30 REPORT—1849, 
est elevation, viz. barometer 14°70 inches, and 24° lower than when the barometer 
had fallen to 19 inches while ascending, the thermometer then standing at 46°. In — 
the last ascent the aneroid barometer was used; it was found necessary to shake it 
at pressure 26°50, and it ceased to act at 24:00 pressure. In descending it again 
began to act at 24°50. The following table gives the principal results : 
Temperature of the Upper Regions of the Air corresponding to certain Barometrical 
Heights, as observed by George Rush, Esq., during five balloon ascents. 




Therm Therm. Therm. Therm. Therm. 
Barometer. May 1837. 4th of Sept. |10th of Sept./27th of June} 4th of Sept. Altitude in feet. 
1838. 1838. 1849. 1849, 
°o ° ° ° °o 
OU ME Wecceealt Gal dae k teks OEY “er nace 74 
30:22 
30:00 60 66:00 
29-90 kates ttt a tees ade ae rn 66 
SOMO? aitbieieve, Oi Pats GOH tee 68:00 
DUO Ol) ccc ecluMoceeReTan || isescae” Gtk sacle 66:00 
27-00 eve doo) hy © Secure 58 teers 65°51 
26:00 idvewat Rib ameter? 55 cho ops 64:50 
BT OVa a. csisee Nm Pemeece ee | ee 63-00 
DAOD, - [PRR sere, Ree ABT a TRIS 61:00 
23:50 DB Nee HE Midd vetinchh be eatet. lieu 6553 for 32° fall. 
DEOO Wits ccts 56:00 AG a cPel ekec tse. 6100 ; 
2240 ohicchak cee LeAsaawesil. ptesstns 54 
DZD Wie bisucewe detail’ Becie ess CY eae peer 54:00 
SOD ie as aners 53°00 40 as Ue 52-46 
BO/OO pete eraaen, lee sae ous iE eel oars 52-00 
UT Dp | orasAnee 46°22 35 scapte 46:00 {18,044 for 20° fall. 
18-00 masteie 42:00 30 
iT Ue Poe sA8 39:00 25 
16°00" MO: 35°00 20 
00 i eens te 25:00 18 
14-7 OD Scdes 25D HE A seaaeacs LIE soaueaMetlen Nass. ce 19,308 for 41° fall. 
24°30 oties see 18-00 Serer eee. wecsscn 20,352 for 43° fall. 

Note.—It has been determined by M. Gay-Lussac, from observations made by him 
during a balloon ascent, in which it is stated that at the temperature of 16° Fahr. 
he attained an altitude of 21,735 feet, the temperature at starting having been 88°, 
that it therefore decreases at the rate of 1° for 352 feet of elevation. 
On Recent Applications of the Wave Principle to the Practical Construction — 
of Steam- Vessels. By J. Scort Russexu, C.E., F.RS. f 
During the last year I have had more than one opportunity of applying the wave — 
principle to the construction of steam-vessels. There is one case, however, in which 
I have been able to apply it to practice under circumstances of greater complexity 
and difficulty than have ever occurred to me, and where it has been successful in 
overcoming difficulties to a greater extent and in a more decided manner than here- 
tofore. The complete success of the principle is no longer to the Members of this 
Association a matter of doubt, especially where its application is not controlled by 
peculiar circumstances. But it will be useful to show, that even in cases where the 
construction is shut up by practical limits and difficulties intractable on ordinary 
rules, the wave principles afford a safe and useful guide. It is also important to 
know at every step how far the experiments made on a small scale are borne out by ~ 
the large, and where the rule is neutralized by the exceptions. , 
During the last year a very difficult problem was proposed to me by the engineer 
of a railway company, which required vessels of a very peculiar construction, limited — 
by the conditions of the case in such a manner as to be pronounced by some im= 
practicable. It was this, to build a steam-vessel that should be fast without great 
length, a good sea-boat without drawing much water, and to carry a great top weight — 

