Page 298

The WISCONSIN ENGINEER
              THE ROCKET-AUTOMOBILE
  This German novelty is the subject of a brief article in
"The Explosives Engineer" by Rudolf Feuchtinger.     The
development of the rocket-car is due to a German engineer,
Fritz Von Open, chief of the firm of Adam Opel,
proprietors of the automobile plant at Russelsheim, with
the assistance of Messrs. Sander and Valier, his aids, as
a preliminary stage to the rocket-airplane and the rocket-
airship. We read:
  "The first official trial was made April, 1928, with an
Opel rocket car on the so-called 'Avusbahn' race-track near
Berlin. The rocket-car, steered by Engineer Fritz von Opel,
reached a speed maximum of 122 miles an hour. *The total
explosive charge of the rockets which were placed in the
rear of the   car and   provided   with  electric ignition,
amounted to about 1,200 pounds.
  'Since the world's speed record for automobiles, which
is at present about 207 miles an hour, was not reached on
the race-track, further experiments and trial drives were
continued with an especially constructed railroad rocket-
car on an unused railroad line near Burgwedel (Hanover)
in June, 1928. The car was started without a driver and
reached a maximum speed of 149 miles an hour on this
track.
  'On a further increase of the rocket charge (about four
times as much), the car was hurled from the rails and
destroyed almost completely.
  "In spite of the failures at the beginning, in a short
time the unexpected difficulties will be overcome.   This
would  mean  a considerable  approach   to the practical
realization of the idea of flying into space."
                                          ___Literary Digest
                    WIRELESS LIGHT
   The ideal of illumination engineers is to produce light
that rivals the sun.  We are soon going to give up the
use of hot-filament electric light bulbs, made of the fine
wire that burns up and causes a deposit of metallic vapor
to form on the glass, thus reducing lighting efficiency. The
proposed lamp will be a crystal globe, free from    wires
bith inside and out. These will be filled with some rare
gas. This lamp will receive its energy from a coil con-
ccaled in the walls of our houses.  Their action is very
similar to the neon glow signs that are so prevalent in the
miodern sign.  It has been found certain gases issue a
highly illuminate glow when subjected to the fluxuating
intensity of a field produced by a high frequency current.
In a high frequency coil the current changes direction
from maximum in one direction to maximum in the opposite
direction many times a second, hence, the field set up by
this current varies, likewise many times a second.   The
electrons in the gas-filled globe are sensitive to the varying
force upon them, traveling first in one direction then in
another. The intensity of their travel makes them lumin-
escent. The feature of this lamp is, that it is practically
wear resistant and cheap to operate as well as being an
asset to the aesthetic beauty of the most luxurious home.
The source of this high frequency power may in time be
transmitted by wireless.             -Popular Mechanics
Blasting Circuits
Lesson No. 3 of
BLASTERS' HANDBOOK
        VEN the way that wires are twisted
        E    together in making connections has
        an important bearing on proper use of
        explosives. Electric blasting is hedged
        around with most elaborate rules and
        precautions. There are series and par-
        allel connections, parallel series and series
        parallel circuits. Blasting machines or
        power circuits for electric blasting are
        surrounded with great mystery.
        In Chapter Three of the Blasters' Hand-
        book this matter of blasting circuits
        is illustrated and comprehensively de-
        scribed. The selection and use of gal-
        vanometers, rheostats and blasting
        machines are explained. Tells how to
        prevent misfires, how to test a circuit,
        how to locate a break, how to use a
        resistance table and many other practical
        phases of blasting circuits.
        The Blasters' Handbook, prepared origi-
        nally for the use of du Pont field service
        men, is an extremely practical reference
        and study work.    Leading technical
        institutions are using the Blasters' Hand-
        book in their classrooms. Pocket size for
        your convenience.
                  This couton will bring vou a cobv
Send it off NOW.
     @  @    t       ~~~~~~IXE-278
REG. U. S. PAT. OFF.   AVE-5
de Nemours & Co., Inc.,
,epartment, Wilmington, Delaware.
or obligation on my part, please send
the "Blasters' Handbook."
Name  -.----------------------.
Dormitory Room No.              Street
City -  -     ---- State
Fig. 55-Parallel connections. A. Power or lighting circuit.
B. Blasting switch for closing circuit. C. Leading wires of
sufficient length to keep the switch "B" a safe distance from
the blast and to reach to the last hole to be fired. D. Bore
holes with electric detonators. E. Connections between the
detonator wires from holes "D" to the leading wire "C".
Volume Sir, No. 8
29(8