40 Experiments on the Adhesion of Iron Spikes, 
A comparison of the results given in the following table, will show 
what order those forms would possess among themselves, in point of 
retentiveness, as well as the advantages of the respective species of 
timber into which they were severally driven. 
TABLE III 
Spikes of various forms—timber of different kinds. 
Ps o. See og 
n 2 a é 5 S| | ee o 
mz isnt ss |££lesisz 2358s ales 
a © 33 =P SoalYinlag |PLS ell sloo 
38 a =s 2°EF SE APERESE OE] ¢ 
S E eg (2 F ia sir sie Slee) ¢ 
7, eal | = Inch.!Inch.| Sq. in. |Inch.| Grs. |Lbs. |p 2 A 
1 |Straightsquare. i Chesinat | 495|.402| 2.83 [3.5 | 942 1995/2.116 1895. 
2 Burden’ S patent 2: 373, 984; 2.64 |3.5 66/1973 2.162} Dec. 8. 
3. \Broad flat. 539, 288) 3.77. |3.5 898 2394|2.663|Dee. 4. 
4 |Narrow flat. toe 390.253) 2.73 13.5 | 566)2223)3. 927 Dec. 8. 
~ (|White oak 
5 |Straight square thorooghiy 405, 402) 2.83 | 3.5 sa 4.129|Dec. 7. 
seasoned, 
6 |Broad flat ye | 288) 3.77 |3.5 | 898.5130/5.712|  ** 
“3 Narrow zt | 253) 2.73 |3.5 | 566)3990/7.049} 
* Burden’s patent. 373.384) Q 3.5 | 866'3905 4. : 
9 Cylindrical with i 485 a4 | a 
cutting edge. SO9F ty =" 3.5 [12113876 3.200) 
10 § |Grooved land swel-| « 
. 
a ores bat not} « 375| 375) .260'|3.5 | 759/42475.662!  « 
Grooved, and bot- 
500/26505.300! * 
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13. |Square. 1 soned three} .405! .402} 2.83 | 3. 942.5967 6.334| Dec. 8. 
years 
5 
3.5 | 898/70407.839} 
5 
14 [Broad flat. °°) .539).985) 3.77 |3 
cies 390) .253) 2.73 13.5 | 566/5273.9.316| © “ 
15 Narrow ei 
(erin et 
16+ filed Seat a ee 3.5 | 92912052.2.208| 1836. 
a8 sates : =n meta ey ae ial ak cad 
: 1 omic sel va 500| * 3.5 NOI 9461/3444 “ 
REMARKS, 
Experiment No. 10.—The measures in this and the two following eases were 
taken outside we flanches. 
Experim — 12.—The weight of the part inserted is given by estimation in 
this experime 
_ Be rimené Nok 16.—In this and the two following experiments, the spikes 
into the timber i in the direction of the length of the fibres. 
The above table furnishes three sets of comparisons for deducing _ 
the relative retaining powers of green chestnut, thoroughly seasoned — 
