President Cassatt's letter appointing the Board contains the following
further instructions:

"You are requested to procure all additional information that may be
needed, sparing neither time nor any necessary expense in doing so, for
I am sure it is not necessary for me to say that, in view of the
magnitude and great cost of the proposed construction, and of the novel
engineering questions involved, your studies should be thorough and
exhaustive, and should be based upon absolute knowledge of the
conditions."

The Board was organized on January 11th, 1902, when it held its first
session, and continued in the performance of its duties until April
30th, 1909, when it was dissolved, its work having been completed.

The Board held regular and special sessions to receive progress reports
from the Chief Engineers in direct charge of construction, and to
consider questions relating to the plans and details of the work
submitted by its members or referred to it by the Management. It then
reported its conclusions to the Vice-President for approval before the
work was undertaken.

The Management earnestly impressed upon the Board throughout the whole
period of its labors, that the Tunnel Extension and facilities were to
be designed and constructed without regarding cost as a governing
factor, the main considerations being safety, durability, and proper
accommodation of the traffic. No expenditure tending to insure these
conditions was to be avoided.