## CURTAThe universal pocketcalculating machine. System C. Herzstark | |

Weight 230 gr. |

CONTINA S.A. Mauren/Liechtenstein |

For the exact time: | |

the pocket watch ... | |

For taking pictures: | |

the miniature camera... | |

FOR CALCULATIONS: | |

THE CURTA | |

high precision pocket calculating machine, performing the four arithmetic operations. |

**Contina S.A.** launches a novelty: **the universal pocket calculating
machine**, robust and efficient. It is a high precision item,
constructed according to the principles of fine-mechanical mass production and
with the experience of several decades provided by the designer
C. Herzstark specializing in the construction of calculating machines.

The picture above shows that the dimensions of this machine are extremely small. One can easily hold it in one hand or put it in ones pocket without any inconvenience. It answers to the long term demand by calculators who wished a less cumbersome machine that could be used anywhere, and it therefore fills a niche that has always existed for calculating machines.

The **Curta** is the indispensable aid for traveling **merchants**,
the **building contractor on the construction site**, the **technician**
in his workshop, the **designer** at his drawing board, the
**scientist** in his lab, and the **student**. Every place where
the use of a noisy machine would be intolerable and where it isn't possible or
practical to bring a heavy and cumbersome machine, like during surveying,
the eminent qualities of the CURTA render it indispensable.
In commercial or technical **offices**, in
**banks** and **administrative offices** as well as behind the
**counter**, the CURTA is especially appreciated for its easy handling.
In fact, until now it was not possible for an operator to use his machine
directly on his writing pad. Therefore he paid the extra effort of numerous
movements of his body, his hands, his head and his eyes, to and from his
writing pad and the calculating machine.
The advantages of the Curta have gained it the approval without reserve of
professionals, and a considerable demand for it from all over the world.

With the Curta a high precision **calculating machine** has been realized
that equals the universal hand driven machines, millions of which are spread
all over the world. According to more than one report the Curta is superior to
many of them, most notably by its simplicity and convenient operation.

the universal machines described above in:

Curta adds, subtracts, multiplies, divides, calculates squares, cubes, square roots. It enables the calculation of invoices, cubatures, percentages, interests, etc. ...

Curta posses mechanisms to prevent invalid operations and special mechanisms to avoid inertia-induced overshooting.

Curta is a small machine. Its easy movement, the continuous carrying of tens on both counters and the single direction of rotation of the crank give it an exceptionally high operating speed.

Curta has a horizontal line of windows for reading the setting The numbers on the counters are very clear because they are engraved and placed close to the surface.

Curta is exclusively manufactured in mass production from selected metals and its high precision assures a complete interchangeability of parts.

Curta doesn't show any perceptible wear after years of use; thanks to the extremely reduced mass of the moving parts, it can endure millions of rotations.

over other machines in:

Diameter max. 35 mm., height 85 mm.

About 230 gr., just a tiny fraction of the weight of the lightest machines with the same capacity produced nowadays.

8 setting digits, 6 digits in the counter, 11 digits in the result register, despite its small size.

due to its harmonic design and pleasing assembly of all its elements.

enabled by high precision machining and a novel economical construction.

due to the small mass of the moving parts.

Thanks to its insignificant weight, the smooth operating mechanism, the nicely rounded and well spaced setting knobs, the well legible digits on a matte background. It is important to note that for desk use, the Curta offers the very particular advantage of not forcing the operator to turn away from his writing to perform his calculations, as we will show now.

Fig. 1: Writing space = calculating space |

The Curta is a four-function machine that an operator uses in one

Fig. 2: Writing space | calculating space |

The Curta avoids that situation, and satisfies therefore in all respects the modern urge for control of strains and nervous stress at work.

Fig. 3 |

On the body of the machine one finds the

Fig. 4 |

The numbers (for example the numbers to be added, one of the two factors of
the multiplication, or the divisor of the division)
are **set** by means of the sliding knobs. It suffices to displace the
knob corresponding to the unit of the digit desired (tens, hundreds,
thousands) until that digit appears in the corresponding setting window.

**Control** of the number set is simple because all digits remain
visible in a **horizontal line** in the setting windows.

The **crank** that drives the mechanism of the machine has a stop that
can be felt easily, and helps in counting the number of revolutions during the
calculation. When the crank is pulled or pushed along its axis, the mechanism
moves between two positions, the lower one for augmentative calculations
(adding, multiplication) and the upper one for diminutive calculations
(subtraction, division). In both cases the crank has to be turned clockwise,
a special stop preventing it from being turned in the opposite direction.

The **revolution counter** (digits in the clear segment) counts the number
of revolutions made by the crank and indicates for addition the number of
terms; for multiplication, the multiplier; for division, the quotient; for
calculation of a root, the root. The revolution counter is operated on at the
window corresponding to the position of the carriage indicated by the arrow.

The **totalisator** (digits in the black segment) indicates for addition,
subtraction and multiplication, the result. For division, it indicates,
depending on the calculation method used, the remainder or the dividend.

The **continuous carrying of tens** on both counters enables a considerable
speed-up for many operations and reduces the number of revolutions of the
crank (*e.g.* for multiplication using the 'simplified method'). It also
enables the addition of multipliers (important for instance for cubatures,
the calculation of interests etc. ...).

**Setting the counters to zero** is done by the handle with a ring (see
fig. 3 and 4). It can be rotated in
two directions. It has two, clearly indicated, stop positions where the clear
segment borders the black one. Both counters can be set to zero in one
movement, or each separately.

Fig. 5
The machine viewed from the back |

**Sample calculation.** The numbers shown in figures 3 and
4 are those of the following multiplication:
645 432 `x` 63 992. The multiplicand can be seen in
the control windows (fig. 3), the multiplier on the
revolution counter and the product on the totalisator
(fig. 4).

The time required for this calculation, including setting the numbers, is about 15 seconds with 29 revolutions of the crank. But if the simplified method of multiplication is used, made possible by the continuous carrying of tens, the time required is about 10 seconds, with only 13 revolution of the crank.

A division with a 6 digit quotient takes 30 seconds on average, including setting the numbers.

All other operations can be done in a minimum amount of time, using methods already known for ordinary machines.

The protective anti-shock case of the Curta |

View of the
precision mechanism of the Curta | |

Fig. 6 View of the Curta without its hull and with detached carriage. |

Fig. 7 Schematic view of the operation of the Curta. |

In the Curta subtraction is reduced to an addition by means of a vertical displacement of the stepped drum, that, when in its upper position, lets a complementary number of teeth engage with the setting gears. These simple operating principles enable a rational and robust construction, which ensures the reliability of the Curta.

Manufacturer:

Manufacturer of office and calculating machines

Mauren / Liechtenstein

Building I, Mauren | |

Building II, Eschen |

Reproduction of texts and illustrations, even partial, is prohibited
without our permission and without indication of the source.

Illustrations and descriptions can be subject to minor modifications.

34 51 6 f

Note: This should be 53 mm, see other brochure. (back)

This Curta brochure has been translated from the French version and converted to HTML by Andries de Man using a copy provided by Skip Godfrey, courtesy of Daniel Lewin. Thanks to Christophe Mery for assistance with the translation. See also an earlier version.

Andries de Man