TWENTY-FIRST ANNUAL REPORT 109 
of buildings along the Southern Boulevard were made for the 
Park engineer, Mr. Beerbower. 
The complete elimination of certain coal-tar derivatives 
brought from Germany has caused a great advance in the prices 
of the essential photographic chemicals. Figures compiled by 
the Motion Picture World, the organ of the motion picture pro- 
ducers, are almost beyond belief. Metol, one of the most neces- 
sary chemicals used in developers for the production of nega- 
tives leaped from $4.50 per pound to $75.00 and $100.00; hydro- 
quinone from 90 cents to $9.00 per pound; oxalic acid from 10 
cents to $5.00. Some of the potashes have advanced 300 per 
cent., and aniline dyes 500 per cent. 
Printing papers have increased from 15 to 20 per cent.; 
and dry plates, because of the scarcity of Belgian glass, which 
is used almost exclusively, have advanced 25 per cent. 
American manufacturers are now producing, in limited 
quantities, substitutes for many of the German products. The 
radical changes that have become necessary in the manufac- 
ture of photographic products have produced correspondingly 
bad effects, and salesmen of one of the large manufactures stated 
that in all the years of their business career there were never 
so many difficulties with plates and paper as have been apparent 
in the last two years. It is to be expected, however, that within 
a few months all these difficulties will be smoothed away, and 
the production of photographic supplies will firmly settle down 
upon an all-American basis. 
Bulletin.—Six numbers of the Zoological Society Bulletin 
were issued in 1916. Several numbers contained very valuable 
and interesting material, furnished by Mr. Beebe from the Trop- 
ical Research Station, and Mr. Ditmars from his expedition to 
the low-lands of the Savannah River. Continued progress in 
the development of photography of the exhibition tanks at the 
Aquarium have furnished the Director with interesting numbers 
for that department of the Society’s work. The rapid increase 
in the prices of printing papers forced the Society to secure a 
stock of paper for the Bulletin sufficient to last until 1918. 
Annual Report.—The ANNUAL REPORT for 1915 was issued 
in its regular form, and at the usual time. 
Zoologica.—Numbers 3 and 4 of Volume II. were devoted 
