On the Production of Steam from heated Iron. 85 
and cold water upon a clean surface, varying the correspondent por- 
tions of each from $oz. to 20z. at each experiment. 
els Jals els [ets ats ses 
dint eo =i e+ i ee os 
See [SEE | Se [S52 |sse | 238 
mes [TEs Es . |aEs Pee} Tees 
sess a FSS mt be fn ee fy Ey pee ieee 
[eee] [S85 | Tees | ece | ese] eos 
SoZs goes | SSRs [ESCES | SSes | Fase 
E Saf eliats Sar [Sa We Sete | no A'3 
Oe Vi Sow Oo "Oo w O Aged Row @d 2 . oO 
QDaeoxrjna or NReoxr aos aox 2=G,e0 
2 CHa oc es -ofan x2 vcs avad ao ae oO 
nD Ss ig = | ~ ~~ — { 
gas neal N a) pial fe hap cS a 
“ie Ea : oe : o . o é Oo a > 
; nN ° it ° Al 2 a ° a ° oO 
si/ajSjal/Sials lta} 8] aj} s 3 
? a he he tea fn he 
e\2lsl2/g /2|g]2l gl] 2l¢ g 
oe e > = e | = = 
Woe u “i i rT ul rT] u ul i 
1 {104 108 150 182 266 40 
2 137 158 220 
3 | 96 102 150 9 
4 84 | 126 ceased 60 9 
5 {100 : 
6 94 ‘Ieeased 30! 8 
7 | 90 % t 6,5 
8 79 6 
9 | 95 ceased 60” 6 
“ 74 a 64 
90 visiblyred 60 
2 80 EE. ee 75 
80 clear red 73 
14 74 Ae 3S 
Mean. 93.5] 76 | 105 | 88.5] 150 |13i.5| 182 | 158 | 226 | 220] constant 80” 
(Ratio, 12371 | Li86:1] 14:1 | 11st; 1° | 120971 
The mean of all these ratios is 1.183 which shows that with*a 
clean surface the limited quantity of hot water requires 18,5; per 
Cent. longer to effect its vaporization from the red hot metal than an 
equal quantity of water at 60°; so that though the times are vastly 
different in this course from what were given in the last, the relation 
1S nearly the same, being only 3 per cent. more favorable to the cold 
Pee. than when the surface was incrusted with earthy matter. Ac- 
“dental circumstances sometimes vary or even invert the relative 
a for hot and cold water, but such discrepancies are easily refer- 
(0 their proper causes. The limits of this paper compel the 
Postponement of several courses of experiments. 
