Page
ROAD TRANSPORT
100 Year Ago
On June 1: 1834, century ago.> at Chalk Farm the first god was cut for the London and Birming- ham Rallway, of which Robert Stephenson was the engineer. That, same year saw the brickla- yers busy on the 800 arches for the "rallway from Southwark to Deptford, the signing of the 'Act for the London and Southampton line dhd the discussion in Parlia ment of the Bill for the Great " Western Railway. During the previous hundred years, first by the reconstruction of roads and bridges and improvements in horse-drawn vehicica, secondly by the cutting of canals, and thirdly by the application of steam po- wer on road and rall a great ad- · vance had been made in the pro- gress of inland transport and men had already begun to look back on the past as somewhat re- inote, One writer in 1525 gaid "It is true that we who in this age are accustomed to roll along on hard and even roads, at the rate of 8 miles or 9 miles an hour,
can hardly imagine the incon- venience which beset our great- grandfathers when "they had to undertake a journey... Even in the middle of the eighteenth cen- tury travel was very slow and Watt as a youth took fourteen duys on the journey from Glas- gow to London, while Smeaton was six days getting to Plymouth from London.
A New Era
would
Thanks to the work of such na Wade. Telford. Metcalfe, McAdam. Trevithick and Stephenson; a new era in communication had been ushered in and a map of the Bri- tish Isles a century ago show a network of some 120,000 miles of road, some 2.000 miles of "canal and a few short lengths of railways joining more or less im- portant cities and towns: There were lines from Darlington to Sidekton. Canterbury to White- table, Bolton. Dundee to Newtyle and from Liverpool to Manches- ter, besides others either in opera- tlon or under construction.
METAL WINDOWS
MANUFACTURER":
MADE IN
HONGKONG
4
FROM
IMPORTED" BRITISH
MATERIAL
95%% BRITISH.
THE TAI YING STEEL WINDOW MFG. CO.
TELEPHONE: 27482.
OFFICE: 89/85, CHUN YONG STREET. FACTORY-NORTH-POINT, HONG KONG.
HONG KONG DAILY PRESS, SATURDAY, AUGUST 4, 1934.
ENGINEERING AND BUILDING
THE HEAT INSULATION OF BUILDINGS
Heat Transmission Through
Materials
As the general subject of the transmissioni of heat through material touches the sphere of engineering at many points, there are probably few engineers who, during the course of their careers. have not had- occasion to "study the related principles with a view "to applying them to practical problems. The theoretical aspect of the conduction of heat was enunciated more than a century ago by Fourler in his classical treatise "Theorte Analytique de la Chaleur," and the brillarice of Heaviside's genius later elucidat- ed the subject by means of the operational calculus, but the pra- tical application of experimental investigations is a matter that claims the close attention of pre- sent-day engineers and physicists. Heat transmission through mat- eals such as are used in build- ng construction is naturally, ‘& subject of direct Interest to en- gineers concerned in the design and operation of cold-storage in- stallations, but it is equally im portant to those engaged on the, erection of all types of buildings that are constructed in countries subject to extreme variations of a.mospheric temperature such as
the case over consider- able areas, of the North American continent Appreci- zole commercial importance is attached to the questions in 'volved in instances where the cost of fuel is high, as, for instance, in Ontario, where all the used for heating purposes is im- parted from the United States or England. In consequence. Ameri- Can and Canadian engineers have devoted much time to devising in- vestigations into the subject in such a marner, that the results
coal
can be directly applied to practi- cal cases of building construction.
Hot Plate Method The experimental examination of the subject consists in deter- ming the coefficients of heat transfer through the materiał used in the construction of a gi- ven wall. This test may be car- ried out by means of the hot- plate method in which the ma- terial under investigation is placed between two plates, one of these consisting of an electrically heat-. ed plate" that is supplied with a measured quantity of heat, while the other plate la cooled by wa- ter, or refrigerated brine. Buch a method is specially adapted to testing samples of homogeneous materials with surfaces that are suficiently smooth to ensure rea- sonably good contact between th plates and the specimen under test. By this means, the uncer- tainty attached to the value of the coefficients of heat transfer between the interfaces is avoided, and for this reason the method is frequently used to determine the thermal conductivity from surface'
surface of "a materjal. How- ever, the method can be used only.. for examining materials that are fairly uniform in composition, to ensure that representative results are obtained from relatively small samples. Provided that the char- acter of the various factors which operate in the hot-plate method are known. It is manifest that the apparatus forms a comparatively quick and easy means of carrying put the necessary tests on a given material, acid it is therefore, of more than passing interest to ob- serve that Professor E. Ar Allcut. of Toronto University," has lately
AN ELECTRIC LIGHTING PLANT
THAT CAN BE
CARRIED IN
ONE HAND
PYGMYLYTE
undertaken comparatively
Ex-
haustive investigations into the factors that influence results de- rived from the hat-plate method. Previously. It was known that the meun temperature between the hot and cold sides of the speci- men affected the results, but de- Anite data was not available as to the effect of a variation in the range of temperature when the mean value was kept constant, Professor Allcutt's experiments have, we understand, shown that the temperature range does not materially affect the results when, a constant mean temperature is maintained between the two sur. faces of the material under test. and they have demonstrated that' the heat conductivity increases in direct proportion to the mean temperature in the case of number of materials that had not hitherto been examined. The influence of the pressure exerted test plece by the two on the plates when such soft materials as kapok or `eel gress quilt was being examined might well have formed a factor that influenced the heat transmission coefficients obtained from this apparatus, but the tests in question have shown that considerable varia- tions of pressure did not affect the results to any marked degree. Professor ABent's experiments
B
Qur
have "undoubtedly extended knowledge of the possibilities con- cerning the hot-plate method, and the publication in due course of his conclusions may be expected to form a definite contribution to the general subject of the trans- mission of heat through insulat- Ing materials. "Engheering."
CONDITIONS IN SINGAPORE
A brochure, compiled by the publlelty committee of the Rotary Club of Singapore, for the purpose of making known the stages of development of Singapore from its foundation, and also some- thing of its administrative, com- mercial, Industrial and social activities at the present time, has recently been published by the Rotary Club and the Municipal Commissioners of Singapore. The brochure, which is well written and most attractively illustrated, contains numerous articles on such matters as the foundation of the prescut, town by Sir. Thomas Stamford Raffles in 1810 and its history and growth, the port and municipality of. Sin- gapore, police, public health, me- dical institutions, climate, rail- road and air transportation, com- merce and Industries, rubber manufactures, and, tin smelting. Other chapters on. Mife in Sin- gapore and hints to sightseers are-- Intended for the guidance of visi- tors, while a number of helpful maps and plans' are also included. The brochure gives the reader an excellent idea of the general con-
MEASURING THE THE GROWTH OF
SMOKE
In The Atmosphere,
The existing methods of deter- mining smoke pollution are based on estimates by the eye of the density of the 'smoke, either un- alded, or with the help of Ringel- mann charts, or of ruled trans- parent screens, These refine- ments have been introduced to overcome the arbitrary nature of a simple estimate by the eye, but varying conditions of observation
render their applications difficult, and liable to considerable errors. An apparatus for measuring the optical intensity of smoke issuing from a chimney is now in use; in this. the eye, has been replaced by a photo-electric cell, as the means of measuring the amount of light received from a deonite area of the smoke, as compared with that from an equal area of the sky. In the absence of any reflected light, this
apparatus
鎵
would provide a measurement of pollution. However, there is component of reflected light pre- sent in the total received from the observation of smoke, which modifies the direct relationship between measured optical den- sity and pollution in the case of dense smokes. The reflected light also varies with different types of smoke. and under different conditions of its illizmination,
Ultra-Violet Filter
To minimise the error an ultra- violet filter can be used with the instrument, but even so, reflec- tion introduces an unknown fac- tor, and it is therefore necessary to determine the general'remtion- ship between apparent brightness of the smoke and the amount of pollution. Correction has also to "be made for light scattering by the air between the smoke and the apparatus. "It has been found; by observation of the six general classifications of density of smoke,
16
THE POST...
The exercise of the faculty of Invention has brought innumer- able benefits to mankind and as applied to travel, tarnsport and communication, it has, to adopt the characteristic phrases of Ma- caulay, acelerated motion, anni- hilated distance and facilitated: intercourse, "correspondence, all friendly offices, all despatch of business. A yardstick by which the growth of intercourse and cor- respondence can be measured is the activity of the Post Office, the recent report on which presented to Parliament showed that the transactions of the Post Office with the public for the year end- ing March 31, 1933, amounted to about £880,000,000 while the staff employed was about a quarter of a million. Among the Items deals with in the year ending March 31, were 6,640,000,000 letters, 151,-- 666,000 parcels, 50,030,000 register- ed letters and parcels, and in- numerable, postal orders, «tele- grams and telephone calls.
A century ago when the des- patch of letters from St. Martin's- le-Grand by mail coach was one of the sights of London, the re- venue of the Post Office was but a million and half, and the staff about five thousand. The charges then were, of course, much hig- her than they are to-day, inland letters being charged 8d. for 50 miles, 10d. for 120 miles, and 1s. Id up to 300 miles. Postage over- seas was just as expensive, 25. 10d, being charged on a letter to Gibraltar. There were probably few sound reasons, for such ex- cessive charges, even with horse transport, buth with the coming of the railway it was evident that they were' quite unnecessary and the year 1840 saw the introduc- tion of the penny post. From that time onwards there has been a steady increase in that inter- course" and correspondence Ma caulay spoke of."
that there is a definite instrumen- Sinoke As A Corrosive
has
tal reading for each, and therefore been possible to use this apparatus to And whether the smoke from a chimney is of grea- ter density than 3 prescribed limit.
Tests have shown that the jet dust courter provides a satisfac- tory measure of the number of insoluble particles usually present In the air. Attention has also been paid to the development of an improvement in the automatic Alter. involving "operation by weights, rather than by water. The new instrument can be adapa ted to provide a record of the wind at the time of each observa- tion. Its use should prove valu- able when it is desired, not only to find the amount of suspended impurity, but to determine the direction from which it comes. ---
ditions of life in Singapore and reflects great credit on all those who have taken part in its pro÷- duction.
*
The effects of atmospheric pal- lation on the corrosion of iron are now under observation. In the case of iron, the relation between corrosion and pollution is probably just as intimate as has been formerly found withi copper, but the resulting · pro- ducts pehave in a fundamentally "different manner. The iron, salisi produced are flocculent, and very loosely adherent, and thus, afford no appreciable protection against.
their continued action, while presence may even accelerate the corrosion of adjacent metal In atmospheres containing the usual small concentrations of sulphur dioxide, a certain critical humi: dity is necessary for appreciable corrosion to occur. Above this value, commonly in the region of 68 per cent relative humidity. the rate of attack may increase enermously. The rusting of iron is also further affected by the suspended solid particles in the Eir."Engineering.".
IDEAL FOR MATSHEDS,
MOTOR LAUNCHES, and
small up-country - Bonga-
lows, etc., etc.
Uses, only gallon of petrol and oil mired per hour. Needs No Attention what-
ever, weight complete 56 lbs.
As Supplied to the Houston Everest Expedition
For Constructural Work of Every
Description
Use Green Island Cement
United National Corporation, Ltd.,
National Commercial Bank Building,
HONG KONG.
Phone
32602
GENERAL
WHERE GREEN ISLAND CEMENT IS MADE
VIEW OF THE GREEN ISLAND CHMANN WORKS TAKEN FROM THE SKA.
Issued by the
GREEN ISLAND CEMENT CO. LTD.
FLOOR
EXCHANGE BUILDING