1898-99.] | MAGNETIC INFLUENCE OF SUN ON THE EARTH AND ON COMETS. 351 
sun spots are more permanent, and break out into renewed activity from 
time to time, as do volcanic regions on the earth. I have a long series 
of recurrences in several years, but instance 1896, premising that while 
the observations were made here, with imperfect appliances, the latitudes, 
longitudes, and areas have been kindly furnished by Mr. Maunder from 
his Greenwich observations :— 
1896. 
February 24. A fine spot, central...... Area”: 80° Lat.i64 “Long. 220° 
March ZR ew AUlAr ee SPOttee . ks, 5.5 «5 eens O Dem ict Ti eeu TiGrs 
April 20.. A fine spot OF BO oee Hits. poe a ife ye a2 Ge 
June 14.. An enormous spot....... Ce TOO bee a Oe 215, 
July Ao oe a\ TeNCoOle oe ob Geers Sonim O oe TAR hate A fi 
Septembern-5.- )Astine sroup |... :.... CS Sop elt {ye 202, 
October 30.. A noteworthy spot ...... Scale TOG dapat ust fa TW20R' 
November 26., A spotted region, central. rs 100 GF Nie) SS ives)” 
December 23%. Aine Spotificss. «ss. s+. ‘oe. OO co ss — 
1897; 
Jannainyn Zien Au orOUpie rcs clires cre. cet ak27.0 Toe oy Ow 
No spot of any consequence was noted in May, August, or the begin- 
ning of October, but here are ten occurrences within the year of con- 
siderable spots, in the same region. If we omit the November spot, 
owing to the difference of longitude, and that in December, not cata- 
logued at Greenwich as in the same solar region, there still remain eight 
occurrences. 
I support this view by a remark of Tacchini’s on a spot of 1898 :— 
“ Notevole fu il bel gruppo di macchie del febbraio, che nel giorno 
14 trovavasi al centro del disco fra i paralleli di —6° e —12° per un’ es- 
tensione in longitudine di circa % del raggio del disco solare, cosa piut- 
tosto rara in epoca di minimum dell’ attivita solare. Dopo quasi un’ 
intiera rotazione cioe intormo all’ 11 de marzo, un nuovo gruppo di 
macchie trovavasi nella parte centrale del disco cioe nella stessa regione 
del gruppo del 14 febbraio, ma un poco pit al sud e pressoche della 
stessa estensione, cioé 5’. 3, cz0 che prova come in quella regione abbia 
perdurato a lungo la causa tnterna capace di produrre macchie per molto 
tempo nella stessa localita, cio che non potrebbe spiegarsi colla sola differ- 
enza di velocita nelle zone superficiali.” 
So far Tacchini, reading from the book of observational Astronomy. 
We will now open the magnetic page and carry the history farther by 
the aid of the curve of Horizontal Force (in scale divisions like preced- 
ing ones) from January Ist to April 2oth. 
*The areas are calculated in millionths. 
tGiven in Mr, Pursey’s charts as nearly central on this day. 
{Mr. Maunder kindly supplied this : omitted on Mr. Pursey’s chart. 
