Page:EB1922 - Volume 31.djvu/318

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GLASS, CARTER—GLASS

Glenconner Park in 1914, and the Dawsholm Park in 1920. In 1911, 121 ac. of the grounds of Pollok House were given to the Corpora- tion for use as a public park for a period of ten years. Statues of Lord Kelvin (1913), Lord Roberts (1916) and Thomas Carlyle (1916) have been erected in the Kelvingrove Park.

The increase of population has led to some anxiety about the water supply. An additional supply from Loch Arkjet came into use in 1914, but in the same year a bill to secure additional water from Loch Voil and Loch Doine was rejected by a committee of the House of Lords. A Glasgow Water Order was, however, obtained in 1915 giving power to impound the waters of the river Turk in Glenfinlas and to convey the water thus obtained by a tunnel to Loch Katrine. The commencement of the necessary work was delayed by the war, and immediate relief was obtained by a Provisional Order (1919) enabling the Corporation to raise the level of Loch Katrine. In 1919 the Corporation purchased 24,110 ac. in the watershed areas of Loch Katrine and Loch Arkjet at a cost of 71 ,850. The average daily quantity of water sent into the city was in 1920 79,147,673 gallons.

Important developments of the municipal undertakings (gas, electric light and power, tramways and slaughter-houses) were delayed by the war. A Housing Committee of the Corporation reported that a total of 57,000 houses of 3, 4, or 5 rooms was urgently required, and it was hoped to build 7,000 by the summer of 1922 ; plans and schedules for nearly 4,500 had been prepared, and 300 timber houses had been completed by the end of 1920. The esti- mated cost of 4,443 permanent houses, including streets and sewers, was 4,763,686. A new justiciary building was opened by Lord Dunedin on July 7 1913.

During the period of voluntary recruiting for service in the World War the total enlistments in the city of Glasgow numbered 178,000 (inclusive of recruits from areas outside the boundaries).

The amount invested in the various forms of War Loan was approximately 83,500,000, and subscriptions for benevolent purposes connected with the war reached a total of 5,000,000.

GLASS, CARTER (1858- ), American politician, was born at Lynchburg, Va., Jan. 4 1858. He studied in the schools of his native town; learned the printer's trade, which he followed several years; and became proprietor of the Daily News and the Daily Advance, the morning and evening papers of Lynchburg. He was elected to the Virginia State Senate for two terms (1890-1903) and was a member of the State Constitutional Convention in 1901. He was elected to the national House of Representatives to fill the unexpired term (1902-3) of P. J. Otey, deceased, and was continuously reflected thereafter to serve through 1919. As chairman of the House Banking Com- mittee he was active in framing and passing the Federal Reserve Bank Law. In 1918 he resigned from the House to enter the Cabinet of President Wilson as Secretary of the Treasury, succeeding William G. McAdoo. Under his guidance the fifth Liberty Loan was floated in April 1919. In Nov. 1919 he was appointed by Governor Davis of Virginia to serve in the U.S. Senate for the unexpired term (1910-25) of Thomas S. Martin, deceased, and he resigned as Secretary of the Treasury. He was chairman of the Committee on Resolutions at the National Democratic Convention in 1920.

GLASS (see 12.86). During 1910-20, and more especially during the period of the World War, very considerable developments in the glass industry occurred, both in the glass produced and in the varieties of glass manufactured. In the following article attention is, of necessity, given to the British glass industry. In certain respects the art of glass-making has for long been at a very high level in Great Britain. The products of leading manufacturers in the London, Stourbridge and Manchester districts, so far as table-ware, ornamental glassware and coloured glasses for windows are concerned, have, for many years, been of as fine a quality as any obtainable elsewhere. Indeed some of the ornamental glassware made in England has long been unrivalled. There is no need to amplify what has been said in the earlier article on these matters. When the war drew attention to the British position in respect of glass generally, it was in the direction of scientific glassware and special glass for certain industries, that the deficiencies were realized. Glass for scientific purposes may be taken to include optical glass and all glassware used in laboratories.

Laboratory Glass. To deal with laboratory glassware in the first place. Before the war it may be said that nearly all the

glass and glass apparatus used in laboratories throughout the United Kingdom was obtained from abroad. The main kinds of glass required for laboratory purposes may be grouped thus: Soft glass for tubing, and for a number of articles and vessels where the highest resistance to chemical action is not required, glass highly resistant to chemical action; very hard glass for combustion tubing; glass for thermometers.

Soft Glass. Such a glass must be soft enough to be readily worked in a flame, and must stand prolonged heating without showing the changes in appearance and working qualities generally described as devitrification. Before chemical glassware of foreign origin became practically universal in laboratories, vessels and apparatus in great variety were made from lead glass. Many examples have survived long and continued usage. Their appearance at the present time shows how good this glass was in respect of its general resistance to chemical change, and their survival probably is to be ascribed largely to the property of such glass, when well made, of withstanding changes of temperature. Lead glass for chemical use has certain disadvan- tages. It may contaminate solutions with lead, and some varieties of it are specially prone to show surface darkening when exposed to solutions of alkaline sulphides. Again, in working lead glass in the flame, the care needed to avoid reduction of the lead with consequent blackening made the introduction of a workable glass free from lead a very welcome change to those who had not mastered the art of working lead glass. Experience has shown that the many advantages claimed for non-lead glass as a material for laboratory apparatus have been proved, and there is no likelihood of a return, nor adequate reason for a return, to lead glass. Common custom has, however, directed the attention of laboratory workers so markedly away from lead glass that it may be worth mentioning here that this glass can be made of such high resistance to the action of water, and of many solutions which also abstract alkali from glass, that in some special cases vessels made from it are only surpassed by silica in resistance to chemical change. As one instance, certain colloidal preparations can be kept far longer in vessels made from a suitable lead glass than is found to be possible with any of the chemical resistance glasses of the non-lead type. The durability of well-made lead glass is a matter of common experience in table glassware, many examples of which have been in constant or occasional use for years, exposed to variable atmospheres and all the processes incidental to cleaning, without showing any noticeable disintegration or discoloration of their surfaces. It is hot intended here to advocate the use of lead glass for general scientific other than optical .purposes, but only to suggest that it has certain properties which are useful, and which might advantageously be more fully considered than has been the custom in dealing with glasses for laboratory use.

In the early days of the war it was recognized that there would be a serious shortage of laboratory vessels. A simple sodium-calcium-silicate glass was known to be unsuitable since the readiness with which it devitrifies in a flame makes it impossible to produce from it any articles which have to be lamp-blown, and tubing made from it is practically useless to workers in laboratories. The immediate advance made was the addition of alumina, either as such, or preferably in the form of felspar. The use of alumina for retarding devitrification and for rendering a glass workable in the flame was known in Great Britain, and at least three British manufacturers had for some years produced glasses containing various percentages of alumina up to about 10%.

It is unnecessary to go in detail through the stages of development of the so-called soft soda glass, but one or two points may be men- tioned. Quite early in the production of thjs kind of glass it was recognized that a sodium-potassium-calcium-aluminium-silicate type of glass had most satisfactory general properties, that arsenic was not permissible, and that the only constituent other than those indicated which might be added was a small amount of manganese dioxide, to disguise the green colour due to the presence of iron in the material used. The formula given here shows the approximate com- position of a batch mixture expressed in percentages of silica and oxides of the metals in the various ingredients of the batch : SiOj, 68; A1 2 O 3) 4; CaO, 7; K 2 O, 6-5; Na 2 O, 14-5. Manufacturers vary