30 , REPORT—1845, ~ 
by the stations hitherto established, will be at least brought nearer to a 
solution. 
1. The winter rain which falls at the external limit of the N.E. trade, is 
changed in southern Europe to a spring and autumn maximum, connected 
by a less precipitation in winter; these twe maxima, when we come to the 
Alps, join themselves to form a summer maximum, and from thence north- 
wards we find no season free from rain; everywhere on the interior of the 
continent and as far as Holland the maximum is in summer. Does the 
southern hemisphere show similar relations ? 
2, The annual distribution of the atmospheric pressure gives the most cer- 
tain means of deciding whether a station within the region of trades or of 
monsoons belongs meteorologically to the northern or to the southern half of 
the globe. Where lies this limit, and how broad under different meridians is 
the indifferent zone, which is to be regarded as this limit? 
3. The so-called irregular variations of the barometer are regarded by some 
persons as only the effects of currents of air of unequal temperature and 
moisture ; other persons distinguish the effect of currents from the effect of 
undulations progressing in the manner of waves of sound, and propagating 
themselves with great velocity over large portions of the earth’s surface. 
From the latter hypothesis the consequences appear to me to be,— 
a. That they will not propagate themselves towards one side, but peri- 
pherically. 
6. That they must penetrate from the temperate into the torrid zone also. 
ec. That they will give rise to pheenomena of interference. 
Hourly observations on single days are capable of showing which view is 
correct. 
4. Investigations on the non-periodic variations of the distribution of tem- 
perature on the surface of the earth having shown that no unusual cold takes 
place anywhere without an unusual warmth by its side as a compensation, 
we ask,— ° 
a. Whether these oppositions are always in the same hemisphere ? 
6. Or whether similar oppositions exist also between the two hemispheres? 
5. Is there towards the outer limits of the monsoons an increase of the 
mean annual atmospheric pressure as in the trade zones? 
6. Are we justified, in regard to the distribution of the mean atmospheric 
pressure on the surface of the earth, in distinguishing the pressure of the dry 
air from that of the atmosphere of vapour in the manner which in the consi- 
deration of the periodical variations has shown itself fruitful in consequences? 
To question 2, “ Do you consider that private research has,” &c., I think I 
may answer,—The effect of great scientific undertakings is an enduring one, 
not limited to the present. What would meteorology have been without the 
Manheim Society, which first made it possible to subject to a closer exami- 
nation simultaneous observations made with compared instruments? What 
important scientific works are founded on these collections! yet these works 
all belong to a period much later than that of the activity of the system of 
the Manheim Society. It would not therefore be surprising if we could not 
yet see any important consequences from the present undertaking. It is not so 
however: the fact that the previously-known periodic annual variation of the 
atmospheric pressure in the region of the monsoons extends from thence to the 
whole of central Asia (as I have shown in detail in Pogg. Annal, 58, p. 176), 
and the complete distinction of the continental from the sea climate, are a 
discovery for which we have to thank the Russian observatories. The possi- 
bility within the torrid zone of resolving the diurnal variations of the baro- 
meter into their coexistent elements (vapour and dry air) is due to the 
