t or
down?"

"I had one eye on her, sir; I was afraid she was coming into the shop
after me, and my arm was too sore for me to want her to clinch hold on
it again. So when she started to go, I took a step nearer, and saw her
move toward the curbstone and hold up her hand. But it wasn't a car she
was after, for none came by for several minutes."

The fold between Mr. Gryce's eyes perceptibly smoothed out.

"Then it was some cabman or hack-driver she hailed. Were there any empty
coaches about that you saw?"

The boy had not noticed. He had reached the limit of his observations,
and no amount of further questioning could elicit anything more from
him. This Mr. Gryce soon saw, and giving him into the charge of one of
his assistants who was on duty at this place, he proceeded back to the
ill-omened house where the tragedy itself had occurred.

"Any one waiting for me?" he inquired of Styles, who came to the door.

"Yes, sir; a young man; name, Hines. Says he's an electrician."

"That's the man I want. Where is he?"

"In the parlor, sir."

"Good! I'll see him. But don't let any one else in. Anybody upstairs?"

"No, sir, all gone. Shall I go up or stay here?"

"You'd better go up. I'll look after the door."

Styles nodded, and went toward the stairs, up which he presently
disappeared. Mr. Gryce proceeded to the parlor.

A dapper young man with an intelligent eye rose to meet him. "You sent
for me," said he.

The detective nodded, asked a few questions, and seeming satisfied with
the replies he received, led the way into Mr. Adams's study, from which
the body had been removed to an upper room. As they entered, a mild
light greeted them from a candle which, by Mr. Gryce's orders, had been
placed on a small side table near the door. But once in, Mr. Gryce
approached the larger table in the centre of the room, and placing his
hand on one of the buttons before him, asked his companion to be kind
enough to blow out the candle. This he did, leaving the room for a
moment in total darkness. Then with a sudden burst of illumination, a
marvellous glow of a deep violet color shot over the whole room, and the
two men turned and faced each other both with inquiry in their looks, so
unexpected was this theatrical effect to the one, and so inexplicable
its cause and purpose to the other.

"That is but one slide," remarked Mr. Gryce. "Now I will press another
button, and the color changes to--pink, as you see. This one produc