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mending the publication of the same in the Transactions ; 
which was so ordered. 
The Committee to which was referred the paper on the 
Magnetism of Rocks, &¢., by Major T. B. Brooks, reported 
that, since the Legislature of Michigan had recently made 
an appropriation for the publication of the whole Report of 
the Survey of Major Brooks’ District, they recommend that 
the Secretaries be requested to prepare an abstract notice of 
the paper for the Proceedings. The report was concurred 
in. 
Prof. Chase, according to notice given, gave an explana- 
tion of his method of estimating the Sun’s mass and dis- 
tance by the energy of flames, with diagrams and tables. 
Prof. Persifor Frazer, Jr., communicated the results of his 
spectroscopic observation of the late Auror: 
Dr. R. E. Rogers exhibited the capacities of « fine Holtz 
Electrical Machine, and described his proposed modification 
of its form for purposes of instruction. 
The prime plate is replaced by horizontal plates, laid upon wine glasses, 
or upon removable rubber stand- 
Med ft fo les lec Sete. ards. The rotating plate is made 
By RE Rogers MD. to rotate horizontally over them, 
its axis passing vertically down- 
ward through the table, the driving 
wheel being underneath. Two 
standards carry the. combs, ete., 
and can be swung round out of the 
way. Every part of the machine 
can be removed in a charged state, 
to be tested and compared with its 
condition before removal. 
The Secretary exhibited a water-color picture of a geo- 
logical sectional | model of Morrison’s Cove, in Middle Penn- 
sylvania, painted by Mr. J. W. Harden, C. and M. Engineer, 
of Philadelphia, and invited attention to the highly artistic 
style and beauty of the work. 
Pending nominations, Nos. 689 to 692 were read, spoken 
to, and balloted for. New nominations, Nos. 693 and 694, 
were read. There being no further business, the ballot-boxes 
