How far can I see with this Spy Glass? The distance at which an observer can see objects depends upon two considerations: First, the power of the instrument; and second, the condition of the atmosphere. All that is needful is to multiply the distance at which the unassisted eye can see objects clearly, by the given power of the glass. For instance, the atmosphere being clear and steady, this Spy Glass will enable a person to make out an object one mile distant with the same distinctness that he can see it at a distance of 130 yards with the unassisted eye. It is an excellent instrument. Price $2.50. Postage and packing 12 cents extra.
SPY GLASS, NO. 2276.
Given for new subscriptions amounting to $5.00 and 25 cents cash additional.
This glass has Rosewood body and 3 draws. Length, 16 inches drawn out; 6 inches closed. Power 16 times. The object-glass is 1⅛ inches in diameter. Price $3.50. Postage and packing 13 cents extra.
SPY GLASS, NO. 2278.
Given for new subscriptions amounting to $10.00 and 50 cents cash additional.
Length 30 inches, drawn out, 10 inches closed. The object-glass is 1⅝ inches in diameter. Power 25 times. This is a powerful and excellent telescope. An object a mile distant will appear as though but a few rods away. Price $7.00. Postage and packing 50 cents extra, or sent by express at receiver’s expense.
FIELD GLASS, NO. 379-3.
Given for new subscriptions amounting to $15.00 and 40 cents cash additional.
