November 4, 1920] 



NATURE 



ill 



annealing and liability to breal< with changes of tem- 

 perature. Table glass is well annealed, so that the 

 defect in question is not insuperable, and a want of 

 care in the manufacture is suggested. The increased 

 loss by breakage has become a serious consideration 

 in the running of practical classes since British glass 

 has been in use. .'Ks pointed out in previous corre- 

 spond'-nce, the danger of restricting import lies in 

 the lack of inducement to further improvement. 



W. M. Bayliss. 

 University College, London. 



The points raised by Mr. Jenkinson in his letter 

 on the subject of laboratory and scientific glassware 

 published in Natljre of October 28 should direct the 

 attention of users of such glassware to the quality of 

 the British-made product as compared with other well- 

 know Continental brands. 



No single type of glass can be superior to all others 

 for all purposes. One glass may be superior as 

 regards attack by water and acids, but inferior in 

 resf)ect to attack by alkaline solutions. As it would 

 obviously be highly inconvenient in practice for 

 chemists to use different types of glass for different 

 reactions, a general average must be taken, and a 

 study of the papers in the Journal of the Society of 

 Glass Technology referred to by Mr. Jenkinson will 

 convince any unbiassed person that the quality of 

 British laboratory glass has been proved fully equal, 

 if not superior, to that of any other laboratory glass 

 from whatever source it may have been obtained. 



In the earlier days of the war complaints were 

 frequently heard as to the finish of British-made 

 articles. Either they were too thin, too thick, un- 

 even, or the colour and shape were unsatisfactory, etc. 

 Whilst these complaints were frequently justified, 

 they were chiefly due to lack of experience. The 

 blowing of laboratory glassware of the desired thick- 

 ness and even throughout requires considerable ex- 

 perience on the part of the glass-blower, and blowers 

 trained in this branch of the industry were not avail- 

 able. The glass u.sed in the manufacture of labora- 

 tory ware is much harder (less fusible and with a 

 shorter viscosity range) than that to which the blowers 

 were accustomed, and this militated against the rapid 

 acquirement of the technical skill necessary to produce 

 the best class of ware. 



The hardness of the glass and the undesirability 

 of using flning agents such as arsenic and antimony 

 rendered it very difficult to obtain the molten glass 

 homogeneous and free from small gas-bubbles, and 

 necessitated increased furnace temperatures during 

 melting, thus calling for alterations in the design of 

 furnaces in use or the erection of new furnaces of 

 special type. 



The colour of British laboratory glass is admittedly 

 inferior to that of the best foreign glass. This is due 

 to the purity of the materials usecl, particularly the 

 sand. British sands can be obtained with nearly the 

 same degree of freedom from iron as the best Con- 

 tinental sands, but not in considerable quantity or of 

 constant quality. For special purposes, where frc«- 

 dom from colour is essential — e./f. Nessler cylinders — 

 specially sel<yted qualities of ftntish sands may be 

 used, or even imported sands, but from the general 

 point of view of trie chemical and scientific classware 

 industry it is Absolutely essential that we should be 

 able to' produce highly efficient laboratory ware with- 

 out recourse to the importation of any material from 

 outride the Empire, and so far as possible with only 

 British materials. 



Further experiment and experience both with 

 materials and melting operations will undoubtedly 

 lead to improvement in the appearance of the product, 



NO. 2662, VOL. 106] 



and we claim that as British manufacturers, with the 

 aid of British men of science, we have mastered the 

 difficulties attendant on the production of the neces- 

 sary quality of glass so successfully. They will, given 

 fair opportunity, master the less essential, but never- 

 theless desirable, property of pleasing appearance. 



Scientific apparatus, particularly lamp-blown ap)- 

 paratus, has received a considerable amount of atten- 

 tion from manufacturers and men of science interested 

 in the technology of the glass industry. 



It is a fact, unfortunatfely, that in pre-war days the 

 best work of this class was done by German and 

 .Austrian lamp-workers. This work is now carried 

 on largely in this country (to a considerable extent 

 by disabled soldiers and sailors), and great progress 

 has been, and continues to be, made. Research work 

 on the most suitable types of glass tubing for lamp- 

 working purposes has been carried out with very suc- 

 cessful results (Journal of the Society of Glass Techno- 

 logy, 1917, vol. i., p. 61; iqi8, vol. ii., pp. 90, 154). 



Manufacturers have followed up suggestions for 

 possible improvement, sometimes with success and 

 sometimes otherwise, but generally associated with 

 considerable trouble and expense, and we may fairly 

 claim that great improvement has been achieved in 

 this direction, and that few grounds for legitimate 

 complaint remain on the score of the annealing of 

 British-made laboratory ware. 



\ further and most important section calls for 

 mention, namely, the production of graduated ap- 

 paratus. To some extent this is a factory operation, 

 but the production of accurate and trustworthy 

 graduated apparatus calls in addition for the most 

 highly skilled, careful, and experienced work and 

 supervision. The work entailed is much greater than 

 appears on the surface. Experimental work has been 

 carried out at the National Physical Laboratory and 

 at .Sheffield llnivorsity, and the testing department 

 of the National Physical Laboratory has drawn up 

 stringent regulations for the certifying of first-class 

 graduated apparatus, so that such apparatus with 

 the National Physical Laboratory certificate of 

 accuracy can be relied upon to be quite as trustworthy 

 as the well-known Germ'an apparatus with the 

 Reichsanstalt certificate. 



Complaints and unfavourable comparisons have 

 frequently been made in connection with British 

 laboratory ware, and very few expressions of apprecia- 

 tion or gratitude to those manufacturers who stepped 

 into the breach to supply an absolutely indispensable 

 article, knowing that their productions were far from 

 perfect, but striving, with the help of the best scientific 

 aid in the country, to improve the quality of their 

 ware. Very great progress has been made, but under 

 the abnormal conditions ruling at present in this 

 country it is essential that stability should be assured 

 for some time to come until the industry has had 

 time to settle down from what is practically an 

 experimental stage to normal working conditions. 



Is it conceivable that the research work done by 

 Sir Herbert Jackson, Prof. Turner, the National 

 Physical laboratory, and others, and the patient and 

 frequently thankless efforts of manufacturers to 

 render this country independent in such an essentially 

 key industry, should be wasted ; and that the valuable 

 experience already gained should be lost on account 

 of the flooding of the English market with Con- 

 tinental productions — made so easy by the present 

 rate of exchange between England and Germany — 

 and the consequent transference of our energies to 

 less essential, but certainly more lucmtlve, directions? 



FlMNK Wood. 

 (Wood Bros. Glass Co., Ltd.) 



Borough Flint Glass Works. Bamtley, 

 November 1. 



