When points for comparison fail us, our eye, one of the most imperfect of instruments, never gives us an accurate idea of objects, and it is for this reason that we have placed upon the annexed figure a five-story Paris house, drawn to the same scale as the "Grizzly Giant," one of the most ancient _Sequoiæ_ of the Mariposa Grove, in California. This true vegetable giant is 105 feet in diameter at the base, and 69 feet at 13 feet from the ground. It has, like many of the _Sequoiæ_ that surround it, been struck by lightning, but, in spite of that, its total height is still more than 300 feet. Some of its branches are more than six feet in diameter. Those who have seen our old oaks in the forest of Fontainebleau will be able to compare the effect of time and lightning upon such venerable relics, these in California being possibly contemporaries of the Roman Empire. A few of the trees have been razed to the base, and serve as floors for dancing halls, while others, that have fallen, have been cut lengthwise and serve as bowling alleys. What especially distinguishes the wonderful region in which these _Sequoiæ_ grow is the cleanness and beauty of the plains upon which they are found. In the virgin forests of South America, under the influence of a warm and damp atmosphere, the vegetation is so rank that, in order to open a passage, one is obliged to use an ax on the vines and thickets of interlaced plants. In California, on the contrary, the _Sequoiæ_, which are situated at an altitude of from 5,000 to 7,000 feet above the Pacific Ocean, are easily accessible. The routes are almost traced by nature, dangerous animals are rare, the summer temperature is delicious there, and hotels are everywhere being erected, as in Switzerland, to serve as a retreat and promenading place for tourists.--_La Nature._ [Illustration: THE "GRIZZLY GIANT," ONE OF THE CALIFORNIAN SEQUOIÆ.] * * * * * A CATALOGUE containing brief notices of many important scientific papers heretofore published in the SUPPLEMENT, may be had gratis at this office. THE Scientific American Supplement. PUBLISHED WEEKLY. Terms of Subscription, $5 a Year. Sent by mail, postage prepaid, to subscribers in any part of the United States or Canada. Six dollars a year, sent, prepaid, to any foreign country. * * * * * All the back numbers of THE SUPPLEMENT, from the commencement, January 1, 1876, can be had. Price, 10 cents each. * * * * * All the back volumes of THE SUPPLEMENT can likewise be supplied. Two volumes are issued yearly. Price of each volume, $2.50, stitched in paper, or $3.50, bound in stiff covers. * * * * * COMBINED RATES--One copy of SCIENTIFIC AMERICAN and one copy of SCIENTIFIC AMERICAN SUPPLEMENT, one year, postpaid, $7.00. A liberal discount to booksellers, news agents, and canvassers.