(under subclass 235) Water tube boilers provided with coils of tubes not coming within the definitions of other subclasses covering water tube boilers of the coil type.
SEE OR SEARCH THIS CLASS, SUBCLASS:
169+, for vertical coiled water tubes located within a vertical flue.
244+, 248 and 249+, for various types of coil tube boilers.
355+, for analogous water tube boilers incorrectly said to be coil boilers.
