28 
- — ~r- ■""TT""- '-"'' 
POPULAR SCIENCE NEWS. 
[Kkkkuaky, 1891. 
[Specially Obserred for Popular Science News.] 
METEOROLOGY FOR DECEMBER, 1890, 
WrXTI REVIEAV OF THE YE.\R. 
TKMl'ERATLHE. 
Average Thermometer. 
Lowest. 
Highest. 
Range. 
At7A. M 
At2P. M 
At9P. M 
Whole month .... 
Second average . . . 
20.90° 
28.84' 
24.29' 
24.68° 
24.68° 
2° 
15° 
4° 
2° 
3° 
39° 
48° 
40° 
48' 
48° 
37° 
83' 
3«' 
4«' 
4fl' 
Last 20 Decembers . . 
Second average . . . 
28.75° 
28.48° 
I 21.29' 
I In 1876. 
20.98' 
38.81° ( 
in 1889. i 
3e..54° 
15.52° 
15.,56' 
Tear of 1890 
Last 20 Years .... 
48.68° 
47.71° 
2° 
( 45.15° 
\ in 1875. 
90° 
50.42° ) 
in 1889. ( 
88' 
.1.27' 
'ITie present December has been an unusually 
cold one, having been exceeded only three times 
in the last twenty years. Tlie lowest point 
reached by the mercury was 2° above, on the 
30th, and this was tlie coldest day, with' an aver- 
age of 10°. The higliest point was 48°, on the 
23d, wiiich was also tlie warmest day, averiigiug 
39.33°. The entire montli was 4.07° below the 
mean in December for twenty years. The nioutldy 
range during this period lias l)een a full 15.50° ; 
the daily range the present December was 46°. 
The daily extremes of this month in twenty years 
have been —13° in 1883, and 65° in 1873,— a range 
of 78°. 
The average temperature the last yeai- was 
48.68°, or 0.87° above the average for the last 
twenty years. For the extremes see above table. 
The unusually warm January and Februiiry more 
than counterbalanced the cold December. ITie 
almost equal temperature of January, February, 
and March, 1890, was remarkable. Cold January 
was only 1.14° below March. 
SKY. 
TTie face of the sky the last month, in 93 ob- 
servations, gave 48 fair, 16 cloudy, 18 overcast, 7 
rainy, and 4 snowy, — a percentage of 51.6 fair. 
The average fair the last twenty Decemtiers lias 
been 50.1, with extremes of 40.9 in 1887, and 75.3 
in 1877,- — showing 1.5 per cent, more fair than 
usual, although there has been a very heavy 
amount of precipitation. 
The last year was remarkable for unusual cloudi- 
ness, being nearly 5 per cent, less fair — or more 
cloudy — than usual, including eight of the twelve 
months. 
PRECIPITATION. 
The amount of precipitation the last month — 
including at least 10 inches of melted snow — was 
7.87 inches. The average for the last twenty-two 
Decembers has been only 4.13 inches, witli ex- 
tremes of 0.73 in 1875, and 7.89 in 1884— the only 
instance barely exceeding the present. This large 
amount fell almost entirely on three days, as fol- 
lows: 4..30 inches on the 17th, 2.24 on the 26th, 
and 1.13 on the 3d. About 1 inch of snow fell on 
the 3d and 6tb, and 8 inches or more on the 26th. 
The snow fell rapidly nearly all day, with but 
little wind, till about dark, when it changed to 
rain, and, again growing cold, left the snow in 
good condition for excellent sleighing until the 
present time. 
The amount of precipitation the last year was 
Iarg(^, being 54.54 inches, including 43 inches of 
melted snow. More than half the entire amount 
of precipitation fell during three months, — March, 
October, and December, — leaving most of the 
growing season deficient. The average amount 
the last twenty-two years has been 47.46 inches, 
with extremes of 32.26 in 1883, and 64.40 ui 1888. 
PRESSURE. 
ITie average pressure the past month was 29.951 
inches, with extremes of 29.36 on the 27th, and 
30.48 on the 25th,^a range of 1.12 inches. The 
average of the last seventeen Decembers has been 
29.958, with extremes of 29.804 in 1870, and 30.073 
In 1879, — a range of .269 inch. The average daily 
movement the past month was .369 inch, while 
this average in seventeen Decembers has been only 
.269, with extremes of .190 and .369, — .showing the 
movements this last month to have been greater 
than any preceding December on my record. 
Some of the larger movements were .88 on the 
4th, .72 on the 17th, with ten other days having a 
movement of .40 or more. Tliese movements have 
been excelled only three times in all the months 
for seventeen years. 
The average yearly pressure in seventeen years 
has been 29.957, with extremes of 29.914 in 1878, 
and 29.993 in 1883,— a range of only .079 inch. 
The average daily movement in seventeen years 
has been .185 inch, with extremes of .158 in 1877, 
and .211 in 1887,— a range of .053. 
■as 
3o 
si 
a' 
^-, i^ '^ ^, 'y, rj] ti rn y, \r i'^ ft 
U "3 is 8 2 S 8 a S "= "S '" 
^ ^ ^ fc fei ^ ^ ^ ^ &; ^ ^ 
§0050QOMeO-*QOS 
t-lOOrH©OOOOf 
I T* as i-H 1 
M ■>* --I 
X) Oi Oi 
r^-*tn'4"iM(CXi:DO0!PQOCD 
.+ 
^ 
a 
o 
I I + I + I I 1 ++ I -I- 
+ 
ooccos©i"*rH^eo«osF4t-^ 
8SSo8§SgSS82 
I I ++ I I I 
I + + 
-*eoot-'^u5»0"*"^SSccio 
t-;C:00'^COOOeO«0'*t-;0 
§.- 
B 
irar-i-iOsaDicotftficOMt- 
+ -+- + + + I I T-h I +T 
+ 
spcoioooorHcioi-* 
5i««'Sioeot..«SeoS< 
e .a 
h !^ e >• M-S 
WINDS. 
TTie average direction of the wind the last 
month, calculated as usual, was W. 30° 58' N., 
while the average for the last twenty-one Decem- 
bers has been \V. 20° 6' N., or very nearly W. N. W. 
The extremes have been VV. 10° 10' S. and W. 59° 
29' X.— a range of 60° 39', or about five and a half 
points of the compass. The relative progressive 
distance travelled by the winds the last month 
was 69.97 units, and during the last twenty-one 
Decembers 1,194 such units, an average of 56.86, 
— showing less opposing, or easterly, winds the 
last month than usual. 
'i'he average direction of the wind the last 
twenty-one years, combining over 23.000 observa- 
tions, has been \V. 12° 23' X., with extremes of 
W. 6° 38' S. in 1880, and W. 31° 24' N. in 1888,- a 
range of 38° 2'. The extreme months have been 
July, W. 24° 20' S., and April, W. 40° 50' X.,— a 
range of 65° 10'. The relative progressive dis- 
tance travelled the last year was 594.9 units, and 
the last twenty-one years 10,486 such units, a 
yearly average of 499.3 units, — showing less east- 
erly winds than usual the last year. 
'Hie accompanying table condenses the principal 
results of this report, enabling one to compare 
the year 1890, month by month, in each depart- 
ment of observation, with that of the average of a 
series of years, shown in the colunni immediately 
preceding. By comparing this table with that 
presented a year ago, we learn how small is the 
modification by the new average, though it be an 
unusual one. 
It is interesting to remark that by comparing 
the average temperature and precipitation of this 
locality with that of all Xew England, as reported*? 
in the Bulletins of the New England Meteorological 
Society, from about 150 observers, the average* 
are very nearly equal. 
Erratum. — In my last report I regret to find a"' 
sad mistake in regard to the winds of Xovember. 
niey were somewhat peculiar, which probably led 
to the erroi'. Please correct in j'our next issue- 
thus : Under winds, for " W. .36° 9' X., or X. W^ 
by W.," read W. 12° 46' X., or VV. by X. : and for 
" VV. 18° 24' X." read AV. 16° 58' X. " 
D. VV. 
Xatick, .Tan. 6, 1891. 
[Specially Computed for POPCLAB Science News.] 
ASTROXOMICAL PHEXOMEXA FOR FEBRU- 
ARY, 1891. 
Mercury is a morning star throughout the 
month, and comes to western elongation on Feb 
ruary 5, when it is nearly 26° west of the sun, and 
rises more than an hour and a half before it. I| 
will remain visible as a morning star, low down 
near the horizon, a little south of east, during tha 
first part of the month. Venus is also a morning 
star, and reaches western elongation on February| 
13, at which time it rises about three hours befop 
the sun. It will be very bright, but not as brigh^ 
as it was during Janu.ary. Mars is still an even 
ing star, and sets a little after 9 I*. M. It is moV'd 
iug quite rapidly among the stars toward tlie eass 
and north, so that the time of the setting of thfl 
planet varies only a few minutes during thcf 
month. .■Vt the end of the month the distance o| 
Mars from tlie earth is about double that of thfli 
earth from the sun. Jupiter is too near the su 
to be seen during the month, and changes from ao 
evening to a morning star by passing conjunction 
with the sun on the morning of Fetiruary 13^ 
Saturn comes to opposition with the sun on 
March 3. During February it will come to thti 
meridian somewhat after midnight. It is in the 
eastern part of the constellation Leo, and move 
westward and northward about two degrees dur 
ing the month. As seen in the telescope thu 
minor axis of the rings will be a little larger thai) 
in January. This increase will continue until thfj 
end of April, when the ratio between the axes wilj 
be about ten to one. After that the minor axil 
