BECAUSE of demand the present text has been off the market for some time, so the author has taken the opportunity of bringing some of the matter up to date and also of incorporating applications of ...

The members of the Franklin Institute of Philadelphia took their seats for their annual meeting last week in an atmosphere of ill-concealed excitement. Weeks before, the committee on awards had ...

THE comparator principle is well known in the accurate determination of lengths. It may also be applied to the measurement of time intervals. By installing an extra electrode system in a standard type ...

Professor John Trowbridge delivered a lecture last night in the Jefferson Physical Laboratory, under the auspices of the Engineering Society, on "Cathode Rays." The large lecture room was filled to ...