502 REPORT—1905. 
CAPE TOWN. 
WEDNESDAY, AUGUST 16. 
The following Papers were read :— ; 
1. Cape Town Colonial Dutch Architecture. By C. H. Smirn. 
Architecture at the Cape of Good Hope from 1652 to 1850—The earliest Cape 
Post Office, Post Office stones, &c.—First building at the Cape, Van Riebeek’s 
Fort—Present Castle: its constructions and details—Plan and views—Castle 
gateway—Interior of Castle—KHntrance to Council Chamber—Old building on 
Castle outworks, now demolished. 
The works of Simon Van Der Stel at Constantia—Plan of house and descrip- 
tion—Wine-house Constantia and sculptured pediment—The work of the 
sculptor Anzigt at the Cape: Pulpits, Dutch Reformed and Lutheran Churches, 
Developments under Willum Adrian Van Der Stel—Old church, Cape Town— 
Plan of typical peninsular town house, Cape farm-houses—The progress of 
Stellenbosch—The conspiracy against the Van Der Stels and their fall—I]lustration 
of the Governor Willum Van Der Stel’s house and estate as shown in the accu- 
sation—Illustration of the Governor Willum Van Der Stel’s house and estate as 
shown in his defence, 
2, Steam Turbines as applied to Ocean Laners. 
By Professor J. Harvarp Biirs, LL.D. 
THURSDAY, AUGUST 17. 
The following Papers were read :— 
1. Roller-bearings. By Tuomas W. How, L.R.G.S. 
The present divergence of opinion as to the practical application of roller-bear- 
ings to movable and fixed machinery is attributed to their limited application 
and consequent trials, to the expense of re-fitting existing plant, and to the diffi- 
culty of obtaining comprehensive data of economies effected. 
The requirements of a satisfactory roller-bearing are that the various parts 
must be proportioned with reference to their relative movements, and constructed 
of materials suitable to withstand the stresses imposed upon them. For heavy 
loads the author recommends high-class finish and hardened steel, but for light 
loads milder steel of good quality, with due regard to luad in each case. 
The efficiency of roller-bearings largely depends upon true parallelism, proper 
spacing of rollers, and proportionate diameter, length, and hardness of the rollers, 
in order to withstand fatigue. 
Of the various contrivances for spacing the rollers the author regards the 
‘Empire’ floating cage as the most satisfactory, owing to its simplicity of con- 
struction and easy adjustment. 
Solid rollers are advocated rather than spiral, hollow, or rollers threaded on 
spindles. Provision for end-thrust or lateral movement of a roller-bearing is 
necessary, and several methods are described. 
The author, whilst contending that roller-bearings should be produced at 
reasonable cost, regards first cost as secondary to ultimate economy in motive 
power, measured by savings in coal or electrical current per annum, and lubrication. 
Recent tests on line shafting electrically driven fitted with roller-bearings 
effected a saving of 24°4 per cent. of the power required to run the motor and 
counter-shaft with machines in full work. 
Earlier unsuccessful experiments made with roller-bearings are attributed 
to causes now well understood and avoided, such as excessive rigidity and 
