The Rev.Thomas L.
Ambrose joined the mission near the close of 1858, the Rev.John H.
Shedd and wife in 1859, and the Rev.Henry N.Cobb and wife in 1860, with direct reference to the mountain field; and the Rev.Amherst L.
Thompson and Rev.Benjamin Labaree, with their wives, and Frank N.
H.Young, M.D., in 1860, to strengthen the force on the plains, together with Misses Aura Jeannette Beach and Harriet N.Crawford.
Mr.Thompson had given much promise of usefulness, but died at Seir, August 25, 1860, only fifty-four days after his arrival.

Miss Beach was to be associated with Miss Rice, who had rendered efficient service in the girls' Seminary as the associate of Miss Fiske, but was then alone and overburdened.
The unexpected but providential withdrawal of so many older laborers, at this juncture, was not favorable to a more enlarged occupation of the field; and the plan of forming a station on the western side of the mountains, was not carried out.

The height of Amadiah above the plain of Mesopotamia, and its salubrity in summer were found to have been overestimated; and further researches made it evident, that the demands of so trying a mountain field were more than the average health of missionaries would be able to endure at any season of the year.

Indeed, impaired health obliged Mr.and Mrs.
Cobb, who had been specially designated to the mountain district, to return home within two years; and, to their own great regret and that of their associates, they have never been able to rejoin the mission.
The Nestorian helpers, as a class, were pronounced able and faithful men, remarkably so for Orientals.

But they could not fully take the place of missionaries.