Monthly rainfall at the royal observatory, greenwich, 1815-1903

  • View
    217

  • Download
    0

Embed Size (px)

Text of Monthly rainfall at the royal observatory, greenwich, 1815-1903

  • KASH-GREENIVICH RAINFALL, 1515-1903 291

    MONTHLY RAINFALL AT T H E ROYAL OBSERVATORY, GREENWICH, 1815-1 003.

    BY WILLIAM CARPENTER NASH, late of the Roynl Observatory, Greenwich.

    [Read May 18, 19041.

    Ix iindertakiiig the onerous task of drawing up an authoritative table of rainfall for the long period embraced in the observatory series, i t appeared necessary a t the outset to inquire fully into the circumstances relating to the early history of the register. For several years prior to the establishment of the regular meteorological service a t the Royal Observatory in 1841, a Meteorological Journal had been kept there (unofficially) by A h . Belville and other members of the staff: This Journal practically begins in the year 1511, but i t was not until December 18 I4 that rainfall began to bc observed. No information is given in the Journal with regard to the position of the gauge, which is incidentally referred to here and there in the register as Troughtons. Its position, however, appears to be defined by the following statement prefixed by the Astronomer-Royal (the late Sir George Airy) to a manuscript table of rainfall from 1515 to 1560, preserved in the Iioyal Observatory records : To 1833 or thwecibouts the rain-gauge was in the front Court, on a small plot of grass near the N.E. Dome ; from that time to 1840 on thc leads of the Library. The readings since 1840 are those of raingauges on the ground in the hIagnetic Grounds.

    The observations were made a t first with considerable regularity, but after Mr. Belville had changed his residence from the Observatory to the town of Greenwich in 1822, they were made less regularly, as his attention seems to have been engrossed by his own private journal a t Park Row. It does not appear, however, that Mr. Belville considered the Observatory journal as in any sense an official document, and in the Relville Journals (now the property of the Royal Meteorological Society) the Observatory observations made by him are included. Although the Observatory journal was partly in abeyance from 1822 to 1526 it would appear that the rain- gauge was never removed from the Observatory, and that the references to rainfall in the Belville Journals are entirely based upon Observatory records until 1828, when Mr. Belville commenced an independent series of rainfall observations a t his private residence (then Park Terrace, Green- wich), After 1830 the observations for the journal at the Observatory were mainly made by Mr. Rogerson.

    I n 154 1, upon the establishment of the Meteorological Department under the conduct of Mr. Glaisher, a Crosley self-registering gauge was mounted in the grounds in January for daily observation, followed in February by an eight-inch cylindergauge of the ordinary construction for monthly measurement. The original six-inch Troughton gauge was retained in its position on the roof of the Library, a t the height of

    1 22 feet above the ground. 2 It is interesting to note that Mr. Rogersou ako kept a private journal from 1534 to

    1853 at his residence at Croonis Hill, Greenwich, and that his observations were printed monthly in the .\-a titical Magaziiie.

  • 292 N A S H 4 H E E N W I C H RAINFALL, 1815-1903

    33 feet above the ground, and other gauges were also introduced a t greater elevations. The monthly gauge continued to be the standard for reference until March 1861, when another gauge of similar construction and dimen- sions was mounted by its side, to be used for daily observation. [The introduction at this time of graduated measuring glasses marked a con- siderable advance in accuracy of measurement.] At the beginning of 1899, on account of the extension of the Observatory buildings, the standard gauge was shifted to a more exposed situation 400 yards east of its former position, check-gauges being retained in the Observatory grounds.

    The monthly values given ill Table I. are based upon the records given by the gauges specified in the foregoing statements, attention being given to the following notes relating to necessary corrections, etc. 1840. February.- 0.60 in. marlwl uncertain in journal, the gauge

    1820. h1arch.-No record. 1.50 in. adopted by Mr. Glaisher. 1834.

    proving defective.

    June 11.-An accident to the gauge prevented its [record] being carefully ascertained. Monthly amount taken as entered.

    December.-Only one entry (0.0s in.), but in the weatlirr nvtcs several entries r e l d n g to snow appear between December 1 3 and 29. On BSth, snow noted 3 iriches deep. Next rain entry in journal is on Janunry 7, 1830, 0-65 in. noted as in part melted snow. I t is considered that three-fifths of this ntnount should belong to the December fall, and the record has therefore been increased by cO.10 in. The Cobhum record is 0.42 in.

    November.-hin left in gauge and measured with December amount. Divided proportionally by reference to Belvilles record.

    183% February.-Left till end of March : divided proportionally hy reference to Belvilles record.

    1832 to 1840 (inclusive).-All records considered to have been made a t the height of S? feet above the ground: reduced to ground level using the proportion established by comparative records made between 1841-1850. [1838 included on the authority of Belvilles record.]

    August.-Left till end of September : divided proportionally by reference to the record given by another gauge.

    1829.

    1831.

    The corrected values are printed in italics. 1855.

  • NISH-GREENWICH RAIPJFALTJ, 1815-1003 293

    TABLE L-NONTIILY RAISFALL A r THE KOYAI. OI:SEI~YATORY, CBEKNWICII, FROM 1815 TO 1903.

    j k EARS. 1 Jan. I --

    in. I 1815 .7S 181b 1.90 1817 2.85

    1819 2 .12 1520 1.73

    1818 1.73

    ' IS21

    1825 1826 1S27 182s is29 1830

    I S46 1847 I S48 IS49 I 850

    1851 is52 1853 18-54 I855 1856 1857 185s 1859 I 860

    1861 1862 1863 I 864 1865 I 866

    242 240 2.82 1.38

    I .50

    2.70 3.60

    I .40 1.47 2.63 2.60

    .75

    .80 1.81

    a 5 5 1.79 271 4 8

    3.32 3.68

    I .20

    I .20

    2.1 I

    ~

    ~

    Feb.

    in.

    1.47 1.19 1.S9 2.67 .60

    .04 9 s

    3'17 2.34 .86

    I .66 .60

    I .04 1.17 2.28

    244 .37 4' 00

    .44 2.89

    1.83 -..r9 1.70 r '3'

    1-32 1-05 2'39 2.32 *93

    I 4 7 1.39 2.60 2.30 I .40

    1.25

    9 I .48

    1.20

    2.00

    1.21 I .00 1.10

    .20 1.70 236

    1.10

    1.80 4 6

    *76 1.75 4.03

    Mar.

    in.

    1.71 1.90 3.45 1.53

    , I .50

    3.45 1.39 I .36 I 6 9 1.30 1.66 2.40 .S6 .60 .2S

    2.03

    1.03 4 9 260 "117 55

    1.09 1.94 170

    1.35 1.90 *5 I

    2.30 1.51

    .77 3. I 0 .60 .40

    4 0 5 . I 7

    1.50

    .32 I .98

    4 3 .80

    1.35 1.86

    2.15

    3.54 .70

    2.53 .85

    I .63

    -

    2.00

    1.22

    .sa

    1.10

    .\pril,

    in. 2 4 7 I .94 .06

    2.99 2.82 I .48

    1.82 2.56 1.75 1.89 1.75 .97

    1.16 2.17 4.35 2.54

    1.55 .40

    r.;r 2-0

    r.04 2.71 1.21

    5s f .44 .ro

    1.92 .43

    1.72 $35 .55

    3.05 .99 344 1.98 2.25

    2.30 .49

    3.21 .59 .09

    2.28 I .40 2.25 2.17

    -

    I .oo

    4 3 2.82

    -45 4 2

    '40 2.44

    May.

    in. 2.14

    I .95 4.12 2 . 5 j 2.9s 3.57

    I .90 .74

    3'77 2.97 2.47 2.39 1.47 '45

    1.96

    1.52

    '55 .'?5 '97 3'00 r.32 99

    1.50 1.66 2.03

    2.06 2.09 3.75 .30

    I .50 1.40 *40

    3.70 2.30

    .so 1'90 1.50 3.5' I .80 3.45 .33

    2.35 3.90

    1.79 2.84 1.25

    4.37 1.94

    -

    2.22

    2.21

    2.00

    2.00

    July.

    in. 1.57 3.91 3.86 439

    4 3 s

    -

    2.00

    2 4 2 4.07 3-30 1.81

    . I 0 2 . a 1.25

    3.7b 1.69

    3.09 .70

    1.65 5.3' .-as

    r.70 r.56 1.97s 7' 7' 1.63

    3.60 2.96 2.42 2.1s 1.85 I .50 .67

    1.98 2.90 2.82

    4 2 0 2.25 5.48 1.75 5.25

    .90

    3'00 3.30 2.80

    6.4:

    1.10

    2 2 0 1.66 .88 .27

    2.27 1.62

    Aug.

    in. I .s; 2.30

    2.53 .07 .36

    1.70

    1.92 1.81 2.68 3.95 2.48 I .69 1.05 3.75 4.33 3.55

    1.77 3.44 r.7r 3' 27

    a 63 4.j2

    2.7r, r.oJ

    -

    1.10

    f .Of

    2.20 1.78 3.62 1.71 3.10 400 1.95 4 2 5

    .45 1.70

    2.60 4.35 2.75 2.61 I .40 2.42 2.50 1.50 1.13 3.68

    .57 3.01 1.82 1.31 3.97 2.42

    -~ bapt. Oct.

    in. ~ in. 1.07 ~ 2 39 1.96 2.61

    4 1 2.39 3.78 1.89 3.13 2 1 3 2.23 2.64

    3.40 2.42 1.37 3.60 4 9 , 3.96

    2.56 2.69

    --

    j . 2 1 I2.44

    3.27 3.24

    1.97 4J

    1.98 37

    4' 15 313 r Q,- 2.99 4.95 2 94

    395 3.99 .46

    1.19

    1.79 I .56 2.38 3.25 1.35

    '50 3 80

    *9 1.95 2.80

    3'40 46

    3% 3.10

    1.46 1.61 2.95 2.76 .16

    3'90

    2 1 2

    1.41 I .67 .66

    1.97 2.49 I '29 '47 p.20 p"7 2.46 r.99 r.90 1.62

    5.95 1.41 1.25 1.01 1.38 5.13

    ? 50 2.70 1.58

    2.18 3.75 4.23 2.42 5.20 1.91 Q.20

    I -44 3 60 1.60

    *88 4.07 1.82 I .06 5'90 2.09

    2.00

    Nov.

    in. 1.37 2.74 1.80 2.49 2.69 1.76

    4.33 3.66 1.55 j .8S 2.85 2.46 1.17 .85

    1.32 3.09

    1.45 14'7 1.60 I '50 ' 3 7 a67 1.85 3'50 494 3.16

    3.70 4.25 2.30 4.50 2.40 1.52

    1.50 2.1s

    .65 6.00 1.95 1 9 1.50 1.25

    1.35 .SO

    2.90 2.50

    5.07

    1.59 2.57 2.39 I .48

    -

    2 a o I .20

    1.00

    Dec:

    in. 2.05 2.82 353 1.34 3.48 1.57

    4.72 2.26 2.48 3.55 2.92 1.28

    3.33 2'33

    .48