1887.] On the Heating Effects of Electric Currents, 



287 



Tin-Lead Alloy. 



Diameter of wire. 



In 



inches. 



In 



cenl% 

 metres. 



Standard 

 wire 

 gauge 

 No. 



Current in amperes. 



Shellac 



flake 

 melted. 



Wire 

 red hot. 

 Visible 

 in air. 



Wire 

 fused. 



Fusing 

 current 

 calculated 

 from the 

 formula 



Amperes. 



Constant 

 "a" 

 when 

 d ex- 

 pressed 

 in inches. 



O'OIO 

 0'012 

 0-014 

 0-020 

 0-026 

 0-030 

 0-033 

 0-036 



025 

 0-030 

 036 

 0-051 

 0-066 

 076 

 0-084 

 0-091 



33 

 30 

 28 

 25 

 22 

 21 

 21 

 20 



1 2 -333 



4-586 

 7 -566 

 It- 102 

 11 -102 

 13 516 



# 



2-132 



2 -494 



2-735 



[ * 



2-373 



12-855 



3-097 



# 



3-298 



3-942 



4-586 



# 



5-309 



5-792 



6 -838 



# 



8-206 



9 -331 



9-978 



# 



11 -102 



12-070 



12 -070f 



# 



12-550 



14 -000 



14 -000f 



•# 



14 -240 



14 962 



14 -962f 



| 2-491 

 | 3-274 

 | 4-127 

 | 7-046 

 1 10 -220 

 1 12 -670 

 1 14 -620 

 1 16 -660 

 Mean = 



2731-7 

 2354 -7 

 2774-2 

 2420*1 

 2385-5 

 2321 -5 

 2333 -9 

 2189-7 

 2433 9 



* With shellac. 



f Fused immediately after faint redness was visible. 



