Sciences of Meteorology and Terrestrial Magnetism. 177 



in exact proportion to the solid globules united. The diameters of the 

 original globules were estimated at '001 to "003 of a millemetre, or 

 ■000039 to -000118 of an inch! Those condensed from boiling water 

 were also irregular in form, and from '02 to "03 of a millemetre, or from 

 •000787 to -OOllSl of an inch in diameter. When the glass sHp, with 

 its balsam coating, was laid upon grass covered with hoar frost, 

 globules gradually formed on the surface. These were estimated at less 

 than -0001 of a millemetre, or -000003937 or 4-millionths of an inch 

 in diameter ! ! Water at 107° F. gave globules of the same size as those 

 from the breath. A further proof of the non-vesicular character of the 

 globules was their permanency when enclosed between the glass plates. 

 Besides, globules of air or other gases were found to be very different 

 from these ; they were larger and darker. On one of them, from -01 to 

 •02°""- in diameter, an extensive landscape of trees, houses, &c., was pro- 

 jected. Bright objects, viewed through the water globules of '001 to 

 .QQgmm. jjj diameter, were surrounded by a halo, like those seen around 

 the sun and moon. — But it is unnecessary to abstract this paper in 

 greater detail. It is well worthy of a careful perusal by those who ai-e 

 interested in the subject, and will be found very curious and instructive. 

 The views put forward do not lessen the difficulties attendant on an 

 explanation of the cause of the suspension of clouds. But so little defi- 

 nite knowledge is possessed by us as yet on this subject, so far as I am 

 aware, that I must content myself by a reference to the works already 

 quoted for the prevalent notions. No change has been introduced into 

 the nomenclature of clouds ; that of Mr. Luke Howard, proposed in 

 1802, is still used by meteorologists. Many new and curious observa- 

 tions on the subject of clouds and serial currents will be found scattered 

 through the instructive and fascinating work already referred to, Prof. 

 C. P. Smyth's Residence Above the Clouds. 



A series of ver^' ingenious experiments has recently been contrived 

 by Mr. Jevons, of the Royal Mint at Sydney, N.S.W., to illustrate the 

 mode of formation of the different varieties of cloud. By peculiar appa- 

 ratus of his own devising, liquids of different specific gravities, specially 

 adjusted, arc mixed, one liquid being injected into the other. The 

 effects produced exhibit to the eye a close resemblance to those observed 

 in the atmosphere ; and he uses these as proofs of a theory of the origin 

 of clouds, differing in some respects from that generally received, and 

 described in works on meteorology. The papers will be found in the 

 Philosophical Magazine for July, 1857, and April, 1858. 



(20.) Very little progress has been made of late years towards the 

 construction of a theory of rain, founded on the true basis of a careful 

 induction of facts. Tlie observations of Professor PhiUips, so admirably 



Vol. IV.— No. 1. 2 a 



