1868. | Mechanical Science. 541 
miles, which is now dry, will have to be filled from the waters of 
the Red Sea, and it will be curious to note the influence on the sur- 
rounding atmosphere of the evaporation from this source, which on 
the above supposition must nearly reach the astounding quantity of 
360,000,000 cubic feet per diem, or 250,000 feet per minute. 
Adverting to our armour-clads, the President argued that, in 
order to render the combined operations of a fleet effective, the 
vessels constituting it ought to be as nearly as possible of the same 
speed, and that the protection to be afforded to a ship by armour- 
plating should be made subservient to speed and steadiness. He 
deprecated the reception of the performance of a ship in smooth 
water as any test of her speed and behaviour when at sea. Turn- 
ing to the question of our coast defences, Mr. Bidder expressed his 
opinion that the advance in the science of gunnery had put an end 
to the embrasure system; he considered that men were really better 
protected in the open country than when crowded together behind 
embrasures and exposed to the fire of a powerful artillery. His 
address concluded with some remarks on the improvements in tele- 
graphy, expressing a hope that this country might before long 
possess an independent line of telegraphic communication with 
India, by way of Gibraltar and the Cape. 
With two or three remarkable exceptions, the papers read in 
the Mechanical Section were neither so able nor so interesting as 
those which have been contribnted at former meetings of the British 
Association. The Section, though fairly, was never very numerously 
attended, and we missed the presence of several men eminent in 
the engineering world, who are generally with us at our annual 
congress. Norwich being the capital of a strictly agricultural 
county, the town selected for this year’s meeting presented few 
attractions to mechanical engineers. ‘To the civil branch of the 
profession the drainage of the low-lying lands of Norfolk is a 
question of some importance; and a paper was read by Mr. R. B. 
Grantham “On the Broads of East Norfolk, having reference to 
Water-Supply, Storage, and Drainage,” possessing some local inte- 
rest, but which without maps of the district to which it relates 
would be unintelligible to the general reader. 
The paper which perhaps more than any other attracted attention, 
and gave rise to an interesting discussion, was that by Mr. Whit- 
worth, “On the Proper Form of Projectiles for Penetration through 
Water.” His object was to show that a flat-headed shot when fired 
at a small angle of depression is better calculated to penetrate an 
object aimed at under water than one with a hemispherical or coni- 
cal head. The author exhibited to the meeting the photograph of 
a plate which had been placed with its bull’s-eye under water and 
fired at with a one-pounder gun, of which the angle of depression 
