04, REPORT—1896. 
water circulated, a weight of 1,500 lb. being required to take the power of the 
engine. 
This brake never worked satisfactorily, and though every expedient was tried, 
it was found impossible to conduct a trial with any regularity beyond 30 indicated 
horse-power. Moreover, owing to the flywheel being overhung, and a weight 
hanging upon it, during a long trial, the bearing nearest the wheel almost 
4nvariably became heated. Beyond this, it was found that for practical pur- 
poses a 3-ton wheel was unnecessarily large for any trials. A brake, of which 
a descriptive diagram was shown, was therefore designed, the weight of the fly- 
-wheel being about 15 ewt., instead of 3 tons, and the framing being so arranged 
that the load was taken off the bearing. This brake at once remoyed the difficulty 
of heating, and a regular series of trials were made up to about 60 horse-power, 
which during one session served quite satisfactorily for the work of the students. 
Beyond this, however, it was impossible to get regular runnings with the brake. 
The loads were taken by a hemp cable, five coils of which passed round the wheel, 
which is in the form of a broad pulley, and acted by taking advantage of the 
power of coil friction. To get steady runnings it was found necessary to keep 
the rope wet, a stream of water flowing upon it. 
It had been originally intended to have the form of Froude hydraulic brake, as 
modified by Professor Osborne Ieynolds, and it became evident that nothing but a 
hydraulic brake would solve the problem of taking up continuously 150 horse- 
power. The question of cost had prevented this form of brake from being obtained 
originally from Messrs. Mather and Platt, and the same reason led toa modified design 
of the hydraulic brake, in which the chief cause of expense in the Reynolds type 
“was avoided, viz. by doing away with the considerable amount of coring for air and 
water passages in the castings, and also in constructing the main part in cast iron 
instead of gun-metal, and further, in having it single acting. For this, and other 
apparatus, funds were provided through the kindness of Mr. Charles W. Jones (of 
Messrs. Lamport and Holt) and Mr. R. R. Heap. 
The author then proceeded to explain by means of models the action of the 
brake, and the features which were peculiar in the new brake, which were as 
follows :— 
(1) The vortex is artificially produced. 
(2) The brake is single acting. 
(3) The pressure is downwards, so as to take the weight of the brake off; in 
fact, practically not to take off the weight of the brake only, but also of 
the flywheel. 
(4) Autographic recording and registering arrangements are employed. 
(5) Special arrangements are adopted by which automatic action is secured. 
These various points were considered in detail and described by means of draw- 
‘ings, but it was pointed out that as far as the actual work of the trials for the 
students were concerned, none of the refinements mentioned were necessary. An 
extremely simple form of brake was quite sufficient to maintain the engine running 
perfectly steady under the highest steam pressures 
The various features in which the engine itself has been improved were then 
mentioned, and may be summarised as follows :— 
() A sid of drain tanks, so as to measure the water condensed in the steam 
jackets, 
(2) A erate tank has been provided, into which the water from these drain 
tanks is thereby checked. 
(3) A new special tank for the exact calibration of feed-water supply has been 
rovided, which works in connection with the injector by which the 
oiler is supplied. 
(4) A special arrangement has been devised by which the indicator diagrams 
can be conveniently and rapidly taken by students, 
(5) A system of checking and graduating the indicator springs, which has been 
found most valuable in operation by means of a duplex standard steam 
gauge. 
