36 KANSAS CITY REVIEW OF SCIENCE. 
Qne more thing is needed. If several rods are placed upon an edifice, they 
should be connected with one another by horizontal rods like themselves. And 
they should also be connected directly with all large masses of metal upon the 
exterior of the building, such as gutters, spouts, cornices, crestings, balconies, or 
metallic roofings. Thus the line of least resistance may be made to communicate 
with nearly all parts of a wooden house, and the protection rendered more sure 
and complete. 
Let me sum up these directions, fitting them for an ordinary dwelling house 
of moderate expense. I will not give a description of an absolutely perfect light- 
ning-rod, but simply of one which will serve all common purposes. Make it of 
three-quarter inch galvanized iron, and let the gilded tip project as much as two 
feet above the ridge-pole or chimney top. See that it connects with the proper 
metallic masses, render it continuous to the ground, and conduct its termination, 
divided into three branches, either into a body of water, or else let it plunge four 
feet below the surface beneath your water-spout. With two such rods any dwell- 
ing of common size may be considered proof against the lightning. 
Some trials were made lately on the Seine, at Paris, to determine the best 
way of breaking up river ice with dynamite. Bernard and Lay, assisted by two 
specialists, Flegy and Streits, of the Nobel Dynamite Company, directed the 
operations and recorded the results. The best effect was obtained by placing 
three cartridges of 406 grammes of dynamite beneath the ice, each connected 
with an electric machine on the bank of the river. When the cartridges were 
exploded it was found that the ice was shattered a distance of about eighty me- 
ters and through a width of from five to six meters. The pieces of the fractured 
ice were, moreover, found to be very small, and easily carried down stream 
past obstructions such as bridge piers. 
The amphioxus, a fish-shaped animal of a very low grade of development 
which affords Haeckel one of his firmest stepping-stones in the lively work on 
evolution, has been the subject of very interesting observations on the part of 
Henry J. Rice, at Fort Wool, on the Chesapeake. He had the good fortune to 
find two males, a ripe female and twenty young. The animal stands on de- 
batable ground between the vertebrates and invertebrates, and received its name 
from its shape. Amphioxus is the Greek of Mr. Yarrel for ‘‘sharp at both 
ends.” Descriptions of the habits, structure and deyelopment of this curious 
primitive animal are being issued in the American Naturalist by Mr. Rice. 
