Indication of the efficiency of the draught may be gained by holding smoke-paper at the orifice of the hood. The definition of efficient exhaust in some regulations for the removal of fumes, as in the Tinning Regulations, is that it shall not be deemed to be efficient unless it removes smoke generated at the point where the fume originates. Accurate gauging, however, of the draught can only be done with an anemometer, so as to determine the number of linear and cubic feet passing through the throat per minute. Only rarely does one find an occupier alive to the value of the use of such an instrument. The importance of this point has been recognized in the Regulations for Heading of Yarn, by the requirement that the speed of each exhaust opening shall be determined once in every three months at least, and recorded in the general register. We prefer to use Davis’s[A] self-timing anemometer, which gives readings in feet per second without the need of a watch. Other useful anemometers--Casella’s or Negretti and Zambra’s--require to be timed. [A] It is not available for velocities exceeding 1,200 linear feet per minute. The details of all routine observations on localized exhaust ventilation might well be entered on a card hung up in the workroom. Such a card drawn up by our colleagues, Miss Lovibond and Mr. C. R. Pendock, has the following headings: FIRM............................... PROCESS........................... FANS: No..... Kind................ Size....... Maker................. Motive power........ H.P........ Method of driving..... Other load.......... Condition of driving.. Screen.............. Dust col- Direction........... lection.... Periodic cleaning... HOODS: No..... Kind................ Size....... Structure........... Distance between each.. DUCTS: No..... Kind................ Size................ Length..... Section............... Structure........... Periodic cleaning... FRESH-AIR INLETS: No.... Kind................ Position............ Size................ Fixed or temporary..