6 Proceedings. 



some inequality in the shape or texture of the surface of 

 the wall. No unevenness is visible, which shows what a 

 delicate test we have in the deposit of dust in tracing slight 

 inequalities in the nature of a surface." 



The following " Memorandum on Lifeboats, as to the 

 relative values of Stability versus Self-righting Power," was 

 read by the author, Mr. Joseph Corlsett : — 



" Lifeboats have been in use for more than a century, 

 but the self-righting principle was only introduced in 1852 

 by the Northumberland Prize Committee. This Committee 

 recorded the principle as a contested one, but decided 

 to try it. No methodical competitive trial of the principle 

 has ever been made, and it has been continuously chal- 

 lenged as being so detrimental to the working powers of a 

 lifeboat as to be not worth having. The Southport Life- 

 boat disaster in December, 1886, when the crews of two 

 self-righting lifeboats were all drowned, except two men, 

 called public attention very urgently to the dangers of 

 these boats ; but, unfortunately, the genera! drift of criticism 

 was that lifeboats should be made more positively self- 

 righting than heretofore. Professor Osborne Reynolds read 

 a paper before this Society, ' On Methods of Investigating 

 the Qualities of Lifeboats,' in which he advocated experi- 

 ments with models. The Committee of the Royal National 

 Lifeboat Institution appointed a special sub-committee 'to 

 make a searching investigation into the self-righting and 

 other properties of the Institution's boats,' and thiscommittee, 

 after three months of laborious inquiry, and experiments with 

 self-righting boats, made its final report, in April, 1887, 

 recommending the introduction of copper air-cases in place 

 of canvas-covered wooden ones, and ' a careful revision of 

 the weights and materials used in the several parts of the 

 boats, ensuring increased stability, strength, and sea- 

 worthiness, at the same time largely increasing their 

 self-righting power,' also recommending the appointment 



