little longer.

The joint is begun exactly as in the first method, and the manipulation
is the same until after the preliminary tight joint (_b_, Fig. 6) is
made. The flame is reduced as usual, but instead of rotating the tube in
the flame, only one part of the circumference is heated, and this is
allowed to shrink thoroughly before blowing. It is then blown gently so
that it becomes a slight swelling on the tube, and the operation
repeated on an adjoining part of the joint. Three or four repetitions of
the operation will usually cover the whole circumference of the joint,
in a small tube, the result being a swelling roughly similar to the
first thick bulb in the first method (_d_, Fig. 6). If all the lumps of
the original joint have not been removed by this operation, it may now
be repeated upon such parts as may require it. The thickness of the wall
in the bulb should be about the same as that in the original tube. The
whole of the expanded joint is now heated as uniformly as may be until
soft enough so that it begins to shrink a little, and the swelling is
gently drawn down to the same diameter as the main tube, as in the first
case. Any irregularities in the finished joint may be corrected by local
reheating, shrinking or blowing as required.

=Discussion.=--In using this method, especially with larger sizes of
tubing, it is very important to keep the whole circumference of the
joint hot enough during the operation so that it does not crack apart at
the part which has not yet been worked. For that reason the first
heating, shrinking and blowing should be performed as quickly as
possible, leaving the resulting irregularities to be corrected later,
rather than attempting to reblow the same part of the joint several
times in succession until it is satisfactory. Care must be taken in this
as in the first method that the blowing follows immediately upon the
completion of the shrinking and removal of the object from the flame:
delay in blowing will cause shrunken places where the joint meets the
original tubes, on account of the cooling and setting of the glass
before it was blown. Most beginners err in being afraid to shrink the
part of the joint enough before blowing it. On small tubing, the
shrinkage may often extend so far that the inner surface of the shrunken
part reaches the center of the tube. Insufficient shrinking results in
failure to remove the lump formed at the original joint. It is often of
advantage, aft