iently to subject them to the local taxing power. In a typical
case the Court held that oil shipped from Pennsylvania and held in tanks
in Memphis, Tennessee for separation, distribution and reshipment, was
subject to the taxing power of the latter State.[573] The delay in
transportation resulting from these proceedings on the part of the
owners, the Court pointed out, was clearly designed for their own profit
and convenience and was not a necessary incident to the method of
transportation adopted, as had been the delay of the logs coming from
Maine in Coe _v._ Errol. The distinction is fundamental.[574]

Applying this rule in more recent cases, the Court has upheld State
taxation: on the use and storage of gasoline brought into the State by a
railroad company and unloaded and stored there, to be used for its
interstate trains;[575] on gasoline imported and stored by an airplane
company and withdrawn to fill airplanes that use it in their interstate
travel;[576] on supplies brought into the State by an interstate
railroad company to be used in replacements, repairs and extensions,
and installed immediately upon arrival in the taxing State;[577] on
equipment brought into the State by a telephone and telegraph company
for operation, maintenance, and repair of its interstate system.[578] In
all these cases the Court applied the principle that "use and storage"
are subject to local taxation when "there is an interval after the
articles have reached the end of their interstate movement and before
their consumption in interstate operation has begun."[579] On the other
hand, in the absence of such an "interval," the Court declared invalid
State gasoline taxes imposed per gallon of gasoline imported by
interstate carriers as fuel for use in such vehicles, and used within
the State as well as in their interstate travel.[580]

THE DRUMMER CASES; ROBBINS _v._ SHELBY COUNTY TAXING DISTRICT

But there is one situation in which goods introduced into one State from
another have until recent years enjoyed a special immunity from taxation
by the former, and that is when they were introduced in consequence of a
contract of sale. The leading case is Robbins _v._ Shelby County Taxing
District,[581] in which the Court, after a penetrating survey of
commercial practices, ruled that "the negotiation of sales of goods"--in
this instance by sample--"which are in another State, for the purpose of
introducing them into the State in which the n