Mechanical Calculating Pencil, 1876

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I've seen a number of unusual calculating machines, but this one--patented by Marshall Smith in 1876) seems one of the smallest, and efficient--if not limited--varities.  It is the second edition so-to-speak of a  mechanical, graphite pencil, operating this time without rotors or any other internal mechanical devices.  It was evidently a big seller--hosted in part, so it seems, by The Scientific American itself--having sold some 5,000 units.

United States

Patent Office.

MARSHALL M. SMITH, OF GEEE1Í TOP, MISSOUEI.

IMPROVEMENT IN ADDING-PENCILS.

Specification forming part of Letters-Patent No. 180,949, dated August 8, 1876 ; application filed

July 11, 1876.

To all whom it may concern:

Be it known that I, Marshall M. Smith, of

reen Top,

county

of

Schuyler

, and State

of

Missouri

, have invented a new and Im-

proved Adding-Pencil, of which the following-

is a specification :

Figure 1 is a side view of my improved

„ pencil, part being broken away to

show the construction. Fig. 2 is a cross-sec-

tion of the same taken through the line x x,

Fig. 1.

The object of this invention is to furnish

an improved adding-pencil, simple in con-

struction, inexpensive in manufacture, con-

venient in use, and reliable in operation.

The iuventiou consists in the combination

of the flange provided with the nine digits

and zero, and the milled flange provided with

the letters, with the slotted case, and the

grooved cylinder, as hereinafter fully de-

scribed.

Similar letters of reference indicate corre-

sponding parts.

A is a hollow cylinder, which is slotted lon-

gitudinally, and in which is placed a cylinder,

B. The cylinder B is swiveled at its upper

end to the upper end of the case A, and has

a spiral groove formed in it, from its lower to

its upper end, to receive the pointer, which

is forced up the slot of the case A and the

groove of the cylinder B, by turning the said

cylinder within the said case. Upon the cyl-

inder B, along the spiral groove, or between the

coils of said groove, is formed a series of con-

secutive numbers. Around the lower end of

the case A is formed a ring-flange, D, upon

which is formed the nine digits and the zero,

as shown in Fig. 2. Around the lower end

of the cylinder B is formed a ring-flange, 0,

upon which are formed the. letters of the al-

phabet, or as many of said letters as there are

numbers in each coil of the cylinder B. The

edge of the flange C is milled, to enable it to

be more easily turned. Upon the lower end

of the cylinder B is formed a pencil or point-

er, E.

In using the pencil to add up a column of

figures, as the point E is placed upon a figure

to be added, the eye seeks the same figure

upon the flange D, and notices the letter upou

the flange C, that stands directly opposite

said figure. The flange C is then turned to

bring the said letter opposite the zero upon

the said flange D. This turns the cylinder B,

and carries the pointer up the groove a corre-

sponding distance, and it now points to a

number upou said cylinder equal to the sum

of the said figure and the number previously

obtained.

When the column has been added, and the

sum noted, the cylinder is turned back to

bring its pointer to the zero-mark of its num-

bers, and the next column is added in the

same way, and so on.

Having thus described my invention, I claim

as uew and desire to secure by Letters Pat-

ent—

The combination of the flange D, provided

with the nine digits and zero, and the milled

flange 0, provided with the letters, with each

other, and with the case A and the grooved

cylinder B, substantially as herein shown and

described.

Comments

[Ray Girvan]

The Rechnerlexicon has full PDFs of this patent, as well as the one for its earlier incarnation coinvented with Fletcher W. Potts:

http://www.rechnerlexikon.de/files/patent/US180949.pdf

http://www.rechnerlexikon.de/files/patent/US175775.pdf

The Adding Pencil Co. of St Louis, MO, was still selling them through ads in Popular Science and Popular Mechanics in the mid-1920s. For instance: http://tinyurl.com/kv4eks

[Jeff]

Am I mis-reading or is the Adding Pencil Co. ad misleading? It seems to be claiming that all you do is press the pencil tip on some numbers and it adds them automatically. Must one behave like a counting horse and press the tip nine times for "nine"? Then it continues and says that it adds as you write. This is all different, I think, from the claims in the patents above. Would've been a late-night TV ad, if they'd had TVs.

[Ray Girvan]

The one in the ad looks as if it operates in a different way from the dial-twist of the 1876 one. The graduations near the tip suggest that to add x, you push down until the tip slides into the body of the pen by x notches, and x is added to the total (after which presumably the tip disengages and springs back ready for the next input).

If you zoom in on this other ad in Popular Science - http://tinyurl.com/ls2vgb - you can see the graduations are numbered consistently with this.