Regular Meeting, August 7th, 1865.

President in the chair.

Nine members present: Dr. C. T. Jackson, visitor.

Donations to the Cabinet: Three boxes of shells; Duplicate fossils of the U. S. Exploring Expedition; Types of Dana’s Geology; Fossils from the Upper Missouri; Miscellaneous fossils of the United States, received from the Smithsonian Institution; Trachytic porphyry from the “Basalt” Cliff, three miles from the Big Tree Grove, Calaveras, presented by Dr. Jackson.

Donations to the Library: Annual Report of the Museum of Comparative Zoology of Cambridge, 1864; Proceedings of the Academy of Natural Sciences of Philadelphia, for January, February and March, 1865; Proceedings of the American Academy of Arts and Sciences, June-September, 1864; Review of American Birds, by Prof. S. F. Baird; Proceedings of Albany Institute; The Law of Increase and the Structure of Man, by F. A. Liharyik; Oration and Poem delivered at the Commencement of the College of California; Proceedings of the Royal Horticultural Society of London; Meteorological Results, Toronto, 1860-2; Magnetical Abstracts, Toronto, 1854-60, 1856-62.

Dr. Ayres remarked the appearance of a species of Barracouta, (Sphyrena Argentea,) on the coast of California, off Point Conception.

Dr. C. T. Jackson read the following paper, relative to the Big Trees of Calaveras County.

MEASUREMENTS OF THE HEIGHT AND CIRCUMFERENCE OF TWENTY-FIVE OF THE “BIG TREES,” (SEQUOIA GIGANTEA,) IN CALAVERAS COUNTY, BY DR. CHARLES T. JACKSON AND MR. JOSEPH B. MEADER, AUGUST 2d AND 3d, 1865.

Instruments made use of:—

The horizontal point was fixed upon each tree, and the angle measured by the Reflecting Semicircle, and protracted by it.

The circumference of the trees was measured above the swell of the roots, about six feet, where the stem takes its proper form.

Several measurements, originally made with too high an angle, were taken over again with a longer base, so as to avoid the error of refraction in the glasses of the mirrors.

We trust, therefore, that the following measurements will be found to be correct.

NAME OF TREE.HEIGHT.
Feet.
CIRCUM.
Feet.
Arbor Vitæ Queen25831
Pride of the Forest26050
Andrew Johnson27332
Bay State28048
Edward Everett26546
Henry W. Beecher29145
William C. Bryant30549
Abraham Lincoln28144
Mother of the Forest[15]30563
Daniel Webster27049
General Jackson32042
General Scott32745
General Washington28452
Beauty of the Forest258
Two Sentinels315
Old Kentucky27745
Mother and Son26964
T. Starr King36650
Trinity30848
Salem Witch310
Henry Clay24144
Empire State27550
Vermont25944
Granite State28650
John Torrey, (Nobis)50
(All the above-named trees are the Sequoia Gigantea.)
A Sugar Pine, (P. Lambertiana)165
A Yellow Pine, (P. Engelmann)23227
Another of same species22019

[15] Bark off Mother of the Forest to the height of 121 feet.

The stump of the “Original Big Tree” measured in six diameters, gives for mean, 23 ft. 1⅓ in., diameter inside of the bark,—which was two feet thick.