' ' J on Aluminium. 401 



The excessive sonorousness of aluminium is best shown by example 

 (l«.-ge suspended bar being struek). Faraday has remarkedTfter 

 Zr^Z"'^ T^""*'^ '" "^^ '^"^""'"^y' '"^^^ '^- soura Traduced by 



:i rdsrtZ?^he%rargt;r^ - --^ ^^^^ '^' 



Its tensile strength yaries between 12 and U tons to the inch (te-^t 



sample wh.eh was shown having been broken at 13 ton or 27 000 



bs. j ordinary cast iron being about 8 tons. Comparing the stren" th 



tl: i'eTerth" "Thf" '%"'^ ""?:"• i* '^ ^i™' '» ^^t:i:,TC. 



, fw 111 • ° , ^.P"*"^" 8™"'y of ""St aluminium is 2 • 58 but 



after rolling or haramenng tliis figure is increased to about 2-B8 



3-5,'^.t:r^le?dT8'74frr""^ ''-'^ '> -^^- '^ '■'' '--^^^ 

 betJet ^^^i:'Jz^:^,::-^^z^^ - ''-^ 



As no reliable information has ever been malp T^nKl,V* ^r. +i • 



itfwTe'tm'irT^ ^'""^'^ '^'^^^rZ^ 

 1 ''as aware, fiom information gained at the works at Oldbury that 



Loo nt'o?7r '° ^' KT'^t'^" of contained iron materially^kS 

 Its pomt of fusion, and it has been undoubtedly due to this cause tl.nt 

 such wide limits are given for the melting pint Under these c ir 

 cumstances two samples were forwarded for testing, ofwhich No 1 

 containing i per cent, of iron, had a melting point of 700' C ; wlfe^,as 

 No 2, containing 5 per cent, of iron, does not melt at 700=> aTd 

 {flonTnor '^"' *'''" temperature but undergoes incipie:;! 



According to Faraday, aluminium ranks very hi<.h amon- 

 metallic conductors of heat and electricity, and he fo .nd that i? 

 conducted heat better than either silver or Conner ThT^^l'^ i: . 

 s also very high, which accounts for lengihT Le'r e^S f^r Tn 



Chemically, ,ts properties are well worthy of study 



Air, eitlier wet or dry, has absolutely no effect on aluminium at the 



~7,Hr''^'r'"ri '"'."^f p^p*'--'^ - -^y posses"" iTa 1'': 



li^ht^o;, 7t, ^^'^'•/^'?'J tl^e pure metal in mass undergo^es only 

 light oxidatMm even at the melting point of platinum. ^ 



•;thri?-i % iT^T' '",'"'" ^"^^'^ '° " current of oxygen burns 

 'letl h/ '"'*■ '^'"'f ^^'^^ "§'''• (Experiment shown) If the 

 i2i,^r P"?'."'"'^'^ ^^^ '^r^'^^' o'' it '^'^atever, even at a red-heat 

 IIa^H «™»P0i>uds also are without action on it while 



ith Vl/'°"rr"T^"°""^ "^'"■'y "" »^'^1« '-""Id be discolou ed 

 tef sal^f^l^nditSr""'^"' ^'°™ "^^"°"^"^^^ ^-"^ '""'"'"^"'^ 



■ate^a:^pt^^:rit-ih tLit ^;^si;-r 



rdrochloric acid or caustic alka^. Heatil'in'a'ttaosph^f ^f 



2 I 2 



