A wire of one-tenth inch diameter of Lead breaks with .

lbs.

29 1/4

Emerson.

Do.

do.

Tin

do.

49 1/4

"

Do.

do.

Copper

do.

299 1/4

"

Do.

do.

Brass

do.

360

"

lbs.

A wire of one-tenth inch diameter of Silver breaks with

. 370

Emerson.

Do.

do.

Iron

do.

. 450

"

Round bar, 1 inch

do.

"

do.

. 63320

Rumford.

The relative cohesive strength of the metals are, according to Sickengen, as follow: -

Gold . . . . .. . . . . . . . . .. .

150,955

Silver . . . .. . . . . . . . . . . .

190,771

Platina . . . .. . . . . . . . .. . .

262,361

Copper . . . .. . . . . . . . .. .

304,696

Soft Iron . . . .. . . . . . . . .

362,927

Hard Iron . . . .. . . . . . .. .

559,880

But their hardness, according to Cavallo, follows this order, viz., Iron, Platinum, Copper, Silver, Gold, Tin, Lead.

Banks observes that iron is about four times as strong as oak, and six times as strong as deal. Wood is from seven to twenty times weaker transversely than longitudinally. It becomes stronger both ways when dry.