Abstract: The invention relates to a bronze-tinted or grey-tinted soda lime silicate glass, in particular for the manufacture of flat glass by the casting process or by the float process, with a basic composition for the soda lime silicate glass of:______________________________________ SiO.sub.2 : 66-74 weight % Al.sub.2 O.sub.3 : 0-3 weight % TiO.sub.2 : 0-0.15 weight % CaO: 7-12 weight % MgO: 2-6 weight % Na.sub.2 O: 10-15 weight % K.sub.2 O: 0-3 weight % BaO: 0-0.04 weight % SO.sub.3 : 0.1-0.4 weight % ______________________________________The invention resides in the fact that it contains the following colorants additives: ______________________________________ Fe.sub.2 O.sub.3 : 0-0.45 weight % V.sub.2 O.sub.5 : 0.0-0.5 weight % MnO.sub.2 : 0.5-2 weight % NiO: 0.0-0.05 weight % CuO: 0.0-0.1 weight % CoO: 0.0-0.008 weight % ______________________________________the sum of the weight percentages of the constituents forming the soda lime silicate glass being 100.

Abstract: A low alkali borosilicate glass composition comprising60 to 78% by weight of SiO.sub.210 to 25% by weight of B.sub.2 O.sub.33.5 to 6.0% by weight of R.sub.2 O, wherein R.sub.2 O represents Na.sub.2 O, K.sub.2 O and/or Li.sub.2 O,2.0 to 6.5% by weight of CeO.sub.2, and0.25 to 8.0% by weight of Sb.sub.2 O.sub.3 and/or As.sub.2 O.sub.3,the percentages being based on the total weight of the glass composition. The glass composition of the invention are suitable for use as protective covers for solar cells, especially solar cells which are used in satellites.

Abstract: Glass compositions with a particularly high alkali resistance comprise, in weight percentages:______________________________________ SiO.sub.2 45 to 65% ZrO.sub.2 6 to 20% RO 20 to 45% ______________________________________The total of SiO.sub.2 + ZrO.sub.2 + RO being not less than 94% by weight of the glass, where RO represents CaO, in an amount from 20 to 45%, with or without lesser amounts of further divalent oxides of the group consisting of MgO, SrO, BaO and ZnO, the balance (if any) of the composition consisting of compatible constituents such as TiO.sub.2, Al.sub.2 O.sub.3, B.sub.2 O.sub.3, Fe.sub.2 O.sub.3, F.sub.2 and R.sub.2 O, where R.sub.2 O represents K.sub.2 O, Na.sub.2 O or Li.sub.2 O, the amount of any one of these compatible constituents not exceeding 5% by weight. Preferably R.sub.2 O does not exceed 3%.

Abstract: Alkali-resistant continuously-drawn glass fibers, for use in the reinforcement of cement products, are composed of SiO.sub.2 67 to 82 mol.%, ZrO.sub.2 7 to 10 mol.%, R.sub.2 O 9 to 22.5 mol.% (where R = Na, up to 5 mol.% of which may be replaced by Li or K), F.sub.2 3 to 9 mol.% and Al.sub.2 O.sub.3 (computed as AlO.sub.1.5) 0 to 5 mol.%, the permissible maximum value of the total of SiO.sub.2 + ZrO.sub.2 + AlO.sub.1.5 being on a sliding scale dependent on the content of ZrO.sub.2 and ranging (when F.sub.2 = 9 mol.%) from 89 mol.% when ZrO.sub.2 is 7 mol.% down to 87 mol.% when ZrO.sub.2 is 10 mol.%, the said maximum value being reduced by a further 5 mol.% over the whole scale when F.sub.2 = 3 mol.%. The fiberizing temperature is below 1350.degree. C and the liquidus temperature is at least 40.degree. C below the fiberizing temperature. Preferably, to ensure that the fiberizing temperature is below 1320.degree. C, the said maximum value of SiO.sub.2 + ZrO.sub.2 + AlO.sub.1.5 is further reduced by 1 mol.