642 TRANSACTIONS OF SECTION G. 



the largest size. The new work is composed of hard shale bricks set in Portland 

 cement mortar. The internal linings of the smaller structures and the inverts 

 of the larger ones are formed with red-pressed bricks, which make a smooth and 

 durable surface. The large culverts cross railways, canals, and rivers. Owing 

 to the presence of water it was found necessary in some sections to use com- 

 pressed air ; this method of construction was most successfully employed without 

 the application of the working shield. In some instances lengths of upwards 

 of three-quarters of a mile were constructed from one air-lock. Little trouble 

 was experienced from air-leakage, although the depth beneath the surface did 

 not exceed 30 feet, and in many places it was much less. The work is being 

 carried out under the direction of the Rivers Committee of the City Council, 

 and the writer desires to record his indebtedness to that Committee and to the 

 Chairman (Alderman Frowde, J. P.) and the Deputy- Chairman (Councillor West) 

 for the great assistance and encouragement he has from time to time received 

 in dealing with the many difficulties that have arisen during its progress. 



2. The Manchester Electrical Undertaking and the projected Barton 

 Station. By S. L. Pearce.^ 



3. The Special Work in the Mechanical Erigineering Department of the 

 Manchester Municipal School of Technology. By Professor A. B. 

 Field. 2 



The following account is submitted mainly in view of the intended visit of 

 the British Association to the Municipal School of Technology. 



Much research work upon lathe cutting tools was carried out by the late 

 Dr. J. T. Nicolson in the School of Technology, starting some ten years ago. 

 The work has been continued at Manchester since then, and led to the develop- 

 ment of a very complete dynamometer gear for measuring the various components 

 of force upon the tip of the tool when taking a heavy cut. This apparatus, 

 as constructed to Dr. Nicolson's design, can be inspected in the Engineering 

 Laboratories at the School, and will be shown in action on an 18-in. heavy lathe. 

 An apparatus upon similar lines for measuring the various forces acting upon 

 a milling cutter is also exhibited ; this apparatus having been built to the 

 design of Mr. Dempster Smith, who was associated with Dr. Nicolson in his 

 work. Mr. Dempster Smith is continuing this line of research in co-operation 

 with a Committee of the Manchester Association of Engineers. 



In the materials testing laboratory, in addition to standard testing work, 

 researches have been in progress by Mr. W. C. Popplewell upon the effects of 

 repeated reversals of stress, using the rotating-beam method. The apparatus 

 used is open to inspection. In the same laboratory will be found under way a 

 research upon the failure of alloy-steel tubular struts of short length. Such 

 struts fail by a process of crinkling, as distinguished from the collapsing of an 

 ordinary long strut. The effects of various methods of end-constraint are being 

 investigated in this connection, and corresponding tensile tests of samples of the 

 material made. 



In the gas engine laboratory experiments are being conducted by Professor 

 Okamoto, of Osaka, to investigate the rate of loss of heat of the contents of a 

 gas-engine cylinder, dividing this quantity into two items, which may be 

 generally comprised under the headings ' conduction ' and ' radiation.' 



Other special work in the department is in hand for the War Office, and is 

 not open to discussion now. 



' S«e Engineering, Septemher 24, 1915, p. 309. 

 ' See The Engineer, September 17, 1915. 



