TRANSLATORS’ PREFACE.
Dr Rathgen has, in his preface, stated the aim of this handbook, and it is with a desire to further this aim that we have prepared an English translation.
Claiming but limited experience in this field of research we have only added such explanatory notes as seem in some way to bear upon the subject or likely to be useful in a handbook of this kind (viz. the method of taking squeezes, Appendix A, and a few footnotes which are signed and enclosed in square brackets). We take this opportunity of thanking Dr Rathgen for his interest in our undertaking, for his kindness in supplying much additional matter which did not appear in the German edition, and also for the loan of the blocks for Figs. [22] and [23]. Figs. [7], [9]-[12], [30]-[33], and [37], are from photographs of objects treated by ourselves.
Our thanks are especially due to Dr W. A. Caspari, of the National Physical Laboratory, for his invaluable help in the revision of the translation, and for his advice and suggestions in reference to the more technical aspect of the work.
York,
December 1904.