434 SECTIONAL TRANSACTIONS.—G. 
arranged that there was no shear stress on this central 20 inches. From the 
unstressed ends of every beam specimens were cut and turned for compression 
tests. In the case of the beams a deflectometer was used in order to determine 
carefully the limit of elasticity. The various results obtained in both sets of 
tests are given in a series of tables. After the beams were broken, tests were 
made of the percentage of moisture present, measurements were made of the 
width of the annual rings and of the nature of the growth of the wood. The 
tests of the wood for pit-prop purposes were carried out for the Forestry Com- 
mission. The props were tested just as received, the bark was left on, and the 
ends were carefully squared; the load was applied by means of compression 
blocks with spherical backs. The results obtained were given in a series cf 
comparative tables. 
2. Prof. Aurx. R. Horne, O.B.E.—Ezperiments on the Mechanical 
Properties of Scots Pine. 
The investigations relate to the cross-breaking strength and the elasticity of 
Scots Pine, as determined from experiments made upon about 300 test specimens, 
taken from 18 trees from 6 forests in the north of Scotland. The specimens 
were of a size such as is used in constructional work. Laws are established 
giving the relations between breaking strength, elasticity, and dry density. 
Information has been obtained regarding the percentage of moisture in the 
trees as cut, and its distribution. The rate of loss of moisture during seasoning 
has been investigated; and the period of seasoning desirable in practice has 
been determined. <A note was added regarding the ‘ blueing’ of timber. 
3. Dr. B. C. Laws.—Stresses in Ships’ Plating Due to Fluid 
Pressure. 
This paper referred to means used for Aavaboiseee stress values in plates of 
rectangular form fixed at their boundaries and subject to uniformly distributed 
loads, and indicated the effect of fluid pressure on the ultimate stress in mild 
steel plates used in ship construction when considered jointly with the stresses 
induced in the material on account of local or structural bending of the vessel. 
Later the paper dealt with the question of stiffened or reinforced plates, and, 
in the absence of complete experimental investigation, an endeavour was made to 
trace the effect of the reinforcement in bringing about a redistribution of stress 
in the material. 
4, Dr. E. M. Horsspurcu.—The Fracture of Wire in Steel Ropes. 
Forces in Lope-wires.—Tension approximately constant throughout the 
length of a rope-wire, when the rope hangs vertically, and supports a load. 
Rope Modulus.—The modulus of elasticity of a rope. The load a continuous 
function of the extension. Shape of the strain-stress rope curve. Possible 
analytical representation. Rope modulus as a gradient. Its maximum value. 
Small values. 
Efficiency of a Steel Rope.—Its strength compared with the sum of the 
strengths of the wires. Difficulties which arise. 
Tension in a Rope-wire.—The cup and cone fracture. A family of slip sur- 
faces. Combined tension and bending. 
V'orsion of a Rope-wire.—Susceptibility to torsion tests. Combined tension 
and torsion. 
Spring Effect in Winding Ropes.—Flexibility test. 
Some Effects of Wear.—Abrasion. Denting. 
Some Age Lffects in Rope-wire.—Loss of toughness after prolonged use. 
Hardness. The representation of fatigue curves. 
5, Prof. T. Hupson Bears and Mr. Wm. Gorpon.—The Influence of 
the Width of the Specimen upon the Results of Tensile Tests 
of Mild Steel and Rolled Copper. 
The research originated in an attempt to re-establish the critical ratio of 
width to thickness which Barba has shown to give a maximum elongation, but 
the scope of the investigation ultimately became much wider. ‘The paper dealt 
ee 
