368  ON  THE  KELATIVE  POWEE  OE  JIETALS  AND  ALLOTS  TO  CONDUCT  HEAT. 
Found. 
Calculated. 
Silver = 
= 1000.  I 
Found. 
Calculated. 
“ Yellow  brass”  ...  • 
rCu=64-0  1 
Zn  = 56‘0 
rCu=80-0  1 
17-80 
22-73 
558 
712 
“ Pumps  and  pipes”  < 
Sn=  5*0 
Zn=  7*5 
LPb=  7-5  . 
rcu=:8o-o  ^ 
13-60 
22-57 
426 
707 
“Mud  plugs”  ■< 
Sn  = 10-0 
^Zn=10-0  j 
rCu  = 82-05  1 
12-60 
24-00 
394 
754 
“Large  bearings”  ...5 
Sn  = 12-82 
)> 
11-00 
23-97 
345 
751 
hZn=  5-13  j 
1 
It  is  extraordinary  to  find  what  a low  conducting  power  these  alloys  possess ; for  with 
the  exception  of  the  alloy  named  “ Yellow  brass,”  they  do  not  conduct  heat  better  than 
wrought  and  cast  iron.  This  is  due  to  the  impurities  of  the  metals  employed,  and  shows 
the  advantage  that  there  will  be  in  substituting  for  them  some  of  the  much  cheaper 
alloys  above  described. 
We  hope  that  the  results  contained  in  this  paper  will  prove  interesting  to  the  mem- 
bers of  the  Royal  Society,  and  deserve  their  approbation. 
We  shall  shortly  have  the  honour  to  forward  Part  II.  of  this  paper  “ On  Amalgams.” 
