.

That the range in soil temperature was much greater at Station 3 than at Station 5, and
at the 3-inch depth than at the depth of 6 inches at both stations, is shown graphically by
Figure 20, previously referred to, which gives the hourly traces from soil thermographs for the
season of 1907 at each station. Figures 21 and 22, which have already been discussed, bear
directly upon this question of air and soil temperatures. While the maximum at 3 inches
occurred at both stations from 4 to 6 p. m., and the minimum from 6 to 7 a. m., the maximum
and the minimum at 6 inches at Station 3 occurred a few hours later, and at the 6-inch depth
at Station 5 the maximum occurred from 8 to 9 a. m. and the minimum about 5 p.m. The
curve at Station 3 at the 3-inch depth is, of course, abrupt as compared with the curves at the
other exposures.

Figure 19, also previously referred to, shows the curve of the soil thermograph records at
Stations 3, 4, and 5 for the week of September 23-30, inclusive, 1906. The great range in
temperature in the thinly vined and newly sanded section as compared with that in the peat
bog with moss is apparent, while the one exposed in the heavily vined and newly sanded sec-
tion has an intermediate value. The changes in soil temperature at Station 3 are again shown
to be abrupt as compared with those at the other stations, the minimum being below as much
as the maximum was above. Of course, the location at Station 3 was responsive to changes in
air temperature, while the changes where the vegetation was dense lagged behind and were
relatively slight.

A soil thermograph was located in the reservoir so as to secure a continuous record of water
temperature 12 inches below the surface, while an air thermograph was placed in a shelter
over the bog 5 inches above the surface. In Figure 26 are shown the curves of these two
instruments, and also the curve of the soil thermograph over a peat and moss bog, for the week
of September 23-30, inclusive, 1906. Here we have an interesting illustration of the daily
variation in temperature in three elements—air, earth, and water—within a comparatively
small area.

84

In Figure 27 the curves of air temperature, water temperature, and soil tempegature for
the week of September 16-23, inclusive, 1906, are illustrated. It is interesting to note the
lagging of the changes in temperature of the soil and water behind those of the air.

Relation between dew-point and minimum temperature-—A dry atmosphere permits freer
radiation of heat from the ground than moist air. Moist air absorbs part of the heat radiated
from the ground, and consequently does not permit as low temperatures as when the air is dry.
The marsh region of Wisconsin, however, is almost always humid at night, but remarkably low
temperatures, nevertheless, occur in spite of these humid conditions. It may be that under
such conditions the air some little distance above the bog is relatively dry and permits rapid
radiation through it.

It has long been supposed that a relation exists between the dew-point and the ensuing
minimum air temperature, and that, if the dew-point at the time of observation in the evening
was higher than 32°, frost should not be expected that night. It was believed that, the dew-
point having been reached, latent heat would be given off in the operation of condensation
and prevent any further fall in temperature. This is a plausible theory, and many cranberry

1%, ’
i 28 29, 30
= + 3 =
=F = z
+ $ ze
2 =
—+ + = =: +
a === : E =
: :
== == 2==5
= = SETS

Fic. 26.—Temperature curves of air, soil and water for Mather, Wis., September 23 to 30,1906. Air temperature in shelter over bog

; temperature of water in reservoir 12” below surface, —x—x—x—x—x—x—x—x; soil temperature 3/’ deep in peat bog with
Moss -==-----—----_-__-_.
y PWS #¢ § § XM? eM 4 MD OM 46 6 ME FS 60 1 5 Z b We 9 ¢/
6 aie BSS SS 70 7 F120 27 5 22S
4 = é = Sa = E = = Z = z
=i = = = =
ana —— ————— z : ==: =Sesaee

= =====

Fic. 27.—Temperature curves of air, soil and water for Stations 3 and 5, Mather, Wis., September 16 to 23,1906. Air temperature, station
5, in shelter, ; soil temperature, station 5, 3 in. deep, —x—x—x—x—x—x—x; soil temperature, station 3, 3 in. deep
temperature of water in reservoir, 12 in. below surface ------

growers have confidence in it, but the observations made on the bogs show that the dew-point
itself is no indication whatever of the ensuing minimum temperature.

The dew-point observations were made at Mather with the Assman aspiration psychrom-
eter exposed on the upland about 4 feet above the ground at Station 1 and on the bog about 1
foot above the ground at Station 4. During the season of 1907 the dew-point on the upland
was generally lower at 9 p. m. than at 6 p. m., the average difference for the season being 1.9°.
(Tables 20 and 20a.) However, the ensuing minimum temperature in the shelter at Station 1
was almost invariably lower than the 9 p. m. dew-point reading, the average depression for
the season being 3.3°.

The latest dew-point observation made daily at Station 4 was at 6 p.m. On account of
the larger amount of moisture prevalent on the bog, the dew-point was naturally higher there
than on the upland, there being an average difference between the 6 p. m. readings of 1.5°.
The average of the dew-point readings for the season of 1907 at Station 4 was 7.6° higher than
the mean of the ensuing minimum air temperatures in the shelter at the same station on the
bog, as compared with an average difference of 8.2°, noted in the season of 1906. Moreover,
at Station 4 the minimum in the open averaged 2.6° lower than in the shelter. (Table 1.) The

85

average temperature at one of the coldest points on the bog in the open—the 5-inch height at
Station 2—-was 13.7° below the average of the dew-point readings at Station 4 during the
season of 1907. On some nights the temperature in the shelter at Station 4 was 18° to 20°
lower than the dew-point. On one night, September 29-30, it was 28° lower, and this in spite
of the fact that the relative humidity on the bog early the previous evening was as high as 94
per cent. The temperature in the open at Station 2 was often as much as 25° lower, and on
September 30 it was 30° lower. In a few cases the ensuing minimum temperatures were higher,
as for instance on June 3 and 10, July 11, August 31, and October 9 and 15, when the weather was
cloudy. During cloudy weather the dew-point and the minimum temperature at Station 4
were often the same. According to these observations the formation of dew and fog has no
appreciable effect in preventing the fall of the minimum temperature to a low point, such a fog
often lying in a thin stratum over the marsh; in fact, the greatest departures often occurred on
nights of dew and fog when the sky above was clear. Of course, latent heat is given off in the
process of condensation, but the amount is obviously small as compared with the vast area of
cold air overlying the moorland. Table 22 should be used in connection with Table 20 for pur-
poses of comparison regarding fog and dew.

It is apparent then from the above that in the moorlands the dew-point in the evening
is no indication of the ensuing minimum temperature. Naturally if the air were drier, the tem-
perature would fall to a lower point, but the air is usually humid in the bogs, as stated above.
The vapor in the air is so great that ordinarily on clear cool nights dew forms even at sunset.
In spite of the fact that the air may be saturated with moisture, the temperature frequently
continues to fall steadily through the night, demonstrating that the latent heat given off in
condensation has but little effect in retarding the fall in temperature. The thermograph traces
of the instruments exposed in the open often show a steady decline in temperature on nights
of dew and fog when the sky is clear.

86

TasLe 20.—CompParison oF Dew-PoINT READINGS ON THE UPLAND AT 6 AND 9 P. M., with ENsuING. Minium
TEMPERATURES IN THE SHELTER; ALSO OF DEW-PoINT READINGS ON THE MARSH aT 6 P. M., WITH ENSUING
Minimum TEMPERATURES, AND DIFFERENCES AT STATION 4; ALSO ENsuinG Minruum TEMPERATURES IN OPEN,
AND DIFFERENCES AT STaTION 2, MaTHeER, Wis., 1907.

[Dew-point readings occurred the previous day-]

June. July. August.
—— | :
letod 1 shelter Marsh fon eeahetien Hees Eeoreas tates Marsh.
= = = —e = ———— j | —

Day | | od Station 4— | Station 2— Me | Stati Station 2— | _ Spe Station 2—
mem | | pom, | shelter. | 23pehes, | point, | | sheter, | Sieber, | point “shelter, | Sinehes

ON t= 0 P= Ps es (ea =e =e = West pees steers Pct |=) CS) (a0 Ps esa

PRU hl en ap) Vee te EI | = Foye eared Wace tal ert t ci eed lec & Pad Mint Wosbee SH WS Ui tel |

elealalol/a|/Ala | a oS |e 2 o/l/a/l/AlslaAa A os |S alo|/a/Ala A
Ta reeie 34] 83| 36] 34) 35/+1| 28| —6| 64) 62] 59) 62) S8|—4] 52) —10) 57) 58] 55| 62) 58/9} 47) —15
essecee 40| 41| 39] 43| 36|-7| 29) —14) 83} 40] $8} 53] 97/16) 29| —24) 82/ 47) 46| 49) 45|—4) 39| —10
eae ae 46| 49| 55] 48) 55|+7| 53) +5) 50) 60) 48) S51} 47|- 4] 38) —13| 52) 53] 48) 54) 47\—7] 40) —14
gira sa 52] 50] 41| 51| 42/—9) 35) —16| 67| 61) 51) 65] 51\—14| 45) —20| 49) 48) 39] 54) 43|—11| 34) —20
Se oeee 44| 45] 44] 42) 44/+ 2) 38) —4] 66] 65] 60) 66| G1/—5| 59| —7)| 54) 61] 59) 56) 59|+ 3] 58| +2
Geweeres 36| 40| s4| 39| 36/—3) 28) —l1| 70| 68| 58) 70| 58|—12| 53| —17| 57| 56] 54) 59) 52\/—7]| 46] —13
Tees eae | 45] 45] 48] 48) 48) 0) 45| — 3] 56) 54| 51| 60) 51|-9]} 43) —I17| 70] 63) 57) 71| 56|—15| 48) —23
Blapeeee | 38] 39] 36| 42) s5|—7) 28) —14| 69] 67| 59| 67| 55|—-12| 47| —20| 58257] 55) 62| 56/—-6) 51) —11
Disease 39| 39! 41 42) 40|— 2 | 32| —10) 62| 63) 61| 63) 60|— 3) 51) —12| 59) 59| 54| 60) 54\-6} 49/ —I1
noe sear 47| 43| 54| 46] 55|+ 9} 53} +7] 57| 56] 50| 59] 50/—9]| 42| —17| 70| 69] 59| 69! 60\—9/ 55] —14
TEE Soe 60| 57| 47] 61| 46|-15| 39| —22| 59| 60| 60| 59| 61|+ 2| 6o| +17| 71] 70| 7%} 72| 70\—2| 7| —2
54| 50] 53] 54] 53 |—1 50 | — 4) 60} 60] 51) 60) 48/—12| 42) —18) 56| 42| 53 57| 49|—8| 40| —17
51| 50| 44] 54] 42|-12| 34] —20] 60| 59] 54| 61) 52/—9]| 44) —17| 56| 57] 50) 58 49\-9| 42] —16
46| 48| 39] 50) 40/-10| 31| —19| 62] 59| 62| 62| 62] 0| 56) —6| 58| 50) 53) 59| 53\-6]| 46) —13
5L| 53] 43] 60| 41|—19) 35) —25| 69| 67] 68| 68) 68} 0} 68| 0 | 64| 60| 56| 64, 56|-8| 50] —14
56| 54] 54] 56| 53|-3 46) —10| 64| 60| 51) 66) 52/-14| 46| —20| 66) 64| 61| 66) 62\—4] 58) —8
70| 68) 70) 70) 69/—1) 68| —7| 70} 67) 57) 70) S2}—18) 45 | —25 | 60| 52) 52) 54 50\—-4] 43) —1
64| 65| 59] 67! 57|-10| 50) —17| 56) 59] 50) 63| 50/13] 44) —19/ 60] 60] 57| 59) 54/—5|/ 48) —I
64| 56] 57] 64} 56|/—8]| 47) —17/} 62] 62] 56] 64] 57|—7]| 52] —12) 67] 66] 65| 68| 65/—3| 65] —3
56) 55| 51| 61| 50|—11] 42| —19] 67| 65] 61] 66] 59|—7] 50| —16| 54] 51| 45| 52| 42|-10| 34] —18
58| 55| 49] 60! 49|-11| 41| —19| 62| 67| 64| 69| 65|—4] 60; —9] 47| 43! 47| 49, 48\—1]| 36] —13
64] 62] 61} 64| 62|— 2) 50 | —5| 68) 66| 64] 68} 63\|—5]| 57) —l1] 53} 50) 43 41/12} 34] —19
67| 65| 60] 67| 60/—7| 54| —13| G1| 59) 53) 63] 52/11) 49° —14 56| 53) 54] 55| 54\—1| 47] —8
63| 64| 54] 65| 55|-10! 50| —15| 67| 65! 64] 67| 64|—3! 59; —8| 67| 61! 54) 67| 51/16! 41| —26
66] 61| 58) 69| 57|-12| 53) —16 60] 64] 53| 64] 54|-10/ 50° —14| 52| 48) 48) 52) 43-9) 33| —19
4g| 52| 48] 51| 48\/—3| 41] —10| 64] 62| 49] 65| 48|-17| 42, —23| 52] 49] 51] 58| 50\— 8) 42] —16
49| 53| 45| 54| 43|-11| 35] —19| 68| 50] 45| 60] 46|-14| 41 —19| 57| 55| 56| 56| 56] 0| 56 0
ps ee ceed 56| 54| 43] 61] 44|-17| 37| —24|) 59| G1] 59| 60| 59/—1] 55| —5]/ 63) 62} 58| 64| 56!-8| 50) —14
DOR eres 58| 56/ 51] 59] 50|—9]| 43] —16| 59] 58/ 57| 60| 56|/—4) 48 —12/ 64| 56] 51| 63] 51 |—12| 44] —19
30S-ee oe) 64] 62] 58| 65| 56/—9| 49) —16| 53] 53] 53] 56] 50|—6| 45 —11| 64| 64) 64] 64) 64) 0} 62; —2
EVs aryl (eee ese lee eae oe ve ee a bass Seecoar 66 | 62) 58) 66 55 |-11 | 48 —18| 67| 61) 58 54 | 58+ 4 52) —2
Means.| 52.9) 52.1) 49.1) 54.9) 48.6|—6.3) 42.3 —12.6 62.3) 60.7| 55.6) 63.0 54.9|—8.1| 49.0 —14.0) 59.1 56.3) 54.0) 59.4) 53.1\—6.3 tae

' ! i

Highest and lowest readings are in italies.

—— ee

87

TABLE 20.—Comparison oF Drw-PoINT READINGS ON THE UPLAND AT 6 AND 9 P. M., with EnsuinGc Minimum
TEMPERATURES IN THE SHELTER; ALSO OF DEw-POINT READINGS ON THE MARSH AT 6 P. M., WITH ENSUING
Minrmum TEMPERATURES AND DIFFERENCES AT STATION 4; ALSO ENSUING MINIMUM TEMPERATURES IN OPEN,
AND DIFFERENCES AT StTaTIon 2, MatHER, Wis., 1907—Continued.

September. October.
ee ee 1— ETE. Upland Seton 1— | Merah

Day of month. H Station 2— | | Station 2—

Dew-point. | Station 4—shelter. 5 inches, Dew-point. | Station 4—shelter. 5 inches,

Mini- | exposed. Mini: | exposed.
mum. ; af 7 me = q ra aes 4] ; eal ie ~
6p.m.|9p.m. Soe rrr heneesl Mini- | Difler-| 6p, m.|9p.m.| sa ridin, Wenesal eames tapes
4 val 70 6 (|) 5 61} —15 | 40) 35] 33) 39 33 | —6 7 =i
61 55 53| 61 i!) =) 42) —19| 50] 61) 52] 52) 68 0 45 ary
48 50 50 54 ry eae 40) —14 54 | 46 46| 54| 43| —11 36 Sil
54 52 52 56 3) —3 45) S11 ear ei etree o 47) 10 |e 29
52 49 44 57 44] —13 Sool 41 44) 4 Sr] 7 | io
53 52 41 56 41) —15 36) PR 50 44 44 49 aN 7 34 =15
57 55| 54 56 a) Son ets ee 51 50 55 44 11 37 —18
i cetant ea 58 5g)|) 56 58 56 | — 2 Ge) ae) 44 32 23 44 22;| —g2 16 —28
QUEeaes eke 8 aoe oc. 49 50; 40 52 40| —12 Bi) ey) 7 41 40 32 40| +8 | 33 tom
LORE ee ce ee 49 43! 38 48 42) —6 30 18 43 38 35) 43 |) S|) | aa
51 47| 45 53 45) —8 a7 16 29 30)| 35). 42 ca ae) al, ls
54 52 48) 59 43 | —16 By) ee 30 36 29 30 | 29) —1 23 =
TEI a ia 59 571 50.| 61 47'| —14 40) —21 31 22 25 32| 22) —10 16 | —16
Tey eee eee: Sa ' 61 58| 62 66} 60; —6 i) 3h) 28 26 22 Gi 20) "6 16 —10
[ote ea ees eee 64 59 63 64 60) —4 54) 10 38 so! 44 36) 44) 4:8 39 +3
1G ee ee | 63 66 67! 73 66| —7 64| —9| 44 42| 36 39 36| —3 29 —10
i (aati anne aneee | 63 58 53 67 52| —15 44) 93 52 44 39 50 33 | —17 27 —23
Tp aeseelaes sere AST Baile Meztieessy) east te Sei] — Si) P56] 7 46) 24) 24 Bai 2 12 ee ds =18
66 61 61| —9 58 —12 20| 26 27 26 22| —4 18 —8
5 59 | —12 Br | —14 33/135 28 36 2719) 22 14
38 | —16 30) —24 29 25 19 28 18} —10} 43)/ —15
35) | -—-1 Oey)! =i} 34} 33] 40 41 36/ —5| 31 —10
44) —6| 37) =13| 48] 27 | 30} 45) 26] —19| 22) —23
fey) su) ay) rey) a | 29 | 26) ees) —2ieleedsi i) 28
25) —15 20 | ° —20 29 31 28 | 35 25) —10 17 =18
35| —7 25| —17 23 a} 19 29 18| —l1 12 —17
Sail|, —=16)|io7!|) =23'| ea2| ao |) ar) easy esa) =a) “oo! = 6
|| 35) —1 20 22 7 20 16) —4 10| —10
30| —16|/ 25) —21 29 25 3 35] 28) —7 2%| —9
2i| —28 19 | =—80 40| 38 7 40 | = 83 35 =5
seek Hpi nace ete eee VR 90) WC) 37 41 35] —6 29 =i)
Means..........-. | 53.1] 50.9] 47.1) 56.3] 46.6|—9.7| 40.4) —15.9| 37.7| 35.3 |’ 33.4] 39:0) 31.4] —7.6| 25.3)|| —13.7

Highest and lowest readings are in italics.

5

88

TABLE 20¢,—MonTHLY AND SEASONAL MraNS—DeEw-poINT AND ENsuING MINIMUM TEMPERATURES, MATHER
Wis., 1907. >

June. | July. August. | Se pens October. | Means.
Upland: |
- Station 1, shelter—
Dew-point. oF | ° ° ° 5 .
GD See Shea oi 5 a oe ie ps et oe et Nea ae 52.9 | 62.3 59.1 53.1 37.7 | 53.0
S}ppnesees Bde 2 2. 5 acts eae See eee ache ee eae ces 52.1 60.7 | 56.3 50.9 35.3 | 51.1
Minimtim z..\ccs sezesatygoseiec he soos ater eee RE ok oe See eee 49.1 | 55. 6 54.0 47.1 33.4 47.8
Marsh: eee ee | r a ies
} |
Station 4, shelter | | |
Dew-point. | |
Gi nS ee ie eS se Se oct ees a ence 54.9 | 63.0 59.4 56.3 39.0 | 54.5
Mina inn those = pee ae ae ae ne ae ea ee ce nee eee ee 48.6 54.9 53.1 46.6 31.4 46.9
Difference y= Sh fees UE coe se a A ee ee ee = 6.3) —sd | =16:3|| —i9.71| = 76 | = 7.6
Station 2, 5 inches, exposed— apa | i: : |
MMM Wine tenia a ce Are Sew gS we en ee eS ee ae Seber | 42.3 | 49.0 47.1 40.4 25.3 40.8
Difference! 9-25 cesses eee ree ee Bn RSE BERS aa caaet os epennocan rae —12.6 —14.0 —12.3 —15.9 —13.7 | —13.7

Dew-point readings at Berlin.—Observations of dew-point and the ensuing minimum air
temperature made at Berlin in 1906 confirm the results obtained at Mather. Even though
the air was saturated in the early evening and dew formed rapidly, the temperature often fell
steadily in spite of the large amount of latent heat liberated by the condensation of water vapor
into dew, as on the night of September 23-24. Of course the fall in temperature was not so
rapid when the humidity was high and the dew was forming fast, but there was, nevertheless,
usually a steady fall on clear nights. The moist condition simply tended to lower the rate of
cooling, and it is probable that the radiation of heat from the dewdrops themselves was great.
Aside from reference to the tables compiled from Mather observations, a few comparisons made
at Berlin are given below between the dew-point in the evening preceding nights of frost with
the ensuing minimum temperature.

Minimum aa
Dew-point | temperature, (fini
previous | shelter read- | - noe 2 Bia
evening. | ings, Sta- |° “20: =
tion 1. as

= = . = = | =
° ° °
Speen ols is Sane A nee ee ocean soc OC OEE Senso soso Aeone pe aees ser eeSreae ca Ssasosstessss 56 42 28
Rep reml Der 4p oe eee ana een ee ne ee eee at a eee eee eed moceccasesresoessosSses| 50 41 29
fst e}o} Fete OX oo SS eer sere nese oe SAHOO SRE CES Eee Or cS sabe east ous eelbadsesmesscosmcou ested 48 38 - 29
pet ett OPT on Coe pen OS Satins poss on Stee eins en at erin os ee ooma encom sa kiasoesnete soc saed AT 36 24
See ant a2 gene sqesnge sacs osnbeovessboeoseetins Sa PeOSE Se ono ten senaS Sq Os Tasos Stee ssaco ves sesSos AT 41 28
Septembens0ie = .2---2 soe --=e- = Bros ae Hs DS ORAS oman Topas Seo eSsenssr Tsao Saracen esibte ssarsiesses | 41 | 38 23
OYE Ha) a ns oe ie ie DO OE eae GIO DET SSSE Fae Os Seated ene aes Oar r fossa danpoestdzet eogsaces 46 | 29 19

| |

PAVOTAR OSS, oo. aos oot se eee ete eee cla wie a Sate a ae enc gm ene ieee 47.9 | 37.9 25.7

In a dry section at some little distance from water and bog land there may be some con-
nection between the dew-point and the ensuing minimum temperature. When a high degree
of moisture is present in the air as over a moorland, and when the temperature falls rapidly in
the evening, as it usually does on clear nights, the point of saturation is reached in a brief
period.

Fog over marshes and low temperatures —Fog, even though light, has been supposed by
some to be a preventive of frost, but this is not quite true; in fact, fog may form over a bog
on almost any clear cool night following a warm day when the soil has been heated and the air
for some distance above the surface highly charged with water vapor. The rapid radiation
from the surface and humid air on a clear night after a warm day carries the temperature
below the dew-point, and fog is immediately formed. It is often said that the formation of

89

fog under such conditions indicates a rapid fall in temperature, and cranberry growers are
accustomed to look for a frost when on a clear night light fog forms over the moorland. On
such nights the radiation of heat from the particles of fog serves even to lower the tempera-
ture of the air. Of course, the radiation of heat from the ground is more or less arrested as the
fog increases, but it is surprising what little effect fog seems to have in preventing low night
minimum temperatures in the bogs.

Special observations on critical nights at the Berlin marsh, September, 1906.—Personal
observations in the bog at Berlin, 1906, during several nights when low temperatures occurred,
convinced the writer that high humidity and even fog have hardly any effect in retarding the
fall in temperature. Even when the bog seemed reeking with moisture, the temperature fell
steadily. Often during critical nights, observations of special conditions were made nearly
every hour in certain portions of the marsh. There was little opportunity for this kind of
work until September, as the temperature during the summer was far above the normal.

On August 27 the exposed minimum temperature at Station 5, in the ‘‘ferns,’”’ at the 5-
inch height was 30.5°, while near the surface at the same place the minimum was 32.2°, and
in the shelter at Station 1 it was 45.5°. No frost, however, was observed that morning at any
point in the bog. On the morning of September 5 the minimum temperatures were 28.3° at
the 5-inch height and 32° at the surface at Station 5, and 42° in the shelter at Station 1. Again,
no hoar frost was observed, although the exposed minimums registered several degrees below
the freezing point. The ferns, however, were damaged by this low temperature, as they began
to wither immediately afterwards, and some slight damage was noted in the neighboring low-
lands outside the marsh. Occasionally light frost may occur in the bogs and pass unnoticed,
disappearing very early in the morning, and the writer has known of several instances where
frost was not observed, although damage to vegetation gave evidence of its occurrence. While
these minimum temperatures, of course, do not represent the temperature of the air, yet, even
if they represent approximately the temperature of the plants and vines, hoar frost might be
expected when these readings fell a few degrees below freezing. The first date on which frost
was actually observed at Berlin was September 14, under conditions quite similar to those of
the 5th. The shelter minimum at Station 1 was 41.3°, while the minimums at the 5-inch
height and at the surface at Station 5 were 28.8° and 32.6°, respectively. The morning of the
14th was clear, but with fog over the marsh. (Fig. 6.) Light frost was observed first on the
wooden car tracks at the intersections where the rails had been spliced, but not on the main
portions of the track, or on the cross-ties lower down. (Figure 17 shows the tracks and
cross-ties.) These splices were about 4 inches above the surface of the marsh, and afforded a
better opportunity for radiation. A peculiar phenomenon was noticed at Station 5: The
maximum and the minimum thermometers at the 5-inch height were found completely covered with
frozen dewdrops, dew having been deposited sometime during the night, after which the tempera-
ture fell to the freezing point. The thermometers resting on the surface were absolutely free from
frost or moisture of any kind. This is a most striking example of safety at the surface and frost
and possibly destruction a few inches above. Some frozen dewdrops were also found on the tops
of the splices already referred to. Ordinarily, dew formed on vines and other objects at an
elevation of a few inches above the ground sooner than at the immediate surface, doubtless
because at that elevation there was no direct connection with the warm ground and the radia-
tion was freer, the dew-point was more readily reached, rather than because of any difference
in the amount of moisture. A light frost occurred at Mather and Cranmoor on September 14,
as well as at Berlin, temperatures below freezing being reported in all the Wisconsin bogs. The
frost on the 14th would probably have been more severe had the soil been colder; but it was
comparatively warm, because of a hot wave of several days preceding the cool spell. On the
14th considerable differences prevailed between the temperatures on the uplands and in the
bogs, as is usual under such conditions.

Light frost was again observed at Berlin on September 24, freezing temperatures being
recorded at both exposures at Station 5, but the temperatures were not so low at Cranmoor

90

and Mather, the sky there becoming overcast before midnight. The Berl marsh was quite
wet from recent rains, especially in the east portion where the water was almost up to the
surface. The water had been partially drained from the west portion, but it was still wet,
especially on low ground. In the big ditch near Stations 2, 3, and 4, the water was but 2 to 3
inches below the surface. The sky was clear during the entire night. About 7 p. m. on the
23d fog was first observed along the main ditch; after midnight the fog mereased and spread
over the bog, and by 3 a. m. it was very dense. The whole marsh seemed to be reeking with
moisture. The relative humidity was 100 per cent continuously after 10 p. m., yet the tempera-
ture fell rather uniformly until 4 a. m.; then after remaining stationary about an hour it rose
gradually. In the morning frost was observed on most of the wooden car tracks, especially
where they were situated away from the water. None was observed on the cross-ties resting
on the surface of the bog, and while frost was seen generally on the tracks, it was more pro-
nounced on the edges and on the upper side of the splices covering the joints of the rails, where
radiation was freest. In other words, frost was heavier at a slight elevation on account of
freer radiation than at the immediate surface, this being consistent with the readings of the
thermometers. The minimum temperature on top of the tracks was 27°. A thermometer
placed in the vines, a few inches above the surface and just touching three berries, registered a
minimum of 31°. The instrument and the exposed berries were covered with frost, but the
berries near the ground were not frosted. Frost was also observed on the leaves, vines, and
grasses, but no damage as a result was afterwards noticed. A thermograph placed in the
“ferns’’ where the vegetation had been trampled was covered with frost and registered a
minimum of 26°. Invariably lower minimums were found in sections that had been trampled
than in the unpicked sections where the vines and grasses stood upright.

Frost occurred in all marshes on September 27 and 28, it being heavy at Berlin on the 27th
and light on the 28th, increasing cloudiness after midnight of the 27th preventing the frost
from becoming severe. Dew did not form rapidly on the first night. At 10 p. m. the shelter
thermometer at Station 1 registered 50° and the dew-point was 46°. The marsh was com-
paratively dry, in strong contrast with the moist conditions of a few days previous. The
shelter thermometer at Station 1 fell from 50° to 45° between 10.30 p. m. and 11 p. m., but there
was no sign of frost at the latter hour; the tracks were dry and the dew-point was 43°. Some
fog appeared about midnight, the temperature continued to fall steadily, and frost was observed
first on the metallic covering of the thermograph in the ‘“‘ferns’’ at 1 a. m., where the tempera-
ture had fallen to 28°. A few minutes later it was observed on the splices of the car tracks
near by, and by 2 a. m. on the entire track. At that time the temperature on top of the track
was 27° and on the cross-ties 31.5°. At 4 a. m. these readings were 24° and 30°, respectively.
A thermometer placed in the midst of berries about 5 inches above the surface recorded 28°,
and another about an inch above the surface, 29°. The thermometer at the 5-inch height in
the “ferns”? at Station 5 on the morning of the 27th registered a minimum of 24.4°. Frost
was again most noticeable on the marsh where the vines had been trampled and hardly notice-
able where they stood upright. Although the berries were covered with frost, it had evidently
not penetrated the skin, and no resulting damage was apparent later. The frost on the 28th
was light in the various sections.

The most important frosts of the autumn season of 1906 occurred on September 30 and
October 1. The barometer was high in the marsh region on these two nights, as on previous
occasions when low temperatures occurred. The weather maps showing the distribution of
pressure will be discussed later. At Berlin, on the 29th, the temperature did not fall rapidly
until late in the evening, as the sky was covered with clouds, which did not disappear until
after 10 p.m. The temperature then fell rapidly, reaching a minimum of 23.2° in the “‘ferns”’
at Station 5 on the marsh. J//eavy frost was general over the entire bog, but the berries were
apparently not frozen, and no resulting damage was noticed, although flowing was not resorted to."

«The berry when green can usually withstand a temperature in ‘‘the open’’ of about 28°, and when fully
matured, of 23° or 24°, depending, of course, upon the duration of the critical temperature.

91

On the morning of October 1 the most severe frost of the season occurred, the temperature
in the “ferns”? at the surface being 23° and at the 5-inch height 19°. On the wooden cross-
ties of the track the minimum was 18°, and 4 inches lower at the surface it was 22°. A ther-
mometer placed in the midst of a bunch of berries about 5 inches above the surface registered
22° and another instrument 1 inch above the surface, between the berries, registered 24°.
The shelter minimum at Station 1 was 29.4°, while a thermometer on a board walk on hard
land near Station 1, where heavy frost occurred, registered 22.8°. The temperature of the water
in the reservoir at daybreak was 53°, and in two small ditches it was 37° and 39°. All the
berries remaining unpicked were frozen hard as marbles, with the exception of those near the
surface of the dry sanded section where the minimum temperature was 35.8°. As the berries
thawed out, however, only
about 33 per cent of them SEPTEMBER-OCTOBER
showed injury. In other 29th. 30th. (St.
words, about one in three noon mdt. noon mdt. noon

was soft and semi-transpar- 7 oa
ent, and the other two were AERIS SUEEE ETAT Pur TET Patt Ts
firm and apparently in good BEI ==ae ae, 2225
Sf} 2 Sea ea
=

condition. The berries that Bale
were exposed directly to the

sun’s rays in the morning
thawed out rapidly and
showed the effects of the
frost, there being an unusual-
ly rapid rise in temperature
on the morning of October 1.
(Figure 28 shows the thermo-
graph traces in shelter and
on the marsh.) The major-
ity of the berries were located
below the thick growth of
vines and other vegetation,
so that the sun’s rays did

= =
not directly strike them and ad SeEeeee A oN ===) a
warm them vpidly, o0d eee pe ee ber eS See Eee

the thawing was, as a result,

mamunaernne UUHHT HTH

inks!

gradual. If the morning of iN FERNS

October 1 had been cloudy, IN SHELTER Soop ooo
permitting the slow thawing Fic. 28.—Berlin, Wis.

out ot the uppermost berries, Temperature curves in shelter Station 1, and in open in the ferns Station 5, noon

Peas A 3 September 29 to noon October 1, 1906. Uncorrected readings.
it is possible that the entire

crop might have escaped serious injury. Other fruits as well, after having been frozen, fail
to show the effects of frost when the thawing is gradual.

Effect of frost on the cranberry.—The resisting power of the cranberry increases steadily as
it matures. In the autumn, when colored and fully matured, the berry can withstand a tempera-
ture many degrees lower than when green and unripe. As it ripens it not only colors but the
skin thickens, and its content changes somewhat and offers an increased resistance to frost.
Growers state that sometimes, although no damage is apparent after freezing weather, the berry
thus exposed is chilled, and if placed near a fire will become semi-transparent and soft, resembling
somewhat a baked apple, and show all the characteristics of having been frozen. An experi-
ment was made on the morning of September 30 by placing some of the chilled berries near a
fire, but no deterioration was detected in any of them. It is said that berries exposed to frost
on two successive nights, after apparently having escaped injury the first night, will on the
morning following the second night exhibit symptoms of being frozen, even though the cold
on the second night is not as severe as on the first. It is supposed that the low temperature

92

of the first night starts a certain disintegration in the cranberry which is completed during the
second night. >

According to Prof. KE. R. Lake,? low temperature congeals the watery part of the cell
sap and also the intercellular water content of the plant. Within certain limits this is not or
may not be injurious, providing the protoplastic contents of the cell are able to absorb the
water and do this before the cell structure collapses as a result of insufficient cell turgor.
Frequently the frosting of plants is followed by a sudden rise in temperature, in which case
much of the water which was part of the cell sap in the normal condition of the plant escapes
through the cell wall into intercellular spaces, or even from the plant entirely, and thus the
protoplasm of the cell being unable to assume its normal condition becomes disorganized and
decomposition follows.’

Disadvantage from reflowing.—It was possible to reflow only a portion of the Berlin marsh
previous to frosts, and reflowing was seldom attempted there, as the drainage was poor,
and the water could not be drained off quickly. As the picking season advances the water
becomes colder and it is consequently more trying on the cranberry pickers. When a marsh
has been reflowed the pickers on the day following seldom start work until noon, in order to
avoid the dampness, as they object to working in a wet marsh and sometimes refuse to do so.
Where the drainage is poor, the cranberry grower has sometimes to decide between leaving his
marsh dry and risking the damage from frost, or reflowing and chancing the desertion of his
pickers. In either case, the harvest is affected. It is important that as many pickers as
possible be held until after the crop is gathered. On the Appleton marsh at Mather there is
usually ample water supply and fairly good drainage under ordinary circumstances, and it is
invariably flooded in anticipation of frost. Aside from the discomforts caused to the pickers
working in a wet marsh, frequent reflowing softens the terminal buds, so that they are easily
bruised by the pickers, and the crop of the following year is seriously affected as a consequence.°

Special data in connection with forecasting frost in the cranberry marshes.—The subject of
local conditions in the bogs having been treated in detail, it is important that the discussion now
turn to the relation existing between the temperature in the bogs and the general weather
conditions throughout the country, as shown by the daily weather maps. Reference now will
be made to maps of various types, especially during the years 1906 and 1907, which have pre-
ceded critical conditions in the Wisconsin bogs, in order that assistance may be afforded the
forecaster and the cranberry grower in determining the probability and severity of frost.

Discussion of daily weather maps and local conditions in connection with frosts in the Wis-
consin bogs in 1906.—Observations in the bogs during the season of 1906 were of course incom-
plete, although some data from Mather, Berlin, and Cranmoor are available from May 21 to the
end of the season. It may be well now to refer to:the severe frost which occurred on May 28,
and the light frosts on June 11, 12, and 13 of that year, in connection with the weather maps
issued at that time.

The weather map of May 27 shows a storm central over the southern portion of Illinois
and Indiana, and a high-pressure area in Manitoba, encircled by a 30.2-inch isobar, with temper-
atures in the Dakotas and at Moorhead of about 40°. General rains prevailed throughout
- Wisconsin on May 27, with strong northeast to north winds. The maximum temperatures in
shelters at Berlin, Mather, and Cranmoor were, respectively, 47°, 54°, and 53°.. On the morning
of the 28th the storm center had passed to the Middle Atlantic coast, while the high-pressure
area had moved to the western Lake Superior region, a ridge extending southward over the
Middle States. The pressure in the Wisconsin moorlands was approximately 30.15 inches, and
the wind was light northeast with clear weather. The minimum temperatures were 21° at
Mather, 29° at Berlin, and 28° at Cranmoor, with severe frosts at all three marshes.

The frosts of June 11, 12, and 13, 1906, were the only frosts which occurred during that
month, and while they were not severe they nevertheless occurred at a critical time, and were

a Prof. E. R. Lake in Oregon Climate and Crop Bulletin, July, 1900.

6 Professor A. G. McAdie states in Climatology of California (Bulletin L, U. S. Weather Bureau) that fruit
growers in California have found it advantageous to interpose some screen early in the morning between the sun’s
rays and the frosted fruit.
cIn many bogs the berries are gathered by raking instead of picking.

93

remarkable for their duration. The weather maps for June 10, 11,12, and 13 furnish an expla-
nation of these persistently low temperatures. On the morning of June 10 the barometer was
low in both the northeastern and southeastern portions of the country, and a high-pressure
area was centered at Winnipeg, where the barometer was 30.2 inches and the temperature
below 50°. The HIGH moved eastward over the northern Lake region, steadily increasing in
magnitude. On the morning of the 13th it reached from the St. Lawrence to the upper
Mississippi Valley, with the center in Ontario, and encircled by a 30.4-inch isobar, the pressure
in the bogs being about 30.25 on the 11th and 30.30 on the 12th and 13th. There was but
little barometric gradient in the moorland sections on the mornings of June 11, 12, and 13; the
wind was light from the northeast, and the weather clear both day and night. The appended
table shows the maximum shelter temperatures on June 10, 11, and 12, and the minimum
temperatures on the bog on June 11, 12, and 13.

= =
| Maximum temperatures in | Minimum temperatures on
| shelter. | bog.@
|

| Mather. Berlin. Cranmoor. Mather. | Berlin. | Cranmoor.

1906. ° | 2 1906. ° ° | °

Tuned eee ee ee alas x 74 | 71 | AD | vat ees tee eee 28 35 | 35
June 11 | 72 | 66 | (33) FANTINI ee tee ects ee 28 | 33 | 34
DUAL 2 ee see 71 67 G8 Wine 32.2n225- ss .ceeewe ease ee 4 26 33 31

a At Berlin and Cranmoor the minimum thermometers were not at this time located at the coldest places on the marshes. At the coldest
point the temperature ordinarily had to fall to 28° or 29° before frost was observed.

Frost was observed in the three cranberry marshes and generally throughout the moor-
lands on these days. The minimum temperature readings at Mather better represent the
general temperature conditions than those at Berlin and Cranmoor, as the thermometer readings
at the latter place were affected by water from reflowing, and moreover the thermometer at
Berlin was not at that time located in the ‘‘ferns,’”’ the coldest point on the bog. The Berlin
minimum readings above are for Station 2, which it was later found averaged 3° to 4° higher
than in the “‘ferns.”” These frosts disappeared before sunrise each morning as the temperature
rose.

No soil observations are available to show the temperature of the soil in the marshes at
that time, as the soil thermometers had not been installed. However, there isno doubt that the
temperature of the soil was low, and had much to do with the occurrence of the frost. There
had been no unusually warm weather in the season of 1906 previous to June 10 that would serve
to heat the soil to any great extent. It was found in the observations of 1907 that there was an
irregular increase in soil temperature from the beginning of the season to about the middle of
August. In that year the soil temperatures at the 3-inch depth in the peat bog at Mather on
the corresponding dates in June were not above 52.5°, as compared with a maximum of 69.5°
on August 12. During the middle and late summer, when the maximum air temperatures in
the shade reach 70° or higher, there is ordinarily little probability of frost the ensuing night,
because under such conditions the soil is heated considerably beneath the direct rays of the sun.
At other times during the season maximum temperatures as high as 75° may be succeeded by
frost. Frost very seldom occurs in the summer months on a night following a clear sunshiny
day, and it can occur under these circumstances probably not later than June 15. Had the
weather conditions of this period, as far as pressure, clear sky, and maximum temperature are
concerned, occurred during July or August, frost would not have formed, because the ground
would have been warm enough to prevent the temperature at its surface from fallimg to the
freezing point.

During this period of three days in 1906 several of the growers retained the water over
their marshes both day and night, or at least up to the surface, thus saving the supply of water
which might otherwise have become exhausted. Unless the cold is expected to continue, growers
after reflowing begin to drain off the water at daybreak, because if it remains on the bog during

94

a warm sunshiny day there is danger of scalding the berries and vines. No additional frosts
occurred at Mather in the summer of 1906, and the first frost in the autumn was on SéPtember 14.

This first frost at Mather in September, 1906, was a light one. The pressure at the time
was 30.24 inches, rising, and the preceding day, the 13th, had been partly cloudy with
77 per cent of sunshine, while the night had been clear, there being, however, a light fog
during the early morning of the 14th. The temperature had been steadily falling since the
11th, a maximum of 90° having occurred on that date. On the 13th the highest temperature
in the shade was 68°, and the temperature of the soil had been much reduced; in fact, it was
lower at 6 p. m. at all stations on the bog than on any previous evening in September. At the
time of the minimum temperature of 31° on the 14th there was an absolute calm on the bog.
A fresh breeze had been blowing from the north the day before, partially evaporating the mois-
ture produced by the rain which had fallen on the 12th, and as a consequence lowering the
temperature at the surface of the soil.

Reference to the weather map of the 13th shows that the high-pressure area was then
centered over the eastern portion of South Dakota, the center being inclosed by a 30.2-inch

isobar with temperatures as low as 40°. The ba-
SEPTEMBER, 1906 rometer rose rapidly in the moorland sections dur-
2 3rd. 24th. ing the day, the center of the HIGH moving directly

noon mdt. noon eastward to the Lake Superior region, where the
pressure was 30.4 inches on the morning of the 14th.
Had the soil been colder, the general conditions pre-
vailing on the 14th would have caused a more severe
frost; for, although the temperature of the soil had
been lowered, as already stated, it had previously
been very warm as a result of the hot wave of sev-
eral days’ duration.

While frost occurred in the marsh at Berlin on
the morning of September 24, the lowest ‘‘exposed”’
temperature at Mather was only 38°. The condi-
tions seemed to be very favorable for low tempera-
ture in all moorland sections, but the clear weather
at Mather on the night of September 23 was fol-

| #
~2= lowed by increasing cloudiness before midnight, and
== SEE: the temperature, which had previously been falling,
rose until 2 a. m., and then remained nearly sta-
tionary until 5 a. m. of the 24th. (Figure 29 shows
the thermograph traces in shelter, Station 1, at each
Traces of thermograph in shelter from noon, September 23to marsh.) The area of high barometer passed east-

BERLIN
Viele) =o eoee

Fic. 29.—Mather and Berlin, Wis.

yon, Septe ar 2: 906. . 7 = mn = ©
ee ag laa eas ward with its center over Lake Superior, and was

followed by a low-pressure area in the far Northwest. A light wind from the north prevailed
at Berlin, which was nearer to the center of the high, while at Mather, located farther west, the
wind had shifted to the southeast with increasing cloudiness under the influence of the LOW
in the northwest, referred to above.

The first severe frost at Mather in the fall of 1906 occurred on the morning of September 27,
and this was followed by another frost on the 28th. In both cases heavy dew was observed
on the uplands, but no frost. Frosts, however, were general on both these dates in all the Wis-
consin cranberry marshes. The barometer at Mather on the morning of the 27th was 30.36
inches, rising, and 30.16 inches on the morning of the 28th, falling. The night of the 26th-27th
was clear, while the night of the 27th-28th was partly cloudy, and, probably because of the par-
tial cloudiness, the minimum temperature, 31°, on the 28th was not as low as the minimum
temperature of the 27th, 28°. Rain had occurred on the night of the 25th—26th, followed by a
fresh wind during the daytime of both the 26th and the 27th. The maximum temperature
in the shade on the 26th was 68°, and 69° on the 27th. Of course, this was late in the season,

95

and with clear weather the maximum temperatures would have been much higher if the days
had been longer. The soil temperatures had been steadily falling, and on the 28th the lowest
6 p. m. readings of the month up to that time were recorded. The center of the high-pressure
area on the 26th was well to the north, as shown by the weather map, with freezing temperatures
in the British Northwest. The temperature at Moorhead, Minn., on the morning of the 27th
was as low as 38°.

Heavy frost again occurred in all the Wisconsin bogs on the mornings of September 30
and October 1. Light rain had occurred at Mather September 28, and a fresh wind from the
north prevailed during the daytime of the 29th, with cloudy weather and 67 per cent of sunshine,
The maximum temperature on the 29th in the shelter at Station 1 at Mather reached only 67°.
The barometer, which was only slightly above normal on the morning of the 29th, 30.04 inches,
rose steadily during the day and night, reaching a height of 30.42 inches on the morning of the
30th. Frost began to appear in portions of the Mather marsh at 10 o’clock on the night of the
29th, and it was general over the entire marsh on the following morning, the minimum tempera-
ture at Station 2 over the moss being 25°, and 32° in the shelter at Station 1. On the morning
of the 30th light fog lay over the marsh. Although the weather was clear on the 30th, the maxi-
mum temperature in the shade reached only 65°, and the soil temperature remained low on the
29th and the 30th. The exposed minimum temperature on the morning of October 1 at Station
2 was 25°.

The weather maps of September 29 and 30 and October 1 should be studied in connection with
these frosts. An area of high barometer of great magnitude covered the Northwestern States,
the 30.4-inch isobar inclosing the Dakotas and the eastern portions of Montana and Wyoming,
and freezing temperatures were reported in North Dakota. The movement of the HIGH was
directly eastward, reaching the western Lake region and Upper Mississippi Valley by the morning
of the 30th, and the St. Lawrence Valley by October 1. On the latter date the barometer
remained high over Wisconsin, as a ridge reached westward over the Lake region from the

St. Lawrence Valley. A tropical storm, which had on the 27th caused great destruction at
Mobile, was pushing northward through the interior of the country, and had advanced as
far as St. Louis by the morning of the 29th. The high pressure area, however, moving directly
southeastward, crossed its path and forced the LOW backward to the Gulf coast. The shift-
ing of these areas brought down the cold air in a great mass over the Middle States on the
morning of September 30.

Discussion of daily weather maps and local conditions in connection with frosts in the Wis-
consin bogs in 1907.—Table 21 has been made quite comprehensive in order to show all the
weather conditions that may be needed in connection with the study of the occurrence of frost
in the bogs at Mather during the season of 1907. It is intended to supplement the tables which
have preceded, and may be used in connection with Mather observations of various kinds. The
barometric pressure, rainfall, wind velocity and direction, state of weather both day and night,
and the amount of sunshine are most important in addition to temperature data.

In 1907 the observations began on May 12. During the balance of that month there were
eight days on which the temperature ‘‘in the open” at Station 2 fell to freezing or below. On
May 19, although the temperature was as low as 28°, no frost was seen, and on the 27th, when a
temperature of 27° occurred, none was seen, although thin ice was observed early in the morning.
A so-called “dry freeze,” however, is often more dreaded by the cranberry grower than a heavy
hoar frost. Nevertheless, it is evident that these ‘‘exposed”” minimum temperatures at Station
2 were considerably lower than the actual temperature of the air. Low temperatures are so
common in the Wisconsin bogs during the month of May and the first decade of June that it
should not be necessary to make any special reference to the weather maps for that period.
During the spring and early summer comparatively low temperatures often occur when the
barometer is below normal, but never in midsummer. The lowest temperatures, moreover,
almost invariably occur with high barometer. On May 20 and 21, for instance, when tempera-
tures of 18° and 21°, respectively, were reported, the pressure was 30.30 inches and 30.32 inches.

51936°—Bull. T—10——7

96

The frost of June 8 was severe, the minimum temperature at Station 2 being 28°. The moss
on the bog was frozen hard in places, and there was a heavy coating of frost on the instruments
and vegetation. The air over the bog was calm, and the wind on the upland, 7 miles an hour
from the north. The minimum temperature in the shelter at La Crosse, Wis., was 48°. The
weather the day before, June 7, was cloudy and threatening, with a maximum of 64° in the shade.
The unsettled conditions cleared away at 9 p. m and the pressure mcreased. On the morning
of the 8th the center of the high-pressure area was over the Lake Superior region, and the barome-
ter on the bog was 30.04 inches. Although the temperature was as low on the Ist and the 6th,
only light frost was observed on these dates.

The last frost in June was on the 14th. On the morning of the 13th an area of high pres-
sure was located over the Lake Superior region, the highest reading being 30.16 inches, at Port
Arthur. This area seemed to spread southward, and had settled over Wisconsin by the morning
of the 14th, with a pressure at Mather of 30.10 inches. The maximum temperature in the shelter
at Station 1 was 75°, about 5° above the average maximum that may be expected on days pre-
ceding frost. There was a quick recovery in temperature during the daytime of the 14th, the
maximum reaching 81°. The lowest temperature at Station 2 on the 14th was 31°, while the
minimum at La Crosse was 50°.

On July 2 the lowest temperature at Station 2 was 29°. There was a heavy dew in the
morning, but no frost was observed. Light frost may have occurred in portions of the marsh
before daybreak ; if so, it disappeared before the observer reached the bog. The sky on the pre-
vious night was clear and the pressure on the morning of the 2d was 30.10 inches. <A calm
prevailed on the bog, and the wind velocity and direction was 5 miles, north, on the upland.
The minimum temperature at La Crosse was 50°. A fresh northwest wind had prevailed the
the day before in the bog region, accompanied by sprinkles of rain, while the maximum tem-
perature in the shade was 71°. Reference to the weather map of July 1 shows a generally
unsettled condition from the Lakes westward to the eastern slope of the Rockies. The pressure
in the latter section was 30.14 inches and this gradually shaded off to a low pressure of 29.70
inches in the St. Lawrence Valley. The barometric gradient was not decided, but the condi-
tions prevalent on the Ist were sufficient to cause fresh northwest winds. The lowest tempera-
ture reported from any station in the Northwest was 44° at Minnedosa. On the morning of
the 2d the high-pressure area reached in a wide belt from the Lake Superior region southwestward
over Wisconsin, Iowa, and Nebraska to Colorado; and on that morning in the bog region the
wind had fallen to practically a calm.

No freezing temperatures were observed again at Mather until September 9 and 10, when
30° was recorded at Station 2, but no frost was noted on either of these dates. On the weather
map on the morning of the 8th appeared a seemingly typical condition—a low-pressure area over
Lake Michigan and a high-barometer area encircled by a 30.30-inch isobar over the northern
Rocky Mountain region. Temperatures were as low as 38° at Moorhead and Devils Lake.
During the ensuing twenty-four hours the HIGH moved slightly southeastward, retaining its
magnitude, but the LOW over the Lake region moved but little and lost force, the pressure in
the center being 29.90 inches, as compared with 29.78 inches the previous morning, September
8. Frost was reported on the morning of September 9 from the regular Weather Bureau sta-
tions at Devils Lake, Bismarck, Williston, and Havre, with minimum temperatures of 36°.
An unusual change in the general conditions occurred during the 9th, as both the high and the
low pressure areas moved directly southward. Frosts were still prevalent in the Northwest,
with persistently low temperatures, but cloudiness prevailed over the bog region on the nights
of September 9 and 10 and prevented any severe freeze. While the temperature was 30° on
the bogs on both these dates, readings of 45° and 46°, respectively, were reported from La Crosse.
The maximum temperature in the shade at Mather was 65° on the 8th and 68° on the 9th.
The barometer on the two mornings was 30.02 inches and 30.04 inches, respectively. There
was but 50 per cent of sunshine on the 8th, the day being partly cloudy, and as a consequence
the soil was not heated materially. The general weather conditions in the Northwest seemed

97

to be ideal for producing severe frost in the Wisconsin bogs on both the 9th and the 10th, and
it was prevented only by the cloudiness.

A temperature of 30° was again recorded over the moss at Station 2 on September 21, but
no frost was observed. The barometer was just normal, 30 inches, and some cloudiness had
occurred during the previous night. The maximum temperature on the 21st was only 62°, but
the temperature fell rapidly after sunset, a minimum of 23° being recorded over the moss at
Station 2 on the morning of the 22d. There was a well marked low pressure area over Lake
Superior on the morning of the 20th, the barometer being 29.50 inches at Marquette, while a
high encircled by a 30.20 inch isobar covered the northern Rocky Mountain region. The HIGH
moved directly eastward, so that on the morning of the 21st it extended from the Rocky Moun-
tains to the Missouri River valley, and killing frosts and freezing temperatures were reported
from North Dakota. This area then moved southeastward during the next twenty-four hours,
and-on the 22d it was centered in Missouri, the highest barometer being at Kansas City, 30.18
inches. The barometer at Mather on the morning of the 22d was 30.08 inches. While the
minimum temperature over the moss at Station 2 was 23°, in the shelter at Station 1 it was 31°,
and at La Crosse, 38°. On the 21st on the moorlands partly cloudy weather prevailed with 70
per cent. of sunshine, and a fresh northwest wind which died away to a calm on the bog by the
morning of the 22d. Killing frosts were general on the marshes on the 22d; some frost was
observed even the night before at 10.30 p. m.

Killing frosts were again reported in the bogs on the 25th, 26th, 29th, and 30th, and light
frost on the 27th, as two areas of high pressure, one after another, pushed from the northern
Rocky Mountain region southeastward over the central valleys. The temperature was so low
within these areas that general frosts occurred on the uplands of the Middle States on September
25, 26, and 30. The nights, of course, were gradually becoming longer and the soil was growing
colder, making the occurrence of frost more likely. The minimum temperature at Station 2 on
the morning of the 30th was 19°, and frost was very heavy. The pressure was 30.32 inches, the
wind very light from the west, and there had been only 33 per cent of sunshine the day before.
The frosts of the 25th and 26th occurred also with high pressure, but on the mornings of the 27th
and 29th, the barometer was but slightly above the normal. The minimum temperature at
La Crosse on September 30 was 36°.

The cranberry marsh at Mather was reflowed in anticipation of these September frosts, and
the sections that had not been picked were reflowed from time to time during the first half of
October. Frosts, of course, were quite frequent during the month of October; so frequent, in
fact, that it is not necessary to make any special study of these conditions in connection with the
weather maps. Picking usually terminates early in October, and frost warnings are therefore
not needed. The observations, however, were continued until the end of October, in order to
complete the meteorological record for the season, insuring data up to the time that frost enters
the ground. Moreover, after the crop has been picked, the observations were free from the
complications usually arising from reflowing. The temperature over the moss at Station 2
during the month of October fell below freezing twenty-four out of the thirty-one days, the
lowest temperature being 10° on October 28. On that date, the minimum temperature at La
Crosse was 22°. The first ice was noted on October 8, and snow fell on the 19th. Damp ground
was frozen on the 18th, and ice in the main reservoir was noted on the 21st, the minimum
temperature on the latter date being 13°.

From a study of Table 21, it will be observed that frosts occurred usually on clear and com-
paratively calm mornings, with pressure above the normal, While high barometer is appar-
ently not essential in the spring and early summer and in the autumn, frost never occurs during
the warm months of July and August, and the first decade of September, while the ground is
warm, except with a pressure considerably above the normal. Table 21 has been made compre-
hensive in order to afford opportunity for those interested to study in detail the subject of the
temperature conditions in the bogs.

98

TaBLe 21.—Datty WearHEeR Conpitions, MatHer, Wis., 1907.

MAY. 7
Barometer—Rising ne
(R), falling (F), sta- Relative humidity. vine aaa Rainfall. Wind.
tionary (S). Lae Te
WX ee and e
5 a | verage ve- | locity at time o
foo Gogh ae locity. minimum tem-
Up- x evel perature.
7 a.m. 7 p.m. Marsh.|7a.m.|7p.m.|Total.} ing
land. dizecs
T | tion. '
oR Marsh. pa Marsh. ae Marsh.) Upland. | Marsh.

eee 29.62-S 29. 58-F 95 94 96 100 45 46 0. 57 0.15} 0.72) NW 7.5 4.4| NW 14 3
a Reeeene 29.56-S | 29.70-R 97 100 92 100 37 39 24 02 26 Ww 9.8 6.3} W 10 8
Gis cee 29.80-R | 29.80-F 85 92 79 96 50 | 53 Ol 03 04) SW 1OSON (eae |) WS 3
ny Geeeoe 29.82-S | 29.80-R 90 92 35 47 36 41 = 26 0 26| NW 8.0 RAN SINE df 1
1 oaeee 29.88-S | 29.88-R 57 59 32 46 28 33 0 0 o| NW 14.7 8.6} NW 7/ 2
LOE eee 30.00-R | 30.06-R 49 47 52 45 29 24 0 0 0; NW 14.5 81) NW 6 2
Presa se 30.30-R | 30.24-S 52 48 47 60 29 32 0 0 0} NW 8.0 4.0) NW 5 2
Qa css 80.32-S | 30.16-F 76 72 54 54 39 38 0 1 T.| SW 7.2 3.3! N 1] Calm
22 nian 29.96-F | 29.94-S 84 91 83 91 47 | 2. s47 1.65 -01] 1.66] NE 8.6 45] SW 8 2
235% Jeno 30.08-S | 30.08-F 89 92 71 82 44 46 0 0 0 E 10.7 &4] N: 8 5
DA nee 30.12-S | 30.00-F 76 78 58 59 40 40 0 Tr: SES E 16.6 8.6] NE 12 2
25 = cnr oe 29.78-F | 29.60-F 83 | 87 95 97 46 47 - 03 -14 -17| NE 14.4 7.5| NE 16 7
26 625-1 29.60-S | 29.80-F 97 100 100 100 35 36 02 a.08 | @.10| NW 12.3 (EHF || SINT 3 4
ihe cle 30.00-S | 30.06-S 50 62 39 48 28 32 ie 0 ate NW 16.4 10.1 | NW 12 6
ZB ein 30.06-F | 29.94-S 57 55 me 50 43 40 0 0 0| SW 14.2 625) |S e 1
BeBe Re | 30.00-S | 29.96-R 56 53 53 55 43 43 0 0 0); SW 7.3 3.1} SW 2/ Calm
bees 30.00-F | 29.98-S 86 88 53 53 46 46 0 0 0); SE 7.0 3.4] NE 5] Calm.
Giles beeon 30.02-R | 29.94-F 68 71 40 40 34 34 10 0 -10 E 11.5 5. Du) INE 1

Means!|-o- 2 -cce |Laree 7a 75 63 68 39 41 | 62.88 5,43 | 63.31 | NW 11.8 6.2} NW 9 3.1

a Part snowfall. > Total.

Marsh wet and water in ditches high last half of month, due to frequent periods of cloudy and showery weather. Heavy rain on the 22d together

with flooding on the night of the 26th caused surface water to remain around Station 7 from the 22d to June 2, inclusive.
Means for humidity and dew point for nineteen days.

Highest and lowest readings are in italics.

99

TaBLe 21.—Daitty WEATHER Conpitions, Maruer, Wis., 1907.

MAY
Temperature. Weather.
sete eee Differ: Per Miscellaneous.
1, Upland. Sta- ce
tion2, a Previous Da cent
mini- Tone night. y- sgire
; Fee) | a= || mini- shine.
Maxi- | Mini- pears

mum. | mum.

81 36 35 — 1] Cloudy......-- Partly cloudy. 52 | Weather cleared after noon; distant lightning observed in evening.
81} 64 60 =A NI OIGR eects ee loane do}. 73 | Clear morning; partly cloudy afternoon; cloudy night with distant
| | lightning.
48 | 45 45 0} Cloudy.-.---.-- Cloudy==-----> 0) Showery, thunderstorm conditions.
41 36 36 Ones Gepssones bosce dors -=--5- 0 | Low, dense clouds continuous; light fog blowing across marsh 7 to
| 7.40a.m.
65 35 34 os Le |e Gos-aeasre Partly cloudy. 36 | Cloudy until 10 a. m., partly cloudy to cloudy remainder of day;

distant thunder and lightning in evening.

71 40 32 86 | Light fog early a. m. to 6.40 a. m.

68 48 32 89 | Increasing cloudiness by night.

53 39 28 87 | Partly cloudy during day with strato-cumulus clouds.

56 28 18 92 | Increasing cloudiness late in afternoon. Frost in morning, ice in por-
tions of ditches, ground frozen in moist sections. Fog over ditches
and reservoir 7 to 8 p. m.

65 27 Gradually increasing cloudiness during day, overcast after 2.30 p. m.,
heavy thunder before midnight. Heavy frost in morning.

53 45 Low clouds. Heavy thunderstorm in morning.

57 44 Clearing after sunset.

59 44 Alto-stratus clouds.

49 45 Stratus clouds; light fog 6 p. m. into the night.

48 43 Frequent snow flurries with rain in evening.

55 32 Thin ice observed this morning. No hoar frost seen.

69 34 Frost in morning.

72 41 Light dew in morning.

68 45 Do.

68 AT

61.3 40.9

aIn open over bog.
Highest and lowest readings are in italics.

100

TaBLe 21.—Dartry WEATHER ConpriTIoNs, MATHER, Wis., 1907—Continued.

_
JUNE.
(B) falling GE estes Relative humidity. Dew-point, Rainfall. Wind.
tionary (S). Uacbrte
| = - Average ve- eee ae
Lote EE OTe IE oa UL Veatt Ere locity. minimum tem-
7a.m. 7 p.m. we Marsh.) 7a.m.| 7p.m.| Total. Ss perature.
direc-
UP" | Marsh. | UP: | Marsh Mon. | Up- Marsh
land. *| land. land. sh. | Upland. | Marsh.
|

eee 29.90-F | 29.76-F | 57 58 40 49| 40 43 0 0 0| NE 9.9 43| NE 8 1
Deictecs 29.74-S | 29.72-S 56 56 44 52] 46 48 ) 0 0| Sw 6.2 2.8| NE 4! Calm.
25.22 29.70-R | 29.70-R| 90 | 91 78 79} 52 51 7 0.26} 0.26| SW 7.4 Bees Ts} 4
y een 29.56-F | 29.66-R} 96 91 81 73| 44 42 0 an T.| NW | 10.9 6.7| W 1] Calm.
fi aeact 29.86-R | 29.94-R| 74 68 37 49| 36 39 | 0.05 0} .05| NW | 15.8 8.9] NW 12 8
6oeacees | 30.02-F | 29.94-F | 54 60 50 64) 45 48 0 ) Os 6.7 3.3} SW 2} Calm.
Ragas Le 29.88-S | 29.92-S 61 60 49 66 | 38 42 0 ty) 0) SE 10.8 4.8] SE 8 3
Bie t 30.04-S | 30.04-R| 64 71 40 48 | 39 42 0 tt) 0| £E 9.7 4.0| N 7] Calm.
Sees | 30.00-F 53 57 51 53] 47 46 0 0 0 SE 15.5 7.1! E 6) Calm.
sete 29.62-F 77 80 94 96} 60 61 . 06 Sigh || aGsy)| 1D 16.2 729) ey 22 10
pO hese 29.64-R 72 72 90 94] 54 54 0 -02] .02| SW 9.3 319)|) Sees 1
Oe eee 29.82-R 92 90 80 85 | 51 4 0 0 0| NE 9.4 4.1] N 7| Calm.
1c eee 29.98-R 78 7 42 53| 46 50 0 0 0, NE 9.3 4.1} NE 6] Calm.
i Cee 30.10-R | 30.06-F | 63 60 44 80} 51 60 0 0 0| SE 6.7 2.8| NE 7] Calm.
(poe ee 30.12-F | 30.00-R| 75 95 45 46} 56 56 0 0 0| SW 8.0 3.2} NE 5] Calm.
Tess: 30.12-F | 30.06-S | 69 61 66 70} 70 70 i) 0 0} SW | 13.4 5.4| SW 5| Calm.
7 eee 30.14-S | 30.06-R| 79 72 64 80} 64 67 0 1 T.| SW | 10.6 4.9} SW 8 2
18sec 8 30.10-S | 30.06-R| 95 93 74 79| 64 64 - 08 0} .08| NW 5.4 3.0| NW 4) Calm.
eee 30.00-F | 29. 90-S 77 74 54 72| 56 61 0 0 o| NW 5.4 2.7) NW 6 1

205 2B pe 29.90-F | 29.88-R| 76 70 61 72) 58 60 0 0 o| sw 6.0 2.7| W 3] Calm
Ais Ae 29.94-F | 29.88-R| 70 74 89 95| 64 64 0 213))|, 2133] (SE 8.2 4.0| SE 3] Calm.

Cole eae | 29.90-S | 29. 82-S 92 96 82 BZ 167, 67 22 PH) Ve22N SSW |) dese 5.7| SE 10

VA ree 29.90-S | 29.86-R| 90 93 87 98] 63 65 .07 Stee 07) | ans) stl 203i 7S 1

OY Geass 29.94-F | 29. 88-S 92 97 76 92] 66 69 0 an a, Ss 6.0 2.8| N 3] Calm
25s. ee 29.86-R | 29.92-S st | 83 55 61] 48 51 - 68 T.| .68| NW | 10.6 5.8| NW 5] Calm.
62: 30.00-S | 30.02-S | 78 70 60 88] 49 54 0 0 0| NW |} 10.2 5.8 | NW 10 7

27 30.06-F | 29.94-F | 81 69 65 90} 56 61 0 0 0, WwW 5.9 2.8) NW 4] Calm

|

DS 29.92-F | 29.82-S 93 90 68 76] 58 59 0 0 0! sw 6.0 2.4| NW 1] Calm.
20: eae | 29.84-S | 29.76-S 62 72 72 78| 64 65 0 TM T.| SW 7.4 29} S 4] Calm.

B0.paa 29.80-F | 29.70-R| 73 69 94 95] 64 62 0 .13] .13| SW | 10.2 4.3] S 5] Calm
i} = ———E~

Mears > ese area eee 76 76 | 74] 54 56 |a1.16 | a1.11 |a2.27| SW 9.2 4.3 |NW 6.1 1.4

@ Total.

Marsh continued wet fore part of month, and flooding occurred on the nights of the 5th and 13th. Decidedly warmer weather set in

immediately after the 13th, and by the end of the month the marsh was considerably drier and the water in the ditches about normal.

Highest and lowest readings are in italics.

TasBLe 21.—Dainy WEATHER ConpiITIONS, MATHER, Wis., 1907—Continued.

Temperature.

Shelter Station
1, Upland.

Miscellaneous.

Light frost in morning.

Heavy dew in morning; fog over marsh beforesunrise. Distant light-
ning in evening.

Partly cloudy in evening.

Dense fog in early morning; heavy gale after 3 p. m.

Light frost in morning. Moss and moist ground frozen; strawberry
leaves on uplands frosted. Heavy dew observed in spots.

Clearing after 9 p. m.

Frost in morning. Moss frozen hard in places. Some instruments,
especially thermographs, heavily coated with frost.

ie

31 | Distant thunder in early morning.

33 | Heavy dew began to form before sundown.

100 | Heavy fog over marsh in evening.

100 | Heavy dew in morning; frost observed in patches.
94 | Heavy dew in morning.

63 | Thunderstorm conditions.
99 | Heavy dew and dense fog over marsh in early morning.

Partly cloudy. 73 | Thunderstorm conditions.

80 | Thunderstorm conditions. Heavy dew and dense fog in morning.

100 | Heavy dew and dense fog over marsh in evening.
Oba eae 100 | Heavy dew and dense fog over marsh in early morning and again at

Maxi- | Mini-
mum. | mum
72 36
77 39.
61 55
70 41
68 44
72 34
64 48
75 36
72 41
66 oA
62 47
63 53
75 44
81 39
82 43
91 54
4 70
83 59
84 57
83 bly
84 49
80 61
76 60
87 54
71 58
70 48
77 45
79 43
82 51
83 58
76.1 49.1

night.
Heavy dew and dense fog over marsh in early morning.
Thunderstorm conditions.
Do.

an open over bog.
Highest and lowest readings are in italics.

102

TasLe 21.—Darmy WerATHER ConpiTions, MarHer, Wis., 1907—Continued.

>
JULY.
Barometer— Rising
(R), falling (F), sta- Relative humidity. Dewonotttr Rainfall. Wind.
tionary (S). Pos
A Direction and We
m > verage ve- | locity at time o:
Pett ‘Daan. as locity. minimum tem-
Ss Up- Ane perature.
7a.m. 7 p.m. Marsh. |7a.m.|7p.m.| Total.| ing
a land, direc- 3 ee
UP- | Marsh. | UP> | Marsh | eer | Op | stars: | place Mare
land.| Marsh.| janq, | Marsh. lana, | Marsh.) Upland. | Marsh.
) ee 29.86-R | 29.98-R 83 83 76 79 53 53 te De eT eNi 11.6 7.0| NW 8 =)
Decne 30.10-F | 30. 06-S 76 76 58 65 50 51 0 0 0 ne 4.5 1.8} N 5} Calm.
Sheaedses 30. 10-F 29. 90-S 98 96 90 96 67 65 0.35 0.35 | 0.70 SW 8.6 3.7| SW 3] Calm.
Ch ope 30. 00-S | 29. 94-F 76 95 88 100 66 65 0 . 03 .03 | SE 10.1 5.1] SE 2] Calm.
fer asas 29. 82-S 29. 84-R 80 86 93 90 70 7 2.15 OL 2.16 N 7.3 4.0} SE 9 3
(ees 29.92-R | 29.90-R 88 95 56 78 56 60 0 0 0} NW 5.5 2.8) NW 3 i
LESS e aoe 29.90-F | 29.82-R 78 78 91 83 67 69 0 0 0); SW 5.9 257)|) “We ©2)| Calm:
Cpesaace 29.92-S | 29.92-R 77 65 66 77 62 63 0 0 0}; NW 6.8 3.5] NW 4 1
9.......| 29.96-S | 29.90-S 72 71 62 68 57 59 0 0 0| NW 5.6 2.9) NW 4 2
OD Ses | 29.92-F | 29.82-S 90 89 81 82 59 59 0 05). .05) NE 4.5 2.0} N 5] Calm.
| NE
1 Sees 29.84-R | 29.92-R| 94 98 70 76 60 60 03 7 03 eo 6.0 3.4] NE 3 1
12) 5-2-5: 30. 04-S 30. 00-F 81 81 70 77 60 61 0 0 0 SE 4.8 1.9 N 4] Calm.
Nee sence 29.94-F | 29.80-S 79 72 60 69 62 62 0 0 0| SW 1.4 4.8 S 4] Calm.
Me ecto 29.74-S | 29.72-S 87 95 85 91 69 68 18 - 02 -20 SW 10.1 5.1 Ss 8
Lerner 29.54-F | 29.74-R 96 100 74 93 64 66 52 13 -65 | NW 10.4 5.8| SE 12 7
iene sooc 29.92-S 29. 88-S 93 98 80 92 70 70 0 02 02 SW 7.5 3.6 N 4} Calm.
i aeeee 30.06-S | 30.10-S 7 83 56 81 56 63 0 0 0} NW 8.9 GRO i 5 il
tS ece 80. 12-S | 30. 00-F 92 98 69 86 62 64 0 03 03 SE 5.6 2.3| NW 4] Calm.
Sh) 5 Bend 29. 94-F 29.90-R 95 96 72 91 67 66 09 0 09 Ww 8.2 4.5; SE 4] Calm.
Oe seeeee 29. 98-S 29. 96-R 86 83 58 95 62 69 0 0 0| NW 5.2 2.6 Wa 6 2
P] eee 29. 90-F 29. 70-S 97 98 99 100 68 68 89 3.89 | 4.78 Ss 7.2 3.5| S 4 | Calm.
22 ce eres 29.86-R | 29.96-R 91 93 70 91 61 63 02 0 02; NW 9.0 5.2) NW 5 3
PRE sacar 29.98-F | 29.84-F 84 80 82 93 67 67 0 iin iy SW 6.3 2.8) N 3] Calm.
DAS en a 29. 80-S 29. 80-S 76 76 61 91 60 64 0 0 0; NW 7.5 4.0} SW 5 2
202 eeceen 29. 78-F 29.66-R 82 94 87 92 64 65 0 . 02 02 SW 8.8 4.9 N 2 | Calm.
26 asap 29.98-S | 30.02-S 74 75 93 93 68 60 0 0 0| NW 8.3 48} N 8 4
27......-| 30.04-F | 29. 90-F 83 85 70 76 59 60 0 0 0; SW 5.4 2.5) W 2) Calm
2B Snes 29.84-F | 29.76-R| 74 74 64 66 59 60 T 0 T WwW 9.6 5.2| SW 5] Calm.
Ye 29.92-S | 29.94-R | 86 81 59 75 53 56 0 0; NW 9.4 5.0) NW 9 3
SOF a ces 29.98-F | 29.92-S | 74 74 86 89 66 66 0 -20 20; NW 8.6 4.5| NW 4] Calm.
Cio sareas 29.92-S 29. 86-F 76 80 54 95 57 62 0 0 0; NW 9.2 4.8) NW 8 3
| |
Mearis||. 22-25 s eee | Besos we | 84 85 75 85 62 63 | @4.23 | a4.75 |a8.98 | NW 7.7 3.9 | NW 5. 0 1.2
@ Total.

With the exception of a heavy rain on the 5th which kept the water in the ditches high for several days, the condition of the marsh during
the first half of the month was nearly normal. A period of showery weather set in on the 14th, culminating in an unusually heavy rain on the 21st,
which completely flooded the marsh and raised the water in the reservoir 4 inches above high-water mark. This was further augmented by the
breaking down of a dam on the marsh above. Station 7 was covered with water to adepth of nearly 12 inches for three days after the 21st, and the
water did not entirely disappear until the 1st of August.

Highest and lowest readings are in italics.

103

Taste 21.—Damty WEATHER ConpiTIons, Matuer, Wis., 1907—Continued.

JULY.
|
Temperature. ; Weather.
ce ees Bites Per Miscellaneous.
a a tien, Mint Previous Da oe
me 3 mini- | from night. Ae Sane
wo | ee | EES) Sa shine.
Maxi- | Mini- aan
mum. | mum
71 59 52 — 7] Cloudy........ Partly cloudy. 72 | Heavy dew in evening.
Ste 38 29 OP Gi Claire Chern ee 100 aed ate in OEMS No frost observed, but light frost probably
{| oceurred in portions of marsh before daybreak.
85 48 38 —10| Partly cloudy.) Partly cloudy. 59 | Dense fog in early morning and previous night. Severe thunder-
; storm conditions in vicinity.
77 51 45 — (6 ||, Clearso. J22-2.-|0- =. dOozeneneet= 51 | Severe thunderstorm in evening with hail and heavy rain, flooding
marsh and injuring cranberries.
84 60 59 — 1) Partly cloudy.|..... Colt) ee ae! 70 | Thunderstorm conditions in morning.
79 58 53 —+9) || Cloudy... ---2-}5-2-- GOz22-52=22 7 | Dense fog in early morning, clearing about 2 p. m.
84 51 43 28!) Clears 2-2". 2: Clear =2¢- | 90 | Distant thunderstorm in evening.
82 59 ATA eee do... Partly cloudy.| 68
79 61 51| —10 | Cloudy @loudysen se 68
79 50 42 — 8| Partly cloudy.}..... oteee= ck 5 35
79 60 60 0} Cloudy.:...... Partly cloudy. 46
81 51 42| —9]| Partly cloudy-|..... do | gt
83 54 44] —10]..... dotece- 2. 2c] 5 do el
82 62 56 — 6| Cloudy........ Cloudy... .--.- 40
79 68 68 0} eee orwenseashonoes (Olireenen es 47 | Clearing toward night.
81 51 46 — 5| Partly cloudy-.}..... dO -tedscd 38 | Distant lightning in evening.
80 57 45 —12 | Clear.........- @lear=s :--s<2 100
77 50 44 — 6| Partly cloudy.| Cloudy........ 29
84 56 52 (ues 4} Cloudy........ Partly cloudy. 66 | Thunderstorm in early morning.
85 61 50 —11 | Clear...:...... homers dooce. sa S4
72 64 60 — 4] Cloudy........ Cloudy......-- 0 | Heavy thunderstorm flooding marsh and reservoir.
79 64 57 — 7) Partly cloudy. Partly cloudy-| 75
81 53 49 — A) |) Clear... 222-22). 222- do-.. .| 79 | Distant thunderstorm in evening.
81 64 OO} || | 05) ears dose. sec 5: }\@lear cases 100
85 53 49 — 4} Partly cloudy. Partly cloudy. 56
75 49 42 ay fil eee dozs2.. 224 Clears. 100
75 45 41 ee dosa-e Cloudy......-- 57
81 59 55 — 4/| Cloudy........ | Partly cloudy. 82
77 57 48 — Clears. -- Claéarta er ks 97
82 53 45 Si eens do.........| Partly cloudy. 80 | Thunderstorm in afternoon.
79 58 48 LON aera dase. a-02 iy Clean sie once = 94 | Cloudy in evening.
79.7 55.6 B08 ie — On) one ees oe ae nea: coon 68

aIn open over bog.
Highest and lowest readings are in italics.

104

TasLe 21.—Datry WeatHerR Conpitions, MatrHer, Wis., 1907—Continued.

>
AUGUST.
(R), falling (Bate Relative humidity. Dewpoint, Rainfall. Wind.
tionary (S). ps a
Direction and ve-
nam. | 7pm |e ee
7a.m. | 7p.m. ee Marsh.|7a.m.|7p.m.|Total.| ing perature:
direc-
UP | Marsh. | |UP= | Marsh Bee” | Up | iaerabs || Upianae| Mase
land. SD. Jand. : land. aerate | etal
97 97 | 87 gi] 52 49] 0.51] 0.09] 060] NW | 128] 7.4] NW 5] Calm.
90 g1| 72 80] 52 s4] 01 T.| .o01| Nw | 9.9] 5.9] NW 10 4
88 92] 65 90} 49 54 0 0 o| Nw | 63] 3.4] NW 8 3
90 98| 67 72| 54 56 0 0 o| sw | 99] 48] S 3] Calm.
97 g2| 71 91] 37 59| ~ .10 0} a0) Menvvaee |eeideoul es v6s6) |S Wweell 7
82 88| 86 g2| 70 71 T.| .05; .05| Sw | 128] .5.2| S~ 5|\Calm.
79 72| 62 90| 58 62 0 0 o| Nw | 60] 3.3] Nw io 4
90 96| 86 g1| 59 60 0 T.| T.| SE S13'||| 9 aes 1
73 76| 79 89] 70 69 T. ol as 6.2) 2.9] SE 5] Calm.
62 s2| 72 72) 71 72 0 Ol ai) & 1.5| 5.8] S 6/ Calm.
88 s7| 64 71| 56 57} .06| .54| .60| SW | 126] 66] SW 7 5
66 73| 56 77| 56 58 0 0 o| Nw | 9.4] 46} NW 8| Calm.
82 84] 54 73| 58 59 0 0 o| Nw | 48] 22] Nw 5
76 93} 81 92| 64 64 T. 0] .| SE 7.9| 3.5] NE 4| Calm.
iphaee 30.00-F | 29.80-F | 80 7| 81 88| 66 66 0 T.| T.] 8s 10%80|)" 6y3i|| Sato 2
16 ee 29.80-R | 29.88-R| 88 88 | 55 48| 60 54] 1.35 o| 1.35} Sw | 15.0] 85] SW 5 2
7a oe 30.04-S | 30.06-R| 64 ig\| oi 86) 60 59 | 0 0 o| Nw | 53] 22] Nw 6 1
rites! 30.16-F | 29.96-F | 85 86) 74 s2| 67 68 0 0 o| sw | i159] 86] SW 6| Calm.
igus 29.90-S | 30.00-R| 76 76| 70 69| 54 52| 2.98 34| 2:62| SE | 122] 6.6] SE 6 2
D0 aed 30.28-S | 30.22-S | 69 si| 69 95| 47 49 0 0 o| Nw | 7.5] 40] Nw 12 1
|
zie 30.24-S | 30.14-F| 73 36| 69 79| 53 53 0. 0 o| sw | 38] 17] sw 2| Calm.
aoe a 30.20-F | 30.00-F | 85 91) 76 63| 56 51 0 0 o| Sw} 85| 3.5) SW 3| Calm.
Paper dia. 29.90-F | 99.72-R| 78 62] 82 84| 67 67 0 T T.1 sw | 128| 5.7| Sw 5 1
gna 29.90-R | 29.92-R| 64 67| 51 70| 52 52| 37 o| .37] sw | 13.5| 7.4] Sw 10 3
Osa ae 30.04-F | 29.96-F | 74 Ba] By 7 | 52 58 0 0 o| Nw | 68| 36] NW 5 2
iaeeeee 29.94-S | 29.76-F | 91 95| 97 99] 57 56 Ol) <78)|) s781|( SE ths|| Byala su) 1
Pee shee 29.80-R | 29.92-R| 97 98 | 83 80] 63 64 . o| T.| sw | 44] 24] sw 3 2
28 ea 30.04-R | 30.00-S | 69 so] 83 85| 64 63 0 0 o| Ww 2.5| 1.0] NE 4| Calm.
Ogee 29.98-S | 29.90-S | 69 95| 95 93| 64 64 0 T.| T.| SE 5.5| 2.5] SE 2] Calm.
20 eee 29.98-R | 30.00-R| 92 97| 56 86] 54 67| 24 T.| .24! Nw | 32| 4] N 2 1
pies 30.14-F | 30.08-S | 97 ss| 76 80] 74 76 05 T.| .05| SE 7.3| 3.3] E 4] Caim.
sw sw
Means ||! oe. 22 Ik ee 81 36| 72 s2| 59 60 | 24.97 | a1.80 | 06.77 Ra 8.8) 4.4 hew® ON antes

2 Total.

Marsh continued wet and water in the ditches igh all of the month.

Highest and lowest readings are in italics.

O_o EEE

105

TABLE 21.—Datty WEATHER ConpitTions, Maruer, WIs., 1907—Continued.

AUGUST.
Temperature. Weather.
ces piber DIRE Per Miscellaneous.
ay tion 2, male Previous Day. cent
mini- | from night. sine
mum.@ rar F
Maxi- | Mini- quik Smee
mum, | mum. :
68 55 AT —8| Partly cloudy.| Partly cloudy. 49 | Thunderstorm in early morning.
68 46 39 a7) GLOW ye eee = ase) Git hesorecer 55
68 48 40 = FW Ole ence cool sosed Gli ose see 90 | Dense fog over marsh in evening.
74 39 34 a $y) | CODE Kee sea fe ee dozte-s-5 = 69
79 59 58 —1)....- (areas ace||) OEM tees se 90
84 54 46 —8| Partly cloudy.) Partly cloudy. 47 | Thunderstorm conditions.
80 57 48 =)9)| (Clegiase=== ==. | ClCAT~ [= =~ 94
76 55 51 — 4} Partly cloudy. Westen 18
85 54 49 — 5] Cloudy...-...--| Clear--....---- 90
89 59 55 — 4)| Partly cloudy. ze 83 | Cloudy late in the evening.
80 4 70 — 4] Cloudy..-...-.- Partly cloudy. 48 | Heavy thunderstorm in morning.
79 53 40 —13)| Clear: -----.-- (Qi Sa gonese 100
81 50 42 Ei) eae DOSeewere es |onee (ieee cecok 95 | Moderately heavy dew in morning.
85 53 46 — 7| Partly cloudy-|-.--- (st) ae 80
82 56 50 — 6 | Clear......-..- Partly cloudy. 84 Thunderstorm inevening. Light dew in morning.
79 61 58 — 3| Partly cloudy-| Clear........-- 100
85 52 43 — 9 | Clear. Bee eee dOeesen 100
84 57 48 —Q/]...-.- (pee Reseed ence Got ese 100 | Moderately heavy dew in morning.
74 65 65 0: Cloudy... -- - - Partly cloudy. 49 | Thunderstorm conditions.
66 43 34 Oi Cleste == aeena= Clear: Jen—- === 100 | Dew began before sunset; fog over marsh inevening. Cloudy at mid-
night.
74 47 36 —11 | Partly cloudy-.}-..-.- dos-----s- 91 | Fog appeared over marsh at sunset.
74 43 34 == ON OLA ate ner = eter (hye me ee 91 | Heavy ground fog over marsh at 5 a. m.
78 54 47 —7| Partly cloudy.| Partly cloudy. g2 | Thunderstorm.
72 54 41 —13 |..--- dOseeer = aloes do 92
73 48 33 9) | WOlGRRe oe — <= Cleator seas 95
64 51 42 — 9| Partly cloudy-| Cloudy----..-. 10
69 56 56 0 | Cloudy.-...---- Partly cloudy. 36
76 58 50 | —8| Clear...-...-.- Gleani-< 3. 4 100
68 51 44 — 7) Partly cloudy.| Cloudy--...--. | 4
75 64 62 — 2] Cloudy.-.-.-.-- Partly cloudy. 50
89 58 52 == (Biileetrze Ose nee | Oleare sec ans 85
716.7 54.0 47.1 (740) | es Pad Score onee | 74 ,
| J

aIn open over bog.

Highest and lowest readings are in italics.

106

Tasie 21.—Datry WeaATHER ConpitTIons, MATHER, Wis., 1907—Continued.

_
SEPTEMBER.
Barometer — Rising *
| (R), falling (F), Relative humidity. Dewpoint, Rainfall. Wind.
z 7 p.m.
stationary (S).
12
| ‘ Direchior ead ae
2 s Average ve- ocity at time o
ffaig uses ghia a locity. minimum tem-
Jp- vall- erature.
7 a.m. 7 p.m. ee Marsh. | 7 a. m. | 7p. m. | Total. nee, B
tion.
| UP | Marsh.| UP) | Marsh. UP: | Marsh.| Upland. | Marsh.
| ——=-
Neeence 30.02-S | 29.90-R| 76 | 78 72 71 | 61 61 in, 0 T.| NW | 11.1 6.2] NW 8 2
29.86-S | 73 76 | 68 76| 48| 54 0 0 0| NW} 110] 6.2) NW 9 4
29. 84-S 74 90 S4 95| 54 56| 0.01} 0.01] 0.02| NW 8.0 4.5| NW 6 2
29.92-R | 87 93 78 | 92) 52] 57 0 -03| .03| NW 9.1 5.3] NW 10 4
. 30.06-S } 84 77 7. 94| 53 | 56 0} 0 0} NW 7.8 4.0} NW 12 6
Bziesnse 30.08-F | 29.94-F | 91 91 88 so| 57 56 | O| .04| .04) WwW 4.0 1.5] SW Calm.
| |
|
Cee He 29.78-F | 29.80-R| 94 96 | 98 97| 58 58| .31 | Well) soe }u{| \ 1D 5.6 258) |(a ey a0 6
Heeaee 29.82-S | 29.92-R|] 96 98} si'| 94) 49 52 Pal 0} .27| NW 9.5 5.2| NW 6 2
9 30.02-R | 30.08-R] 7 80 70 70) 49 | 48 0) 0 o| NW 9.3 5.1] NW 12 3
29.96-F | 92 91 7 95] 51 | 53 0} .01} .o1) NW 3.2 1.1} N 4] Calm.
29.98-R | 87 | 92 62 78 | 54 59 | O- 0 0) NW | 108 5.6| NW 4 1
30.12-S 80 80 75 79 50 61 0) ans T.| SW 7.4 26/ W 6] Calm
eeeceis! 30.14-R | 30.00-S | 74 76] 67 82} 61} 66 O 0 0| SE | 14.4] 7.2] SW 2] Calm.
14 30.00-S | 30.00-R| 65 76 80 81| 64] 64 0. 0 0| SW | 14.5 5.9| SW 15 4
30.10-F | 65 68 | 50 65) 63 73 0) 0 0| SW | 10.4 4.5| W 6 1
30.04-R | 96 96 75 86) 63 67 14 0 -14| SW 10.1 5.0| SW 13 4
29.98-F | 97 97 97 98| 63 63 OL M75 | ees Ou ONE | mde 5.8| SW 5 2
29.92-F | 94 97 80 85] 67 | 70 25 IT ie 25a eS Wien | eal O82) all uti oe 2
29.72-F | 97 95 75 85| 69 | 71 40 | 0} .40| NE | 14.0 6.8| NE 6] 3
29.98-R| 94 94 66 85) 49 | 54 4 | O| .41| W 14.6 8.2| NW 17 | 13
30. 06-S 74 81 47 73) 31| 36 0, 0 o| SW | 13.1 6.9| SW 4 1
29.76-F | “56 77 94 94} 49) 50 0} ere T.| SW | 188 4.0} SW 4 a
23 eee 29. 48-F | 29.36-R | 89 95 65 80, 48 54 -10 14) .24| W 13.3 7.3| W 10 1
Vee 29.58-R | 30.02-R| 77 81 68 88] 34 40 0 me T.| NW | 19.5] 11.4] NW 30 10
30.26-F | 66 87 65 83 | 36 42 0 0 0} WwW 8.1 4.3] W 6] 3
30.08-F | 82 83 66 80| 44 50 0 0 0| SW 9) 3.1| SW 4] 1
29. 90-S 98 94 80 87| 44 | 46 0 0 0| NE | 10.2 4.8| NE 3) Calm.
29.96-S | 92 74 52 74| 38 46 0 0 0| NE 7.9 3.6| NE 9 5
30.06-R | 70 72 87 94) 46 | 49 0 .02] .02| NW 7.5 41| 8S 1} Calm.
30.30-F | 71 86 81 95} 40 39 0 0 0 Ss 5.1 20) W 3] 2
Means.|........... | ade aie 82 86 74 85} 52 55 | @1.90| 21.00 |a2.90| NW 9.9 5.0 | NW7.7 2.8 |
a Total.

Marsh continued wet and water in ditches high all of the month, flooding in anticipation of frost being frequent during latter part of the month.
Highest and lowest readings are in italics.

107

Tapie 21.—Datry WEATHER ConpiTions, Maruer, Wis., 1907—Continued.

SEPTEMBER.
Temperature. Weather.
: Differ- A
Shee Biotin ae en co Per Miscellaneous.
den pum | Tygies | pas, |
am mums) mie | ee
Suan a a
|= = = =
80 70 61 — 9} Partly cloudy.| Clear......-..- 94 | Cloudy in evening.
68 53 42 eee Gee eaoad Somes dO = so2%-2 100
65 50 40 LON eee doze 2 Partly cloudy. 41
66 52 45 = FPO rs Weaeeeee Seer doses -: 60
71 44 36 = #:)|| (QE NSE SER see Clears e-=--=-- 80 | Fog began to form about 8 p. m.
67 41 33 — 8 | Partly cloudy.| Cloudy...-.... 9 | Fog quite dense in morning, especially over marshes; grass very wet
from dew and fog.
64 54 55 =F 1) | Cloudye-2--5--|-2--< done gees: 1
65 56 56 Oo) eases rales sone Partly cloudy 50
68 40 30 VON Gears eran eee Cleans eee ee 100 | Dew began to form at 6 p. m.; light fog over marsh in evening.
64 38 30 — 8] Partly cloudy.) Cloudy.....--. 24 | Although minimum temperature was low, no frost was observed.
73 45 37 ot Mae Cosas a Partly cloudy 60
78 48 37 SI (OG en Clear: coe. - 2: 72 | Increasing cloudiness in afternoon.
80 50 40 —10| Partly cloudy.!.-.-.- dommes = 100
82 62 57 S|) (ORI 25 eae E gee! (aloes See 93 |
8&4 63 54 Hh |e do Partly cloudy. 88
81 67 64 — 3]| Cloudy..-.---- Clear. - eae 85 | Thunderstorm in morning.
74 53 44 — 9] Partly cloudy-.| Cloudy.--.--.- 31 Do.
79 58 56 — 2| Cloudy-...---. Partly cloudy. 46 | Thunderstorm conditions.
84 61 58 = 3 o..c8 GOs. Sse sihes GOueere =e 63 Thunderstorm in early morning.
66 60 57 0 feneers GiNeRe reas Glears=2----5- = 72 |
62 38 30 — 8| Partly cloudy.| Partly cloudy 70 |
64 31 23 Shieh) | AO EEE a oeee spose BOtrcaea 70 | Killing frost in morning; frost first observed last night at 10.30 on
marsh.

62 45 37 —8 18
49 43 40 —3 21 | Clearing at night.
55 28 20 = 8 100 | Killing frost.
63 34 25 — 9} Partly cloudy-| Partly cloudy. 38 Do.
55 34 27 — 7| Cloudy..-.---- ‘Gloudy:--22--= = 0 | Light frost.
60 7 35 — 2)....- dos Sse: ss Partly cloudy. 72 | Ground fog on marsh after 5.45 p. m.
60 29 25 — 4) Partly cloudy.) Cloudy-........ 33 | Killing frost.
61 28 19 — 9| Clear........-. Partly cloudy. 86 | Killing frost, very heavy deposit.

era) ae) |u| 0: 792 ee cee PS bee v2 59

|

aIn open over bog.
Highest and lowest readings are in italics.

108

TaBLe 21.—Datty WeaATHER Conpitions, MaTHeER, Wis., 1907—Continued.

OCTOBER. -
eee) falling Fe Relative humidity. Dewpoint, Rainfall. Wind.
stationary (S). Be

Direction and ve-

nam | 7pm ce | tees ee

7 a.m. 7p.m. ee Marsh. | 7 a. m.|7 p.m. | Total. aoe fusiir
Ao q_| Marsh ee Marsh. eo es Marsh. | Upland. | Marsh.
|

29. 86-F 80 85 73 85 | 50 52 0 0.08 0. 08 SE 13.0 6.5 SE 5 2

29. 90-S 85 | 98 63 74 | 54 54 0. 04 0 -04) SW 5.7 2.2} SW 6 1

29. 80-R 89 | 94 88 97| 54 56 .09 | -O1 -10| SW 7.6 4.0| NE 7| Calm.

29. 88-S 86 89 60 57] 41 | 36 -O1 0 -O1 Ww 8.6 4.4 Mi 8 2

30.00-F | 58 68] 94 95| 50 | 49 0 0 o| Nw | 79] 3.7] NW 6 2

29. 60-F 77 74 | 56 89} 48 55 0 0 0 SW 14.4 6.5| NW 6 1

29. 94-R 90 96 | 88 92 44 44 02 . 06 -08 | NW 11.4 6.5 | NW 12 2

30. 10-F 83 88 39 60 27 32 0 0 0 SW 8.7 3.8 | SW 1

29. 98-S 50 46 | 80 86) 42 43 0 TT T.| NW 15.9 8.1} NW 9 4

29. 86-S 67 70 } 41 75 29 42 0 0 0} NW 16.2 8.9| NW 3 1

30.14-R | 88 s7| 61 60} 30] ~—30 03 T.| .03| Nw | 140| 84] Nw 10 7

30.32-S | 85 so| 77 8 | 31] 32 0 0 0| Nw | 102! 61] NW 12 7

30. 32-F 82 80 56 84 28 | 26 0 0 0| NW 5.6 2.5| NW 4 3

30.12-S 62 81 | 56 53 38 36 SUK T. SW 7.8 3.2} SW 5) Calm.

30.14-S 76 93 | 72 63 44 39 .10 0 .10 SW 8.0 3.8 SE 6 | 4

30. 12-S 94 96 83 82 52 50 0 0 0; SW 5.4 1.9| SW 2) Calm.

30.10-R| 81] 70] 51 44| 46| 36 0 0 0| Sw | 13.7) 69] NW 6] Calm.

30. 40-F 76 | 64 | 48 7 20 | 26 0 0 0| NW 8.8 4.8) NW 9} 7

30. 04-F 72 79 75 82! 33%] 0 TY Ty SW 5.6 2.6| NW 4 1

30.36-S | 56] 5] s1| 85| 29] 28) 0 0 o| N 6.9| 37] NE 9 4

30. 10-F 78 | 84 65 87 34 | 41 0 0 0 SW 10.6 4.0| SW 3 1

29.94-R 57 | 79 72 87 48 45 0 0 0 WwW an ley/, Di aN eS 4

| 30. 18-S 88 | 7 51 76 42 | 46 Ty toy MS SW 5.4 2211) SE 6 1

Pee 30.14-F | 29.98-R 46 87 | 47 77 29 | 35 0 0 0); SW 11.5 ont Ss 6 3
262 S25 .s5 30. 22-R | 30. 32-S 53 74 | 47 81 23 | 29 0 0 0 N ech) 3.9] NW 8 3
Deen 30.22-F | 29.90-F | 93) 99| 56 64} 32] 35 0 T T.| sw | 8.0] 34| Nw 6 1
Vt fee 29.94-R | 30.26-R 91 90 58 61 20 20 T ult T.| NW 14.7 8.7] NW 17 2
2 aa ae 30. 30-F | 30. 18-S 98 89 54 84 29 35 0 0 0 SW 6.1 2.4) SW 4] Calm.
Soe 30. 16-S 30. 22-S 78 71 | 92 88 40 40 0 p be E 8.7 4.1} NE 5 2
302232525 30.26-R | 30.30-F 89 79 91 97 41 41 lb 05 05 SE 9.5 46] SE 7 3

Be 30. 26-F 30. 14-F 92 ,90 | 72 56 43 35 10 0 os 10 SBN ssc. sec} sac eee E 6 2 t
Means.|..........- |Gaeeen el 77 | 81 66 77 38 39 a. 39 a.20/} 2.59} SW 9.6 4.8 | NW 6.6 2.3
| | | !
@ Total.

Marsh was much drier this month than at any time previous this season, except in the latter part of June, although water in the ditches remained

high until about the 10th of the month.

Highest and lowest readings are in italies.

109

TasBLe 21.—Datry WEATHER CONDITIONS, MATHER, Wis., 1907—Continued.

OCTOBER.
Temperature. Weather.
| Shelter Station Differ- Miscellaneous.
| 4, Upland. Sta- | ence— Per
tion 2, | mini- Previous cent
mini- | mum night. Day. of
See eta shine
| ase AE ame |
60 33 Pal —316 Partly cloudy.| Cloudy-....... 21 | No frost or dew observed.
75 52 46 — 7| Cloudy......-. Partly cloudy. 65
“70 46 36 —10 | Partly cloudy.) Cloudy.-......-. 15
62 41 27 —14 )...-- 002522222: | Partly cloudy. 70 | Light frost.
66 41 27 —14 | Clear....-....- | Clear. ...-...-- 83 Do.
74 44 34 —10 Partly cloudy-|....- Monemecse- 85
bl 50 37 —13 jnn- =e dokesa-s22 Cloudy..-.-...- 0
56 23 16 =f) | ClearennS2s525 Partly cloudy. 75 | Heavy and killing frost; looked like light snow; thin ice formed.
52 40 33 =| Cloudy. 0
60 35 25 —10 | Partly cloudy. 72 | No frost observed.
48 35 2% | —9/-....- domes s eee il
43 29 23 — 6 | Cloudy........ 13 | Heavy and killing frost; ice formed.
50 25 16 — 9] Clear-........- 100 | Killing frost and ice; aurora in evening.
62 22 16 = 6 )}-:-.. dose 3cc-- 7 Killing and heavy frost and ice.
60 44 39 — 5| Cloudy........ 67
69 36 29 — 7) Partly cloudy.|..-.. Gorse. =e 7 | Dense fog from last midnight until 11 a. m.
71 39 27 —=12'|' Clear=—-<--5-- (Clear. :=2--c-< 89 | Light fog in evening over marsh.
48 24 18 100 | Killing frost, light in amount, but damp ground froze.
43 27 18 0 | First snow flurry of the season; severe freeze.
48 28 22 100 | Freezing.
54 19 13 100 | Very heavy deposit of frost. Ice on reservoir.
66 40 31 83
57 30 22 98 | Frost.
64 29 18 86 | Freezing.
49 28 V7 100 | Frost.
53 19 12 — 7] Partly cloudy.; Partly cloudy- 69 | Heavy frost in morning.
87 34 29 — 5| Cloudy........ Cloudy.....-.-| 0 | Snow in morning.
53 17 10 —7 | 100 | Exceedingly heavy frost deposit.
49 32 26 — 6 34
45 37 35 —2 10 |
56 37 29 — 8 44
56.5 | 33.4) 25.3) —8.1 58
| | |

aIn open over bog.

Highest and lowest readings are in italics.

110

Comparison between temperatures in the bog at Mather, Wis.,and at United States Weather Bureau
Office, La Crosse, Wis.—While numerous references have been made to the minimum té@mperature
readings at La Crosse, a more complete comparison between the temperature at that place and
Mather should be of interest, especially to those who are well acquainted with the daily weather
map. Forecasters must look to the forecast chart for their general information, and many of
them are accustomed to consider reports from certain stations as “‘keys’’ to conditions prevailing
in adjacent sections. a Crosse may be considered as a ‘“‘key”’ to the cranberry marsh region
of Wisconsin. It is situated about 55 miles southwest of Mather, and isanold established station
of the Weather Bureau. The thermometers at La Crosse were at the time of this investigation
located in an instrument shelter on the roof of the federal building. Thus far the study has
been confined mainly to the temperature conditions in the bogs, showing the wide range in
even the same bog; and references have been made to the general weather conditions prevail-
ing as shown by the daily weather maps. Some mention has also been made of the tem-
perature readings at La Crosse in connection with the marsh readings in Wisconsin, and now
a comparison of observations of temperature at both La Crosse and Mather for the entire season
of 1907, Tables 22 and 22a should prove interesting. The maximum temperature readings are
not included in the table, as a comparison of them does not seem to be important.

The minimum shelter readings at Station 1 at Mather averaged 5.2° lower than at LaCrosse
(Table 22a), and the average difference was greatest in June, 7.1°, and least in September, 3.6°.
The temperature in the shelter over the moss at Station 2 on the bog averaged 8.7° lower than
at La Crosse, and the greatest monthly difference was again in June, 10.8°, and the least in
September, 6.4°. The minimum exposed over the moss at the height of 5 inches on the bog
averaged 11.9° lower than at La Crosse, and the greatest monthly difference was in June, 13.9°,
and the least in May, 8.5°. The minimum in the open on the bog at Mather averaged 3.2°
lower than that in the shelter nearby. The greatest difference on any one day in the various
months between the temperature at la Crosse and that in the open over the moss at Mather was
20° in May, 24° in June, 21° in July, 19° in August, 20° in September, and 22° in October.
Often there were days of very little difference when the weather was cloudy, and there were a
few instances where the temperature in the bog at Mather was even higher than at La Crosse.
This is not surprising in view of the fact that these stations are 55 miles apart, and that occasion-
ally the weather conditions at the two places differ considerably. What we should consider in
the study of these readings is the average difference under all conditions, the average difference
when the pressure is high and the weather clear, and the extreme differences. While extreme
differences of 22 to 24 degrees may occur, there are usually days in every month when the tem-
perature in the bog is 20° lower than at La Crosse. The average difference when the weather
is clear and the pressure high is about 18°, so that when the temperature at La Crosse is 50°
during the conditions favorable for frost, it is probable that the temperature at the coldest places
on the bog is as low as 32°. The latter has reference, however, to the reading of a minimum
thermometer in the open, and ordinarily, the reading of the exposed minimum at the coldest
point in the bog must be below 30° to cause any damage. On August 8, 1904, when the mini-
mum temperature at La Crosse was 48°, the memorable midsummer freeze occurred which
destroyed the greater portion of the Wisconsin crop, minimum temperatures in the bogs
being as low as 26°. Frost usually formed on the thermograph before it did on the vegetation,
indicating that the black metal cover of the instrument loses heat even more rapidly than the
vines and grasses. Again, temperatures of 30°, 29°, and even 28° have been observed when no
frost was seen, but unless frost is looked for on such mornings at the very time of minimum
temperature, there is no proof that frost did not occur. When the temperature is below freezing
for a brief period only, light frost may form for a few minutes just before daybreak, and disappear
as soon as the temperature rises to the melting point. Even should frost occur during any night
insummer, the temperature would have risen above the freezing point by sunrise.

aiy

Hae

MarHer, Wis., SEASON oF 1907.

Le 22_Minimum TEMPERATURES AT WEATHER Bureau, La Crosse, Wis., AND AT DIFFERENT LOCATIONS AT
?

May. June.
Readings| Shelteron Set aanee Sea aae, Readings| Shelter on gehelier ony | Be,
Day of month. aior Ree Pan | ROSS tare ae Mat or Wis. moss, m Beas
Weather | Mather, Wis. | rather, wis. | eather Mather, Wis. | yrather Wis.
office, office,
‘La Crosse, | | La Crosse, | |
Wis. Read- | Differ- Read- Differ-| Read- | Differ- Wis. Read- | Differ-| Read- | Differ- Read- | Differ-
} ings. | ence. | ings. ence. ings. ence. ings. ence. ings. ence. ings. ence.
o ° ° ° ° | ° °
45 By) =o) 32) 13 28 =I
47 20) |e Gp || (EatGs 29 =18
55 55 0 Geel) | 53 =i
48 41 -—7 38 —10 | 35 —13
49 44 = 5 Ae) -38 —1
46 ee ake Si) | eee 28 ==18
50 4g| —2 ATaleeeai! i °45 5
48 i ae) su |) Sat? 28 —20
56 41) =16 | 36 | —20 32 =)
58 54) — 4 S| = 4 53 =
57 47| —10 44) —13 39 18
45 36) —9 37| —8 35 || —10 54 533] —1 51] —3 50 —4
56 esi 98 Gf) +65 60) +4} 49 44)|| — 5 W)| =i 34 —15
41 45,)° + 4 45| +4 45) + 4) 50 ey)| =n 35] —15)| 31 —19
36 36 0 36 | 0 36 0 55 | 5) Sie) 39} —I6 | 35 —20
37 35)| —2 35| —2 wh) ag 65 54) —11 49 | —16 | 46 —19
50 40'| —=10 35) —15 30) —18 68 70; +2 66| —2| 63 —5
50 ECM) eae) 35) —15 32| —18 65 59|- —6 oN | iis | 50 15
42 391) — 3 33] —9 2g) |e 14 59 ave — 2 SOu E29 47 =)
33 Oy) = Si))) 12 18) —15 58 oe <7 45) | —13 42 —16
41 er) —14 23°|; =18 21| —20 59 49] —10 45| —14 41 =i
46 apy 44)\ 2) “|| = 66 6) — |, 5) 59 = 7
47 44] —3 44] —3 44) = 3 66} 60/ —6 ey] 54| —i2
50 Aa AG Dy =i 40), —10 62 sae 8 Ri) = s 50 —12
48 Ao 8 45] = 3 44) —4 63 Ball — 5 Bi] = Fi 53 —10
40 431 +3 45| +76 45) +6] Gi) ke eG 46 eal 41 —13
38 a2) 16 Sear Sie) i 52 45) = 7% 329i) 518 | 35 ==)
41 Saupe 7 gi] uf a} =14 56 43) 18 aes) 37 | =19
50 Ae —19 34| —16 30 |
53 bE) = 39] =14 36
50 ST 18 46} 4 45
44.7" 40.9} =3.8|\~ 38a) 66) 36.2) =s5| 56.2) 491] =7-1|° 45.4] —=10:8| 42.3| —13.9

the various exposures at Mather.

51936°—Bull. T—10——8

Highest and lowest readings are in italics.

NotE.—Columns headed ‘‘ Difference’’ have in every case reference to the readings at the La Crosse office as compared with readings at

112

TABLE 22.—Miniuum TEMPERATURES AT WEATHER BuREAU, LA Crosser, WIS., AND AT DIFFERENT Logations at
Martner, Wis., SEASON or 1907—Continued.
July. August.
= i
| P
lReadings Shelter on Soe eT ee A aren Readings Shelter on Sree: above tates
Dey afmonth. “|iofrom. | Upland, | Tosa, |) Ope mes | stom | ake Wis, | eave: | inenone
ARE | Mather, Wis. Mather, Wis. | ‘Bureau ? Mather, Wis. Mather, Wis.
office, = office,
La Crosse, | | LaCrosse,
Wis. Read- Differ- | Read- | Differ-| Read- | Differ- Wis. Read- | Differ- | Read- | Differ- | Read- | Differ-
ings. ence. | ings. | ence. | ings. | ence. ings. | ence. | ings. | ence. | ings. | ence.
° ° ° ° ° ° ° ° ° ° ° ° ° °
58 59 +1 55 —3 52 —6 53 55 + 2 52 -—1 47 —6
50 88 —12 32 —18 29 —A1 52 46 —6 43 9 39 —13
59 48 =l1 41 —18 38 —21 51 48 —3 43 — 8 40 —i1
65 51 —14 47 —18 45 —20 50 39 —11 56 —14 34 —16
70 60 —10 61 —9 59 —i1 63 59 —4 59 a 58 — 5
64 58 —6 55 — 9 53 —Ii1 64 54 —10 48 —16 46 —18
61 51; —10 46 —15 43 —18 61 57 —4 51 —10 ; 48 —13
65 59} —6 50 —15 47 —18 63 55 —8 53 —10 51 —12
64 61 —3 54 —10 51 —13 62 54 —8 52 —10 49 —13
60 50 —10 45 —15 42 —18 69 59 —10 57 —12 55 — 14
62 60 —2 60 —2 60 —2 63 14 +11 v2 +9 70 +7,
59 51 —8 44 —15 42 —17 58 53 —5 43 —15 40 —18
63 54 —9 47 —16 44 —19 60 50 —10 46 —14 42 —18
63 62 —1 61 —2 56 —7 62 53 —9 49 —13 46 —16
66 68 + 2 68 +2 68 +2 64 56 —8 54 —10 50 —14
62 51 —i11 49 —13 46 —16 64 61 —3 59 —5 58 =
61 57 —4 48 —13 45 —16 58 52 — 6 47 —l1 43 —15
60 50 —10 47 —13 44 —16 66 57 -9 51 —15 48 —18
67 56 At 53 —il4 52 —15 58 65 +7 65 ar if 65 ar tf
64 61 —3 53 =l1 50 —14 50 43 —7 39 —il 34 —16
66 64 —2 62 —4 60 —6 52 47 -—5 40 —12 36 —16
66 64 —2 60 — 6 57 —9 51 43 — 8 38 —13 34 —17
60 53 —7 of = 50 —10 61 54 —-7 51 —10 47 —l4
69 64 —5 61 —8 59 —10 57 54 -3 45 —12 41 —16
65 53 —12 53 —12 49 —16 52 48 —4 38 —14 33 —19
58 49 -9 46 —12 42 —16 59 51 —8 46 —13 42 —17
57 45 —12 45 —12 41 —16 60 56 —4 55 —5 56 Se
63 59 = 57 = 6 55 — 8 60 58 —2 54 —6 50 —10
61 57 — 4 51 —10 48 —13 61 51 —10 48 —13 44 —l7
57 53 =i 46 —lI 45 =12 66 64 —2 64 —2 62 —*4
62 58 —4 53 —9 48 —14 69 58 —11 55 —14 52 —17
‘Means= -eeraeea- 62. 2 55.6 —6.6 51.7 | —10.5 49.0 | —13.2 59.3 54.0 —5.3 50.1 —9.2 47.1 | —12.2

Norte.—Columns headed ‘‘ Difference’’ have in every case reference to the readings at the La Crosse office as compared with readings at

the various exposures at Mather.

Highest and lowest readings are in italics.

113

TABLE 22.—MINIMUM TEMPERATURES AT WEATHER BuREAU, La Crossp, WIs., AND AT DIFFERENT LOCATIONS AT
Marner, Wis., SEASON or 1907—Continued.

September. October.
Readings Shelter on a oat Sheen Readings| Shelter on Stolen Cas abevaanee
Day of month irom Mater Wis. MOSS, _ Sings) | SO ll ae ais MOSS, Eonar
Weablien g Mather, Wis. | rather, Wis. | Wcather yu’) Mather, Wis. | weather Wis,
office, |_ office, ie |
La Crosse, La Crosse,
Wis. Read- | Differ- | Read- | Differ-| Read- | Differ- Wis. Read- | Differ- | Read- | Differ-| Read- | Differ-
ings. | ence. ings. | ence. ings. ence. | ings. | ence. ings. ence. | ings. | ence.
° ° ° ° ° ° ° ° ° ° ° ° ° °
62 70 +8 65 + 3 61 —1 49 33 —16 32 -17 27 —22
55 53 —2 47 —8 42 —13 55 52 —3 49 —6 45 —10
56 50 —6 45 —11 40 —16 53 46 —7 40 —13 36 —17
53 52 =1 45 a8 45 —8 44 41 —3 32 —12 27 —17
50 44 —6 41 — 9 36 —14 45 41 —4 33 —12 27 —18
50 41 —9 38 —12 33 -17 66 44 —l11 39 —16 34 —21
59 54 —5 56 —3 55 — 4! 40 50 +10 41 +1 37 —=13
47 56 +9 56 +9 56 +9 32 23 -—9 21 —1l1 16 —16
45 40 —5 36 —9 30 —15 40 40 0 39 =i 33 = ff
46 38 —8 36 —10 30 —16 40 35 —5 29 —l1 25 —15
49 45 —4 42 —7 37 —12 39 35 —4 32 —7 26 =13
52 48 —4 40 —12 37 —15 33 29 —4 28 C3 i) 23 —10
60 50 —10 44 —16 40 —20 25 25 0 21 —4 16 — 9
64 62 —2 59 = 5 57 iif 34 22 —12 20 —14 16 —18
66 63 = 3 58 = 5 54 —12 7 44 —3 43 = 31)! 39 = ts
63 67) a4 Gal) abe 64| +1 44 36; —8 Su) Sr] i SG
61 53 —8 48 —13 44 17 44 39 —5 30 —l4 27 —17
62 i) =n 58| —4 56| —6 32 ons Bi = 0 |] =i
66 61 —5 61 —5 58 —8 32 27 —5 23 -—9 18 —14
50 60 +10 59 +9 57 +7 32 28 —4 27 —5 22 —10
42 38| —4 35; —7 30; —12 28 19; —9 18 —10 13 —15
38 all =F 29| —9 23| 15 42 40) eee a) 7) at] =n
47 45| —2 43 — 4 37 —10 34 30 —4 27 —7)} 22 —12
40 43 +3 43 + 3 40 0 40 29 —11 23; —17 18 —22
33 28 —5 25 — 8 20 —13 30 28 —2 24 —6 17 —13
45 34 =11 29 —16 25 —20 29 19 —10 18 I 12 =ilf/
42 34 —8 32 —10 27 —15 25 34 +9 32 cia 29 + 4
43 37 —6 39 —4 35 —-8 22 17 —5 16 —6 10 —12
40 29 —I1 29 =i1 25 —15 42 32 —10 29 —13 26 —16
36 28 — 8 26 —l11 19 —17 41 37 —4 36 =p 35 = Gy
ppee=tISed SeStered Eareeaee Ebossccs Scenes fae asend Ransenoe 35 37 +2 34 = 29 —5§
50.7 47.1 —3.6 44.3 —6.4 40.4 | —10.3 38.2 33.4 —4.8 29.9 —8.3 25.3 —12.9

Highest and lowest readings are in italics.

TABLE 22a.—MoNnTHLY AND SEASONAL MEANS or MiNImuM TEMPERATURES AT WEATHER BuREAU, LA Crosse, Wis.,
AND AT DirFERENT Locations at MATHER, WIS., TOGETHER WITH DIFFERENCES BETWEEN THE READINGS, 1907.

. é At 5 inches above
Readings, | "ifatben Wis” | Staoss Slathers Wise’ | mash, over mos, in
Month. La Crosse,
Wik 9 |=
Readings. | Difference. | Readings. | Difference.) Readings. | Difference.
° ° ° ° ° ° °

44.7 40.9 —3.8 38.1 — 6.6 36. 2 — 8.5

56. 2 49.1 —7.1 45.4 —10.8 42.3 —13.9

62. 2 55. 6 —6.6 51.7, —10.5 49.0 —13.2

59.3 54.0 —5.3 50.1 — 9.2 47.1 —12.2

50.7 47.1 —3.6 44.3 — 6.4 40. 4 —10.3

38.2 33.4 —4.8 29.9 = 8:3) 25.3 —12.9

51.9 46.7 —5.2 43.2 — 8.7 40.0 —11.9

@ Means for twenty days.

Note.—Columns headed ‘ Difference” have in every case reference to the readings at the La Crosse office as compared with readings at
the various exposures at Mather.

114

Temperature conditions in the bogs during the seasons of 1908 and 1909.—The principakeatures
of the season of 1908 in the Wisconsin bogs were as follows: Frost occurred on June 11 and 15 at
both Cranmoor and Mather, the exposed minimums in the bog at the latter station being 29°, and
28.9°, respectively; frost was again noted at both stations on August 20, 23, and 24; and again
in September on the 2d and the 3d, the rest of the month being warm until the 28th when kill-
ing frost occurred; also on the 29th and 30th. There was ample water supply in the Wis-
consin bogs for reflowing, and no damage, as a consequence, occurred to the crops from these
frosts. ;

In 1909, frost occurred at Mather, June 15 and 18, but no frost was reported at Cranmoor
on any date in June. Frost was again reported at Mather on July 19, when the lowest exposed
minimum was 29°. On that date the lowest temperature at Cranmoor was 32.8°, but no frost
was observed. On August 30, frost was observed at Mather, but none at Cranmoor, the minimum
at Mather registering 23°. The temperature was unusually low in the bogs during September,
in strong contrast to the September of 1908, frost being reported on 11 dates at both Mather
and Cranmoor. On these days the exposed minimums over moss at Mather were as follows:

° | °
September 1....-- BARA CORE ado An Cease Boshi 15 | September 2): .---sas-as-ceieee Smee ee ees 14
Septem lier) cee ese ee oe aes are ee eee ea 16}|\Seplember 26.2. eeee 5 os eee eee ne aes 13
September(G: sess ec ee Cia «meee en eee 22)|'September 272.552. sc aaese peek essa oe eee eee 12
Septem per Obes eee ere eee eee ae ee 24'| ‘September 28... 222 cc/s-5. 25) -ee ans sebee eee ee ee 26
Sete mb eri 23 meee eee see eee eee 24:) September30.--224...sciee cee cent hee eee eee 22
SSE pera by er 24 eee ee

These conditions were most extraordinary, and following, as they did, a season of compara-
tive drouth, the growers were unable to properly reflow their marshes. In fact the larger portion
of the Wisconsin crop was destroyed by the frosts of September 1 and 2, 1909, not more than
25 per cent of the entire crop being eventually saved.

The conditions as shown by the weather map indicated plainly the coming of the frosts
during the year 1909, and ample warnings were issued from the forecast center at Chicago. It
is unfortunate that water supply was not available for reflowing, as in previous years. The
season of 1909 in the moorland sections was the driest in about a dozen years, while in the few
years immediately preceding, there was complaint of too much rainfall rather than of too little.

Temperature of the water in the reservoir.—Much has been said already about the low tem-
perature prevailing over damp ground, and it has been shown that over a saturated soil the
minimum temperature, especially on clear, cool nights is low. It may therefore seem strange
that additional water is used in order to ward off frost. A reservoir usually has about three
times the acreage of the bog that it is intended to flow or reflow. The time required to flow a
marsh depends upon the head of water at the main gate of the reservoir, ahd upon the depth
of the water already in the ditches. If the ditches are nearly empty, much time is required,
but the Wisconsin growers usually have water in their ditches up to within about a foot of the
surface of the marsh. Through capillarity this water rises through the peat, and if the water
is within 6 inches of the top of the ditches the marsh is very wet. By pressing down upon
the soil along the edge of the ditches, even though the water therein is considerably below the
surface of the marsh, the water is squeezed out as from a sponge. During a dry, warm season,
growers are accustomed to let the water remain low in the ditches, in order to save their supply,
but as cold weather approaches it is the custom to turn on additional water from the reser-
voir. It is often possible to reflow an entire marsh in from two to four hours. The water in
the reservoir is usually comparatively warm, and although it loses heat as it passes through
the ditches on a cool night, light frost is sometimes avoided by merely increasing the depth of
the water in the ditches. At other times, however, the water is raised just to the surface of
the marsh, and only when a severe frost is expected are the vines and berries completely covered
with water. The water turned onto the marsh on these occasions in anticipation of frost usually

115

has a high temperature as compared with the water that is found from day to day in the peat
soil of the bog. This latter partakes of the temperature of the soil itself, and is one of the
important factors in preventing the heating of that very soil in the daytime, and consequently
one of the direct causes of the low minimum air temperatures at night. If the water is low
in the reservoir, as happens during a drought, and during a cool period its temperature is reduced,
nothing can be gained by flowing unless there is sufficient supply to completely cover the bog.
To bring this cold water just to the surface would be to reduce the temperature of the air still
further by evaporation. Reference has already been made to the drouth in the Wisconsin
bogs in the summer of 1909. Few growers had sufficient water supply to reflow in anticipation
of the severe frosts of September 1 and 2 of that year, and it has been said that the growers
who did not attempt to reflow suffered less injury than those who used their limited supply
of water, chilled as it must have been.

While, as has been stated before, in order to be effective, the acreage of the reservoir should
be three times that of the cranberry marsh, the reservoir of the Fitch marsh at Berlin was
hardly half the size. There are other marshes in Berlin that have no protection in the shape
of reservoirs. The Sackett marsh depends upon the Fox River for its water supply, the water
being pumped from the river whenever there is need of flowing or reflowing.

A Richard soil thermograph placed in the reservoir at the Appleton marsh, with its bulb
about 12 inches below the surface, has furnished an interesting series of readings of water tem-
perature for the season of 1907. (Fig. 14.) The temperature of the water responded to the
varying changes in the temperature of the air. There was an irregular increase through June
and July to the middle of August, the highest maximum occurring on August 7, 79°, with
the exception of a maximum of 81° which occurred on June 17 and 24, during and following
a protracted period of high temperature. The highest minimum, 73°, occurred on June 22
and August 11. The highest and the lowest temperatures each month were respectively as
follows: May, 67° and 42°; June, 81° and 53°; July, 77° and 66°; August 79° and 58°; Sep-
tember, 70° and 46°; October, 60° and 35°. The absolute range for the season was therefore
46°. The following are the mean daily maximum and minimum temperatures each month:
May, 58° and 49°; June, 70° and 63°; July, 74° and 69°; August, 70° and 64°; September,
61° and 55°; October, 49° and 42°. Throughout the season, the lowest temperature of the
day usually occurred at about 5 a.m. and 6 a.m. The maximum occurred in May at 4 p. m.,
and as the season advanced it occurred later and later each day until midsummer, after which
it gradually occurred earlier in the afternoon, so that in October the time of maximum was
2p.m. The greatest daily range in the temperature of the water was 16° on June 1, and there
were a number of days when the temperature varied only 2° or 3°, during cloudy weather.
The lowest temperature in October, 35°, occurred on the night of the 27th-28th. Figures 26
and 27, previously referred to, show the relation existing between the temperature of the water
in the reservoir and the temperature of the air and of the soil at Mather, Wis., for two selected
weeks in 1906.

Observations were not made regularly of the temperature of the water in the ditches, but
there is no doubt that on clear, cool nights it was much lower than that in the reservoir, as the
latter had considerably less volume and lay in the midst of the cold bog. Observations made
at Berlin on October 1, 1906, showed a temperature of 53° im the reservoir, and temperatures
of 37° and 39° in two small ditches. The ditches at Berlin where these observations were
taken were shallow, the water being scarcely more than a foot in depth. At Mather, on the
other hand, the ditches were 3 feet in depth, and they were consequently able to carry a con-
siderable volume of water.

While the water turned on from the reservoir into the ditches gradually loses heat, it, in
turn, communicates heat to the marsh even before the surface of the marsh is covered. The
thermograph sheet shows several instances when, after the water had been turned on, not only
the fall in temperature over the bog was arrested, but a rise actually occurred for a brief period,
although this was followed again by a fall. The thermograph sheet, at Station 3, in the open

116

for June 5-6, 1907, shows this graphically. (Fig. 30.) At about 10 p. m. the temperature
had fallen to 37°; during the next two hours an irregular curve was described. At midnight
the temperature had risen to 42°, after which it gradually fell. On the same night, the ther-
mograph trace of the instrument at Station 5, on the bog, shows that from 10 p. m. until nearly
midnight the fall in temperature was retarded somewhat. (Fig. 30.) The water in reflowing
was colder upon reaching Station 5, as it was farther away from the reservoir than Station 3;
moreover, on the night of June 5, the water was not so high in the section around Station 5
as around Station 3, on account of the slight difference in elevation of the two stations. The
lowest temperature at Station 3 was 33°, while at Station 5 it was 32°. At Station 2, over
moss and outside the cranberry marsh where flooding was not practiced, the minimum tem-
perature was 28°. The temperatures at Stations 2 and 5 as a rule differed but little, as stated

| JUNE, 1907.
5th éth 5th 6th

noon mat. noon noon mdt noon

Ee,

ire neice

222520 J2=2a222a2=2=222=22 222 SasGnanae:
Fie. 30.
Station 3 Station 5

Thermograph trace in ‘‘open” over bog from noon, June 5, 1907, to noon, June 6, 1907, showing effect of flow-
ing of marsh on temperature of air. Stations3 and 5, Mather, Wis.
before, the average difference between the exposed minimums at the 5-inch height for the
entire season of 1907 being but 0.1°. It is therefore probable that reflowing the marsh on this
night was responsible for the difference in temperature of 4° between Stations 2 and 5.

CONCLUSION.

Advantages gained from sanding, draining, and cultivating —It is obvious from a study of
the observations presented in the foregoing tables that sanding, draining and cultivating serve
to decidedly modify low night air temperatures; and it is strange, at first thought, that Wis-
consin growers do not sand their marshes. Many of them, however, object to the use of sand
on the ground that the natural peat soil produces cranberries of better quality. Again, as
previously stated, gravelly sand, such as is used on Cape Cod, is not available in the moorland
region of Wisconsin, and ordinary fine sand packs too closely and permits a rank growth of
vegetation. The Wisconsin grower states that he can secure better returns financially by
using his money in extending his marsh rather than in sanding it, because there are vast
areas in Wisconsin available for cranberry culture as compared with the restricted region of
Cape Cod; and that if the vines are planted in sand, the cost of preparing the bog for planting

an l7

is doubled, without doubling the returns as a result; but this statement is not accepted by
Professor Whitson and his assistants connected with the experiment station at Cranmoor.
As a matter of fact, the average yield per acre in Cape Cod is 40 barrels; in New Jersey, 30
barrels; and in Wisconsin, only 20 barrels. There are even authentic reports of 200 barrels
per acre raised on Cape Cod under most favorable circumstances. It is not denied, however,
that sanding is valuable in warding of frost, and the fact that reflowing is seldom required at
the experiment station where intensive farming is practiced is, of itself, of the greatest impor-
tance. Sanding is obviously needed far more in Wisconsin than in Massachusetts, because
the temperature averages much lower in Wisconsin, as has been shown in the introduction of
this bulletin. If sanding had been practiced generally in Wisconsin, much of the crop that
was destroyed by the frosts in September, 1909, through lack of water for reflowing, would
have been saved. The estimated damage, as a result of the frosts of September 1 and 2, 1909,
alone, to the entire Wisconsin crop was 50 per cent, while the loss at the Cranmoor Experi-
ment Station was only 2 per cent. Moreover, only about 25 per cent of the crop was eventually
saved because of the numerous severe frosts later in the month, to which reference has already
been made.

The sanding is usually done during the winter, when the flood covers the marsh. The
sand is spread over the ice and it gradually sinks to the surface of the bog in the spring as the
ice melts.* Cape Cod growers generally sand every few years, adding a layer of about half an
inch in thickness, but in Wisconsin no regular custom has been followed. While the greater
portion of the Appleton marsh at Mather had been sanded to a depth of about 2 inches in 1898,
no further sanding was done until the winter of 1905-6, when a portion of the marsh previously
sanded was covered with another layer. Weeding or cultivating has been practiced to a con-
siderable extent, but the growth of vegetation is so rank in many of the bogs that much work
is required in order to make any showing. The drainage is steadily being improved, the ditches
have been placed closer together and are usually kept clean so as to assist in draining as well
as in rapid reflowing.

A study of the general and local conditions necessary for frost in the marshes.—The natural
conclusion from the data presented is that the study of local conditions in the marshes is of
much importance. It is apparent that the temperature varies greatly in adjoining bogs and
even in different portions of the same bog. During a frosty night damage may result in one
portion of a bog and not in another, but serious frosts are usually general and not local. A
grower may wish to conserve the water supply if the season is dry and the water low, because
‘f he makes too liberal use of it, means for reflowing may not be at hand later when great danger
threatens. In view of the fact that reflowing should not be resorted to any oftener than is
absolutely necessary, the forecaster and the grower have between them a problem to solve
that is sometimes very difficult. When low temperature threatens it must be first determined
whether the night is to be clear, the barometer high, and the wind light. Of greatest impor-
tance is the clearness of the atmosphere, as there will be no decided fall in temperature during
any night unless the clouds clear away; even passing clouds over a marsh often raise the tem-
perature several degrees. But local conditions seldom determine the condition of the sky.
The reasons for cloudiness must be found in the movement of the areas of high and low
pressure; and these reasons are not always apparent on the face of the weather map. The
work of forecasting frost for the cranberry marshes is important and requires constant vigilance.
True it is that damaging frosts seldom occur in midsummer. The frost of August 7-8, 1904,
was abnormal—in fact, a phenomenal condition. The forecaster should know that such a low
temperature is not likely to happen in every July or August, because it is far from being the
fact, and it can only occur under circumstances on every side favoring its development. It is
therefore a well-marked condition—one that would attract the attention of the forecaster almost
instantly as he scans the weather map. Ordinarily, areas of high barometer do not bring frosts to
the cranberry marshes of Wisconsin in the midsummer months, even though they are of considerable
magnitude, have comparatively low temperature, and move across the northern tier of states.

an Massachusetts the sanding is now done mostly in the autumn, before the winter flow has been turned on.

118

The temperature of the soil is usually too high during the warm season to permit the
formation of frost, and it is quite impossible for it to occur during these months followiff® a day
of sunshine. On the other hand, frost occurs easily in the moorlands on clear nights during
the spring, early summer, and autumn when the soil is cold. As stated before, the conditions
such as obtained during June 11, 12, and 13; 1906, would not be sufficient to cause frost later
in the summer after the ground had become warm. In determining whether frost warnings
should be issued, not only the weather maps must be studied carefully, but also the tempera-
ture conditions in the bogs produced by recent hot or cold spells. The temperature of the
soil is an important factor at any period of the growing season, and the reading of the maximum
thermometer is of much value, indicating, as it does, in a measure, the amount of heat conveyed

to the soil during the daytime. Should the maximum temperature in the shelter be below 70° on

any day, and be followed at night by clear sky and light wind, barometer above normal and rising,
there is strong probability that frost will follow in the bogs, especially if the pressure reaches a height
of 30.20 inches or more and the center of the HIGH passes over Wisconsin or the Lake Superior region.
The theory that frost does not follow rain has no foundation. In fact, a day of light rain
accompanied by a fresh wind which facilitates evaporation at the surface of the soil is often
followed by a frosty night, as evidenced by numerous instances in 1907. (See Table 22.

Should it be expected that the minimum temperature at La Crosse or St. Paul will fall
below 50°, ordinarily there is danger of damage in the cranberry marshes.on any clear night.
Severe frosts have occurred in the bogs when the temperature at La Crosse was no lower than
48°, as on August 8, 1904, previously referred to. The temperature ‘‘in the open’’ at the
coldest place in the bog must fall below 29° in order that serious damage may oecur. Probably
a temperature for several hours ‘‘in the open”’ as low as 29° would be serious, but there are
many instances of minimum temperatures of 29°, and even of 28°, when no frost or resulting
damage was apparent.

While frost may occur with a pressure not above normal during the spring, early summer,
and autumn, this is not possible during the months of July, August, or early September. The
barometer over the moorlands during the warm months must attain a height ofat least 30.20
inches, so as to permit the cold air to gradually settle over the bog. On July 2, 1907, when
the temperature fell to 29° at Mather with the pressure of 30.10 inches, no frost was observed,
but it is probable that if the pressure were as high as 30.20 inches, a frost would have occurred.
The higher the pressure the heavier the air, and the lighter the wind the more easily the cold
air settles toward the ground.

As stated previously, it is important to determine from the weather map whether the
weather will be clear over the moorlands because, regardless of how cold it is in the Northwest
and how threatening the conditions, there can be no damage done during the growing season
if the weather is cloudy at night; but severe frost may occur early in May before the growing
season, and in October after the berries have been picked, on cloudy and windy nights, but no
damage can then result in the marshes. A perfect condition for frost in the moorlands exists when
a high-pressure area from the Northwest moves eastward with the center over Lake Superior,
sending cool north winds thence over Wisconsin, or when the HIGH settles directly over the
moorlands, following a day, or preferably two, of cloudiness, with some rain and wind, provided
the clouds clear away and the wind subsides in the evening as the temperature begins to fall.¢
While the study of local conditions is of value—temperature and its rate of fall, wind direction
and velocity, humidity and pressure—these conditions may not, during unsettled conditions,
assist materially in determining whether the weather will clear and frost occur before the
following morning. A strong, steady rise in pressure is the best local indication for clearing
weather, and without this the weather will probably remain cloudy. While a high pressure
area moving eastward and southeastward over the Lake region is usually accompanied by clear,
cool weather, occasionally the movements of such areas are abnormal and cloudiness persists in the
front of the HIGH. A remarkable instance of persistent cloudiness was noted from September

@ When a HIGH moves rapidly across Wisconsin, the barometer begins to fall and the wind to rise immediately after the passage of the
crest. Under such conditions, a falling temperature up to midnight is followed by rising temperature during the balance of the night.

ee a eee

ig

2 to 5,1905. On three successive days the pressure was high in the Northwest, reaching 30.44
inches at Prince Albert, and accompanied by freezing temperatures. This area moved slowly
southeastward, gradually losing force, but nevertheless maintaining low temperatures. On the
morning of September 4 the pressure was highest over Manitoba, and frost was general throughout
the Dakotas. The weather, however, although cold in the moorlands, never cleared during
the entire period. Temperatures were as low as 37° on two successive nights, but by reason
of the continued cloudiness frost did not occur in the bogs. A study of the local conditions,
aside from the pressure, would not have enabled a person to determine whether it would clear
on either of these nights. The cloudy weather covered a considerable area, in fact, several
states, and the reason for this condition could not be found in the moorland sections of Wisconsin.
Similar instances have been noted in other Septembers. When cloudy weather prevails over a
large area in front of a HIGH, it may ordinarily be expected to continue, unless there is a steady
increase in pressure between the LOW and the HIGH. In case of doubt, special observations
should be called for by the forecaster in the middle of the afternoon from the cranberry marshes
and a few stations in the Northwest, with special reference to the maximum temperature in
the bogs and the probability of clear weather for the ensuing night. It might be well to have
an observation of soil temperature included in the reports from the cranberry marsh stations
each morning in addition to the data usually telegraphed.

The maps of August 7 and 8, 1904 (Figs. 4, 5), have been included in this bulletin, illus-
trating a perfect condition for the occurrence of frost. The cloudy weather during the 6th and 7th
had prevented the usual warming of the soil, and the breezy weather of the 7th, through evapora-
tion of the moisture near the surface, evidently caused the soil to become colder. _The maximum
temperature in the shelter on August 6 was 76° at Mather and Cranmoor, and on August 7 it
was 65° at Mather and 67° at Cranmoor. We have already shown what a great effect the
temperature of the soil has upon the temperature of the air near the surface during any night,
and that in marshes the places covered with dense vegetation, with thick matting of moss or
thick growth of vines or ferns, are the ones of lowest temperature, especially if the soil has
not been sanded and the drainage is poor. When the soil is largely protected from the sun’s
heat by vegetation and the initial temperature at the surface is low in the evening, compara-
tively low minimum temperatures must result if the night be clear. The situation is even more
pronounced if the previous day has been cloudy, because, as a consequence, the storing of heat
in the soil has been interrupted and the point of critical temperature may therefore be reached
more readily. The relation between the temperature of the soil and the occurrence of frost is noticeable
in that it is practically impossible for frost to occur in the bogs on the first cool night following a warm
spell, but itis likely, if conditions are favorable, on the second night after the soil has become cold.
Growers claim, and with reason, that frost almost invariably occurs on the second night of a
cold spell, and even if it does occur on the first night the frost on the second night is likely to
be more severe.

Frost remains in the soil of an unflooded bog until comparatively late in the season, and
there have been found instances of frost in the soil in marshes as late as July 4. Usually,
however, when the winter flow is taken off in the spring the soil is free from frost. The temper-
ature of the soil tends to gradually increase until after midsummer, and then gradually decrease
again. The soil being cold in the spring and early summer, and again in the fall, frost 1s more
likely to occur then, regardless of the accompanying conditions of atmospheric temperature and
pressure. That is, the ground being cold, frost will occur in the marshes in. May and early in June
under the influence of areas of high pressure and accompanying low temperature that would be far
from sufficient to cause frost during the midsummer months, when heat has been stored up in the soil.
The length of the nights is also very important in estimating the probability of the occurrence of frost,
especially during the months of September and October, as the nights steadily grow longer and afford
greater opportunity for radiation, without compensating insolation.

The forecaster must have in mind the lowest temperature that may occur in the less-
favored sections of the marsh, as it is evident that a wide range in temperature will be found
in practically all marshes. Even with the knowledge that the lowest temperature ‘in the

120

open” will fall below the freezing point, it is not certain that there will be any damage. In
fact, as has been stated before, the result of the investigation indicates that the temperature
“in the open” must fall 2° to 4° below the freezing point in order to cause any serious damage.
But the forecaster need not be the judge of what damage may ensue. It is for him to issue
warnings, stating in his forecast the probability of light, heavy, or killing frost, and, if possible,
how long the cool condition is likely to last; because such information will often assist the
cranberry grower in conserving his water supply. It is very important to know the hour in
the evening that the frost is likely to set in, because if it begins to form before midnight the
damage to ‘unprotected marshes is certain to be serious, as the period of freezing in that event
will continue through several hours till daybreak. When, however, the frost does not begin
to form until nearly dawn there is little probability of damage. For traces of the curves at
Berlin during the nights of September 13-14 and 27-28, 1906, see Figure 31, showing first
in one instance a fall to freezing for only a brief period and in the other the temperature
remaining at a low point for several hours.

SEPTEMBER SEPTEMBER

isth th 27th 2ath
noon mdt. oon noon mat noon

TIT INTE PM PP eM PPM Me Pe MEA

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Fic. 31.—Berlin, Wis., 1906.

Temperature curves in the vines on the marsh, Examples of two days—first, when minimum temperature
touched freezing point for a few minutes—second, when the temperature remained at freezing for several hours.
Irregularity of curves in both cases due to wind or passing clouds.

There is an opportunity for the forecaster to give great assistance to the cranberry grower
and to place in the hands of the latter all the information that may be available. If possible,
it is advisable to send advice twenty-four hours or more in advance at times when the growers
have the water supply low in the ditches, as is customary in the summer time, in order to enable
them to raise the water, thus permitting easy flooding on the ensuing day. With this assistance
the most improved marsh can then be flooded in a brief period. Many growers state that they
want advice even when frost is possible, aswell as probable, so that they may never be found entirely
unprepared. If the water is allowed to get very low in the ditches, it may take twelve hours
or more to flood, as the dry, spongy bog absorbs an immense amount of water. The grower,
having been properly informed, can act accordingly, taking into consideration the probable
conditions, the amount of his available water supply, and the possible damage, should he not
reflow his marsh. When the water is warm during the summer season, and a light frost is
expected, danger can usually be averted by raising the water no higher than the surface of

121

the marsh; yet such flooding affords but little protection should a severe freeze occur. The
grower is well acquainted with the conditions of the vines and the fruit, and knows from
experience when they are most liable to damage. He understands that at certain times during
the season the marsh is practically immune to damage. For instance, after the winter flow
is taken off in the spring and before the terminal buds have swollen and begun to burst there
is little danger of damage, but later the liability is very great. The winter flow is held on
some marshes later than others, but when it is drawn off after May 15 the buds usually begin
to swell five to ten days later. After the upright starts out from the terminal bud it is very
tender, and there is more danger to it than to the fruit bud, as it will freeze more easily. The
fruit blossoms usually appear at Mather about June 10 and the vines are in full bloom about
July 1. The setting of the fruit begins with the falling of the first blossoms and continues
until the vines are out of blossom. The new terminal bud is generally formed by August
10, and often before that date. During 1906 there were many terminal buds fully formed
by August 5. Until the terminal bud is well formed and protected a frost may destroy it,
and thus ruin the prospects of a crop for the ensuing year, aside from the damage to the crop
of the current year. The terminal bud, however, is free from damage by frost usually after
September 1. The fruit itself will freeze most easily just after setting, on account of the large
amount of water it contains, and the riper the berry becomes the more hardy it is, so that when
it is fully matured it can not be damaged except by a severe frost. Information of this character
is of importance to the forecaster, simply because it indicates that the frost warnings have
more value at one time of the year than another; that a frost in July or early in August, for
instance, may wipe out not only the crop of the current year but even the prospects for a crop a
year later. As an actual result of the freeze of August 8, 1904, the crop of that year in the
Wisconsin River Valley was reduced about 40 per cent and that of 1905 about 25 per cent.

It is possible for the forecaster to acquire a high degree of accuracy in special work of
this character. He should never fail to issue warnings previous to serious frosts, and he seldom
should make the mistake of issuing warnings for frosts that do not occur, but he should realize
that it is his duty to save the crop. It is not enough for him to issue warnings in advance of
ten frosts of which the growers take advantage in protecting their marshes, and yet fail to send
a warning in advance of the eleventh frost, which results in great injury. He should realize that he
must carry on this work to a successful conclusion from the beginning to the end of the season, or,
in other words, that he must ‘‘save the crop.’ He may sometimes be excused for issuing warnings
that are not verified, especially if there is ample water supply for protection; but he will never
be excused for failure to issue warnings in advance of serious damage.

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7

W. B. No. 443. Issued Dee. 31, 1910.

LE S22 PEPAREMEN TOF AGRICULTURE,
: WEATHER BUREAU.
BULLETIN T.

FROST AND TEMPERATURE CONDITIONS
IN THE CRANBERRY MARSHES
OF WISCONSIN.

Prepared under the direction of WILLIS L. MOORE, Chief of Weather Bureau,
: By

HENRY J. COX, Professor of. Meteorology.

WASHINGTON:
GOVERNMENT PRINTING OFFICE.
191.0;

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