TRANSACTIONS OF THE SECTIONS. 229 



education will, I fear, be a useless pastime ; but whether that be so or not, I am 

 certain that the accurate and neat representation of the elementary parts of 

 machinery and buildings would be popidar with the pupils and could be efiectively 

 taught. This kind of drawing educates hand and mind in accuracy, it teaches the 

 students the elements of mensuration and geometry, and it affords considerable 

 scope for taste where taste exists. The chief difficulty will be to obtain competent 

 teachers. I should occupy you too long were I to attempt to show how these 

 must themselves be trained. My chief aim to-day has been to claim attention 

 for a most important and wholly neglected branch of education. 



I shall probably be expected to urge the teaching of other natural sciences in our 

 primary schools ; nothing, indeed, would give me gi-eater pleasure than to think 

 this coukl be done. I confess I doubt it ; while our second-grade schools are what 

 they are in this respect, and while the Cambridge examination for a degree in 

 applied science is what it is, I dare not think of natural-science classes in our 

 primary schools. I shall be delighted if I am mistaken ; but I am certain that 

 mechanical drawing deserves our tirst attention, as most immediately useful to the 

 artisan and most easily taught. The very books on natm-al science which are pub- 

 lished in England cannot be properly illustrated for want of a sufficient number 

 of competent draughtsmen ; and ' children would be unable to follow the illus- 

 trations and diagrams if ignorant of the principles on which they are constructed. 

 I look rather to good reading-books, explained by intelligent masters, as the best 

 manner of teaching the elementary and all-important truths of natural science. 

 No man could do better service than in compiling such reading-books, and there 

 are few wants more urgent than that of masters competent to enlarge upon texts 

 which would thus be put into their hands. The education of our worlonen is far 

 more incomplete than that of our professional men. Small additions to existing 

 institutions will meet the want of the latter ; but for the former the institutions 

 have to be erected almost from the foundation. 



On an Apparatus for ivorTcing Toi-pedoes. By Philip Beaham. 



The author of this paper described the various modes of working with torpedoes 

 now extant, and explained their various disadvantages. He then explained his 

 own, which was the propulsion of a torpedo from an invulnerable boat below its 

 water-line by means of the expansion of compressed air. A drawing of the appara- 

 tus was exhibited by the author ; it consisted of a compression-chamber, in which 

 air could be confined to a great pressure, a tube through which the torpedo could 

 be propelled, and a valve arrangement whereby the progressive velocity of the 

 torpedo could be regulated. By means of machinery driven from the engines that 

 move the ship he proposed to compress air into the compression-chamber to 500 lbs. 

 to the square inch, and when within striking-distance of the vessel attacked the air 

 to be suffered to escape behind the shaft of the toi-pedo, driving it with consider- 

 able force so as to strike the vessel attacked below its water-line and then to explode. 

 By the reaction of the force driving the torpedo forwards, whose average statical 

 pressure would be So tons on a diameter of 1-9 shown, the author expects the 

 attacking boat would have its speed considerably diminished, if not entirely neu- 

 tralized, and so prevent the possibility of collision. 



Account of some Experiments iipon a " Carres Disintegrator " at ivoric at 

 Messrs. Gibson and Walker's Flow-mills, Leith. By F. J. Beamwell, O.E. 



CaiT's Disintegrator, as is probably well known to most mechanical engineers, 

 consists e.'=sentially of two disks, eacli tixed upon a horizontal shaft. These shafts 

 are placed in one line ; the disks which they carry at their ends are separated the 

 one fi-om the other by a space of a few inches. Each disk carries a number of bars 

 or studs disposed in several concentiic rings, and standing out at right angles from 

 its face. The concentric rings of studs of the one disk are arranged so as to be in 

 the spaces between the concentric rings of the other disk. The disks are driven in 

 opposite directions, and at a high velocity. The rings of studs, although very 



